static int pkey_ec_kdf_derive(EVP_PKEY_CTX *ctx,
unsigned char *key, size_t *keylen)
{
EC_PKEY_CTX *dctx = ctx->data;
unsigned char *ktmp = NULL;
size_t ktmplen;
int rv = 0;
if (dctx->kdf_type == EVP_PKEY_ECDH_KDF_NONE)
return pkey_ec_derive(ctx, key, keylen);
if (!key) {
*keylen = dctx->kdf_outlen;
return 1;
}
if (*keylen != dctx->kdf_outlen)
return 0;
if (!pkey_ec_derive(ctx, NULL, &ktmplen))
return 0;
ktmp = OPENSSL_malloc(ktmplen);
if (ktmp == NULL)
return 0;
if (!pkey_ec_derive(ctx, ktmp, &ktmplen))
goto err;
/* Do KDF stuff */
if (!ECDH_KDF_X9_62(key, *keylen, ktmp, ktmplen,
dctx->kdf_ukm, dctx->kdf_ukmlen, dctx->kdf_md))
goto err;
rv = 1;
err:
OPENSSL_clear_free(ktmp, ktmplen);
return rv;
}
static int pkey_ec_kdf_derive(EVP_PKEY_CTX *ctx, uint8_t *key, size_t *keylen)
{
EC_PKEY_CTX *dctx = ctx->data;
uint8_t *ktmp = NULL;
size_t ktmplen;
int rv = 0;
if (dctx->kdf_type == EVP_PKEY_ECDH_KDF_NONE)
return pkey_ec_derive(ctx, key, keylen);
if (key == NULL) {
*keylen = dctx->kdf_outlen;
return 1;
}
if (*keylen != dctx->kdf_outlen)
return 0;
if (!pkey_ec_derive(ctx, NULL, &ktmplen))
return 0;
ktmp = malloc(ktmplen);
if (ktmp == NULL)
return 0;
if (!pkey_ec_derive(ctx, ktmp, &ktmplen))
goto err;
/* Do KDF stuff */
if (!ECDH_KDF_X9_62(key, *keylen, ktmp, ktmplen, dctx->kdf_ukm,
dctx->kdf_ukmlen, dctx->kdf_md))
goto err;
rv = 1;
err:
vigortls_zeroize(ktmp, ktmplen);
free(ktmp);
return rv;
}
