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 hmac_sha512_prepare(const uint8_t *key, const uint32_t keylen,
uint64_t *opad_digest, uint64_t *ipad_digest) {
static CONFIDENTIAL uint64_t key_pad[SHA512_BLOCK_LENGTH / sizeof(uint64_t)];
memzero(key_pad, sizeof(key_pad));
if (keylen > SHA512_BLOCK_LENGTH) {
static CONFIDENTIAL SHA512_CTX context;
sha512_Init(&context);
sha512_Update(&context, key, keylen);
sha512_Final(&context, (uint8_t *)key_pad);
} else {
memcpy(key_pad, key, keylen);
}
/* compute o_key_pad and its digest */
for (int i = 0; i < SHA512_BLOCK_LENGTH / (int)sizeof(uint64_t); i++) {
uint64_t data;
#if BYTE_ORDER == LITTLE_ENDIAN
REVERSE64(key_pad[i], data);
#else
data = key_pad[i];
#endif
key_pad[i] = data ^ 0x5c5c5c5c5c5c5c5c;
}
sha512_Transform(sha512_initial_hash_value, key_pad, opad_digest);
/* convert o_key_pad to i_key_pad and compute its digest */
for (int i = 0; i < SHA512_BLOCK_LENGTH / (int)sizeof(uint64_t); i++) {
key_pad[i] = key_pad[i] ^ 0x5c5c5c5c5c5c5c5c ^ 0x3636363636363636;
}
sha512_Transform(sha512_initial_hash_value, key_pad, ipad_digest);
memzero(key_pad, sizeof(key_pad));
}
void SHA256_Final(sha2_byte digest[], SHA256_CTX* context) {
sha2_word32 *d = (sha2_word32*)digest;
unsigned int usedspace;
/* Sanity check: */
assert(context != (SHA256_CTX*)0);
/* If no digest buffer is passed, we don't bother doing this: */
if (digest != (sha2_byte*)0) {
usedspace = (unsigned int)((context->bitcount >> 3) % SHA256_BLOCK_LENGTH);
#if SIRIKATA_BYTE_ORDER == SIRIKATA_LITTLE_ENDIAN
/* Convert FROM host byte order */
REVERSE64(context->bitcount,context->bitcount);
#endif
if (usedspace > 0) {
/* Begin padding with a 1 bit: */
context->buffer[usedspace++] = 0x80;
if (usedspace <= SHA256_SHORT_BLOCK_LENGTH) {
/* Set-up for the last transform: */
MEMSET_BZERO(&context->buffer[usedspace], SHA256_SHORT_BLOCK_LENGTH - usedspace);
} else {
if (usedspace < SHA256_BLOCK_LENGTH) {
MEMSET_BZERO(&context->buffer[usedspace], SHA256_BLOCK_LENGTH - usedspace);
}
/* Do second-to-last transform: */
SHA256_Transform(context, (sha2_word32*)context->buffer);
/* And set-up for the last transform: */
MEMSET_BZERO(context->buffer, SHA256_SHORT_BLOCK_LENGTH);
}
} else {
/* Set-up for the last transform: */
MEMSET_BZERO(context->buffer, SHA256_SHORT_BLOCK_LENGTH);
/* Begin padding with a 1 bit: */
*context->buffer = 0x80;
}
/* Set the bit count: */
*(sha2_word64*)&context->buffer[SHA256_SHORT_BLOCK_LENGTH] = context->bitcount;
/* Final transform: */
SHA256_Transform(context, (sha2_word32*)context->buffer);
#if SIRIKATA_BYTE_ORDER == SIRIKATA_LITTLE_ENDIAN
{
/* Convert TO host byte order */
int j;
for (j = 0; j < 8; j++) {
REVERSE32(context->state[j],context->state[j]);
*d++ = context->state[j];
}
}
#else
MEMCPY_BCOPY(d, context->state, SHA256_DIGEST_LENGTH);
#endif
}
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);
memzero(pctx, sizeof(PBKDF2_HMAC_SHA512_CTX));
}