README.md

@@ -6,15 +6,6 @@ Supported algorithms:
 - HOTP
 - TOTP
 
-## Targets
-
-| Target           | Status        |
-|------------------|---------------|
-| JVM              | Supported     |
-| JavaScript       | Supported     |
-| Native (Linux)   | Supported     |
-| Native (Windows) | Not Supported |
-
 ## Installation
 
 Add the following to your `build.gradle.kts`.
@@ -25,36 +16,24 @@ repositories {
 }
 
 dependencies {
-    implementation("com.infendro:otp:1.2.2")
+    implementation("com.infendro:otp:1.3.0")
 }
 ```
 
 ## Usage
 
 ```kotlin
-import com.infendro.hash.sha1.SHA1
-import com.infendro.otp.SecretGenerator
-import com.infendro.otp.TOTP
-import com.infendro.random.csprng.CSPRNG
-import kotlin.time.Clock.System.now
-import kotlin.time.Duration.Companion.seconds
-
 fun main() {
-    // create a SecretGenerator and TOTP instance
-    val generator = SecretGenerator(CSPRNG.HMAC(SHA1))
+    // create TOTP instance
     val totp = TOTP(
         function = SHA1,
         length = 6,
         period = 30.seconds,
     )
 
-    // generate a secret using SHA1
-    val secret = generator.generate()
-
-    // generate an OTP
-    val otp = totp.generate(secret, now())
-
-    // verify an OTP
-    totp.verify(secret, now(), otp)
+    // generate and verify OTP
+    val now = System.now()
+    val otp = totp.generate(<secret>, now)
+    totp.verify(<secret>, now, otp)
 }
 ```

build.gradle.kts

@@ -1,8 +1,11 @@
+@file:OptIn(ExperimentalWasmDsl::class)
+
 import com.infendro.plugin.infendro
 import com.infendro.plugin.token
+import org.jetbrains.kotlin.gradle.ExperimentalWasmDsl
 
 group = "com.infendro"
-version = "1.2.2"
+version = "1.3.0"
 
 plugins {
     alias(libs.plugins.infendro)
@@ -13,9 +16,13 @@ plugins {
 kotlin {
     jvm()
     linuxX64()
-    js {
-        nodejs()
-    }
+    linuxArm64()
+    mingwX64()
+    macosX64()
+    macosArm64()
+    js { nodejs() }
+    wasmJs { nodejs() }
+    wasmWasi { nodejs() }
 
     repositories {
         infendro()
@@ -24,15 +31,13 @@ kotlin {
 
     sourceSets {
         commonMain.dependencies {
-            implementation(libs.prng)
             implementation(libs.mac)
             implementation(libs.hash)
-            implementation(libs.bytearray)
+            implementation(libs.bytes)
         }
     }
 
     compilerOptions {
-        freeCompilerArgs.add("-opt-in=kotlin.ExperimentalUnsignedTypes")
         freeCompilerArgs.add("-opt-in=kotlin.time.ExperimentalTime")
     }
 }

gradle/libs.versions.toml

@@ -1,17 +1,15 @@
 [versions]
-infendro = "1.0.0"
-kotlin = "2.2.21"
-prng = "1.2.0"
-mac = "1.2.0"
-hash = "1.3.2"
-bytearray = "1.2.4"
+infendro = "1.1.0"
+kotlin = "2.3.0"
+mac = "1.3.0"
+hash = "1.5.1"
+bytes = "1.3.3"
 
 [plugins]
 infendro = { id = "com.infendro.plugin", version.ref = "infendro" }
 multiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotlin" }
 
 [libraries]
-prng = { module = "com.infendro:prng", version.ref = "prng" }
 mac = { module = "com.infendro:mac", version.ref = "mac" }
 hash = { module = "com.infendro:hash", version.ref = "hash" }
-bytearray = { module = "com.infendro:bytearray", version.ref = "bytearray" }
+bytes = { module = "com.infendro:bytes", version.ref = "bytes" }

src/commonMain/kotlin/com/infendro/otp/HOTP.kt

@@ -1,55 +1,32 @@
 package com.infendro.otp
 
-import com.infendro.bytearray.toInt
-import com.infendro.bytearray.toUByteArray
+import com.infendro.bytes.bytearray.toInt
+import com.infendro.bytes.long.toByteArray
 import com.infendro.hash.HashFunction
 import com.infendro.hash.sha1.SHA1
 import com.infendro.mac.HMAC
-import kotlin.math.pow
+import com.infendro.otp.util.pow
+import kotlin.experimental.and
 
 class HOTP(
-    function: HashFunction = SHA1,
-    private val length: Int = 6,
+    val function: HashFunction = SHA1,
+    val length: Int = 6,
 ) {
     private val hmac = HMAC(function)
 
-    fun verify(
-        secret: UByteArray,
-        counter: Long,
-        otp: String,
-    ): Boolean {
+    fun verify(secret: ByteArray, counter: Long, otp: String): Boolean {
         return generate(secret, counter) == otp
     }
 
-    fun generate(
-        secret: UByteArray,
-        counter: Long,
-    ): String {
+    fun generate(secret: ByteArray, counter: Long): String {
         require(counter >= 0)
-
-        val hash = generateHash(secret, counter.toUByteArray())
-        return otp(hash)
+        return otp(secret, counter)
     }
 
-    private fun generateHash(
-        secret: UByteArray,
-        value: UByteArray,
-    ): UByteArray {
-        return hmac.hash(secret, value)
-    }
-
-    private fun otp(
-        hash: UByteArray,
-    ): String {
-        val offset = (hash.last() and 0xFU).toInt()
-
-        var truncatedHash = hash
-            .drop(offset).take(4)
-            .toUByteArray()
-            .toInt() and 0x7FFFFFFF
-        truncatedHash %= 10.0.pow(length).toInt()
-
-        return truncatedHash.toString()
-            .padStart(length, '0')
+    private fun otp(secret: ByteArray, counter: Long): String {
+        val hash = hmac.hash(secret, counter.toByteArray())
+        val offset = (hash.last() and 0xF).toInt()
+        val otp = (hash.toInt(offset) and 0x7FFFFFFF) % 10.pow(length)
+        return "$otp".padStart(length, '0')
     }
 }

src/commonMain/kotlin/com/infendro/otp/SecretGenerator.kt

@@ -1,14 +0,0 @@
-package com.infendro.otp
-
-import kotlin.random.Random
-import kotlin.random.nextUBytes
-
-class SecretGenerator(
-    private val random: Random,
-) {
-    fun generate(
-        bytes: Int = 20,
-    ): UByteArray {
-        return random.nextUBytes(bytes)
-    }
-}

src/commonMain/kotlin/com/infendro/otp/TOTP.kt

@@ -7,30 +7,21 @@ import kotlin.time.Duration.Companion.seconds
 import kotlin.time.Instant
 
 class TOTP(
-    function: HashFunction = SHA1,
-    length: Int = 6,
-    private val period: Duration = 30.seconds,
+    val function: HashFunction = SHA1,
+    val length: Int = 6,
+    val period: Duration = 30.seconds,
 ) {
     private val hotp = HOTP(function, length)
 
-    fun verify(
-        secret: UByteArray,
-        instant: Instant,
-        otp: String,
-    ): Boolean {
+    fun verify(secret: ByteArray, instant: Instant, otp: String): Boolean {
         return generate(secret, instant) == otp
     }
 
-    fun generate(
-        secret: UByteArray,
-        instant: Instant,
-    ): String {
+    fun generate(secret: ByteArray, instant: Instant): String {
         return hotp.generate(secret, counter(instant))
     }
 
-    private fun counter(
-        instant: Instant,
-    ): Long {
+    private fun counter(instant: Instant): Long {
         val ms = instant.toEpochMilliseconds()
         val d = period.inWholeMilliseconds
         return ms / d

src/commonMain/kotlin/com/infendro/otp/util/Math.kt

@@ -0,0 +1,6 @@
+package com.infendro.otp.util
+
+import kotlin.math.pow
+
+internal fun Int.pow(x: Int): Int =
+    this.toDouble().pow(x).toInt()