implement tests

build.gradle.kts

@@ -24,6 +24,13 @@ kotlin {
             implementation(libs.hash)
             implementation(libs.bytearray)
         }
+        commonTest.dependencies {
+            implementation(libs.test)
+        }
+    }
+
+    compilerOptions {
+        freeCompilerArgs.add("-opt-in=kotlin.ExperimentalUnsignedTypes")
     }
 }
 

gradle/libs.versions.toml

@@ -1,8 +1,8 @@
 [versions]
-kotlin = "2.2.10"
+kotlin = "2.2.21"
-mac = "1.1.2"
+mac = "1.2.0"
-hash = "1.2.2"
+hash = "1.3.2"
-bytearray = "1.1.1"
+bytearray = "1.2.4"
 
 [plugins]
 multiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotlin" }
@@ -11,3 +11,4 @@ multiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotl
 mac = { module = "com.infendro:mac", version.ref = "mac" }
 hash = { module = "com.infendro:hash", version.ref = "hash" }
 bytearray = { module = "com.infendro:bytearray", version.ref = "bytearray" }
+test = { module = "org.jetbrains.kotlin:kotlin-test", version.ref = "kotlin" }

src/commonMain/kotlin/com/infendro/kdf/KDF.kt

@@ -0,0 +1,12 @@
+package com.infendro.kdf
+
+interface KDF {
+    val bytes: Int
+    val bits: Int
+        get() = bytes * 8
+
+    fun hash(
+        value: UByteArray,
+        salt: UByteArray,
+    ): UByteArray
+}

src/commonMain/kotlin/com/infendro/kdf/PBKDF2.kt

@@ -1,39 +1,49 @@
 package com.infendro.kdf
 
-import com.infendro.bytearray.addAll
+import com.infendro.bytearray.toUByteArray
-import com.infendro.bytearray.toByteArray
 import com.infendro.bytearray.xor
 import com.infendro.hash.HashFunction
 import com.infendro.mac.HMAC
+import kotlin.math.min
 
 class PBKDF2(
-    private val function: HashFunction,
+    override val bytes: Int,
-) {
+    private val iterations: Int,
-    private val hmac = HMAC(function)
+    function: HashFunction,
+) : KDF {
+    init {
+        if (bytes < 1) throw IllegalArgumentException()
+        if (iterations < 1) throw IllegalArgumentException()
+    }
 
-    fun hash(
+    private val mac = HMAC(function)
-        value: ByteArray,
-        salt: ByteArray,
-        iterations: Int,
-        length: Int,
-    ): ByteArray {
-        val key = buildList {
-            for (i in 1..(length + function.bytes - 1) / function.bytes) {
-                val input = salt + i.toUInt().toByteArray()
 
-                var u = hmac.hash(value, input)
+    override fun hash(
-                var result = u
+        value: UByteArray,
+        salt: UByteArray,
+    ): UByteArray {
+        return buildList {
+            var i = 1
+            while (size < bytes) {
+                addAll(
+                    f(value, salt, i)
+                        .sliceArray(0..<min(bytes - size, mac.bytes))
+                )
+                i++
+            }
+        }.toUByteArray()
+    }
+
+    private fun f(
+        value: UByteArray,
+        salt: UByteArray,
+        iteration: Int,
+    ): UByteArray {
+        return buildList {
+            add(mac.hash(value, salt + iteration.toUByteArray()))
             repeat(iterations - 1) {
-                    u = hmac.hash(value, u)
+                add(mac.hash(value, last()))
-                    result = result xor u
             }
-
+        }.reduce { acc, bytes -> acc xor bytes }
-                addAll(result)
-            }
-        }
-
-        return key
-            .take(length)
-            .toByteArray()
     }
 }

src/commonTest/kotlin/com/infendro/kdf/PBKDF2.kt

@@ -0,0 +1,119 @@
+package com.infendro.kdf
+
+import com.infendro.bytearray.encodeToUByteArray
+import com.infendro.hash.sha2.`SHA-256`
+import kotlin.test.Test
+import kotlin.test.assertContentEquals
+
+class `PBKDF2 Test` {
+    @Test
+    fun `32 bytes, 1 iteration`() {
+        val function = PBKDF2(32, 1, `SHA-256`)
+
+        val expected = ubyteArrayOf(
+            0x12U, 0x0fU, 0xb6U, 0xcfU, 0xfcU, 0xf8U, 0xb3U, 0x2cU,
+            0x43U, 0xe7U, 0x22U, 0x52U, 0x56U, 0xc4U, 0xf8U, 0x37U,
+            0xa8U, 0x65U, 0x48U, 0xc9U, 0x2cU, 0xccU, 0x35U, 0x48U,
+            0x08U, 0x05U, 0x98U, 0x7cU, 0xb7U, 0x0bU, 0xe1U, 0x7bU,
+        )
+        val actual = function.hash(
+            "password".encodeToUByteArray(),
+            "salt".encodeToUByteArray(),
+        )
+        assertContentEquals(expected, actual)
+    }
+
+    @Test
+    fun `32 bytes, 2 iterations`() {
+        val function = PBKDF2(32, 2, `SHA-256`)
+
+        val expected = ubyteArrayOf(
+            0xaeU, 0x4dU, 0x0cU, 0x95U, 0xafU, 0x6bU, 0x46U, 0xd3U,
+            0x2dU, 0x0aU, 0xdfU, 0xf9U, 0x28U, 0xf0U, 0x6dU, 0xd0U,
+            0x2aU, 0x30U, 0x3fU, 0x8eU, 0xf3U, 0xc2U, 0x51U, 0xdfU,
+            0xd6U, 0xe2U, 0xd8U, 0x5aU, 0x95U, 0x47U, 0x4cU, 0x43U,
+        )
+        val actual = function.hash(
+            "password".encodeToUByteArray(),
+            "salt".encodeToUByteArray(),
+        )
+        assertContentEquals(expected, actual)
+    }
+
+    @Test
+    fun `32 bytes, 4096 iterations`() {
+        val function = PBKDF2(32, 4096, `SHA-256`)
+
+        val expected = ubyteArrayOf(
+            0xc5U, 0xe4U, 0x78U, 0xd5U, 0x92U, 0x88U, 0xc8U, 0x41U,
+            0xaaU, 0x53U, 0x0dU, 0xb6U, 0x84U, 0x5cU, 0x4cU, 0x8dU,
+            0x96U, 0x28U, 0x93U, 0xa0U, 0x01U, 0xceU, 0x4eU, 0x11U,
+            0xa4U, 0x96U, 0x38U, 0x73U, 0xaaU, 0x98U, 0x13U, 0x4aU,
+        )
+        val actual = function.hash(
+            "password".encodeToUByteArray(),
+            "salt".encodeToUByteArray(),
+        )
+        assertContentEquals(expected, actual)
+    }
+
+    @Test
+    fun `40 bytes, 4096 iterations`() {
+        val function = PBKDF2(40, 4096, `SHA-256`)
+
+        val expected = ubyteArrayOf(
+            0xc5U, 0xe4U, 0x78U, 0xd5U, 0x92U, 0x88U, 0xc8U, 0x41U,
+            0xaaU, 0x53U, 0x0dU, 0xb6U, 0x84U, 0x5cU, 0x4cU, 0x8dU,
+            0x96U, 0x28U, 0x93U, 0xa0U, 0x01U, 0xceU, 0x4eU, 0x11U,
+            0xa4U, 0x96U, 0x38U, 0x73U, 0xaaU, 0x98U, 0x13U, 0x4aU,
+            0xf7U, 0xadU, 0x98U, 0xc1U, 0xb4U, 0x58U, 0xceU, 0x3fU,
+        )
+        val actual = function.hash(
+            "password".encodeToUByteArray(),
+            "salt".encodeToUByteArray(),
+        )
+        assertContentEquals(expected, actual)
+    }
+
+    @Test
+    fun `64 bytes, 1 iteration`() {
+        val function = PBKDF2(64, 1, `SHA-256`)
+
+        val expected = ubyteArrayOf(
+            0x55U, 0xacU, 0x04U, 0x6eU, 0x56U, 0xe3U, 0x08U, 0x9fU,
+            0xecU, 0x16U, 0x91U, 0xc2U, 0x25U, 0x44U, 0xb6U, 0x05U,
+            0xf9U, 0x41U, 0x85U, 0x21U, 0x6dU, 0xdeU, 0x04U, 0x65U,
+            0xe6U, 0x8bU, 0x9dU, 0x57U, 0xc2U, 0x0dU, 0xacU, 0xbcU,
+            0x49U, 0xcaU, 0x9cU, 0xccU, 0xf1U, 0x79U, 0xb6U, 0x45U,
+            0x99U, 0x16U, 0x64U, 0xb3U, 0x9dU, 0x77U, 0xefU, 0x31U,
+            0x7cU, 0x71U, 0xb8U, 0x45U, 0xb1U, 0xe3U, 0x0bU, 0xd5U,
+            0x09U, 0x11U, 0x20U, 0x41U, 0xd3U, 0xa1U, 0x97U, 0x83U,
+        )
+        val actual = function.hash(
+            "passwd".encodeToUByteArray(),
+            "salt".encodeToUByteArray(),
+        )
+        assertContentEquals(expected, actual)
+    }
+
+    @Test
+    fun `64 bytes, 80,000 iterations`() {
+        val function = PBKDF2(64, 80_000, `SHA-256`)
+
+        val expected = ubyteArrayOf(
+            0x4dU, 0xdcU, 0xd8U, 0xf6U, 0x0bU, 0x98U, 0xbeU, 0x21U,
+            0x83U, 0x0cU, 0xeeU, 0x5eU, 0xf2U, 0x27U, 0x01U, 0xf9U,
+            0x64U, 0x1aU, 0x44U, 0x18U, 0xd0U, 0x4cU, 0x04U, 0x14U,
+            0xaeU, 0xffU, 0x08U, 0x87U, 0x6bU, 0x34U, 0xabU, 0x56U,
+            0xa1U, 0xd4U, 0x25U, 0xa1U, 0x22U, 0x58U, 0x33U, 0x54U,
+            0x9aU, 0xdbU, 0x84U, 0x1bU, 0x51U, 0xc9U, 0xb3U, 0x17U,
+            0x6aU, 0x27U, 0x2bU, 0xdeU, 0xbbU, 0xa1U, 0xd0U, 0x78U,
+            0x47U, 0x8fU, 0x62U, 0xb3U, 0x97U, 0xf3U, 0x3cU, 0x8dU,
+        )
+        val actual = function.hash(
+            "Password".encodeToByteArray().toUByteArray(),
+            "NaCl".encodeToByteArray().toUByteArray()
+        )
+        assertContentEquals(expected, actual)
+    }
+}