Implement streaming API

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

@@ -2,57 +2,45 @@ package com.infendro.hash.sha1
 
 import com.infendro.bytes.bytearray.copyInto
 import com.infendro.bytes.intarray.copyInto
-import com.infendro.bytes.long.copyInto
 import com.infendro.hash.HashFunction
-import com.infendro.hash.util.align
 
-object SHA1 : HashFunction {
-    override val bytes: Int
-        get() = 20
+class SHA1 : HashFunction(20, 64) {
+    private val h = initial.copyOf()
 
-    override val block: Int
-        get() = 64
+    private val w = IntArray(80)
+    private val v = IntArray(5)
 
-    private val initial = intArrayOf(
-        +0x67452301, -0x10325477,
-        -0x67452302, +0x10325476,
-        -0x3c2d1e10,
-    )
+    override fun reset() {
+        super.reset()
+        initial.copyInto(h)
+    }
 
-    private val k = intArrayOf(
-        +0x5a827999, +0x6ed9eba1,
-        -0x70e44324, -0x359d3e2a,
-    )
+    override fun process() = process(buffer.value)
 
-    override fun hashInto(value: ByteArray, destination: ByteArray, destinationOffset: Int) {
-        val input = pad(value)
-        val h = initial.copyOf()
-
-        for (i in input.indices step block) {
-            val block = input.sliceArray(i..<(i + block))
-            process(h, block)
+    private fun finalize() {
+        buffer.append(0x80.toByte())
+        if (buffer.free < 8) {
+            process()
+            buffer.reset()
         }
+        buffer.jumpTo(56)
+        buffer.append(length * 8)
+
+        process()
+    }
+
+    override fun digestInto(destination: ByteArray, destinationOffset: Int) {
+        finalize()
         h.copyInto(destination, destinationOffset)
+        reset()
     }
 
-    private fun pad(value: ByteArray): ByteArray {
-        val length = value.size * 8L
-
-        val size = (value.size + 9).align(block)
-        return ByteArray(size).also {
-            value.copyInto(it)
-            it[value.size] = -0x80
-            length.copyInto(it, size - 8)
-        }
-    }
-
-    private fun process(h: IntArray, block: ByteArray) {
-        val w = IntArray(80)
+    private fun process(block: ByteArray) {
         block.copyInto(w)
         for (i in 16..<80) {
             w[i] = (w[i - 3] xor w[i - 8] xor w[i - 14] xor w[i - 16]).rotateLeft(1)
         }
-        val v = h.copyOf()
+        h.copyInto(v)
 
         repeat(80) { i ->
             val f = when (i) {
@@ -73,4 +61,17 @@ object SHA1 : HashFunction {
             h[i] += v[i]
         }
     }
+
+    companion object {
+        private val initial = intArrayOf(
+            +0x67452301, -0x10325477,
+            -0x67452302, +0x10325476,
+            -0x3c2d1e10,
+        )
+
+        private val k = intArrayOf(
+            +0x5a827999, +0x6ed9eba1,
+            -0x70e44324, -0x359d3e2a,
+        )
+    }
 }