Split projects.

31 files changed, 3404 insertions, 0 deletions

diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
new file mode 100644
index 0000000..68093ca
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -0,0 +1,30 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: "[BUG] "
+labels: bug
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Set '...' in config to '...'
+2. Do in game '....'
+3. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Server Info (please complete the following information):**
+ - LimboAPI Version [e.g. 1.0.1-rc2, downloaded from https://github.com/Elytrium/LimboAPI/actions/runs/1354021163]
+ - /velocity dump link [e.g. https://dump.velocitypowered.com/dotihadufu.json]
+
+**Additional context**
+Add any other context about the problem here.
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..40d732e
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,32 @@
+name: Java CI with Gradle
+
+on: [ push ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ 11, 16 ]
+      fail-fast: true
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2.3.5
+      - name: Set up JDK ${{ matrix.java }}
+        uses: actions/setup-java@v2.3.1
+        with:
+          distribution: adopt
+          java-version: ${{ matrix.java }}
+      - name: Cache Gradle
+        uses: actions/cache@v2.1.6
+        with:
+          path: ~/.gradle
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: ${{ runner.os }}-gradle-
+      - name: Build LimboAuth
+        run: ./gradlew build
+      - name: Upload LimboAuth
+        uses: actions/upload-artifact@v2.2.4
+        with:
+          name: LimboAuth Built On ${{ matrix.java }} JDK
+          path: "build/libs/limboauth*.jar"
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..6259d74
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,32 @@
+name: Java CI with Gradle [PR tests]
+
+on: [ pull_request ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ 11, 16 ]
+      fail-fast: true
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2.3.5
+      - name: Set up JDK ${{ matrix.java }}
+        uses: actions/setup-java@v2.3.1
+        with:
+          distribution: adopt
+          java-version: ${{ matrix.java }}
+      - name: Cache Gradle
+        uses: actions/cache@v2.1.6
+        with:
+          path: ~/.gradle
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: ${{ runner.os }}-gradle-
+      - name: Build LimboAuth
+        run: ./gradlew build
+      - name: Upload LimboAuth
+        uses: actions/upload-artifact@v2.2.4
+        with:
+          name: LimboAuth Built On ${{ matrix.java }} JDK
+          path: "build/libs/limboauth*.jar"
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..442df48
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,120 @@
+# User-specific stuff
+.idea/
+
+*.iml
+*.ipr
+*.iws
+
+# IntelliJ
+out/
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Package Files
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# Virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+*~
+
+# Temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+# Windows thumbnail cache files
+Thumbs.db
+Thumbs.db:encryptable
+ehthumbs.db
+ehthumbs_vista.db
+
+# Dump file
+*.stackdump
+
+# Folder config file
+[Dd]esktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msix
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+# Gradle
+.gradle
+build/
+
+# Ignore Gradle GUI config
+gradle-app.setting
+
+# Cache of project
+.gradletasknamecache
+
+# Gradle Patch
+**/build/
+
+# Common working directory
+run/
+
+# Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
+!gradle-wrapper.jar
diff --git a/HEADER.txt b/HEADER.txt
new file mode 100644
index 0000000..f52ff2f
--- /dev/null
+++ b/HEADER.txt
@@ -0,0 +1,14 @@
+Copyright (C) 2021 Elytrium
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
diff --git a/VERSION b/VERSION
new file mode 100644
index 0000000..6d7de6e
--- /dev/null
+++ b/VERSION
@@ -0,0 +1 @@
+1.0.2
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..ac00097
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,115 @@
+//file:noinspection GroovyAssignabilityCheck
+
+plugins {
+    id("java")
+    id("checkstyle")
+    id("com.github.spotbugs").version("5.0.3")
+    id("org.cadixdev.licenser").version("0.6.1")
+    id("com.github.johnrengelman.shadow").version("7.1.0")
+}
+
+setGroup("net.elytrium")
+setVersion("1.0.3-SNAPSHOT")
+
+compileJava {
+    getOptions().setEncoding("UTF-8")
+}
+
+java {
+    setSourceCompatibility(JavaVersion.VERSION_11)
+    setTargetCompatibility(JavaVersion.VERSION_11)
+}
+
+repositories {
+    mavenCentral()
+
+    maven {
+        setName("velocitypowered-repo")
+        setUrl("https://nexus.velocitypowered.com/repository/maven-public/")
+    }
+    maven {
+        setName("elytrium-repo")
+        setUrl("https://maven.elytrium.net/repo/")
+    }
+}
+
+dependencies {
+    compileOnly("net.elytrium:limboapi-api:1.0.3-SNAPSHOT")
+
+    compileOnly("com.velocitypowered:velocity-api:3.1.0")
+    annotationProcessor("com.velocitypowered:velocity-api:3.1.0")
+
+    implementation("at.favre.lib:bcrypt:0.9.0")
+    implementation("dev.samstevens.totp:totp:1.7.1")
+
+    implementation("com.j256.ormlite:ormlite-jdbc:5.7")
+
+    implementation("com.h2database:h2:2.0.202")
+    implementation("mysql:mysql-connector-java:8.0.27")
+    implementation("org.postgresql:postgresql:42.3.1")
+
+    compileOnly("com.github.spotbugs:spotbugs-annotations:4.5.2")
+}
+
+shadowJar {
+    getArchiveClassifier().set("")
+
+    exclude("META-INF/maven/**")
+    exclude("META-INF/INFO_BIN")
+    exclude("META-INF/INFO_SRC")
+    exclude("google/protobuf/**")
+    exclude("com/google/protobuf/**")
+    exclude("com/mysql/cj/x/**")
+    exclude("com/mysql/cj/xdevapi/**")
+    exclude("org/apache/commons/codec/language/**")
+    exclude("org/checkerframework/**")
+    exclude("**/package-info.class")
+
+    minimize()
+
+    relocate("at.favre.lib", "net.elytrium.limboauth.thirdparty.at.favre.lib")
+    relocate("com.j256.ormlite", "net.elytrium.limboauth.thirdparty.com.j256.ormlite")
+    relocate("com.mysql", "net.elytrium.limboauth.thirdparty.com.mysql")
+    relocate("dev.samstevens.totp", "net.elytrium.limboauth.thirdparty.dev.samstevens.totp")
+    relocate("org.apache.commons.codec", "net.elytrium.limboauth.thirdparty.org.apache.commons.codec")
+    relocate("org.h2", "net.elytrium.limboauth.thirdparty.org.h2")
+    relocate("org.postgresql", "net.elytrium.limboauth.thirdparty.org.postgresql")
+}
+
+license {
+    setHeader(file("HEADER.txt"))
+}
+
+checkstyle {
+    setToolVersion("9.2")
+    setConfigFile(file("${this.getRootDir()}/config/checkstyle/checkstyle.xml"))
+    setConfigProperties("configDirectory": "${this.getRootDir()}/config/checkstyle")
+
+    // The build should immediately fail if we have errors.
+    setMaxErrors(0)
+    setMaxWarnings(0)
+}
+
+spotbugsMain {
+    setExcludeFilter(file("${this.getRootDir()}/config/spotbugs/suppressions.xml"))
+
+    reports {
+        html {
+            getRequired().set(true)
+            getOutputLocation().set(file("${this.getBuildDir()}/reports/spotbugs/main/spotbugs.html"))
+            setStylesheet("fancy-hist.xsl")
+        }
+    }
+}
+
+sourceSets.main.getJava().srcDir(getTasks().register("generateTemplates", Copy) { task ->
+    task.getInputs().properties("version": getVersion())
+
+    task.from(file("src/main/templates"))
+            .into(getLayout().getBuildDirectory().dir("generated/sources/templates"))
+            .expand("version": getVersion())
+}.map {
+    it.getOutputs()
+})
+
+assemble.dependsOn(shadowJar)
diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
new file mode 100644
index 0000000..f6a501f
--- /dev/null
+++ b/config/checkstyle/checkstyle.xml
@@ -0,0 +1,369 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+        "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<!--
+    Checkstyle configuration that checks the Google coding conventions from Google Java Style
+    that can be found at https://google.github.io/styleguide/javaguide.html
+    Checkstyle is very configurable. Be sure to read the documentation at
+    http://checkstyle.org (or in your downloaded distribution).
+    To completely disable a check, just comment it out or delete it from the file.
+    To suppress certain violations please review suppression filters.
+    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
+ -->
+
+<module name="Checker">
+    <property name="charset" value="UTF-8"/>
+
+    <property name="severity" value="warning"/>
+
+    <property name="fileExtensions" value="java, properties, xml"/>
+    <!-- Excludes all 'module-info.java' files              -->
+    <!-- See https://checkstyle.org/config_filefilters.html -->
+    <module name="BeforeExecutionExclusionFileFilter">
+        <property name="fileNamePattern" value="module\-info\.java$"/>
+    </module>
+    <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
+    <module name="SuppressionFilter">
+        <property name="file" value="${configDirectory}/suppressions.xml"/>
+    </module>
+
+    <!-- Checks for whitespace                               -->
+    <!-- See http://checkstyle.org/config_whitespace.html -->
+    <module name="FileTabCharacter">
+        <property name="eachLine" value="true"/>
+    </module>
+
+    <module name="LineLength">
+        <property name="fileExtensions" value="java"/>
+        <property name="max" value="155"/>
+        <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+    </module>
+
+    <module name="NewlineAtEndOfFile"/>
+
+    <module name="TreeWalker">
+        <module name="MissingOverride"/>
+        <module name="FinalClass"/>
+        <module name="RedundantImport"/>
+        <module name="UnusedImports"/>
+        <module name="RequireThis">
+            <property name="validateOnlyOverlapping" value="false"/>
+        </module>
+
+        <module name="OuterTypeFilename"/>
+        <module name="IllegalTokenText">
+            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+            <property name="format"
+                      value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+            <property name="message"
+                      value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+        </module>
+        <module name="AvoidEscapedUnicodeCharacters">
+            <property name="allowEscapesForControlCharacters" value="true"/>
+            <property name="allowByTailComment" value="true"/>
+            <property name="allowNonPrintableEscapes" value="true"/>
+        </module>
+        <module name="AvoidStarImport"/>
+        <module name="OneTopLevelClass"/>
+        <module name="NoLineWrap">
+            <property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT"/>
+        </module>
+        <module name="EmptyBlock">
+            <property name="option" value="TEXT"/>
+            <property name="tokens"
+                      value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+        </module>
+        <module name="NeedBraces">
+            <property name="tokens"
+                      value="LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_IF, LITERAL_WHILE"/>
+        </module>
+        <module name="LeftCurly">
+            <property name="tokens"
+                      value="ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF,
+                    INTERFACE_DEF, LAMBDA, LITERAL_CASE, LITERAL_CATCH, LITERAL_DEFAULT,
+                    LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, METHOD_DEF,
+                    OBJBLOCK, STATIC_INIT, RECORD_DEF, COMPACT_CTOR_DEF"/>
+        </module>
+        <module name="RightCurly">
+            <property name="id" value="RightCurlySame"/>
+            <property name="tokens"
+                      value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_DO"/>
+        </module>
+        <module name="RightCurly">
+            <property name="id" value="RightCurlyAlone"/>
+            <property name="option" value="alone"/>
+            <property name="tokens"
+                      value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
+                    INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF, INTERFACE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+        </module>
+        <module name="SuppressionXpathSingleFilter">
+            <!-- suppresion is required till https://github.com/checkstyle/checkstyle/issues/7541 -->
+            <property name="id" value="RightCurlyAlone"/>
+            <property name="query" value="//RCURLY[parent::SLIST[count(./*)=1]
+                                     or preceding-sibling::*[last()][self::LCURLY]]"/>
+        </module>
+        <module name="WhitespaceAfter">
+            <property name="tokens"
+                      value="COMMA, SEMI, TYPECAST, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_WHILE, LITERAL_DO, LITERAL_FOR, DO_WHILE"/>
+        </module>
+        <module name="WhitespaceAround">
+            <property name="allowEmptyConstructors" value="true"/>
+            <property name="allowEmptyLambdas" value="true"/>
+            <property name="allowEmptyMethods" value="true"/>
+            <property name="allowEmptyTypes" value="true"/>
+            <property name="allowEmptyLoops" value="true"/>
+            <property name="ignoreEnhancedForColon" value="false"/>
+            <property name="tokens"
+                      value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR,
+                    BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND,
+                    LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY,
+                    LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED,
+                    LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN,
+                    NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR,
+                    SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND"/>
+            <message key="ws.notFollowed"
+                     value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+            <message key="ws.notPreceded"
+                     value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="OneStatementPerLine"/>
+        <module name="MultipleVariableDeclarations"/>
+        <module name="ArrayTypeStyle"/>
+        <module name="MissingSwitchDefault"/>
+        <module name="FallThrough"/>
+        <module name="UpperEll"/>
+        <module name="ModifierOrder"/>
+        <module name="EmptyLineSeparator">
+            <property name="tokens"
+                      value="PACKAGE_DEF, IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF, VARIABLE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+            <property name="allowNoEmptyLineBetweenFields" value="true"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapDot"/>
+            <property name="tokens" value="DOT"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapComma"/>
+            <property name="tokens" value="COMMA"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/259 -->
+            <property name="id" value="SeparatorWrapEllipsis"/>
+            <property name="tokens" value="ELLIPSIS"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/258 -->
+            <property name="id" value="SeparatorWrapArrayDeclarator"/>
+            <property name="tokens" value="ARRAY_DECLARATOR"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapMethodRef"/>
+            <property name="tokens" value="METHOD_REF"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+            <message key="name.invalidPattern"
+                     value="Package name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="TypeName">
+            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    ANNOTATION_DEF, RECORD_DEF"/>
+            <message key="name.invalidPattern"
+                     value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MemberName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+                     value="Member name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LambdaParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="CatchParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LocalVariableName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="PatternVariableName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Pattern variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ClassTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Class type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="RecordComponentName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Record component name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="RecordTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Record type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MethodTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Method type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="InterfaceTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="NoFinalizer"/>
+        <module name="GenericWhitespace">
+            <message key="ws.followed"
+                     value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+            <message key="ws.preceded"
+                     value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+            <message key="ws.illegalFollow"
+                     value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+            <message key="ws.notPreceded"
+                     value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="Indentation">
+            <property name="basicOffset" value="2"/>
+            <property name="braceAdjustment" value="2"/>
+            <property name="caseIndent" value="2"/>
+            <property name="throwsIndent" value="4"/>
+            <property name="lineWrappingIndentation" value="4"/>
+            <property name="arrayInitIndent" value="2"/>
+        </module>
+        <module name="AbbreviationAsWordInName">
+            <property name="ignoreFinal" value="false"/>
+            <property name="allowedAbbreviationLength" value="2"/>
+            <property name="tokens"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF, ANNOTATION_FIELD_DEF,
+                    PARAMETER_DEF, VARIABLE_DEF, METHOD_DEF, PATTERN_VARIABLE_DEF, RECORD_DEF,
+                    RECORD_COMPONENT_DEF"/>
+        </module>
+        <module name="NoWhitespaceBeforeCaseDefaultColon"/>
+        <module name="OverloadMethodsDeclarationOrder"/>
+        <module name="VariableDeclarationUsageDistance"/>
+        <module name="CustomImportOrder">
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+            <property name="separateLineBetweenGroups" value="true"/>
+            <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
+            <property name="tokens" value="IMPORT, STATIC_IMPORT, PACKAGE_DEF"/>
+        </module>
+        <module name="MethodParamPad">
+            <property name="tokens"
+                      value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF,
+                    SUPER_CTOR_CALL, ENUM_CONSTANT_DEF, RECORD_DEF"/>
+        </module>
+        <module name="NoWhitespaceBefore">
+            <property name="tokens"
+                      value="COMMA, SEMI, POST_INC, POST_DEC, DOT,
+                    LABELED_STAT, METHOD_REF"/>
+            <property name="allowLineBreaks" value="true"/>
+        </module>
+        <module name="ParenPad">
+            <property name="tokens"
+                      value="ANNOTATION, ANNOTATION_FIELD_DEF, CTOR_CALL, CTOR_DEF, DOT, ENUM_CONSTANT_DEF,
+                    EXPR, LITERAL_CATCH, LITERAL_DO, LITERAL_FOR, LITERAL_IF, LITERAL_NEW,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_WHILE, METHOD_CALL,
+                    METHOD_DEF, QUESTION, RESOURCE_SPECIFICATION, SUPER_CTOR_CALL, LAMBDA,
+                    RECORD_DEF"/>
+        </module>
+        <module name="OperatorWrap">
+            <property name="option" value="NL"/>
+            <property name="tokens"
+                      value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
+                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF,
+                    TYPE_EXTENSION_AND "/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationMostCases"/>
+            <property name="tokens"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF,
+                      RECORD_DEF, COMPACT_CTOR_DEF"/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationVariables"/>
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="allowSamelineMultipleAnnotations" value="true"/>
+        </module>
+        <module name="NonEmptyAtclauseDescription"/>
+        <module name="InvalidJavadocPosition"/>
+        <module name="JavadocTagContinuationIndentation"/>
+        <module name="SummaryJavadoc">
+            <property name="forbiddenSummaryFragments"
+                      value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+        </module>
+        <module name="JavadocParagraph"/>
+        <module name="RequireEmptyLineBeforeBlockTagGroup"/>
+        <module name="AtclauseOrder">
+            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+            <property name="target"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+        </module>
+        <module name="JavadocMethod">
+            <property name="accessModifiers" value="public"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
+            <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF, COMPACT_CTOR_DEF"/>
+        </module>
+        <module name="MissingJavadocMethod">
+            <property name="scope" value="public"/>
+            <property name="minLineCount" value="2"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
+            <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF,
+                                   COMPACT_CTOR_DEF"/>
+        </module>
+        <module name="MissingJavadocType">
+            <property name="scope" value="protected"/>
+            <property name="tokens"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                      RECORD_DEF, ANNOTATION_DEF"/>
+            <property name="excludeScope" value="nothing"/>
+        </module>
+        <module name="MethodName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+            <message key="name.invalidPattern"
+                     value="Method name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="SingleLineJavadoc"/>
+        <module name="EmptyCatchBlock">
+            <property name="exceptionVariableName" value="expected"/>
+        </module>
+        <module name="CommentsIndentation">
+            <property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
+        </module>
+        <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
+        <module name="SuppressionXpathFilter">
+            <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
+                      default="checkstyle-xpath-suppressions.xml"/>
+            <property name="optional" value="true"/>
+        </module>
+    </module>
+</module>
diff --git a/config/checkstyle/suppressions.xml b/config/checkstyle/suppressions.xml
new file mode 100644
index 0000000..caae7d8
--- /dev/null
+++ b/config/checkstyle/suppressions.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+        "http://checkstyle.org/dtds/suppressions_1_2.dtd">
+
+<suppressions>
+    <suppress files=".*[\\/]net[\\/]elytrium[\\/].*" checks="SummaryJavadoc"/>
+    <suppress files=".*[\\/]net[\\/]elytrium[\\/].*" checks="MissingJavadocType"/>
+    <suppress files=".*[\\/]net[\\/]elytrium[\\/].*" checks="MissingJavadocMethod"/>
+
+    <suppress files=".*[\\/]net[\\/]elytrium[\\/].*[\\/]Settings.java" checks="TypeName"/>
+    <suppress files=".*[\\/]net[\\/]elytrium[\\/].*[\\/]Settings.java" checks="LineLength"/>
+    <suppress files=".*[\\/]net[\\/]elytrium[\\/].*[\\/]Settings.java" checks="MemberName"/>
+    <suppress files=".*[\\/]net[\\/]elytrium[\\/].*[\\/]Settings.java" checks="RequireThis"/>
+    <suppress files=".*[\\/]net[\\/]elytrium[\\/].*[\\/]Settings.java" checks="AbbreviationAsWordInName"/>
+</suppressions>
diff --git a/config/spotbugs/suppressions.xml b/config/spotbugs/suppressions.xml
new file mode 100644
index 0000000..3b4b6f6
--- /dev/null
+++ b/config/spotbugs/suppressions.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<FindBugsFilter>
+    <Match>
+        <Bug pattern="EI_EXPOSE_REP2"/>
+    </Match>
+</FindBugsFilter>
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..7454180
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.jar
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..84d1f85
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.3.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
new file mode 100644
index 0000000..1b6c787
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..107acd3
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..bbe3302
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1 @@
+getRootProject().setName("limboauth")
diff --git a/src/main/java/net/elytrium/limboauth/LimboAuth.java b/src/main/java/net/elytrium/limboauth/LimboAuth.java
new file mode 100644
index 0000000..a901bc2
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/LimboAuth.java
@@ -0,0 +1,371 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth;
+
+import com.google.inject.Inject;
+import com.google.inject.name.Named;
+import com.j256.ormlite.dao.Dao;
+import com.j256.ormlite.dao.DaoManager;
+import com.j256.ormlite.field.FieldType;
+import com.j256.ormlite.jdbc.JdbcPooledConnectionSource;
+import com.j256.ormlite.table.TableUtils;
+import com.velocitypowered.api.command.CommandManager;
+import com.velocitypowered.api.event.Subscribe;
+import com.velocitypowered.api.event.proxy.ProxyInitializeEvent;
+import com.velocitypowered.api.plugin.Dependency;
+import com.velocitypowered.api.plugin.Plugin;
+import com.velocitypowered.api.plugin.PluginContainer;
+import com.velocitypowered.api.plugin.annotation.DataDirectory;
+import com.velocitypowered.api.proxy.Player;
+import com.velocitypowered.api.proxy.ProxyServer;
+import java.io.File;
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.file.Path;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+import net.elytrium.limboapi.api.Limbo;
+import net.elytrium.limboapi.api.LimboFactory;
+import net.elytrium.limboapi.api.chunk.Dimension;
+import net.elytrium.limboapi.api.chunk.VirtualWorld;
+import net.elytrium.limboapi.api.file.SchematicFile;
+import net.elytrium.limboapi.api.file.WorldFile;
+import net.elytrium.limboauth.command.ChangePasswordCommand;
+import net.elytrium.limboauth.command.DestroySessionCommand;
+import net.elytrium.limboauth.command.ForceUnregisterCommand;
+import net.elytrium.limboauth.command.LimboAuthCommand;
+import net.elytrium.limboauth.command.TotpCommand;
+import net.elytrium.limboauth.command.UnregisterCommand;
+import net.elytrium.limboauth.handler.AuthSessionHandler;
+import net.elytrium.limboauth.listener.AuthListener;
+import net.elytrium.limboauth.model.RegisteredPlayer;
+import net.elytrium.limboauth.utils.UpdatesChecker;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+import org.slf4j.Logger;
+
+@Plugin(
+    id = "limboauth",
+    name = "LimboAuth",
+    version = BuildConstants.AUTH_VERSION,
+    url = "https://elytrium.net/",
+    authors = {"hevav", "mdxd44"},
+    dependencies = {@Dependency(id = "limboapi")}
+)
+public class LimboAuth {
+
+  private static LimboAuth instance;
+
+  private final HttpClient client = HttpClient.newHttpClient();
+  private final Path dataDirectory;
+  private final Logger logger;
+  private final ProxyServer server;
+  private final LimboFactory factory;
+
+  private Dao<RegisteredPlayer, String> playerDao;
+  private Limbo authServer;
+  private Map<String, CachedUser> cachedAuthChecks;
+  private Component nicknameInvalid;
+  private Pattern nicknameValidationPattern;
+
+  @Inject
+  @SuppressWarnings("OptionalGetWithoutIsPresent")
+  public LimboAuth(ProxyServer server, Logger logger, @Named("limboapi") PluginContainer factory, @DataDirectory Path dataDirectory) {
+    setInstance(this);
+
+    this.server = server;
+    this.logger = logger;
+    this.dataDirectory = dataDirectory;
+    this.factory = (LimboFactory) factory.getInstance().get();
+  }
+
+  @Subscribe
+  public void onProxyInitialization(ProxyInitializeEvent event) throws SQLException {
+    System.setProperty("com.j256.simplelogging.level", "ERROR");
+
+    this.reload();
+
+    UpdatesChecker.checkForUpdates(this.getLogger());
+  }
+
+  @SuppressWarnings("SwitchStatementWithTooFewBranches")
+  public void reload() throws SQLException {
+    Settings.IMP.reload(new File(this.dataDirectory.toFile().getAbsoluteFile(), "config.yml"));
+
+    this.cachedAuthChecks = new ConcurrentHashMap<>();
+
+    Settings.DATABASE dbConfig = Settings.IMP.DATABASE;
+
+    JdbcPooledConnectionSource connectionSource;
+    // requireNonNull prevents the shade plugin from excluding the drivers in minimized jar.
+    switch (dbConfig.STORAGE_TYPE.toLowerCase(Locale.ROOT)) {
+      case "h2": {
+        Objects.requireNonNull(org.h2.Driver.class);
+        Objects.requireNonNull(org.h2.engine.Engine.class);
+        connectionSource = new JdbcPooledConnectionSource("jdbc:h2:" + this.dataDirectory.toFile().getAbsoluteFile() + "/" + "limboauth");
+        break;
+      }
+      case "mysql": {
+        Objects.requireNonNull(com.mysql.cj.jdbc.Driver.class);
+        Objects.requireNonNull(com.mysql.cj.conf.url.SingleConnectionUrl.class);
+        connectionSource = new JdbcPooledConnectionSource(
+            "jdbc:mysql://" + dbConfig.HOSTNAME + "/" + dbConfig.DATABASE + dbConfig.CONNECTION_PARAMETERS, dbConfig.USER, dbConfig.PASSWORD
+        );
+        break;
+      }
+      case "postgresql": {
+        Objects.requireNonNull(org.postgresql.Driver.class);
+        connectionSource = new JdbcPooledConnectionSource(
+            "jdbc:postgresql://" + dbConfig.HOSTNAME + "/" + dbConfig.DATABASE + dbConfig.CONNECTION_PARAMETERS, dbConfig.USER, dbConfig.PASSWORD
+        );
+        break;
+      }
+      default: {
+        this.getLogger().error("WRONG DATABASE TYPE.");
+        this.server.shutdown();
+        return;
+      }
+    }
+
+    TableUtils.createTableIfNotExists(connectionSource, RegisteredPlayer.class);
+    this.playerDao = DaoManager.createDao(connectionSource, RegisteredPlayer.class);
+    this.nicknameValidationPattern = Pattern.compile(Settings.IMP.MAIN.ALLOWED_NICKNAME_REGEX);
+
+    this.migrateDb(this.playerDao);
+
+    CommandManager manager = this.server.getCommandManager();
+    manager.unregister("unregister");
+    manager.unregister("forceunregister");
+    manager.unregister("changepassword");
+    manager.unregister("destroysession");
+    manager.unregister("2fa");
+    manager.unregister("limboauth");
+
+    manager.register("unregister", new UnregisterCommand(this, this.playerDao), "unreg");
+    manager.register("forceunregister", new ForceUnregisterCommand(this, this.server, this.playerDao), "forceunreg");
+    manager.register("changepassword", new ChangePasswordCommand(this.playerDao), "changepass");
+    manager.register("destroysession", new DestroySessionCommand(this));
+    if (Settings.IMP.MAIN.ENABLE_TOTP) {
+      manager.register("2fa", new TotpCommand(this.playerDao), "totp");
+    }
+    manager.register("limboauth", new LimboAuthCommand(), "la", "auth", "lauth");
+
+    Settings.MAIN.AUTH_COORDS authCoords = Settings.IMP.MAIN.AUTH_COORDS;
+    VirtualWorld authWorld = this.factory.createVirtualWorld(
+        Dimension.valueOf(Settings.IMP.MAIN.DIMENSION),
+        authCoords.X, authCoords.Y, authCoords.Z,
+        (float) authCoords.YAW, (float) authCoords.PITCH
+    );
+
+    if (Settings.IMP.MAIN.LOAD_WORLD) {
+      try {
+        Path path = this.dataDirectory.resolve(Settings.IMP.MAIN.WORLD_FILE_PATH);
+        WorldFile file;
+        switch (Settings.IMP.MAIN.WORLD_FILE_TYPE) {
+          case "schematic": {
+            file = new SchematicFile(path);
+            break;
+          }
+          default: {
+            this.getLogger().error("Incorrect world file type.");
+            this.server.shutdown();
+            return;
+          }
+        }
+
+        Settings.MAIN.WORLD_COORDS coords = Settings.IMP.MAIN.WORLD_COORDS;
+        file.toWorld(this.factory, authWorld, coords.X, coords.Y, coords.Z);
+      } catch (IOException e) {
+        e.printStackTrace();
+      }
+    }
+
+    this.authServer = this.factory.createLimbo(authWorld);
+
+    this.nicknameInvalid = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.NICKNAME_INVALID);
+
+    this.server.getEventManager().unregisterListeners(this);
+    this.server.getEventManager().register(this, new AuthListener(this.playerDao));
+
+    Executors.newScheduledThreadPool(1, task -> new Thread(task, "purge-cache")).scheduleAtFixedRate(() ->
+        this.checkCache(this.cachedAuthChecks, Settings.IMP.MAIN.PURGE_CACHE_MILLIS),
+        Settings.IMP.MAIN.PURGE_CACHE_MILLIS,
+        Settings.IMP.MAIN.PURGE_CACHE_MILLIS,
+        TimeUnit.MILLISECONDS
+    );
+  }
+
+  public void migrateDb(Dao<RegisteredPlayer, String> playerDao) {
+    Set<FieldType> tables = new HashSet<>();
+    Collections.addAll(tables, playerDao.getTableInfo().getFieldTypes());
+
+    String findSql;
+    switch (Settings.IMP.DATABASE.STORAGE_TYPE) {
+      case "h2": {
+        findSql = "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = '"
+            + playerDao.getTableInfo().getTableName() + "';";
+        break;
+      }
+      case "postgresql":
+      case "mysql": {
+        findSql = "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = '" + Settings.IMP.DATABASE.DATABASE
+            + "' AND TABLE_NAME = '" + playerDao.getTableInfo().getTableName() + "';";
+        break;
+      }
+      default: {
+        this.getLogger().error("WRONG DATABASE TYPE.");
+        this.server.shutdown();
+        return;
+      }
+    }
+
+    try {
+      playerDao.queryRaw(findSql).forEach(e -> tables.removeIf(q -> q.getColumnName().equalsIgnoreCase(e[0])));
+
+      tables.forEach(t -> {
+        try {
+          String columnDefinition = t.getColumnDefinition();
+          StringBuilder builder = new StringBuilder("ALTER TABLE `auth` ADD ");
+          List<String> dummy = new ArrayList<>();
+          if (columnDefinition == null) {
+            playerDao.getConnectionSource().getDatabaseType().appendColumnArg(t.getTableName(), builder, t, dummy, dummy, dummy, dummy);
+          } else {
+            playerDao.getConnectionSource().getDatabaseType().appendEscapedEntityName(builder, t.getColumnName());
+            builder.append(" ").append(columnDefinition).append(" ");
+          }
+
+          playerDao.executeRawNoArgs(builder.toString());
+        } catch (SQLException e) {
+          e.printStackTrace();
+        }
+      });
+    } catch (SQLException e) {
+      e.printStackTrace();
+    }
+  }
+
+  public void cacheAuthUser(Player player) {
+    String username = player.getUsername();
+    this.cachedAuthChecks.remove(username);
+    this.cachedAuthChecks.put(username, new CachedUser(player.getRemoteAddress().getAddress(), System.currentTimeMillis()));
+  }
+
+  public void removePlayerFromCache(Player player) {
+    this.cachedAuthChecks.remove(player.getUsername());
+  }
+
+  public boolean needAuth(Player player) {
+    String username = player.getUsername();
+
+    if (!this.cachedAuthChecks.containsKey(username)) {
+      return true;
+    }
+
+    return !this.cachedAuthChecks.get(username).getInetAddress().equals(player.getRemoteAddress().getAddress());
+  }
+
+  public void authPlayer(Player player) {
+    String nickname = player.getUsername();
+    if (!this.nicknameValidationPattern.matcher(nickname).matches()) {
+      player.disconnect(this.nicknameInvalid);
+      return;
+    }
+
+    if (!Settings.IMP.MAIN.ONLINE_MODE_NEED_AUTH && player.isOnlineMode()) {
+      RegisteredPlayer registeredPlayer = AuthSessionHandler.fetchInfo(this.playerDao, player.getUsername());
+
+      if (registeredPlayer == null || registeredPlayer.getHash().isEmpty()) {
+        this.factory.passLoginLimbo(player);
+        return;
+      }
+    }
+
+    // Send player to auth virtual server.
+    try {
+      this.authServer.spawnPlayer(player, new AuthSessionHandler(this.playerDao, player, nickname));
+    } catch (Throwable t) {
+      this.getLogger().error("Error", t);
+    }
+  }
+
+  public boolean isPremium(String nickname) {
+    try {
+      HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create(String.format(Settings.IMP.MAIN.ISPREMIUM_AUTH_URL, nickname)))
+          .build();
+      HttpResponse<String> response = this.client.send(request, HttpResponse.BodyHandlers.ofString());
+      return response.statusCode() == 200;
+    } catch (IOException | InterruptedException e) {
+      this.getLogger().error("Unable to authenticate with Mojang", e);
+      return true;
+    }
+  }
+
+  public Logger getLogger() {
+    return this.logger;
+  }
+
+  private void checkCache(Map<String, CachedUser> userMap, long time) {
+    userMap.entrySet().stream()
+        .filter(u -> u.getValue().getCheckTime() + time <= System.currentTimeMillis())
+        .map(Map.Entry::getKey)
+        .forEach(userMap::remove);
+  }
+
+  private static void setInstance(LimboAuth instance) {
+    LimboAuth.instance = instance;
+  }
+
+  public static LimboAuth getInstance() {
+    return instance;
+  }
+
+  private static class CachedUser {
+
+    private final InetAddress inetAddress;
+    private final long checkTime;
+
+    public CachedUser(InetAddress inetAddress, long checkTime) {
+      this.inetAddress = inetAddress;
+      this.checkTime = checkTime;
+    }
+
+    public InetAddress getInetAddress() {
+      return this.inetAddress;
+    }
+
+    public long getCheckTime() {
+      return this.checkTime;
+    }
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/Settings.java b/src/main/java/net/elytrium/limboauth/Settings.java
new file mode 100644
index 0000000..9e59830
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/Settings.java
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth;
+
+import java.io.File;
+import net.elytrium.limboauth.config.Config;
+
+public class Settings extends Config {
+
+  @Ignore
+  public static final Settings IMP = new Settings();
+
+  @Final
+  public String VERSION = BuildConstants.AUTH_VERSION;
+
+  public String PREFIX = "LimboAuth &6>>&f";
+
+  @Create
+  public MAIN MAIN;
+
+  public static class MAIN {
+
+    public boolean ENABLE_BOSSBAR = true;
+    public boolean ONLINE_MODE_NEED_AUTH = true;
+    public boolean FORCE_OFFLINE_UUID = false;
+    @Comment({
+        "Forcibly set player's UUID to the value from the database",
+        "If the player had the cracked account, and switched to the premium account, the cracked UUID will be used."
+    })
+    public boolean SAVE_UUID = true;
+    public boolean ENABLE_TOTP = true;
+    public boolean TOTP_NEED_PASSWORD = true;
+    public boolean REGISTER_NEED_REPEAT_PASSWORD = true;
+    public boolean CHANGE_PASSWORD_NEED_OLD_PASSWORD = true;
+    @Comment({
+        "If you want to migrate your database from another plugin, which is not using BCrypt",
+        "You can set an old hash algorithm to migrate from. Currently, only AUTHME is supported yet"
+    })
+    public String MIGRATION_HASH = "";
+    @Comment("Available dimensions: OVERWORLD, NETHER, THE_END")
+    public String DIMENSION = "THE_END";
+    public long PURGE_CACHE_MILLIS = 3600000;
+    @Comment("QR Generator URL, set {data} placeholder")
+    public String QR_GENERATOR_URL = "https://api.qrserver.com/v1/create-qr-code/?data={data}&size=200x200&ecc=M&margin=30";
+    public String TOTP_ISSUER = "LimboAuth by Elytrium";
+    public int BCRYPT_COST = 10;
+    public int LOGIN_ATTEMPTS = 3;
+    public int IP_LIMIT_REGISTRATIONS = 3;
+    public int TOTP_RECOVERY_CODES_AMOUNT = 16;
+    @Comment("Time in milliseconds, when ip limit works, set to 0 for disable")
+    public long IP_LIMIT_VALID_TIME = 21600000;
+    @Comment({
+        "Regex of allowed nicknames",
+        "^ means the start of the line, $ means the end of the line",
+        "[A-Za-z0-9_] is a character set of A-Z, a-z, 0-9 and _",
+        "{3,16} means that allowed length is from 3 to 16 chars"
+    })
+    public String ALLOWED_NICKNAME_REGEX = "^[A-Za-z0-9_]{3,16}$";
+
+    public boolean LOAD_WORLD = false;
+    @Comment("World file type: schematic")
+    public String WORLD_FILE_TYPE = "schematic";
+    public String WORLD_FILE_PATH = "world.schematic";
+    @Comment({
+        "Custom isPremium URL",
+        "You can use Mojang one's API (set by default)",
+        "Or CloudFlare one's: https://api.ashcon.app/mojang/v1/user/%s",
+        "Or use this code to make your own API: https://blog.cloudflare.com/minecraft-api-with-workers-coffeescript/",
+        "Or implement your own API, it should just respond with HTTP code 200 only if the player is premium"
+    })
+    public String ISPREMIUM_AUTH_URL = "https://api.mojang.com/users/profiles/minecraft/%s";
+
+    @Create
+    public Settings.MAIN.WORLD_COORDS WORLD_COORDS;
+
+    public static class WORLD_COORDS {
+
+      public int X = 0;
+      public int Y = 0;
+      public int Z = 0;
+    }
+
+    @Create
+    public MAIN.STRINGS STRINGS;
+
+    //@Comment("Leave empty to disable.")
+    public static class STRINGS {
+
+      public String RELOAD = "{PRFX} &aReloaded successfully!";
+      public String RELOAD_FAILED = "{PRFX} &cReload failed, check console for details.";
+      public String ERROR_OCCURRED = "{PRFX} &cAn internal error has occurred!";
+
+      public String NOT_PLAYER = "{PRFX} &cСonsole is not allowed to execute this command!";
+      public String NOT_REGISTERED = "{PRFX} &cYou are not registered!";
+      public String WRONG_PASSWORD = "{PRFX} &cPassword is wrong!";
+
+      public String NICKNAME_INVALID = "{NL}{NL}&cYour nickname contains forbidden characters. Please, change your nickname!";
+      @Comment("6 hours by default in ip-limit-valid-time")
+      public String IP_LIMIT = "{PRFX} &cYour IP has reached max registered accounts. If this is an error, restart your router, or wait about 6 hours.";
+      public String WRONG_NICKNAME_CASE = "{NL}{NL}&cThe case of your nickname is wrong. Nickname is CaSe SeNsItIvE.";
+
+      public String LOGIN = "{PRFX} Please, login using &6/login &6<password>. You have &6{0} &cattempts.";
+      public String LOGIN_SUCCESS = "{PRFX} &aSuccessfully logged in!";
+      public String LOGIN_WRONG_PASSWORD = "{PRFX} &cYou've entered the wrong password. You have &6{0} &cattempts left.";
+      public String LOGIN_TITLE = "";
+      public String LOGIN_SUBTITLE = "";
+      public String LOGIN_SUCCESS_TITLE = "";
+      public String LOGIN_SUCCESS_SUBTITLE = "";
+
+      @Comment("Or if register-need-repeat-password set to false remove the \"<repeat password>\" part.")
+      public String REGISTER = "{PRFX} Please, register using &6/register <password> <repeat password>";
+      public String REGISTER_TITLE = "";
+      public String REGISTER_SUBTITLE = "";
+      public String DIFFERENT_PASSWORDS = "{PRFX} The entered passwords differ from each other.";
+      public String KICK_PASSWORD_WRONG = "{NL}{NL}&cYou've entered the wrong password numerous times!";
+
+      public String UNREGISTER_SUCCESSFUL = "{PRFX}{NL}{NL}&aSuccessfully unregistered!";
+      public String UNREGISTER_USAGE = "{PRFX} Usage: &6/unregister <current password> confirm";
+
+      public String FORCE_UNREGISTER_SUCCESSFUL = "{PRFX} &a{0} successfully unregistered!";
+      public String FORCE_UNREGISTER_SUCCESSFUL_PLAYER = "{PRFX}{NL}{NL}&aYou have been unregistered by administrator!";
+      public String FORCE_UNREGISTER_NOT_SUCCESSFUL = "{PRFX} &cUnable to unregister {0}. Most likely this player has never been on this server.";
+      public String FORCE_UNREGISTER_USAGE = "{PRFX} Usage: &6/forceunregister <nickname>";
+
+      public String CHANGE_PASSWORD_SUCCESSFUL = "{PRFX} &aSuccessfully changed password!";
+      @Comment("Or if change-password-need-old-pass set to false remove the \"<old password>\" part.")
+      public String CHANGE_PASSWORD_USAGE = "{PRFX} Usage: &6/changepassword <old password> <new password>";
+
+      public String TOTP = "{PRFX} Please, enter your 2FA key using &6/2fa <key>";
+      public String TOTP_SUCCESSFUL = "{PRFX} &aSuccessfully enabled 2FA!";
+      public String TOTP_DISABLED = "{PRFX} &aSuccessfully disabled 2FA!";
+      @Comment("Or if totp-need-pass set to false remove the \"<current password>\" part.")
+      public String TOTP_USAGE = "{PRFX} Usage: &6/2fa enable <current password>&f or &6/2fa disable <totp key>&f.";
+      public String TOTP_WRONG = "{PRFX} &cWrong 2FA key!";
+      public String TOTP_ALREADY_ENABLED = "{PRFX} &c2FA is already enabled. Disable it using &6/2fa disable <key>&c.";
+      public String TOTP_QR = "{PRFX} Click here to open 2FA QR code in browser.";
+      public String TOTP_TOKEN = "{PRFX} &aYour 2FA token &7(Click to copy)&a: &6{0}";
+      public String TOTP_RECOVERY = "{PRFX} &aYour recovery codes &7(Click to copy)&a: &6{0}";
+
+      public String DESTROY_SESSION_SUCCESSFUL = "{PRFX} &eYour session is now destroyed, you'll need to log in again after reconnecting.";
+    }
+
+    @Create
+    public MAIN.AUTH_COORDS AUTH_COORDS;
+
+    public static class AUTH_COORDS {
+
+      public double X = 0;
+      public double Y = 0;
+      public double Z = 0;
+      public double YAW = 0;
+      public double PITCH = 0;
+    }
+  }
+
+  @Create
+  public DATABASE DATABASE;
+
+  @Comment("Database settings")
+  public static class DATABASE {
+
+    @Comment("Database type: mysql, postgresql or h2.")
+    public String STORAGE_TYPE = "h2";
+
+    @Comment("Settings for Network-based database (like MySQL, PostgreSQL): ")
+    public String HOSTNAME = "127.0.0.1:3306";
+    public String USER = "user";
+    public String PASSWORD = "password";
+    public String DATABASE = "limboauth";
+    public String CONNECTION_PARAMETERS = "?autoReconnect=true&initialTimeout=1&useSSL=false";
+  }
+
+  public void reload(File file) {
+    if (this.load(file, this.PREFIX)) {
+      this.save(file);
+    } else {
+      this.save(file);
+      this.load(file, this.PREFIX);
+    }
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/command/ChangePasswordCommand.java b/src/main/java/net/elytrium/limboauth/command/ChangePasswordCommand.java
new file mode 100644
index 0000000..2373938
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/command/ChangePasswordCommand.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.command;
+
+import com.j256.ormlite.dao.Dao;
+import com.j256.ormlite.stmt.UpdateBuilder;
+import com.velocitypowered.api.command.CommandSource;
+import com.velocitypowered.api.command.SimpleCommand;
+import com.velocitypowered.api.permission.Tristate;
+import com.velocitypowered.api.proxy.Player;
+import java.sql.SQLException;
+import net.elytrium.limboauth.Settings;
+import net.elytrium.limboauth.handler.AuthSessionHandler;
+import net.elytrium.limboauth.model.RegisteredPlayer;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+
+public class ChangePasswordCommand implements SimpleCommand {
+
+  private final Dao<RegisteredPlayer, String> playerDao;
+
+  private final Component notPlayer;
+  private final boolean needOldPass;
+  private final Component notRegistered;
+  private final Component wrongPassword;
+  private final Component successful;
+  private final Component errorOccurred;
+  private final Component usage;
+
+  public ChangePasswordCommand(Dao<RegisteredPlayer, String> playerDao) {
+    this.playerDao = playerDao;
+
+    this.notPlayer = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.NOT_PLAYER);
+    this.needOldPass = Settings.IMP.MAIN.CHANGE_PASSWORD_NEED_OLD_PASSWORD;
+    this.notRegistered = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.NOT_REGISTERED);
+    this.wrongPassword = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.WRONG_PASSWORD);
+    this.successful = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.CHANGE_PASSWORD_SUCCESSFUL);
+    this.errorOccurred = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.ERROR_OCCURRED);
+    this.usage = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.CHANGE_PASSWORD_USAGE);
+  }
+
+  @Override
+  public void execute(SimpleCommand.Invocation invocation) {
+    CommandSource source = invocation.source();
+    String[] args = invocation.arguments();
+
+    if (!(source instanceof Player)) {
+      source.sendMessage(this.notPlayer);
+      return;
+    }
+
+    if (this.needOldPass ? args.length == 2 : args.length == 1) {
+      if (this.needOldPass) {
+        RegisteredPlayer player = AuthSessionHandler.fetchInfo(this.playerDao, ((Player) source).getUsername());
+        if (player == null) {
+          source.sendMessage(this.notRegistered);
+          return;
+        } else if (!AuthSessionHandler.checkPassword(args[0], player, this.playerDao)) {
+          source.sendMessage(this.wrongPassword);
+          return;
+        }
+      }
+
+      try {
+        UpdateBuilder<RegisteredPlayer, String> updateBuilder = this.playerDao.updateBuilder();
+        updateBuilder.where().eq("nickname", ((Player) source).getUsername());
+        updateBuilder.updateColumnValue("hash", AuthSessionHandler.genHash(this.needOldPass ? args[1] : args[0]));
+        updateBuilder.update();
+
+        source.sendMessage(this.successful);
+      } catch (SQLException e) {
+        source.sendMessage(this.errorOccurred);
+        e.printStackTrace();
+      }
+
+      return;
+    }
+
+    source.sendMessage(this.usage);
+  }
+
+  @Override
+  public boolean hasPermission(SimpleCommand.Invocation invocation) {
+    return invocation.source().getPermissionValue("limboauth.commands.changepassword") != Tristate.FALSE;
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/command/DestroySessionCommand.java b/src/main/java/net/elytrium/limboauth/command/DestroySessionCommand.java
new file mode 100644
index 0000000..27dff72
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/command/DestroySessionCommand.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.command;
+
+import com.velocitypowered.api.command.CommandSource;
+import com.velocitypowered.api.command.SimpleCommand;
+import com.velocitypowered.api.permission.Tristate;
+import com.velocitypowered.api.proxy.Player;
+import net.elytrium.limboauth.LimboAuth;
+import net.elytrium.limboauth.Settings;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+
+public class DestroySessionCommand implements SimpleCommand {
+
+  private final LimboAuth plugin;
+
+  private final Component notPlayer;
+  private final Component successful;
+
+  public DestroySessionCommand(LimboAuth plugin) {
+    this.plugin = plugin;
+
+    this.notPlayer = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.NOT_PLAYER);
+    this.successful = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.DESTROY_SESSION_SUCCESSFUL);
+  }
+
+  @Override
+  public void execute(SimpleCommand.Invocation invocation) {
+    CommandSource source = invocation.source();
+
+    if (!(source instanceof Player)) {
+      source.sendMessage(this.notPlayer);
+      return;
+    }
+
+    this.plugin.removePlayerFromCache((Player) source);
+    source.sendMessage(this.successful);
+  }
+
+  @Override
+  public boolean hasPermission(SimpleCommand.Invocation invocation) {
+    return invocation.source().getPermissionValue("limboauth.commands.destroysession") != Tristate.FALSE;
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/command/ForceUnregisterCommand.java b/src/main/java/net/elytrium/limboauth/command/ForceUnregisterCommand.java
new file mode 100644
index 0000000..d45eae9
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/command/ForceUnregisterCommand.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.command;
+
+import com.google.common.collect.ImmutableList;
+import com.j256.ormlite.dao.Dao;
+import com.velocitypowered.api.command.CommandSource;
+import com.velocitypowered.api.command.SimpleCommand;
+import com.velocitypowered.api.proxy.Player;
+import com.velocitypowered.api.proxy.ProxyServer;
+import java.sql.SQLException;
+import java.text.MessageFormat;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
+import net.elytrium.limboauth.LimboAuth;
+import net.elytrium.limboauth.Settings;
+import net.elytrium.limboauth.model.RegisteredPlayer;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+
+public class ForceUnregisterCommand implements SimpleCommand {
+
+  private final LimboAuth plugin;
+  private final ProxyServer server;
+  private final Dao<RegisteredPlayer, String> playerDao;
+
+  private final Component successfulPlayer;
+  private final String successful;
+  private final String notSuccessful;
+  private final Component usage;
+
+  public ForceUnregisterCommand(LimboAuth plugin, ProxyServer server, Dao<RegisteredPlayer, String> playerDao) {
+    this.plugin = plugin;
+    this.server = server;
+    this.playerDao = playerDao;
+
+    this.successfulPlayer = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.FORCE_UNREGISTER_SUCCESSFUL_PLAYER);
+    this.successful = Settings.IMP.MAIN.STRINGS.FORCE_UNREGISTER_SUCCESSFUL;
+    this.notSuccessful = Settings.IMP.MAIN.STRINGS.FORCE_UNREGISTER_NOT_SUCCESSFUL;
+    this.usage = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.FORCE_UNREGISTER_USAGE);
+  }
+
+  @Override
+  public List<String> suggest(SimpleCommand.Invocation invocation) {
+    String[] args = invocation.arguments();
+
+    if (args.length == 0) {
+      return this.server.getAllPlayers().stream()
+          .map(Player::getUsername)
+          .collect(Collectors.toList());
+    } else if (args.length == 1) {
+      return this.server.getAllPlayers().stream()
+          .map(Player::getUsername)
+          .filter(str -> str.regionMatches(true, 0, args[0], 0, args[0].length()))
+          .collect(Collectors.toList());
+    }
+
+    return ImmutableList.of();
+  }
+
+  @Override
+  public void execute(SimpleCommand.Invocation invocation) {
+    CommandSource source = invocation.source();
+    String[] args = invocation.arguments();
+
+    if (args.length == 1) {
+      String playerNick = args[0];
+      try {
+        this.playerDao.deleteById(playerNick.toLowerCase(Locale.ROOT));
+        this.server.getPlayer(playerNick).ifPresent(player -> {
+          this.plugin.removePlayerFromCache(player);
+          player.disconnect(this.successfulPlayer);
+        });
+        source.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(MessageFormat.format(this.successful, playerNick)));
+      } catch (SQLException e) {
+        source.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(MessageFormat.format(this.notSuccessful, playerNick)));
+        e.printStackTrace();
+      }
+
+      return;
+    }
+
+    source.sendMessage(this.usage);
+  }
+
+  @Override
+  public boolean hasPermission(SimpleCommand.Invocation invocation) {
+    return invocation.source().hasPermission("limboauth.admin.forceunregister");
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/command/LimboAuthCommand.java b/src/main/java/net/elytrium/limboauth/command/LimboAuthCommand.java
new file mode 100644
index 0000000..611b1c3
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/command/LimboAuthCommand.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.command;
+
+import com.google.common.collect.ImmutableList;
+import com.velocitypowered.api.command.CommandSource;
+import com.velocitypowered.api.command.SimpleCommand;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import net.elytrium.limboauth.LimboAuth;
+import net.elytrium.limboauth.Settings;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+
+public class LimboAuthCommand implements SimpleCommand {
+
+  @Override
+  public List<String> suggest(SimpleCommand.Invocation invocation) {
+    CommandSource source = invocation.source();
+    String[] args = invocation.arguments();
+
+    if (args.length == 0) {
+      return this.getSubCommands()
+          .filter(cmd -> source.hasPermission("limboauth.admin." + cmd))
+          .collect(Collectors.toList());
+    } else if (args.length == 1) {
+      return this.getSubCommands()
+          .filter(cmd -> source.hasPermission("limboauth.admin." + cmd))
+          .filter(str -> str.regionMatches(true, 0, args[0], 0, args[0].length()))
+          .collect(Collectors.toList());
+    }
+
+    return ImmutableList.of();
+  }
+
+  @Override
+  public void execute(SimpleCommand.Invocation invocation) {
+    CommandSource source = invocation.source();
+    String[] args = invocation.arguments();
+
+    if (args.length == 1) {
+      if (args[0].equalsIgnoreCase("reload") && source.hasPermission("limboauth.admin.reload")) {
+        try {
+          LimboAuth.getInstance().reload();
+          source.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.RELOAD));
+        } catch (Exception e) {
+          source.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.RELOAD_FAILED));
+          e.printStackTrace();
+        }
+      } else {
+        this.showHelp(source);
+      }
+
+      return;
+    }
+
+    this.showHelp(source);
+  }
+
+  private void showHelp(CommandSource source) {
+    source.sendMessage(Component.text("§eThis server is using LimboAuth and LimboAPI"));
+    source.sendMessage(Component.text("§e(c) 2021 Elytrium"));
+    source.sendMessage(Component.text("§ahttps://ely.su/github/"));
+    source.sendMessage(Component.text("§r"));
+    source.sendMessage(Component.text("§fAvailable subcommands:"));
+    // Java moment
+    this.getSubCommands()
+        .filter(cmd -> source.hasPermission("limboauth.admin." + cmd))
+        .forEach(cmd -> {
+          if (cmd.equals("reload")) {
+            source.sendMessage(Component.text("    §a/limboauth reload §8- §eReload config"));
+          }
+        });
+  }
+
+  private Stream<String> getSubCommands() {
+    return Stream.of("reload");
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/command/TotpCommand.java b/src/main/java/net/elytrium/limboauth/command/TotpCommand.java
new file mode 100644
index 0000000..d51da7d
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/command/TotpCommand.java
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.command;
+
+import com.j256.ormlite.dao.Dao;
+import com.j256.ormlite.stmt.UpdateBuilder;
+import com.velocitypowered.api.command.CommandSource;
+import com.velocitypowered.api.command.SimpleCommand;
+import com.velocitypowered.api.permission.Tristate;
+import com.velocitypowered.api.proxy.Player;
+import dev.samstevens.totp.qr.QrData;
+import dev.samstevens.totp.recovery.RecoveryCodeGenerator;
+import dev.samstevens.totp.secret.DefaultSecretGenerator;
+import dev.samstevens.totp.secret.SecretGenerator;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
+import java.sql.SQLException;
+import java.text.MessageFormat;
+import net.elytrium.limboauth.Settings;
+import net.elytrium.limboauth.handler.AuthSessionHandler;
+import net.elytrium.limboauth.model.RegisteredPlayer;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.event.ClickEvent;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+
+public class TotpCommand implements SimpleCommand {
+
+  private final SecretGenerator secretGenerator = new DefaultSecretGenerator();
+  private final RecoveryCodeGenerator codesGenerator = new RecoveryCodeGenerator();
+  private final Dao<RegisteredPlayer, String> playerDao;
+
+  private final Component notPlayer;
+  private final Component usage;
+  private final boolean needPassword;
+  private final Component notRegistered;
+  private final Component wrongPassword;
+  private final Component alreadyEnabled;
+  private final Component errorOccurred;
+  private final Component successful;
+  private final String issuer;
+  private final String qrGeneratorUrl;
+  private final Component qr;
+  private final String token;
+  private final int recoveryCodesAmount;
+  private final String recovery;
+  private final Component disabled;
+  private final Component wrong;
+
+  public TotpCommand(Dao<RegisteredPlayer, String> playerDao) {
+    this.playerDao = playerDao;
+
+    this.notPlayer = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.NOT_PLAYER);
+    this.usage = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.TOTP_USAGE);
+    this.needPassword = Settings.IMP.MAIN.TOTP_NEED_PASSWORD;
+    this.notRegistered = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.NOT_REGISTERED);
+    this.wrongPassword = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.WRONG_PASSWORD);
+    this.alreadyEnabled = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.TOTP_ALREADY_ENABLED);
+    this.errorOccurred = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.ERROR_OCCURRED);
+    this.successful = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.TOTP_SUCCESSFUL);
+    this.issuer = Settings.IMP.MAIN.TOTP_ISSUER;
+    this.qrGeneratorUrl = Settings.IMP.MAIN.QR_GENERATOR_URL;
+    this.qr = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.TOTP_QR);
+    this.token = Settings.IMP.MAIN.STRINGS.TOTP_TOKEN;
+    this.recoveryCodesAmount = Settings.IMP.MAIN.TOTP_RECOVERY_CODES_AMOUNT;
+    this.recovery = Settings.IMP.MAIN.STRINGS.TOTP_RECOVERY;
+    this.disabled = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.TOTP_DISABLED);
+    this.wrong = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.TOTP_WRONG);
+  }
+
+  @Override
+  public void execute(SimpleCommand.Invocation invocation) {
+    CommandSource source = invocation.source();
+    String[] args = invocation.arguments();
+
+    if (!(source instanceof Player)) {
+      source.sendMessage(this.notPlayer);
+      return;
+    }
+
+    if (args.length == 0) {
+      source.sendMessage(this.usage);
+    } else {
+      String username = ((Player) source).getUsername();
+
+      RegisteredPlayer playerInfo;
+      UpdateBuilder<RegisteredPlayer, String> updateBuilder;
+      switch (args[0]) {
+        case "enable": {
+          if (this.needPassword ? args.length == 2 : args.length == 1) {
+            playerInfo = AuthSessionHandler.fetchInfo(this.playerDao, username);
+
+            if (playerInfo == null) {
+              source.sendMessage(this.notRegistered);
+              return;
+            } else if (this.needPassword && !AuthSessionHandler.checkPassword(args[1], playerInfo, this.playerDao)) {
+              source.sendMessage(this.wrongPassword);
+              return;
+            }
+
+            if (!playerInfo.getTotpToken().isEmpty()) {
+              source.sendMessage(this.alreadyEnabled);
+              return;
+            }
+
+            String secret = this.secretGenerator.generate();
+
+            try {
+              updateBuilder = this.playerDao.updateBuilder();
+              updateBuilder.where().eq("nickname", username);
+              updateBuilder.updateColumnValue("totpToken", secret);
+              updateBuilder.update();
+            } catch (SQLException e) {
+              source.sendMessage(this.errorOccurred);
+              e.printStackTrace();
+            }
+
+            source.sendMessage(this.successful);
+
+            QrData data = new QrData.Builder()
+                .label(username)
+                .secret(secret)
+                .issuer(this.issuer)
+                .build();
+
+            String qrUrl = this.qrGeneratorUrl.replace("{data}", URLEncoder.encode(data.getUri(), StandardCharsets.UTF_8));
+
+            source.sendMessage(this.qr.clickEvent(ClickEvent.openUrl(qrUrl)));
+
+            source.sendMessage(
+                LegacyComponentSerializer.legacyAmpersand().deserialize(
+                    MessageFormat.format(this.token, secret)
+                ).clickEvent(ClickEvent.copyToClipboard(secret))
+            );
+
+            String codes = String.join(", ", this.codesGenerator.generateCodes(this.recoveryCodesAmount));
+
+            source.sendMessage(
+                LegacyComponentSerializer.legacyAmpersand().deserialize(
+                    MessageFormat.format(this.recovery, codes)
+                ).clickEvent(ClickEvent.copyToClipboard(codes))
+            );
+          } else {
+            source.sendMessage(this.usage);
+          }
+          break;
+        }
+        case "disable": {
+          if (args.length != 2) {
+            source.sendMessage(this.usage);
+            return;
+          }
+
+          playerInfo = AuthSessionHandler.fetchInfo(this.playerDao, username);
+
+          if (playerInfo == null) {
+            source.sendMessage(this.notRegistered);
+            return;
+          }
+
+          if (AuthSessionHandler.getVerifier().isValidCode(playerInfo.getTotpToken(), args[1])) {
+            try {
+              updateBuilder = this.playerDao.updateBuilder();
+              updateBuilder.where().eq("nickname", username);
+              updateBuilder.updateColumnValue("totpToken", "");
+              updateBuilder.update();
+
+              source.sendMessage(this.disabled);
+            } catch (SQLException e) {
+              source.sendMessage(this.errorOccurred);
+              e.printStackTrace();
+            }
+          } else {
+            source.sendMessage(this.wrong);
+          }
+          break;
+        }
+        default: {
+          source.sendMessage(this.usage);
+          break;
+        }
+      }
+    }
+  }
+
+  @Override
+  public boolean hasPermission(SimpleCommand.Invocation invocation) {
+    return invocation.source().getPermissionValue("limboauth.commands.totp") != Tristate.FALSE;
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/command/UnregisterCommand.java b/src/main/java/net/elytrium/limboauth/command/UnregisterCommand.java
new file mode 100644
index 0000000..aeab6ec
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/command/UnregisterCommand.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.command;
+
+import com.j256.ormlite.dao.Dao;
+import com.velocitypowered.api.command.CommandSource;
+import com.velocitypowered.api.command.SimpleCommand;
+import com.velocitypowered.api.permission.Tristate;
+import com.velocitypowered.api.proxy.Player;
+import java.sql.SQLException;
+import java.util.Locale;
+import net.elytrium.limboauth.LimboAuth;
+import net.elytrium.limboauth.Settings;
+import net.elytrium.limboauth.handler.AuthSessionHandler;
+import net.elytrium.limboauth.model.RegisteredPlayer;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+
+public class UnregisterCommand implements SimpleCommand {
+
+  private final LimboAuth plugin;
+  private final Dao<RegisteredPlayer, String> playerDao;
+
+  private final Component notPlayer;
+  private final Component notRegistered;
+  private final Component successful;
+  private final Component errorOccurred;
+  private final Component wrongPassword;
+  private final Component usage;
+
+  public UnregisterCommand(LimboAuth plugin, Dao<RegisteredPlayer, String> playerDao) {
+    this.plugin = plugin;
+    this.playerDao = playerDao;
+
+    this.notPlayer = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.NOT_PLAYER);
+    this.notRegistered = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.NOT_REGISTERED);
+    this.successful = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.UNREGISTER_SUCCESSFUL);
+    this.errorOccurred = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.ERROR_OCCURRED);
+    this.wrongPassword = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.WRONG_PASSWORD);
+    this.usage = LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.UNREGISTER_USAGE);
+  }
+
+  @Override
+  public void execute(SimpleCommand.Invocation invocation) {
+    CommandSource source = invocation.source();
+    String[] args = invocation.arguments();
+
+    if (!(source instanceof Player)) {
+      source.sendMessage(this.notPlayer);
+      return;
+    }
+
+    if (args.length == 2) {
+      if (args[1].equalsIgnoreCase("confirm")) {
+        RegisteredPlayer player = AuthSessionHandler.fetchInfo(this.playerDao, ((Player) source).getUsername());
+        if (player == null) {
+          source.sendMessage(this.notRegistered);
+        } else if (AuthSessionHandler.checkPassword(args[0], player, this.playerDao)) {
+          try {
+            this.playerDao.deleteById(((Player) source).getUsername().toLowerCase(Locale.ROOT));
+            this.plugin.removePlayerFromCache((Player) source);
+            ((Player) source).disconnect(this.successful);
+          } catch (SQLException e) {
+            source.sendMessage(this.errorOccurred);
+            e.printStackTrace();
+          }
+        } else {
+          source.sendMessage(this.wrongPassword);
+        }
+
+        return;
+      }
+    }
+
+    source.sendMessage(this.usage);
+  }
+
+  @Override
+  public boolean hasPermission(SimpleCommand.Invocation invocation) {
+    return invocation.source().getPermissionValue("limboauth.commands.unregister") != Tristate.FALSE;
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/config/Config.java b/src/main/java/net/elytrium/limboauth/config/Config.java
new file mode 100644
index 0000000..ed5b007
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/config/Config.java
@@ -0,0 +1,392 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.config;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import net.elytrium.limboauth.LimboAuth;
+import org.slf4j.Logger;
+import org.yaml.snakeyaml.Yaml;
+
+public class Config {
+
+  private static final Logger LOGGER = LimboAuth.getInstance().getLogger();
+  private String oldPrefix = "";
+  private String currentPrefix = "";
+
+  /**
+   * Set the value of a specific node. Probably throws some error if you supply non-existing keys or invalid values.
+   *
+   * @param key   config node
+   * @param value value
+   */
+  private void set(String key, Object value, Class<?> root) {
+    String[] split = key.split("\\.");
+    Object instance = this.getInstance(split, root);
+    if (instance != null) {
+      Field field = this.getField(split, instance);
+      if (field != null) {
+        try {
+          if (field.getAnnotation(Final.class) != null) {
+            return;
+          }
+          if (field.getType() == String.class && !(value instanceof String)) {
+            value = value + "";
+          }
+          field.set(instance, value);
+          return;
+        } catch (Throwable e) {
+          e.printStackTrace();
+        }
+      }
+    }
+
+    LOGGER.debug("Failed to set config option: " + key + ": " + value + " | " + instance + " | " + root.getSimpleName() + ".yml");
+  }
+
+  @SuppressWarnings("unchecked")
+  public void set(Map<String, Object> input, String oldPath) {
+    for (Map.Entry<String, Object> entry : input.entrySet()) {
+      String key = oldPath + (oldPath.isEmpty() ? "" : ".") + entry.getKey();
+      Object value = entry.getValue();
+
+      if (value instanceof Map) {
+        this.set((Map<String, Object>) value, key);
+      } else if (value instanceof String) {
+        if (key.equalsIgnoreCase("prefix") && !this.currentPrefix.equals(value)) {
+          this.currentPrefix = (String) value;
+        }
+
+        this.set(key, ((String) value).replace("{NL}", "\n").replace("{PRFX}", this.currentPrefix), this.getClass());
+      } else {
+        this.set(key, value, this.getClass());
+      }
+    }
+  }
+
+  public boolean load(File file, String prefix) {
+    this.oldPrefix = this.currentPrefix.isEmpty() ? prefix : this.currentPrefix;
+    this.currentPrefix = prefix;
+    if (!file.exists()) {
+      return false;
+    }
+
+    try (InputStreamReader reader = new InputStreamReader(new FileInputStream(file), StandardCharsets.UTF_8)) {
+      this.set(new Yaml().load(reader), "");
+    } catch (IOException e) {
+      LOGGER.warn("Unable to load config ", e);
+      return false;
+    }
+
+    return true;
+  }
+
+  /**
+   * Indicates that a field should be instantiated / created.
+   */
+  @Retention(RetentionPolicy.RUNTIME)
+  @Target({ElementType.FIELD})
+  public @interface Create {
+
+  }
+
+  /**
+   * Indicates that a field cannot be modified.
+   */
+  @Retention(RetentionPolicy.RUNTIME)
+  @Target({ElementType.FIELD})
+  public @interface Final {
+
+  }
+
+  /**
+   * Creates a comment.
+   */
+  @Retention(RetentionPolicy.RUNTIME)
+  @Target({ElementType.FIELD, ElementType.TYPE})
+  public @interface Comment {
+
+    String[] value();
+  }
+
+  /**
+   * Any field or class with is not part of the config.
+   */
+  @Retention(RetentionPolicy.RUNTIME)
+  @Target({ElementType.FIELD, ElementType.TYPE})
+  public @interface Ignore {
+
+  }
+
+  private String toYamlString(Object value, String spacing, String fieldName) {
+    if (value instanceof List) {
+      Collection<?> listValue = (Collection<?>) value;
+      if (listValue.isEmpty()) {
+        return "[]";
+      }
+      StringBuilder m = new StringBuilder();
+      for (Object obj : listValue) {
+        m.append(System.lineSeparator()).append(spacing).append("- ").append(this.toYamlString(obj, spacing, fieldName));
+      }
+
+      return m.toString();
+    }
+
+    if (value instanceof String) {
+      String stringValue = (String) value;
+      if (stringValue.isEmpty()) {
+        return "\"\"";
+      }
+
+      String quoted = "\"" + stringValue + "\"";
+      if (fieldName.equalsIgnoreCase("prefix")) {
+        return quoted;
+      } else {
+        return quoted.replace("\n", "{NL}").replace(this.currentPrefix.equals(this.oldPrefix) ? this.oldPrefix : this.currentPrefix, "{PRFX}");
+      }
+    }
+
+    return value != null ? value.toString() : "null";
+  }
+
+  /**
+   * Set all values in the file (load first to avoid overwriting).
+   */
+  @SuppressWarnings("ResultOfMethodCallIgnored")
+  @SuppressFBWarnings("RV_RETURN_VALUE_IGNORED_BAD_PRACTICE")
+  public void save(File file) {
+    try {
+      if (!file.exists()) {
+        File parent = file.getParentFile();
+        if (parent != null) {
+          file.getParentFile().mkdirs();
+        }
+        file.createNewFile();
+      }
+
+      PrintWriter writer = new PrintWriter(file, StandardCharsets.UTF_8);
+      Object instance = this;
+      this.save(writer, this.getClass(), instance, 0);
+      writer.close();
+    } catch (Throwable e) {
+      e.printStackTrace();
+    }
+  }
+
+  private void save(PrintWriter writer, Class<?> clazz, final Object instance, int indent) {
+    try {
+      String lineSeparator = System.lineSeparator();
+      String spacing = this.repeat(" ", indent);
+
+      for (Field field : clazz.getFields()) {
+        if (field.getAnnotation(Ignore.class) != null) {
+          continue;
+        }
+        Class<?> current = field.getType();
+        if (field.getAnnotation(Ignore.class) != null) {
+          continue;
+        }
+
+        Comment comment = field.getAnnotation(Comment.class);
+        if (comment != null) {
+          for (String commentLine : comment.value()) {
+            writer.write(spacing + "# " + commentLine + lineSeparator);
+          }
+        }
+
+        Create create = field.getAnnotation(Create.class);
+        if (create != null) {
+          Object value = field.get(instance);
+          this.setAccessible(field);
+          if (indent == 0) {
+            writer.write(lineSeparator);
+          }
+          comment = current.getAnnotation(Comment.class);
+          if (comment != null) {
+            for (String commentLine : comment.value()) {
+              writer.write(spacing + "# " + commentLine + lineSeparator);
+            }
+          }
+          writer.write(spacing + this.toNodeName(current.getSimpleName()) + ":" + lineSeparator);
+          if (value == null) {
+            field.set(instance, value = current.getDeclaredConstructor().newInstance());
+          }
+          this.save(writer, current, value, indent + 2);
+        } else {
+          String value = this.toYamlString(field.get(instance), spacing, field.getName());
+          writer.write(spacing + this.toNodeName(field.getName() + ": ") + value + lineSeparator);
+        }
+      }
+    } catch (Throwable e) {
+      e.printStackTrace();
+    }
+  }
+
+  /**
+   * Get the field for a specific config node and instance.
+   *
+   * <p>As expiry can have multiple blocks there will be multiple instances
+   *
+   * @param split    the node (split by period)
+   * @param instance the instance
+   */
+  private Field getField(String[] split, Object instance) {
+    try {
+      Field field = instance.getClass().getField(this.toFieldName(split[split.length - 1]));
+      this.setAccessible(field);
+      return field;
+    } catch (Throwable ignored) {
+      LOGGER.debug("Invalid config field: " + this.join(split, ".") + " for " + this.toNodeName(instance.getClass().getSimpleName()));
+      return null;
+    }
+  }
+
+  /**
+   * Get the instance for a specific config node.
+   *
+   * @param split the node (split by period)
+   * @return The instance or null
+   */
+  private Object getInstance(String[] split, Class<?> root) {
+    try {
+      Class<?> clazz = root == null ? MethodHandles.lookup().lookupClass() : root;
+      Object instance = this;
+      while (split.length > 0) {
+        if (split.length == 1) {
+          return instance;
+        } else {
+          Class<?> found = null;
+          if (clazz == null) {
+            return null;
+          }
+
+          Class<?>[] classes = clazz.getDeclaredClasses();
+          for (Class<?> current : classes) {
+            if (Objects.equals(current.getSimpleName(), this.toFieldName(split[0]))) {
+              found = current;
+              break;
+            }
+          }
+
+          if (found == null) {
+            return null;
+          }
+
+          try {
+            Field instanceField = clazz.getDeclaredField(this.toFieldName(split[0]));
+            this.setAccessible(instanceField);
+            Object value = instanceField.get(instance);
+            if (value == null) {
+              value = found.getDeclaredConstructor().newInstance();
+              instanceField.set(instance, value);
+            }
+
+            clazz = found;
+            instance = value;
+            split = Arrays.copyOfRange(split, 1, split.length);
+            continue;
+          } catch (NoSuchFieldException e) {
+            //
+          }
+
+          split = Arrays.copyOfRange(split, 1, split.length);
+          clazz = found;
+          instance = clazz.getDeclaredConstructor().newInstance();
+        }
+      }
+    } catch (Throwable e) {
+      e.printStackTrace();
+    }
+
+    return null;
+  }
+
+  /**
+   * Translate a node to a java field name.
+   */
+  private String toFieldName(String node) {
+    return node.toUpperCase(Locale.ROOT).replaceAll("-", "_");
+  }
+
+  /**
+   * Translate a field to a config node.
+   */
+  private String toNodeName(String field) {
+    return field.toLowerCase(Locale.ROOT).replace("_", "-");
+  }
+
+  /**
+   * Set some field to be accessible.
+   */
+  private void setAccessible(Field field) throws NoSuchFieldException, IllegalAccessException {
+    field.setAccessible(true);
+    if (Modifier.isFinal(field.getModifiers())) {
+      Field modifiersField = Field.class.getDeclaredField("modifiers");
+      modifiersField.setAccessible(true);
+      modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
+    }
+  }
+
+  @SuppressWarnings("SameParameterValue")
+  private String repeat(String s, int n) {
+    return IntStream.range(0, n).mapToObj(i -> s).collect(Collectors.joining());
+  }
+
+  @SuppressWarnings("SameParameterValue")
+  private String join(Object[] array, String delimiter) {
+    switch (array.length) {
+      case 0: {
+        return "";
+      }
+      case 1: {
+        return array[0].toString();
+      }
+      default: {
+        final StringBuilder result = new StringBuilder();
+        for (int i = 0, j = array.length; i < j; ++i) {
+          if (i > 0) {
+            result.append(delimiter);
+          }
+          result.append(array[i]);
+        }
+
+        return result.toString();
+      }
+    }
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/handler/AuthSessionHandler.java b/src/main/java/net/elytrium/limboauth/handler/AuthSessionHandler.java
new file mode 100644
index 0000000..38a464d
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/handler/AuthSessionHandler.java
@@ -0,0 +1,297 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.handler;
+
+import at.favre.lib.crypto.bcrypt.BCrypt;
+import com.j256.ormlite.dao.Dao;
+import com.velocitypowered.api.proxy.Player;
+import dev.samstevens.totp.code.CodeVerifier;
+import dev.samstevens.totp.code.DefaultCodeGenerator;
+import dev.samstevens.totp.code.DefaultCodeVerifier;
+import dev.samstevens.totp.time.SystemTimeProvider;
+import java.nio.charset.StandardCharsets;
+import java.sql.SQLException;
+import java.text.MessageFormat;
+import java.util.List;
+import java.util.Locale;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
+import net.elytrium.limboapi.api.Limbo;
+import net.elytrium.limboapi.api.LimboSessionHandler;
+import net.elytrium.limboapi.api.player.LimboPlayer;
+import net.elytrium.limboauth.LimboAuth;
+import net.elytrium.limboauth.Settings;
+import net.elytrium.limboauth.migration.MigrationHash;
+import net.elytrium.limboauth.model.RegisteredPlayer;
+import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
+
+public class AuthSessionHandler implements LimboSessionHandler {
+
+  private static final CodeVerifier verifier = new DefaultCodeVerifier(new DefaultCodeGenerator(), new SystemTimeProvider());
+
+  private final Dao<RegisteredPlayer, String> playerDao;
+  private final Player proxyPlayer;
+  private final RegisteredPlayer playerInfo;
+
+  private LimboPlayer player;
+  private String ip;
+  private int attempts = Settings.IMP.MAIN.LOGIN_ATTEMPTS;
+  private boolean totp = false;
+
+  public AuthSessionHandler(Dao<RegisteredPlayer, String> playerDao, Player proxyPlayer, String lowercaseNickname) {
+    this.playerDao = playerDao;
+    this.proxyPlayer = proxyPlayer;
+    this.playerInfo = this.fetchInfo(lowercaseNickname);
+  }
+
+  @Override
+  public void onSpawn(Limbo server, LimboPlayer player) {
+    this.player = player;
+    this.player.disableFalling();
+    this.ip = this.proxyPlayer.getRemoteAddress().getAddress().getHostAddress();
+
+    if (this.playerInfo == null) {
+      this.checkIp();
+    } else {
+      this.checkCase();
+    }
+
+    this.sendMessage();
+  }
+
+  @Override
+  public void onChat(String message) {
+    String[] args = message.split(" ");
+    if (args.length != 0 && this.checkArgsLength(args.length)) {
+      switch (args[0]) {
+        case "/reg":
+        case "/register":
+        case "/r": {
+          if (!this.totp && this.playerInfo == null && this.checkPasswordsRepeat(args)) {
+            this.register(args[1]);
+            this.finishAuth();
+          } else {
+            this.sendMessage();
+          }
+          break;
+        }
+        case "/log":
+        case "/login":
+        case "/l": {
+          if (!this.totp && this.playerInfo != null) {
+            if (this.checkPassword(args[1])) {
+              this.finishOrTotp();
+            } else if (--this.attempts != 0) {
+              this.proxyPlayer.sendMessage(
+                  LegacyComponentSerializer.legacyAmpersand().deserialize(
+                      MessageFormat.format(Settings.IMP.MAIN.STRINGS.LOGIN_WRONG_PASSWORD, this.attempts)
+                  )
+              );
+            } else {
+              this.proxyPlayer.disconnect(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.KICK_PASSWORD_WRONG));
+            }
+          } else {
+            this.sendMessage();
+          }
+          break;
+        }
+        case "/totp":
+        case "/2fa": {
+          if (this.totp) {
+            if (verifier.isValidCode(this.playerInfo.getTotpToken(), args[1])) {
+              this.finishAuth();
+            } else {
+              this.sendMessage();
+            }
+          } else {
+            this.sendMessage();
+          }
+          break;
+        }
+        default: {
+          this.sendMessage();
+          break;
+        }
+      }
+    } else {
+      this.sendMessage();
+    }
+  }
+
+  public static RegisteredPlayer fetchInfo(Dao<RegisteredPlayer, String> playerDao, String nickname) {
+    List<RegisteredPlayer> playerList = null;
+    try {
+      playerList = playerDao.queryForEq("LOWERCASENICKNAME", nickname.toLowerCase(Locale.ROOT));
+    } catch (SQLException e) {
+      e.printStackTrace();
+    }
+
+    return (playerList != null ? playerList.size() : 0) == 0 ? null : playerList.get(0);
+  }
+
+  public static RegisteredPlayer fetchInfo(Dao<RegisteredPlayer, String> playerDao, UUID uuid) {
+    List<RegisteredPlayer> playerList = null;
+    try {
+      playerList = playerDao.queryForEq("PREMIUMUUID", uuid.toString());
+    } catch (SQLException e) {
+      e.printStackTrace();
+    }
+
+    return (playerList != null ? playerList.size() : 0) == 0 ? null : playerList.get(0);
+  }
+
+  private RegisteredPlayer fetchInfo(String nickname) {
+    return fetchInfo(this.playerDao, nickname);
+  }
+
+  public static CodeVerifier getVerifier() {
+    return verifier;
+  }
+
+  public static boolean checkPassword(String password, RegisteredPlayer player, Dao<RegisteredPlayer, String> playerDao) {
+    boolean isCorrect = BCrypt.verifyer().verify(
+        password.getBytes(StandardCharsets.UTF_8), player.getHash().getBytes(StandardCharsets.UTF_8)
+    ).verified;
+
+    if (!isCorrect && !Settings.IMP.MAIN.MIGRATION_HASH.isEmpty()) {
+      isCorrect = MigrationHash.valueOf(Settings.IMP.MAIN.MIGRATION_HASH).checkPassword(player.getHash(), password);
+
+      if (isCorrect) {
+        player.setHash(genHash(password));
+        try {
+          playerDao.update(player);
+        } catch (SQLException e) {
+          e.printStackTrace();
+        }
+      }
+    }
+
+    return isCorrect;
+  }
+
+  private boolean checkPassword(String password) {
+    return checkPassword(password, this.playerInfo, this.playerDao);
+  }
+
+  private void checkIp() {
+    try {
+      List<RegisteredPlayer> alreadyRegistered = this.playerDao.queryForEq("IP", this.ip);
+
+      if (alreadyRegistered == null) {
+        return;
+      }
+
+      AtomicInteger sizeOfValid = new AtomicInteger(alreadyRegistered.size());
+
+      if (Settings.IMP.MAIN.IP_LIMIT_VALID_TIME != 0) {
+        long checkDate = System.currentTimeMillis() - Settings.IMP.MAIN.IP_LIMIT_VALID_TIME;
+
+        alreadyRegistered.stream()
+            .filter(e -> e.getRegDate() < checkDate)
+            .forEach(e -> {
+              try {
+                e.setIP("");
+                this.playerDao.update(e);
+                sizeOfValid.decrementAndGet();
+              } catch (SQLException ex) {
+                ex.printStackTrace();
+              }
+            });
+      }
+
+      if (sizeOfValid.get() >= Settings.IMP.MAIN.IP_LIMIT_REGISTRATIONS) {
+        this.proxyPlayer.disconnect(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.IP_LIMIT));
+      }
+    } catch (SQLException e) {
+      e.printStackTrace();
+    }
+  }
+
+  private void checkCase() {
+    if (!this.proxyPlayer.getUsername().equals(this.playerInfo.getNickname())) {
+      this.proxyPlayer.disconnect(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.WRONG_NICKNAME_CASE));
+    }
+  }
+
+  private void register(String password) {
+    RegisteredPlayer registeredPlayer = new RegisteredPlayer(
+        this.proxyPlayer.getUsername(),
+        this.proxyPlayer.getUsername().toLowerCase(Locale.ROOT),
+        genHash(password),
+        this.ip,
+        "",
+        System.currentTimeMillis(),
+        this.proxyPlayer.getUniqueId().toString(),
+        ""
+    );
+
+    try {
+      this.playerDao.create(registeredPlayer);
+    } catch (SQLException e) {
+      e.printStackTrace();
+    }
+  }
+
+  private void finishOrTotp() {
+    if (this.playerInfo.getTotpToken().isEmpty()) {
+      this.finishAuth();
+    } else {
+      this.totp = true;
+      this.sendMessage();
+    }
+  }
+
+  private void finishAuth() {
+    this.proxyPlayer.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.LOGIN_SUCCESS));
+    LimboAuth.getInstance().cacheAuthUser(this.proxyPlayer);
+    this.player.disconnect();
+  }
+
+  private void sendMessage() {
+    if (this.totp) {
+      this.proxyPlayer.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.TOTP));
+    } else if (this.playerInfo == null) {
+      this.proxyPlayer.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.REGISTER));
+    } else {
+      this.proxyPlayer.sendMessage(
+          LegacyComponentSerializer.legacyAmpersand().deserialize(MessageFormat.format(Settings.IMP.MAIN.STRINGS.LOGIN, this.attempts))
+      );
+    }
+  }
+
+  private boolean checkPasswordsRepeat(String[] args) {
+    if (Settings.IMP.MAIN.REGISTER_NEED_REPEAT_PASSWORD && !args[1].equals(args[2])) {
+      this.proxyPlayer.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(Settings.IMP.MAIN.STRINGS.DIFFERENT_PASSWORDS));
+      return false;
+    }
+
+    return true;
+  }
+
+  private boolean checkArgsLength(int argsLength) {
+    if (this.playerInfo == null && Settings.IMP.MAIN.REGISTER_NEED_REPEAT_PASSWORD) {
+      return argsLength == 3;
+    } else {
+      return argsLength == 2;
+    }
+  }
+
+  public static String genHash(String password) {
+    return BCrypt.withDefaults().hashToString(Settings.IMP.MAIN.BCRYPT_COST, password.toCharArray());
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/listener/AuthListener.java b/src/main/java/net/elytrium/limboauth/listener/AuthListener.java
new file mode 100644
index 0000000..2892d79
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/listener/AuthListener.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.listener;
+
+import com.j256.ormlite.dao.Dao;
+import com.j256.ormlite.stmt.UpdateBuilder;
+import com.velocitypowered.api.event.Subscribe;
+import com.velocitypowered.api.event.connection.PreLoginEvent;
+import com.velocitypowered.api.util.UuidUtils;
+import java.sql.SQLException;
+import java.util.UUID;
+import net.elytrium.limboapi.api.event.LoginLimboRegisterEvent;
+import net.elytrium.limboapi.api.event.SafeGameProfileRequestEvent;
+import net.elytrium.limboauth.LimboAuth;
+import net.elytrium.limboauth.Settings;
+import net.elytrium.limboauth.handler.AuthSessionHandler;
+import net.elytrium.limboauth.model.RegisteredPlayer;
+
+public class AuthListener {
+
+  private final Dao<RegisteredPlayer, String> playerDao;
+
+  public AuthListener(Dao<RegisteredPlayer, String> playerDao) {
+    this.playerDao = playerDao;
+  }
+
+  @Subscribe
+  public void onProxyConnect(PreLoginEvent event) {
+    if (!event.getResult().isForceOfflineMode()) {
+      if (Settings.IMP.MAIN.ONLINE_MODE_NEED_AUTH || !LimboAuth.getInstance().isPremium(event.getUsername())) {
+        event.setResult(PreLoginEvent.PreLoginComponentResult.forceOfflineMode());
+      } else {
+        event.setResult(PreLoginEvent.PreLoginComponentResult.forceOnlineMode());
+      }
+    }
+  }
+
+  @Subscribe
+  public void onLogin(LoginLimboRegisterEvent event) {
+    if (LimboAuth.getInstance().needAuth(event.getPlayer())) {
+      event.addCallback(() -> LimboAuth.getInstance().authPlayer(event.getPlayer()));
+    }
+  }
+
+  @Subscribe
+  public void onProfile(SafeGameProfileRequestEvent event) {
+    if (Settings.IMP.MAIN.SAVE_UUID) {
+      RegisteredPlayer registeredPlayer = AuthSessionHandler.fetchInfo(this.playerDao, event.getOriginalProfile().getId());
+
+      if (registeredPlayer != null) {
+        event.setGameProfile(event.getOriginalProfile().withId(UUID.fromString(registeredPlayer.getUuid())));
+        return;
+      }
+
+      registeredPlayer = AuthSessionHandler.fetchInfo(this.playerDao, event.getUsername());
+
+      if (registeredPlayer != null) {
+        String currentUuid = registeredPlayer.getUuid();
+
+        if (event.isOnlineMode()) {
+          try {
+            registeredPlayer.setPremiumUuid(event.getOriginalProfile().getId().toString());
+            registeredPlayer.setHash("");
+
+            if (currentUuid.isEmpty()) {
+              registeredPlayer.setUuid(UuidUtils.generateOfflinePlayerUuid(event.getUsername()).toString());
+            }
+
+            this.playerDao.update(registeredPlayer);
+          } catch (SQLException e) {
+            e.printStackTrace();
+          }
+
+          event.setGameProfile(event.getOriginalProfile().withId(UUID.fromString(currentUuid)));
+        } else if (currentUuid.isEmpty()) {
+          try {
+            registeredPlayer.setUuid(event.getGameProfile().getId().toString());
+            this.playerDao.update(registeredPlayer);
+          } catch (SQLException ex) {
+            ex.printStackTrace();
+          }
+        }
+      }
+    } else if (event.isOnlineMode()) {
+      try {
+        UpdateBuilder<RegisteredPlayer, String> updateBuilder = this.playerDao.updateBuilder();
+        updateBuilder.where().eq("nickname", event.getUsername());
+        updateBuilder.updateColumnValue("hash", "");
+        updateBuilder.update();
+      } catch (SQLException e) {
+        e.printStackTrace();
+      }
+    }
+
+    if (!Settings.IMP.MAIN.FORCE_OFFLINE_UUID) {
+      event.setGameProfile(event.getOriginalProfile().withId(UuidUtils.generateOfflinePlayerUuid(event.getUsername())));
+    }
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/migration/MigrationHash.java b/src/main/java/net/elytrium/limboauth/migration/MigrationHash.java
new file mode 100644
index 0000000..5296534
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/migration/MigrationHash.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.migration;
+
+import java.math.BigInteger;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+public enum MigrationHash {
+
+  @SuppressWarnings("unused")
+  AUTHME((hash, password) -> {
+    String[] arr = hash.split("\\$"); // $SHA$salt$hash
+    return arr.length == 4 && arr[3].equals(MigrationHash.getSHA256(MigrationHash.getSHA256(password) + arr[2]));
+  });
+
+  final MigrationHashVerifier verifier;
+
+  MigrationHash(MigrationHashVerifier verifier) {
+    this.verifier = verifier;
+  }
+
+  public boolean checkPassword(String hash, String password) {
+    return this.verifier.checkPassword(hash, password);
+  }
+
+  private static String getSHA256(String string) {
+    try {
+      MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
+      messageDigest.reset();
+      messageDigest.update(string.getBytes(StandardCharsets.UTF_8));
+      byte[] array = messageDigest.digest();
+      return String.format("%0" + (array.length << 1) + "x", new BigInteger(1, array));
+    } catch (NoSuchAlgorithmException e) {
+      throw new IllegalArgumentException(e);
+    }
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/migration/MigrationHashVerifier.java b/src/main/java/net/elytrium/limboauth/migration/MigrationHashVerifier.java
new file mode 100644
index 0000000..cbe5135
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/migration/MigrationHashVerifier.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.migration;
+
+public interface MigrationHashVerifier {
+
+  boolean checkPassword(String hash, String password);
+}
diff --git a/src/main/java/net/elytrium/limboauth/model/RegisteredPlayer.java b/src/main/java/net/elytrium/limboauth/model/RegisteredPlayer.java
new file mode 100644
index 0000000..55a2e3c
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/model/RegisteredPlayer.java
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.model;
+
+import com.j256.ormlite.field.DatabaseField;
+import com.j256.ormlite.table.DatabaseTable;
+
+@SuppressWarnings("unused")
+@DatabaseTable(tableName = "AUTH")
+public class RegisteredPlayer {
+
+  @DatabaseField(canBeNull = false, columnName = "NICKNAME")
+  private String nickname;
+
+  @DatabaseField(id = true, columnName = "LOWERCASENICKNAME")
+  private String lowercaseNickname;
+
+  @DatabaseField(canBeNull = false, columnName = "HASH")
+  private String hash;
+
+  @DatabaseField(columnName = "IP")
+  private String ip;
+
+  @DatabaseField(columnName = "TOTPTOKEN")
+  private String totpToken;
+
+  @DatabaseField(columnName = "REGDATE")
+  private Long regDate;
+
+  @DatabaseField(columnName = "UUID")
+  private String uuid;
+
+  @DatabaseField(columnName = "PREMIUMUUID")
+  private String premiumUuid;
+
+  public RegisteredPlayer(String nickname, String lowercaseNickname,
+      String hash, String ip, String totpToken, Long regDate, String uuid, String premiumUuid) {
+    this.nickname = nickname;
+    this.lowercaseNickname = lowercaseNickname;
+    this.hash = hash;
+    this.ip = ip;
+    this.totpToken = totpToken;
+    this.regDate = regDate;
+    this.uuid = uuid;
+    this.premiumUuid = premiumUuid;
+  }
+
+  public RegisteredPlayer() {
+
+  }
+
+  public void setNickname(String nickname) {
+    this.nickname = nickname;
+  }
+
+  public String getNickname() {
+    return this.nickname;
+  }
+
+  public void setLowercaseNickname(String lowercaseNickname) {
+    this.lowercaseNickname = lowercaseNickname;
+  }
+
+  public String getLowercaseNickname() {
+    return this.lowercaseNickname;
+  }
+
+  public void setHash(String hash) {
+    this.hash = hash;
+  }
+
+  public String getHash() {
+    return this.hash;
+  }
+
+  public void setIP(String ip) {
+    this.ip = ip;
+  }
+
+  public String getIP() {
+    return this.ip;
+  }
+
+  public void setTotpToken(String totpToken) {
+    this.totpToken = totpToken;
+  }
+
+  public String getTotpToken() {
+    return this.totpToken;
+  }
+
+  public void setRegDate(Long regDate) {
+    this.regDate = regDate;
+  }
+
+  public Long getRegDate() {
+    return this.regDate;
+  }
+
+  public void setUuid(String uuid) {
+    this.uuid = uuid;
+  }
+
+  public String getUuid() {
+    return this.uuid;
+  }
+
+  public void setPremiumUuid(String premiumUuid) {
+    this.premiumUuid = premiumUuid;
+  }
+
+  public String getPremiumUuid() {
+    return this.premiumUuid;
+  }
+}
diff --git a/src/main/java/net/elytrium/limboauth/utils/UpdatesChecker.java b/src/main/java/net/elytrium/limboauth/utils/UpdatesChecker.java
new file mode 100644
index 0000000..71af1bb
--- /dev/null
+++ b/src/main/java/net/elytrium/limboauth/utils/UpdatesChecker.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth.utils;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.URL;
+import java.net.URLConnection;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.TimeUnit;
+import net.elytrium.limboauth.Settings;
+import org.slf4j.Logger;
+
+public class UpdatesChecker {
+
+  public static void checkForUpdates(Logger logger) {
+    try {
+      URLConnection conn = new URL("https://raw.githubusercontent.com/Elytrium/LimboAuth/master/VERSION").openConnection();
+      int timeout = (int) TimeUnit.SECONDS.toMillis(5);
+      conn.setConnectTimeout(timeout);
+      conn.setReadTimeout(timeout);
+      try (BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), StandardCharsets.UTF_8))) {
+        String latestVersion = in.readLine();
+        if (latestVersion == null) {
+          logger.warn("Unable to check for updates.");
+          return;
+        }
+        String latestVersion0 = getCleanVersion(latestVersion.trim());
+        String currentVersion0 = getCleanVersion(Settings.IMP.VERSION);
+        int latestVersionId = Integer.parseInt(latestVersion0.replace(".", "").replace("$", ""));
+        int currentVersionId = Integer.parseInt(currentVersion0.replace(".", "").replace("$", ""));
+        if (latestVersion0.endsWith("$")) {
+          --latestVersionId;
+        }
+        if (currentVersion0.endsWith("$")) {
+          --currentVersionId;
+        }
+
+        if (currentVersionId < latestVersionId) {
+          logger.error("****************************************");
+          logger.warn("The new LimboAuth update was found, please update.");
+          logger.error("https://github.com/Elytrium/LimboAuth/releases/");
+          logger.error("****************************************");
+        }
+      }
+    } catch (IOException e) {
+      logger.warn("Unable to check for updates.", e);
+    }
+  }
+
+  private static String getCleanVersion(String version) {
+    int indexOf = version.indexOf("-");
+    if (indexOf > 0) {
+      return version.substring(0, indexOf) + "$"; // "$" - Indicates that the version is snapshot
+    } else {
+      return version;
+    }
+  }
+}
diff --git a/src/main/templates/net/elytrium/limboauth/BuildConstants.java b/src/main/templates/net/elytrium/limboauth/BuildConstants.java
new file mode 100644
index 0000000..b8d7966
--- /dev/null
+++ b/src/main/templates/net/elytrium/limboauth/BuildConstants.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2021 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboauth;
+
+// The constants are replaced before compilation
+public class BuildConstants {
+
+  public static final String AUTH_VERSION = "${version}";
+}