Files
hash.kt/src/commonMain/kotlin/com/infendro/hash/md/MD5.kt
Infendro 902cb060a1
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remove unsigned support
2026-02-08 14:04:41 +01:00

103 lines
3.4 KiB
Kotlin

package com.infendro.hash.md
import com.infendro.bytes.ByteOrder.LITTLE_ENDIAN
import com.infendro.bytes.bytearray.toIntArray
import com.infendro.bytes.intarray.copyInto
import com.infendro.bytes.ulong.copyInto
import com.infendro.hash.HashFunction
import com.infendro.hash.util.align
object MD5 : HashFunction {
override val bytes: Int
get() = 16
override val block: Int
get() = 64
private val initial = intArrayOf(
+0x67452301, -0x10325477,
-0x67452302, +0x10325476,
)
private val c = intArrayOf(
-0x28955b88, -0x173848aa, +0x242070db, -0x3e423112,
-0x0a83f051, +0x4787c62a, -0x57cfb9ed, -0x02b96aff,
+0x698098d8, -0x74bb0851, -0x0000a44f, -0x76a32842,
+0x6b901122, -0x02678e6d, -0x5986bc72, +0x49b40821,
-0x09e1da9e, -0x3fbf4cc0, +0x265e5a51, -0x16493856,
-0x29d0efa3, +0x02441453, -0x275e197f, -0x182c0438,
+0x21e1cde6, -0x3cc8f82a, -0x0b2af279, +0x455a14ed,
-0x561c16fb, -0x03105c08, +0x676f02d9, -0x72d5b376,
-0x0005c6be, -0x788e097f, +0x6d9d6122, -0x021ac7f4,
-0x5b4115bc, +0x4bdecfa9, -0x0944b4a0, -0x41404390,
+0x289b7ec6, -0x155ed806, -0x2b10cf7b, +0x04881d05,
-0x262b2fc7, -0x1924661b, +0x1fa27cf8, -0x3b53a99b,
-0x0bd6ddbc, +0x432aff97, -0x546bdc59, -0x036c5fc7,
+0x655b59c3, -0x70f3336e, -0x00100b83, -0x7a7ba22f,
+0x6fa87e4f, -0x01d31920, -0x5cfebcec, +0x4e0811a1,
-0x08ac817e, -0x42c50dcb, +0x2ad7d2bb, -0x14792c6f,
)
private val shifts = intArrayOf(
7, 12, 17, 22, 7, 12, 17, 22,
7, 12, 17, 22, 7, 12, 17, 22,
5, 9, 14, 20, 5, 9, 14, 20,
5, 9, 14, 20, 5, 9, 14, 20,
4, 11, 16, 23, 4, 11, 16, 23,
4, 11, 16, 23, 4, 11, 16, 23,
6, 10, 15, 21, 6, 10, 15, 21,
6, 10, 15, 21, 6, 10, 15, 21,
)
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)
}
h.copyInto(destination, destinationOffset, order = LITTLE_ENDIAN)
}
private fun pad(value: ByteArray): ByteArray {
val length = value.size.toULong() * 8UL
val size = (value.size + 9).align(block)
return ByteArray(size).also {
value.copyInto(it)
it[value.size] = 0x80U.toByte()
length.copyInto(it, size - 8, order = LITTLE_ENDIAN)
}
}
private fun process(h: IntArray, block: ByteArray) {
val w = block.toIntArray(LITTLE_ENDIAN)
val v = h.copyOf()
repeat(64) { i ->
var f = when (i) {
in 0..<16 -> (v[1] and v[2]) or (v[1].inv() and v[3])
in 16..<32 -> (v[3] and v[1]) or (v[3].inv() and v[2])
in 32..<48 -> v[1] xor v[2] xor v[3]
else -> v[2] xor (v[1] or v[3].inv())
}
val g = when (i) {
in 0..<16 -> i
in 16..<32 -> (5 * i + 1) % 16
in 32..<48 -> (3 * i + 5) % 16
else -> (7 * i) % 16
}
f += v[0] + c[i] + w[g]
v[0] = v[3]
v[3] = v[2]
v[2] = v[1]
v[1] += f.rotateLeft(shifts[i])
}
for (i in 0..<4) {
h[i] += v[i]
}
}
}