/*
* Hash Derive function defined in NISP SP 800-90 Section 10.4.1.
* This function is used in the Instantiate and Reseed functions.
*
* NOTE: requested_bytes cannot overlap with input_string_1 or input_string_2.
* input_string_1 and input_string_2 are logically concatentated.
* input_string_1 must be supplied.
* if input_string_2 is not supplied, NULL should be passed for this parameter.
*/
static SECStatus
prng_Hash_df(PRUint8 *requested_bytes, unsigned int no_of_bytes_to_return,
const PRUint8 *input_string_1, unsigned int input_string_1_len,
const PRUint8 *input_string_2, unsigned int input_string_2_len)
{
SHA256Context ctx;
PRUint32 tmp;
PRUint8 counter;
tmp=SHA_HTONL(no_of_bytes_to_return*8);
for (counter = 1 ; no_of_bytes_to_return > 0; counter++) {
unsigned int hash_return_len;
SHA256_Begin(&ctx);
SHA256_Update(&ctx, &counter, 1);
SHA256_Update(&ctx, (unsigned char *)&tmp, sizeof tmp);
SHA256_Update(&ctx, input_string_1, input_string_1_len);
if (input_string_2) {
SHA256_Update(&ctx, input_string_2, input_string_2_len);
}
SHA256_End(&ctx, requested_bytes, &hash_return_len,
no_of_bytes_to_return);
requested_bytes += hash_return_len;
no_of_bytes_to_return -= hash_return_len;
}
return SECSuccess;
}
/*
* SHA: Generate hash value from context
*/
void
SHA1_End(SHA1Context *ctx, unsigned char *hashout,
unsigned int *pDigestLen, unsigned int maxDigestLen)
{
register PRUint64 size;
register PRUint32 lenB;
static const unsigned char bulk_pad[64] = { 0x80,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
#define tmp lenB
PORT_Assert (maxDigestLen >= SHA1_LENGTH);
/*
* Pad with a binary 1 (e.g. 0x80), then zeroes, then length in bits
*/
size = ctx->size;
lenB = (PRUint32)size & 63;
SHA1_Update(ctx, bulk_pad, (((55+64) - lenB) & 63) + 1);
PORT_Assert(((PRUint32)ctx->size & 63) == 56);
/* Convert size from bytes to bits. */
size <<= 3;
ctx->W[14] = SHA_HTONL((PRUint32)(size >> 32));
ctx->W[15] = SHA_HTONL((PRUint32)size);
shaCompress(&ctx->H[H2X], ctx->W);
/*
* Output hash
*/
SHA_STORE_RESULT;
*pDigestLen = SHA1_LENGTH;
}
