static bool prf_xor(int nid, const char *secret, size_t secretlen, char *seed, size_t seedlen, char *out, ssize_t outlen) {
digest_t *digest = digest_open_by_nid(nid, -1);
- if(!digest)
+ if(!digest) {
return false;
+ }
if(!digest_set_key(digest, secret, secretlen)) {
digest_close(digest);
while(outlen > 0) {
/* Inner HMAC */
- digest_create(digest, data, len + seedlen, data);
+ if(!digest_create(digest, data, len + seedlen, data)) {
+ digest_close(digest);
+ return false;
+ }
/* Outer HMAC */
- digest_create(digest, data, len + seedlen, hash);
+ if(!digest_create(digest, data, len + seedlen, hash)) {
+ digest_close(digest);
+ return false;
+ }
/* XOR the results of the outer HMAC into the out buffer */
- for(int i = 0; i < len && i < outlen; i++)
+ for(int i = 0; i < len && i < outlen; i++) {
*out++ ^= hash[i];
+ }
outlen -= len;
}