115 lines
3.9 KiB
C
115 lines
3.9 KiB
C
/*
|
|
* Copyright (c) 2023 Stephen Heumann
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
/*
|
|
* This file is a template for computing HMACs using the hash functions
|
|
* from lib65816hash. It is #included from the files implementing the
|
|
* hash functions, with HASH_ALG defined to the name of the hash function.
|
|
*/
|
|
|
|
#define join(a,b) a##b
|
|
#define concat(a,b) join(a,b)
|
|
|
|
#define join3(a,b,c) a##b##c
|
|
#define concat3(a,b,c) join3(a,b,c)
|
|
|
|
#define hash_init concat(HASH_ALG,_init)
|
|
#define hash_update concat(HASH_ALG,_update)
|
|
#define hash_finalize concat(HASH_ALG,_finalize)
|
|
|
|
#define hmac_init concat3(hmac_,HASH_ALG,_init)
|
|
#define hmac_update concat3(hmac_,HASH_ALG,_update)
|
|
#define hmac_finalize concat3(hmac_,HASH_ALG,_finalize)
|
|
#define hmac_compute concat3(hmac_,HASH_ALG,_compute)
|
|
#define hmac_context concat3(hmac_,HASH_ALG,_context)
|
|
|
|
#define BLOCK_SIZE sizeof(context->u[0].ctx.block)
|
|
#define HASH_SIZE sizeof(context->u[0].ctx.hash)
|
|
|
|
void hmac_init(struct hmac_context *context,
|
|
const unsigned char *key,
|
|
unsigned long key_length)
|
|
{
|
|
|
|
unsigned i;
|
|
|
|
// Compute adjusted key (hashed from original key if necessary)
|
|
memset(context->u[0].k, 0, BLOCK_SIZE);
|
|
if (key_length <= BLOCK_SIZE) {
|
|
memcpy(context->u[0].k, key, key_length);
|
|
} else {
|
|
hash_init(&context->u[1].ctx);
|
|
hash_update(&context->u[1].ctx, key, key_length);
|
|
hash_finalize(&context->u[1].ctx);
|
|
memcpy(context->u[0].k, context->u[1].ctx.hash, HASH_SIZE);
|
|
}
|
|
|
|
// Set context->u[0].k to K XOR opad, context->u[1].k to K XOR ipad
|
|
for (i = 0; i < BLOCK_SIZE; i++) {
|
|
context->u[1].k[i] = context->u[0].k[i] ^ 0x36;
|
|
context->u[0].k[i] ^= 0x5C;
|
|
}
|
|
|
|
// Save inner hash context following initial block as context->u[2].ctx
|
|
hash_init(&context->u[2].ctx);
|
|
hash_update(&context->u[2].ctx, context->u[1].k, BLOCK_SIZE);
|
|
|
|
// Save outer hash context following initial block as context->u[1].ctx
|
|
hash_init(&context->u[1].ctx);
|
|
hash_update(&context->u[1].ctx, context->u[0].k, BLOCK_SIZE);
|
|
|
|
// initialize context for use with hmac_update
|
|
context->u[0].ctx = context->u[2].ctx;
|
|
}
|
|
|
|
|
|
void hmac_update(struct hmac_context *context,
|
|
const unsigned char *message_part,
|
|
unsigned long part_length)
|
|
{
|
|
hash_update(&context->u[0].ctx, message_part, part_length);
|
|
}
|
|
|
|
|
|
void hmac_finalize(struct hmac_context *context)
|
|
{
|
|
// finalize inner hash
|
|
hash_finalize(&context->u[0].ctx);
|
|
memcpy(context->inner_hash, context->u[0].ctx.hash, HASH_SIZE);
|
|
|
|
// Compute outer hash
|
|
context->u[0].ctx = context->u[1].ctx;
|
|
hash_update(&context->u[0].ctx, context->inner_hash, HASH_SIZE);
|
|
hash_finalize(&context->u[0].ctx);
|
|
}
|
|
|
|
|
|
void hmac_compute(struct hmac_context *context,
|
|
const unsigned char *message,
|
|
unsigned long message_length)
|
|
{
|
|
// Compute inner hash
|
|
context->u[0].ctx = context->u[2].ctx;
|
|
hash_update(&context->u[0].ctx, message, message_length);
|
|
hash_finalize(&context->u[0].ctx);
|
|
memcpy(context->inner_hash, context->u[0].ctx.hash, HASH_SIZE);
|
|
|
|
// Compute outer hash
|
|
context->u[0].ctx = context->u[1].ctx;
|
|
hash_update(&context->u[0].ctx, context->inner_hash, HASH_SIZE);
|
|
hash_finalize(&context->u[0].ctx);
|
|
}
|