static void *x963_kdf(const EVP_MD *md, const void *in, size_t inlen,
void *out, size_t *outlen)
{
void *ret = NULL;
EVP_MD_CTX *ctx = NULL;
uint32_t counter = 1;
uint32_t counter_be;
unsigned char dgst[EVP_MAX_MD_SIZE];
unsigned int dgstlen;
unsigned char *pout = out;
size_t rlen = *outlen;
size_t len;
if (!(ctx = EVP_MD_CTX_new())) {
KDF2err(KDF2_F_X963_KDF, ERR_R_MALLOC_FAILURE);
goto end;
}
while (rlen > 0) {
counter_be = cpu_to_be32(counter);
counter++;
if (!EVP_DigestInit(ctx, md)) {
KDF2err(KDF2_F_X963_KDF, KDF2_R_DIGEST_FAILURE);
goto end;
}
if (!EVP_DigestUpdate(ctx, in, inlen)) {
KDF2err(KDF2_F_X963_KDF, KDF2_R_DIGEST_FAILURE);
goto end;
}
if (!EVP_DigestUpdate(ctx, &counter_be, sizeof(counter_be))) {
KDF2err(KDF2_F_X963_KDF, KDF2_R_DIGEST_FAILURE);
goto end;
}
if (!EVP_DigestFinal(ctx, dgst, &dgstlen)) {
KDF2err(KDF2_F_X963_KDF, KDF2_R_DIGEST_FAILURE);
goto end;
}
len = dgstlen <= rlen ? dgstlen : rlen;
memcpy(pout, dgst, len);
rlen -= len;
pout += len;
}
ret = out;
end:
EVP_MD_CTX_free(ctx);
return ret;
}
static void *ibcs_kdf(const EVP_MD *md, const void *in, size_t inlen,
void *out, size_t *outlen)
{
unsigned char state[EVP_MAX_MD_SIZE * 2];
unsigned char dgst[EVP_MAX_MD_SIZE];
unsigned int dgstlen;
size_t rlen;
unsigned char *pout;
int i;
dgstlen = EVP_MD_size(md);
memset(state, 0, dgstlen);
if (!EVP_Digest(in, inlen, state + dgstlen, &dgstlen, md, NULL)) {
KDF2err(KDF2_F_IBCS_KDF, KDF2_R_DIGEST_FAILURE);
return NULL;
}
rlen = *outlen;
pout = out;
for (i = 0; i < (*outlen + dgstlen - 1)/dgstlen; i++) {
size_t len;
if (!EVP_Digest(state, dgstlen, state, &dgstlen, md, NULL)) {
KDF2err(KDF2_F_IBCS_KDF, KDF2_R_DIGEST_FAILURE);
return NULL;
}
if (!EVP_Digest(state, dgstlen*2, dgst, &dgstlen, md, NULL)) {
KDF2err(KDF2_F_IBCS_KDF, KDF2_R_DIGEST_FAILURE);
return NULL;
}
len = (dgstlen <= rlen) ? dgstlen : rlen;
memcpy(pout, dgst, len);
pout += len;
rlen -= len;
}
return out;
}
