Infendro/hash.kt
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refactor hash functions

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This commit is contained in:
Infendro
2025-12-01 19:13:58 +01:00
parent 10ba03dedc
commit 8a2848e6e3
7 changed files with 341 additions and 392 deletions
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121
src/commonMain/kotlin/com/infendro/hash/md/MD5.kt
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@@ -12,26 +12,23 @@ object MD5 : HashFunction() {
override val block: Int
get() = 64
private val s = 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,
private val initial = uintArrayOf(
0x67452301U, 0xefcdab89U,
0x98badcfeU, 0x10325476U,
)
private val k = uintArrayOf(
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,
)
private val c = uintArrayOf(
0xd76aa478U, 0xe8c7b756U, 0x242070dbU, 0xc1bdceeeU,
0xf57c0fafU, 0x4787c62aU, 0xa8304613U, 0xfd469501U,
0x698098d8U, 0x8b44f7afU, 0xffff5bb1U, 0x895cd7beU,
@@ -53,64 +50,58 @@ object MD5 : HashFunction() {
override fun hash(
value: UByteArray,
): UByteArray {
var a0 = 0x67452301U
var b0 = 0xefcdab89U
var c0 = 0x98badcfeU
var d0 = 0x10325476U
val ml = value.size.toULong() * 8UL
val h = initial.copyOf()
val l = value.size.toULong() * 8UL
// padding
val paddedValue = buildList {
addAll(value)
add(0x80U)
while (size % 64 != 56) {
add(0x00U)
}
addAll(ml.toUByteArray(LITTLE_ENDIAN))
addAll(l.toUByteArray(LITTLE_ENDIAN))
}
val chunks = paddedValue
// process
val blocks = paddedValue
.chunked(64) { it.toUByteArray() }
for (chunk in chunks) {
val w = buildList {
addAll(chunk.toUIntArray(LITTLE_ENDIAN))
}
var a = a0
var b = b0
var c = c0
var d = d0
for (i in 0..<64) {
val f = when (i) {
in 0..15 -> (b and c) or (b.inv() and d)
in 16..31 -> (d and b) or (d.inv() and c)
in 32..47 -> b xor c xor d
else -> c xor (b or d.inv())
}
val g = when (i) {
in 0..15 -> i
in 16..31 -> (5 * i + 1) % 16
in 32..47 -> (3 * i + 5) % 16
else -> (7 * i) % 16
}
val temp = a
a = d
d = c
c = b
b += (temp + f + k[i] + w[g]).rotateLeft(s[i])
}
a0 += a
b0 += b
c0 += c
d0 += d
for (block in blocks) {
val w = block.toUIntArray(LITTLE_ENDIAN)
process(h, w)
}
return ubyteArrayOf(
*a0.toUByteArray(LITTLE_ENDIAN),
*b0.toUByteArray(LITTLE_ENDIAN),
*c0.toUByteArray(LITTLE_ENDIAN),
*d0.toUByteArray(LITTLE_ENDIAN),
)
return h.toUByteArray(LITTLE_ENDIAN)
}
private fun process(
h: UIntArray,
w: UIntArray,
) {
val v = h.copyOf()
for (i in 0..<64) {
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])
in 32..47 -> v[1] xor v[2] xor v[3]
else -> v[2] xor (v[1] or v[3].inv())
}
val g = when (i) {
in 0..15 -> i
in 16..31 -> (5 * i + 1) % 16
in 32..47 -> (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..3) {
h[i] += v[i]
}
}
}