openssl: RAND_pseudo_bytes() returns 0 if bytes are not cryptographically strong

For our purposes with RNG_WEAK this is fine, so accept a zero return value.

1 files changed, 6 insertions, 9 deletions

diff --git a/src/libstrongswan/plugins/openssl/openssl_rng.c b/src/libstrongswan/plugins/openssl/openssl_rng.c
index 10db6293a..815cf4f0c 100644
--- a/src/libstrongswan/plugins/openssl/openssl_rng.c
+++ b/src/libstrongswan/plugins/openssl/openssl_rng.c
@@ -47,17 +47,14 @@ struct private_openssl_rng_t {
 METHOD(rng_t, get_bytes, bool,
 	private_openssl_rng_t *this, size_t bytes, u_int8_t *buffer)
 {
-	u_int32_t ret;
-
-	if (this->quality == RNG_STRONG)
-	{
-		ret = RAND_bytes((char*)buffer, bytes);
-	}
-	else
+	if (this->quality == RNG_WEAK)
 	{
-		ret = RAND_pseudo_bytes((char*)buffer, bytes);
+		/* RAND_pseudo_bytes() returns 1 if returned bytes are strong,
+		 * 0 if of not. Both is acceptable for RNG_WEAK. */
+		return RAND_pseudo_bytes((char*)buffer, bytes) != -1;
 	}
-	return ret == 1;
+	/* A 0 return value is a failure for RAND_bytes() */
+	return RAND_bytes((char*)buffer, bytes) == 1;
 }
 
 METHOD(rng_t, allocate_bytes, bool,