implement optimizations

This commit is contained in:
2026-01-22 12:50:36 +01:00
parent 3603583d94
commit d07f2658ff
6 changed files with 58 additions and 63 deletions

View File

@@ -1,6 +1,6 @@
package com.infendro.mac
import com.infendro.bytearray.padEnd
import com.infendro.bytes.bytearray.xorInto
import com.infendro.hash.HashFunction
class HMAC(
@@ -9,25 +9,24 @@ class HMAC(
override val bytes: Int
get() = function.bytes
override fun hash(
key: UByteArray,
value: UByteArray,
): UByteArray {
override fun hashInto(key: ByteArray, value: ByteArray, destination: ByteArray, destinationOffset: Int) {
val paddedKey = pad(key)
val innerKey = paddedKey.map { it xor 0x36U }.toUByteArray()
val outerKey = paddedKey.map { it xor 0x5CU }.toUByteArray()
return function.hash(outerKey + function.hash(innerKey + value))
}
private fun pad(
key: UByteArray,
): UByteArray {
return when {
key.size > function.block -> function.hash(key)
key.size < function.block -> key.padEnd(function.block, 0x00U)
else -> key
val inner = ByteArray(function.block + value.size).also {
paddedKey.xorInto(0x36, it)
value.copyInto(it, function.block)
}
val outer = ByteArray(function.block + function.bytes).also {
paddedKey.xorInto(0x5C, it)
function.hashInto(inner, it, function.block)
}
function.hashInto(outer, destination, destinationOffset)
}
private fun pad(key: ByteArray): ByteArray =
ByteArray(function.block).also {
when {
key.size > function.block -> function.hashInto(key, it)
else -> key.copyInto(it)
}
}
}

View File

@@ -5,8 +5,20 @@ interface MAC {
val bits: Int
get() = bytes * 8
fun hash(
key: UByteArray,
value: UByteArray,
): UByteArray
fun hashInto(key: ByteArray, value: ByteArray, destination: ByteArray, destinationOffset: Int = 0)
fun hashInto(key: ByteArray, value: ByteArray, destination: UByteArray, destinationOffset: Int = 0) =
hashInto(key, value, destination.asByteArray(), destinationOffset)
fun hashInto(key: UByteArray, value: UByteArray, destination: ByteArray, destinationOffset: Int = 0) =
hashInto(key.asByteArray(), value.asByteArray(), destination, destinationOffset)
fun hashInto(key: UByteArray, value: UByteArray, destination: UByteArray, destinationOffset: Int = 0) =
hashInto(key.asByteArray(), value.asByteArray(), destination.asByteArray(), destinationOffset)
fun hash(key: ByteArray, value: ByteArray): ByteArray =
ByteArray(bytes).also { hashInto(key, value, it) }
fun hash(key: UByteArray, value: UByteArray): UByteArray =
UByteArray(bytes).also { hashInto(key, value, it) }
}