Check rng return value when generating DH secret in gcrypt plugin

diff --git a/src/libstrongswan/plugins/gcrypt/gcrypt_dh.c b/src/libstrongswan/plugins/gcrypt/gcrypt_dh.c
index 6c4665da2dd2ac12b297fa5c1111d8fc10ad9083..0efd3ba16d3b741bf7f516b5de021bbcc715880c 100644 (file)
--- a/src/libstrongswan/plugins/gcrypt/gcrypt_dh.c
+++ b/src/libstrongswan/plugins/gcrypt/gcrypt_dh.c
@@ -208,9 +208,8 @@ gcrypt_dh_t *create_generic(diffie_hellman_group_t group, size_t exp_len,
        }
 
        rng = lib->crypto->create_rng(lib->crypto, RNG_STRONG);
-       if (rng)
+       if (rng && rng->allocate_bytes(rng, exp_len, &random))
        {       /* prefer external randomizer */
-               rng->allocate_bytes(rng, exp_len, &random);
                rng->destroy(rng);
                err = gcry_mpi_scan(&this->xa, GCRYMPI_FMT_USG,
                                                        random.ptr, random.len, NULL);
@@ -226,6 +225,7 @@ gcrypt_dh_t *create_generic(diffie_hellman_group_t group, size_t exp_len,
        }
        else
        {       /* fallback to gcrypt internal randomizer, shouldn't ever happen */
+               DESTROY_IF(rng);
                this->xa = gcry_mpi_new(exp_len * 8);
                gcry_mpi_randomize(this->xa, exp_len * 8, GCRY_STRONG_RANDOM);
        }