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trezor-firmware/pbkdf2.c
Jochen Hoenicke 32bda8d1d9
Faster PBKDF2 by reusing intermediate results.
The old implementation needed 6 sha transformations per iterations:

- 2 for computing sha512 of seed,
- 2 for computing digests of ipads/opads,
- 2 for computing digests of intermediate hashes.

The first 4 transformations are the same in every iteration so we cache
them.  A new function hmac_sha512_prepare computes these digests.
We made sha512_Transform visible in pbkdf2 and prevent unneccessary
big/little endian conversions back and forth.
2016-07-13 22:17:23 +02:00

148 lines
5.1 KiB
C

/**
* Copyright (c) 2013-2014 Tomas Dzetkulic
* Copyright (c) 2013-2014 Pavol Rusnak
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include <string.h>
#include "pbkdf2.h"
#include "hmac.h"
#include "sha2.h"
#include "macros.h"
void pbkdf2_hmac_sha256_Init(PBKDF2_HMAC_SHA256_CTX *pctx, const uint8_t *pass, int passlen, const uint8_t *salt, int saltlen)
{
SHA256_CTX ctx;
uint32_t blocknr = 1;
#if BYTE_ORDER == LITTLE_ENDIAN
REVERSE32(blocknr, blocknr);
#endif
hmac_sha256_prepare(pass, passlen, pctx->odig, pctx->idig);
memset(pctx->g, 0, sizeof(pctx->g));
pctx->g[8] = 0x80000000;
pctx->g[15] = (SHA256_BLOCK_LENGTH + SHA256_DIGEST_LENGTH) * 8;
memcpy (ctx.state, pctx->idig, sizeof(pctx->idig));
ctx.bitcount = SHA256_BLOCK_LENGTH * 8;
sha256_Update(&ctx, salt, saltlen);
sha256_Update(&ctx, (uint8_t*)&blocknr, sizeof(blocknr));
sha256_Final(&ctx, (uint8_t*)pctx->g);
#if BYTE_ORDER == LITTLE_ENDIAN
for (uint32_t k = 0; k < SHA256_DIGEST_LENGTH / sizeof(uint32_t); k++) {
REVERSE32(pctx->g[k], pctx->g[k]);
}
#endif
sha256_Transform(pctx->odig, pctx->g, pctx->g);
memcpy(pctx->f, pctx->g, SHA256_DIGEST_LENGTH);
pctx->first = 1;
}
void pbkdf2_hmac_sha256_Update(PBKDF2_HMAC_SHA256_CTX *pctx, uint32_t iterations)
{
for (uint32_t i = pctx->first; i < iterations; i++) {
sha256_Transform(pctx->idig, pctx->g, pctx->g);
sha256_Transform(pctx->odig, pctx->g, pctx->g);
for (uint32_t j = 0; j < SHA256_DIGEST_LENGTH/sizeof(uint32_t); j++) {
pctx->f[j] ^= pctx->g[j];
}
}
pctx->first = 0;
}
void pbkdf2_hmac_sha256_Final(PBKDF2_HMAC_SHA256_CTX *pctx, uint8_t *key)
{
#if BYTE_ORDER == LITTLE_ENDIAN
for (uint32_t k = 0; k < SHA256_DIGEST_LENGTH/sizeof(uint32_t); k++) {
REVERSE32(pctx->f[k], pctx->f[k]);
}
#endif
memcpy(key, pctx->f, SHA256_DIGEST_LENGTH);
MEMSET_BZERO(pctx, sizeof(PBKDF2_HMAC_SHA256_CTX));
}
void pbkdf2_hmac_sha256(const uint8_t *pass, int passlen, const uint8_t *salt, int saltlen, uint32_t iterations, uint8_t *key)
{
PBKDF2_HMAC_SHA256_CTX pctx;
pbkdf2_hmac_sha256_Init(&pctx, pass, passlen, salt, saltlen);
pbkdf2_hmac_sha256_Update(&pctx, iterations);
pbkdf2_hmac_sha256_Final(&pctx, key);
}
void pbkdf2_hmac_sha512_Init(PBKDF2_HMAC_SHA512_CTX *pctx, const uint8_t *pass, int passlen, const uint8_t *salt, int saltlen)
{
SHA512_CTX ctx;
uint32_t blocknr = 1;
#if BYTE_ORDER == LITTLE_ENDIAN
REVERSE32(blocknr, blocknr);
#endif
hmac_sha512_prepare(pass, passlen, pctx->odig, pctx->idig);
memset(pctx->g, 0, sizeof(pctx->g));
pctx->g[8] = 0x8000000000000000;
pctx->g[15] = (SHA512_BLOCK_LENGTH + SHA512_DIGEST_LENGTH) * 8;
memcpy (ctx.state, pctx->idig, sizeof(pctx->idig));
ctx.bitcount[0] = SHA512_BLOCK_LENGTH * 8;
ctx.bitcount[1] = 0;
sha512_Update(&ctx, salt, saltlen);
sha512_Update(&ctx, (uint8_t*)&blocknr, sizeof(blocknr));
sha512_Final(&ctx, (uint8_t*)pctx->g);
#if BYTE_ORDER == LITTLE_ENDIAN
for (uint32_t k = 0; k < SHA512_DIGEST_LENGTH / sizeof(uint64_t); k++) {
REVERSE64(pctx->g[k], pctx->g[k]);
}
#endif
sha512_Transform(pctx->odig, pctx->g, pctx->g);
memcpy(pctx->f, pctx->g, SHA512_DIGEST_LENGTH);
pctx->first = 1;
}
void pbkdf2_hmac_sha512_Update(PBKDF2_HMAC_SHA512_CTX *pctx, uint32_t iterations)
{
for (uint32_t i = pctx->first; i < iterations; i++) {
sha512_Transform(pctx->idig, pctx->g, pctx->g);
sha512_Transform(pctx->odig, pctx->g, pctx->g);
for (uint32_t j = 0; j < SHA512_DIGEST_LENGTH / sizeof(uint64_t); j++) {
pctx->f[j] ^= pctx->g[j];
}
}
pctx->first = 0;
}
void pbkdf2_hmac_sha512_Final(PBKDF2_HMAC_SHA512_CTX *pctx, uint8_t *key)
{
#if BYTE_ORDER == LITTLE_ENDIAN
for (uint32_t k = 0; k < SHA512_DIGEST_LENGTH/sizeof(uint64_t); k++) {
REVERSE64(pctx->f[k], pctx->f[k]);
}
#endif
memcpy(key, pctx->f, SHA512_DIGEST_LENGTH);
MEMSET_BZERO(pctx, sizeof(PBKDF2_HMAC_SHA512_CTX));
}
void pbkdf2_hmac_sha512(const uint8_t *pass, int passlen, const uint8_t *salt, int saltlen, uint32_t iterations, uint8_t *key)
{
PBKDF2_HMAC_SHA512_CTX pctx;
pbkdf2_hmac_sha512_Init(&pctx, pass, passlen, salt, saltlen);
pbkdf2_hmac_sha512_Update(&pctx, iterations);
pbkdf2_hmac_sha512_Final(&pctx, key);
}