refactor SHA1 and SHA2

src/commonMain/kotlin/com/infendro/hash/blake/Blake-224.kt

@@ -43,12 +43,25 @@ object `Blake-224` : HashFunction() {
     )
 
     override fun hash(value: UByteArray): UByteArray {
+        val l = value.size.toULong() * 8UL
         val h = initial.copyOf()
         var t = 0U
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(64) { it.toUByteArray() }
+        for (block in blocks) {
+            t += minOf(l - t, 512UL).toUInt()
+            compress(h, block, t)
+        }
+
+        return h.sliceArray(0..6).toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 64 != 56) {
@@ -56,56 +69,39 @@ object `Blake-224` : HashFunction() {
             }
             addAll(l.toUByteArray())
         }.toUByteArray()
-
-        // compress
-        val blocks = paddedValue
-            .chunked(64) { it.toUByteArray() }
-        for (block in blocks) {
-            t += minOf(l - t, 512UL).toUInt()
-
-            val m = block.toUIntArray()
-            compress(h, m, t)
-        }
-
-        return h.sliceArray(0..6).toUByteArray()
     }
 
     private fun compress(
         h: UIntArray,
-        m: UIntArray,
+        block: UByteArray,
         t: UInt,
     ) {
-        // initialization
+        val m = block.toUIntArray()
         val v = UIntArray(16)
         for (i in 0..<8) v[i] = h[i]
         for (i in 0..<4) v[i + 8] = c[i]
         for (i in 0..<2) v[i + 12] = c[i + 4] xor t
         for (i in 0..<2) v[i + 14] = c[i + 6]
 
-        // rounds
-        for (r in 0..<14) {
+        repeat(14) { r ->
             val s = sigma[r % 10]
 
-            // column
             g(v, 0, 4, 8, 12, m[s[0]] xor c[s[1]], m[s[1]] xor c[s[0]])
             g(v, 1, 5, 9, 13, m[s[2]] xor c[s[3]], m[s[3]] xor c[s[2]])
             g(v, 2, 6, 10, 14, m[s[4]] xor c[s[5]], m[s[5]] xor c[s[4]])
             g(v, 3, 7, 11, 15, m[s[6]] xor c[s[7]], m[s[7]] xor c[s[6]])
 
-            // diagonal
             g(v, 0, 5, 10, 15, m[s[8]] xor c[s[9]], m[s[9]] xor c[s[8]])
             g(v, 1, 6, 11, 12, m[s[10]] xor c[s[11]], m[s[11]] xor c[s[10]])
             g(v, 2, 7, 8, 13, m[s[12]] xor c[s[13]], m[s[13]] xor c[s[12]])
             g(v, 3, 4, 9, 14, m[s[14]] xor c[s[15]], m[s[15]] xor c[s[14]])
         }
 
-        // finalization
         for (i in 0..7) {
             h[i] = h[i] xor v[i] xor v[i + 8]
         }
     }
 
-    // round function
     private fun g(
         v: UIntArray,
         a: Int,

src/commonMain/kotlin/com/infendro/hash/blake/Blake-256.kt

@@ -43,12 +43,25 @@ object `Blake-256` : HashFunction() {
     )
 
     override fun hash(value: UByteArray): UByteArray {
+        val l = value.size.toULong() * 8UL
         val h = initial.copyOf()
         var t = 0U
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(64) { it.toUByteArray() }
+        for (block in blocks) {
+            t += minOf(l - t, 512UL).toUInt()
+            compress(h, block, t)
+        }
+
+        return h.toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 64 != 55) {
@@ -57,56 +70,39 @@ object `Blake-256` : HashFunction() {
             add(0x01U)
             addAll(l.toUByteArray())
         }.toUByteArray()
-
-        // compress
-        val blocks = paddedValue
-            .chunked(64) { it.toUByteArray() }
-        for (block in blocks) {
-            t += minOf(l - t, 512UL).toUInt()
-
-            val m = block.toUIntArray()
-            compress(h, m, t)
-        }
-
-        return h.toUByteArray()
     }
 
     private fun compress(
         h: UIntArray,
-        m: UIntArray,
+        block: UByteArray,
         t: UInt,
     ) {
-        // initialization
+        val m = block.toUIntArray()
         val v = UIntArray(16)
         for (i in 0..<8) v[i] = h[i]
         for (i in 0..<4) v[i + 8] = c[i]
         for (i in 0..<2) v[i + 12] = c[i + 4] xor t
         for (i in 0..<2) v[i + 14] = c[i + 6]
 
-        // rounds
-        for (r in 0..<14) {
+        repeat(14) { r ->
             val s = sigma[r % 10]
 
-            // column
             g(v, 0, 4, 8, 12, m[s[0]] xor c[s[1]], m[s[1]] xor c[s[0]])
             g(v, 1, 5, 9, 13, m[s[2]] xor c[s[3]], m[s[3]] xor c[s[2]])
             g(v, 2, 6, 10, 14, m[s[4]] xor c[s[5]], m[s[5]] xor c[s[4]])
             g(v, 3, 7, 11, 15, m[s[6]] xor c[s[7]], m[s[7]] xor c[s[6]])
 
-            // diagonal
             g(v, 0, 5, 10, 15, m[s[8]] xor c[s[9]], m[s[9]] xor c[s[8]])
             g(v, 1, 6, 11, 12, m[s[10]] xor c[s[11]], m[s[11]] xor c[s[10]])
             g(v, 2, 7, 8, 13, m[s[12]] xor c[s[13]], m[s[13]] xor c[s[12]])
             g(v, 3, 4, 9, 14, m[s[14]] xor c[s[15]], m[s[15]] xor c[s[14]])
         }
 
-        // finalization
         for (i in 0..7) {
             h[i] = h[i] xor v[i] xor v[i + 8]
         }
     }
 
-    // round function
     private fun g(
         v: UIntArray,
         a: Int,

src/commonMain/kotlin/com/infendro/hash/blake/Blake-384.kt

@@ -43,12 +43,25 @@ object `Blake-384` : HashFunction() {
     )
 
     override fun hash(value: UByteArray): UByteArray {
+        val l = value.size.toULong() * 8UL
         val h = initial.copyOf()
         var t = 0UL
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(128) { it.toUByteArray() }
+        for (block in blocks) {
+            t += minOf(l - t, 1024UL)
+            compress(h, block, t)
+        }
+
+        return h.sliceArray(0..5).toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 128 != 120) {
@@ -56,56 +69,39 @@ object `Blake-384` : HashFunction() {
             }
             addAll(l.toUByteArray())
         }.toUByteArray()
-
-        // compress
-        val blocks = paddedValue
-            .chunked(128) { it.toUByteArray() }
-        for (block in blocks) {
-            t += minOf(l - t, 1024UL)
-
-            val m = block.toULongArray()
-            compress(h, m, t)
-        }
-
-        return h.sliceArray(0..5).toUByteArray()
     }
 
     private fun compress(
         h: ULongArray,
-        m: ULongArray,
+        block: UByteArray,
         t: ULong,
     ) {
-        // initialization
+        val m = block.toULongArray()
         val v = ULongArray(16)
         for (i in 0..<8) v[i] = h[i]
         for (i in 0..<4) v[i + 8] = c[i]
         for (i in 0..<2) v[i + 12] = c[i + 4] xor t
         for (i in 0..<2) v[i + 14] = c[i + 6]
 
-        // rounds
-        for (r in 0..<16) {
+        repeat(16) { r ->
             val s = sigma[r % 10]
 
-            // column
             g(v, 0, 4, 8, 12, m[s[0]] xor c[s[1]], m[s[1]] xor c[s[0]])
             g(v, 1, 5, 9, 13, m[s[2]] xor c[s[3]], m[s[3]] xor c[s[2]])
             g(v, 2, 6, 10, 14, m[s[4]] xor c[s[5]], m[s[5]] xor c[s[4]])
             g(v, 3, 7, 11, 15, m[s[6]] xor c[s[7]], m[s[7]] xor c[s[6]])
 
-            // diagonal
             g(v, 0, 5, 10, 15, m[s[8]] xor c[s[9]], m[s[9]] xor c[s[8]])
             g(v, 1, 6, 11, 12, m[s[10]] xor c[s[11]], m[s[11]] xor c[s[10]])
             g(v, 2, 7, 8, 13, m[s[12]] xor c[s[13]], m[s[13]] xor c[s[12]])
             g(v, 3, 4, 9, 14, m[s[14]] xor c[s[15]], m[s[15]] xor c[s[14]])
         }
 
-        // finalization
         for (i in 0..7) {
             h[i] = h[i] xor v[i] xor v[i + 8]
         }
     }
 
-    // round function
     private fun g(
         v: ULongArray,
         a: Int,

src/commonMain/kotlin/com/infendro/hash/blake/Blake-512.kt

@@ -43,12 +43,25 @@ object `Blake-512` : HashFunction() {
     )
 
     override fun hash(value: UByteArray): UByteArray {
+        val l = value.size.toULong() * 8UL
         val h = initial.copyOf()
         var t = 0UL
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(128) { it.toUByteArray() }
+        for (block in blocks) {
+            t += minOf(l - t, 1024UL)
+            compress(h, block, t)
+        }
+
+        return h.toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 128 != 111) {
@@ -58,56 +71,39 @@ object `Blake-512` : HashFunction() {
             repeat(8) { add(0x00U) }
             addAll(l.toUByteArray())
         }.toUByteArray()
-
-        // compress
-        val blocks = paddedValue
-            .chunked(128) { it.toUByteArray() }
-        for (block in blocks) {
-            t += minOf(l - t, 1024UL)
-
-            val m = block.toULongArray()
-            compress(h, m, t)
-        }
-
-        return h.toUByteArray()
     }
 
     private fun compress(
         h: ULongArray,
-        m: ULongArray,
+        block: UByteArray,
         t: ULong,
     ) {
-        // initialization
+        val m = block.toULongArray()
         val v = ULongArray(16)
         for (i in 0..<8) v[i] = h[i]
         for (i in 0..<4) v[i + 8] = c[i]
         for (i in 0..<2) v[i + 12] = c[i + 4] xor t
         for (i in 0..<2) v[i + 14] = c[i + 6]
 
-        // rounds
-        for (r in 0..<16) {
+        repeat(16) { r ->
             val s = sigma[r % 10]
 
-            // column
             g(v, 0, 4, 8, 12, m[s[0]] xor c[s[1]], m[s[1]] xor c[s[0]])
             g(v, 1, 5, 9, 13, m[s[2]] xor c[s[3]], m[s[3]] xor c[s[2]])
             g(v, 2, 6, 10, 14, m[s[4]] xor c[s[5]], m[s[5]] xor c[s[4]])
             g(v, 3, 7, 11, 15, m[s[6]] xor c[s[7]], m[s[7]] xor c[s[6]])
 
-            // diagonal
             g(v, 0, 5, 10, 15, m[s[8]] xor c[s[9]], m[s[9]] xor c[s[8]])
             g(v, 1, 6, 11, 12, m[s[10]] xor c[s[11]], m[s[11]] xor c[s[10]])
             g(v, 2, 7, 8, 13, m[s[12]] xor c[s[13]], m[s[13]] xor c[s[12]])
             g(v, 3, 4, 9, 14, m[s[14]] xor c[s[15]], m[s[15]] xor c[s[14]])
         }
 
-        // finalization
         for (i in 0..7) {
             h[i] = h[i] xor v[i] xor v[i + 8]
         }
     }
 
-    // round function
     private fun g(
         v: ULongArray,
         a: Int,

src/commonMain/kotlin/com/infendro/hash/blake2/Blake2b.kt

@@ -36,65 +36,60 @@ class Blake2b(
     )
 
     override fun hash(value: UByteArray): UByteArray {
+        val l = value.size.toULong()
         val h = initial.copyOf()
         h[0] = h[0] xor (0x01010000UL or bytes.toULong())
         var t = 0UL
-        val l = value.size.toULong()
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(128) { it.toUByteArray() }
+        for ((i, block) in blocks.withIndex()) {
+            t += minOf(l - t, 128UL)
+            compress(h, block, t, i == blocks.lastIndex)
+        }
+
+        return h.toUByteArray(ByteOrder.LITTLE_ENDIAN).sliceArray(0..<bytes)
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        return buildList {
             addAll(value)
             if (isEmpty()) add(0x00U)
             while (size % 128 != 0) {
                 add(0x00U)
             }
         }.toUByteArray()
-
-        // compress
-        val blocks = paddedValue
-            .chunked(128) { it.toUByteArray() }
-        for ((i, block) in blocks.withIndex()) {
-            t += minOf(l - t, 128UL)
-
-            val m = block.toULongArray()
-            compress(h, m, t, i == blocks.lastIndex)
-        }
-
-        return h.toUByteArray(ByteOrder.LITTLE_ENDIAN).sliceArray(0..<bytes)
     }
 
     private fun compress(
         h: ULongArray,
-        m: ULongArray,
+        block: UByteArray,
         t: ULong,
         last: Boolean,
     ) {
-        // initialization
+        val m = block.toULongArray()
         val v = ULongArray(16)
         for (i in 0..<8) v[i] = h[i]
         for (i in 0..<8) v[i + 8] = initial[i]
-
         v[12] = v[12] xor t
         if (last) v[14] = v[14].inv()
 
-        // rounds
-        for (r in 0..<12) {
+        repeat(12) { r ->
             val s = sigma[r % 10]
 
-            // column
             mix(v, 0, 4, 8, 12, m[s[0]], m[s[1]])
             mix(v, 1, 5, 9, 13, m[s[2]], m[s[3]])
             mix(v, 2, 6, 10, 14, m[s[4]], m[s[5]])
             mix(v, 3, 7, 11, 15, m[s[6]], m[s[7]])
 
-            // diagonal
             mix(v, 0, 5, 10, 15, m[s[8]], m[s[9]])
             mix(v, 1, 6, 11, 12, m[s[10]], m[s[11]])
             mix(v, 2, 7, 8, 13, m[s[12]], m[s[13]])
             mix(v, 3, 4, 9, 14, m[s[14]], m[s[15]])
         }
 
-        // finalization
         for (i in 0..7) {
             h[i] = h[i] xor v[i] xor v[i + 8]
         }

src/commonMain/kotlin/com/infendro/hash/blake2/Blake2s.kt

@@ -36,40 +36,40 @@ class Blake2s(
     )
 
     override fun hash(value: UByteArray): UByteArray {
+        val l = value.size.toULong()
         val h = initial.copyOf()
         h[0] = h[0] xor (0x01010000U or bytes.toUInt())
         var t = 0U
-        val l = value.size.toULong()
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(64) { it.toUByteArray() }
+        for ((i, block) in blocks.withIndex()) {
+            t += minOf(l - t, 64UL).toUInt()
+            compress(h, block, t, i == blocks.lastIndex)
+        }
+
+        return h.toUByteArray(LITTLE_ENDIAN).sliceArray(0..<bytes)
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        return buildList {
             addAll(value)
             if (isEmpty()) add(0x00U)
             while (size % 64 != 0) {
                 add(0x00U)
             }
         }.toUByteArray()
-
-        // compress
-        val blocks = paddedValue
-            .chunked(64) { it.toUByteArray() }
-        for ((i, block) in blocks.withIndex()) {
-            t += minOf(l - t, 64U).toUInt()
-
-            val m = block.toUIntArray()
-            compress(h, m, t, i == blocks.lastIndex)
-        }
-
-        return h.toUByteArray(LITTLE_ENDIAN).sliceArray(0..<bytes)
     }
 
     private fun compress(
         h: UIntArray,
-        m: UIntArray,
+        block: UByteArray,
         t: UInt,
         last: Boolean,
     ) {
-        // initialization
+        val m = block.toUIntArray()
         val v = UIntArray(16)
         for (i in 0..<8) v[i] = h[i]
         for (i in 0..<8) v[i + 8] = initial[i]
@@ -77,24 +77,20 @@ class Blake2s(
         v[12] = v[12] xor t
         if (last) v[14] = v[14].inv()
 
-        // rounds
-        for (r in 0..<10) {
+        repeat(10) { r ->
             val s = sigma[r]
 
-            // column
             mix(v, 0, 4, 8, 12, m[s[0]], m[s[1]])
             mix(v, 1, 5, 9, 13, m[s[2]], m[s[3]])
             mix(v, 2, 6, 10, 14, m[s[4]], m[s[5]])
             mix(v, 3, 7, 11, 15, m[s[6]], m[s[7]])
 
-            // diagonal
             mix(v, 0, 5, 10, 15, m[s[8]], m[s[9]])
             mix(v, 1, 6, 11, 12, m[s[10]], m[s[11]])
             mix(v, 2, 7, 8, 13, m[s[12]], m[s[13]])
             mix(v, 3, 4, 9, 14, m[s[14]], m[s[15]])
         }
 
-        // finalization
         for (i in 0..7) {
             h[i] = h[i] xor v[i] xor v[i + 8]
         }

src/commonMain/kotlin/com/infendro/hash/keccak/Keccak.kt

@@ -41,20 +41,32 @@ open class Keccak(
     ): UByteArray {
         val state = ULongArray(25)
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(rate) { it.toUByteArray() }
+        for (block in blocks) {
+            absorb(state, block)
+        }
+
+        return squeeze(state)
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        return buildList {
             addAll(value)
             add(domain)
             while ((size % rate) != (rate - 1)) {
                 add(0x00U)
             }
             add(0x80U)
+        }.toUByteArray()
     }
 
-        // absorb
-        val blocks = paddedValue
-            .chunked(rate) { it.toUByteArray() }
-        for (block in blocks) {
+    private fun absorb(
+        state: ULongArray,
+        block: UByteArray,
+    ) {
         val numbers = block.toULongArray(LITTLE_ENDIAN)
         for ((i, number) in numbers.withIndex()) {
             state[i] = state[i] xor number
@@ -62,23 +74,6 @@ open class Keccak(
         permute(state)
     }
 
-        // squeeze
-        return buildList {
-            var i = 0
-            while (size < bytes) {
-                if (i == rate / 8) {
-                    permute(state)
-                    i = 0
-                }
-
-                addAll(
-                    state[i++].toUByteArray(LITTLE_ENDIAN)
-                        .sliceArray(0..<min(bytes - size, 8))
-                )
-            }
-        }.toUByteArray()
-    }
-
     private fun permute(
         a: ULongArray,
     ) {
@@ -112,4 +107,22 @@ open class Keccak(
             a[0] = a[0] xor rc[round]
         }
     }
+
+    fun squeeze(
+        state: ULongArray,
+    ): UByteArray {
+        return buildList {
+            var i = 0
+            while (size < bytes) {
+                if (i == rate / 8) {
+                    permute(state)
+                    i = 0
+                }
+                addAll(
+                    state[i++].toUByteArray(LITTLE_ENDIAN)
+                        .sliceArray(0..<min(bytes - size, 8))
+                )
+            }
+        }.toUByteArray()
+    }
 }

src/commonMain/kotlin/com/infendro/hash/md/MD5.kt

@@ -51,36 +51,38 @@ object MD5 : HashFunction() {
         value: UByteArray,
     ): UByteArray {
         val h = initial.copyOf()
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(64) { it.toUByteArray() }
+        for (block in blocks) {
+            process(h, block)
+        }
+
+        return h.toUByteArray(LITTLE_ENDIAN)
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 64 != 56) {
                 add(0x00U)
             }
             addAll(l.toUByteArray(LITTLE_ENDIAN))
-        }
-
-        // process
-        val blocks = paddedValue
-            .chunked(64) { it.toUByteArray() }
-        for (block in blocks) {
-            val w = block.toUIntArray(LITTLE_ENDIAN)
-            process(h, w)
-        }
-
-        return h.toUByteArray(LITTLE_ENDIAN)
+        }.toUByteArray()
     }
 
     private fun process(
         h: UIntArray,
-        w: UIntArray,
+        block: UByteArray,
     ) {
+        val w = block.toUIntArray(LITTLE_ENDIAN)
         val v = h.copyOf()
 
-        for (i in 0..<64) {
+        repeat(64) { i ->
             var f = when (i) {
                 in 0..15 -> (v[1] and v[2]) or (v[1].inv() and v[3])
                 in 16..31 -> (v[3] and v[1]) or (v[3].inv() and v[2])

src/commonMain/kotlin/com/infendro/hash/sha1/SHA1.kt

@@ -21,42 +21,44 @@ object SHA1 : HashFunction() {
         value: UByteArray,
     ): UByteArray {
         val h = initial.copyOf()
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(64) { it.toUByteArray() }
+        for (block in blocks) {
+            process(h, block)
+        }
+
+        return h.toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 64 != 56) {
                 add(0x00U)
             }
             addAll(l.toUByteArray())
-        }
-
-        // process
-        val blocks = paddedValue
-            .chunked(64) { it.toUByteArray() }
-        for (block in blocks) {
-            val w = buildList {
-                addAll(block.toUIntArray())
-                for (i in 16..<80) {
-                    val word = (get(i - 3) xor get(i - 8) xor get(i - 14) xor get(i - 16)).rotateLeft(1)
-                    add(word)
-                }
-            }.toUIntArray()
-            process(h, w)
-        }
-
-        return h.toUByteArray()
+        }.toUByteArray()
     }
 
     private fun process(
         h: UIntArray,
-        w: UIntArray,
+        block: UByteArray,
     ) {
+        val w = buildList {
+            addAll(block.toUIntArray())
+            for (i in 16..79) {
+                val word = (get(i - 3) xor get(i - 8) xor get(i - 14) xor get(i - 16)).rotateLeft(1)
+                add(word)
+            }
+        }.toUIntArray()
         val v = h.copyOf()
 
-        for (i in 0..<80) {
+        repeat(80) { i ->
             val f = when (i) {
                 in 0..<20 -> (v[1] and v[2]) or (v[1].inv() and v[3])
                 in 20..<40 -> v[1] xor v[2] xor v[3]

src/commonMain/kotlin/com/infendro/hash/sha2/SHA-224.kt

@@ -33,43 +33,45 @@ object `SHA-224` : HashFunction() {
         value: UByteArray,
     ): UByteArray {
         val h = initial.copyOf()
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(64) { it.toUByteArray() }
+        for (block in blocks) {
+            process(h, block)
+        }
+
+        return h.sliceArray(0..6).toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 64 != 56) {
                 add(0x00U)
             }
             addAll(l.toUByteArray())
+        }.toUByteArray()
     }
 
-        // process
-        val blocks = paddedValue
-            .chunked(64) { it.toUByteArray() }
-        for (block in blocks) {
+    private fun process(
+        h: UIntArray,
+        block: UByteArray,
+    ) {
         val w = buildList {
             addAll(block.toUIntArray())
-                for (i in 16..<64) {
+            for (i in 16..63) {
                 val s0 = get(i - 15).rotateRight(7) xor get(i - 15).rotateRight(18) xor (get(i - 15) shr 3)
                 val s1 = get(i - 2).rotateRight(17) xor get(i - 2).rotateRight(19) xor (get(i - 2) shr 10)
                 add(get(i - 16) + s0 + get(i - 7) + s1)
             }
         }.toUIntArray()
-            process(h, w)
-        }
-
-        return h.sliceArray(0..6).toUByteArray()
-    }
-
-    private fun process(
-        h: UIntArray,
-        w: UIntArray,
-    ) {
         val v = h.copyOf()
 
-        for (i in 0..<64) {
+        repeat(64) { i ->
             val s0 = v[0].rotateRight(2) xor v[0].rotateRight(13) xor v[0].rotateRight(22)
             val s1 = v[4].rotateRight(6) xor v[4].rotateRight(11) xor v[4].rotateRight(25)
             val ch = (v[4] and v[5]) xor (v[4].inv() and v[6])

src/commonMain/kotlin/com/infendro/hash/sha2/SHA-256.kt

@@ -33,43 +33,45 @@ object `SHA-256` : HashFunction() {
         value: UByteArray,
     ): UByteArray {
         val h = initial.copyOf()
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(64) { it.toUByteArray() }
+        for (block in blocks) {
+            process(h, block)
+        }
+
+        return h.toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 64 != 56) {
                 add(0x00U)
             }
             addAll(l.toUByteArray())
+        }.toUByteArray()
     }
 
-        // process
-        val chunks = paddedValue
-            .chunked(64) { it.toUByteArray() }
-        for (chunk in chunks) {
+    private fun process(
+        h: UIntArray,
+        block: UByteArray,
+    ) {
         val w = buildList {
-                addAll(chunk.toUIntArray())
-                for (i in 16..<64) {
+            addAll(block.toUIntArray())
+            for (i in 16..63) {
                 val s0 = get(i - 15).rotateRight(7) xor get(i - 15).rotateRight(18) xor (get(i - 15) shr 3)
                 val s1 = get(i - 2).rotateRight(17) xor get(i - 2).rotateRight(19) xor (get(i - 2) shr 10)
                 add(get(i - 16) + s0 + get(i - 7) + s1)
             }
         }.toUIntArray()
-            process(h, w)
-        }
-
-        return h.toUByteArray()
-    }
-
-    private fun process(
-        h: UIntArray,
-        w: UIntArray,
-    ) {
         val v = h.copyOf()
 
-        for (i in 0..<64) {
+        repeat(64) { i ->
             val s0 = v[0].rotateRight(2) xor v[0].rotateRight(13) xor v[0].rotateRight(22)
             val s1 = v[4].rotateRight(6) xor v[4].rotateRight(11) xor v[4].rotateRight(25)
             val ch = (v[4] and v[5]) xor (v[4].inv() and v[6])

src/commonMain/kotlin/com/infendro/hash/sha2/SHA-384.kt

@@ -45,43 +45,45 @@ object `SHA-384` : HashFunction() {
         value: UByteArray,
     ): UByteArray {
         val h = initial.copyOf()
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(128) { it.toUByteArray() }
+        for (block in blocks) {
+            process(h, block)
+        }
+
+        return h.sliceArray(0..5).toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 128 != 120) {
                 add(0x00U)
             }
             addAll(l.toUByteArray())
+        }.toUByteArray()
     }
 
-        // process
-        val blocks = paddedValue
-            .chunked(128) { it.toUByteArray() }
-        for (block in blocks) {
+    private fun process(
+        h: ULongArray,
+        block: UByteArray,
+    ) {
         val w = buildList {
             addAll(block.toULongArray())
-                for (i in 16..<80) {
+            for (i in 16..79) {
                 val s0 = get(i - 15).rotateRight(1) xor get(i - 15).rotateRight(8) xor (get(i - 15) shr 7)
                 val s1 = get(i - 2).rotateRight(19) xor get(i - 2).rotateRight(61) xor (get(i - 2) shr 6)
                 add(get(i - 16) + s0 + get(i - 7) + s1)
             }
         }.toULongArray()
-            process(h, w)
-        }
-
-        return h.sliceArray(0..5).toUByteArray()
-    }
-
-    private fun process(
-        h: ULongArray,
-        w: ULongArray,
-    ) {
         val v = h.copyOf()
 
-        for (i in 0..<80) {
+        repeat(80) { i ->
             val s0 = v[0].rotateRight(28) xor v[0].rotateRight(34) xor v[0].rotateRight(39)
             val s1 = v[4].rotateRight(14) xor v[4].rotateRight(18) xor v[4].rotateRight(41)
             val ch = (v[4] and v[5]) xor (v[4].inv() and v[6])

src/commonMain/kotlin/com/infendro/hash/sha2/SHA-512.kt

@@ -45,43 +45,45 @@ object `SHA-512` : HashFunction() {
         value: UByteArray,
     ): UByteArray {
         val h = initial.copyOf()
-        val l = value.size.toULong() * 8UL
 
-        // padding
-        val paddedValue = buildList {
+        val blocks = pad(value)
+            .chunked(128) { it.toUByteArray() }
+        for (block in blocks) {
+            process(h, block)
+        }
+
+        return h.toUByteArray()
+    }
+
+    private fun pad(
+        value: UByteArray,
+    ): UByteArray {
+        val l = value.size.toULong() * 8UL
+        return buildList {
             addAll(value)
             add(0x80U)
             while (size % 128 != 120) {
                 add(0x00U)
             }
             addAll(l.toUByteArray())
+        }.toUByteArray()
     }
 
-        // process
-        val blocks = paddedValue
-            .chunked(128) { it.toUByteArray() }
-        for (block in blocks) {
+    private fun process(
+        h: ULongArray,
+        block: UByteArray,
+    ) {
         val w = buildList {
             addAll(block.toULongArray())
-                for (i in 16..<80) {
+            for (i in 16..79) {
                 val s0 = get(i - 15).rotateRight(1) xor get(i - 15).rotateRight(8) xor (get(i - 15) shr 7)
                 val s1 = get(i - 2).rotateRight(19) xor get(i - 2).rotateRight(61) xor (get(i - 2) shr 6)
                 add(get(i - 16) + s0 + get(i - 7) + s1)
             }
         }.toULongArray()
-            process(h, w)
-        }
-
-        return h.toUByteArray()
-    }
-
-    private fun process(
-        h: ULongArray,
-        w: ULongArray,
-    ) {
         val v = h.copyOf()
 
-        for (i in 0..<80) {
+        repeat(80) { i ->
             val s0 = v[0].rotateRight(28) xor v[0].rotateRight(34) xor v[0].rotateRight(39)
             val s1 = v[4].rotateRight(14) xor v[4].rotateRight(18) xor v[4].rotateRight(41)
             val ch = (v[4] and v[5]) xor (v[4].inv() and v[6])