From: Martin Willi <martin@revosec.ch>
Date: Thu, 4 Jul 2013 09:09:54 +0000 (+0200)
Subject: openssl: RAND_pseudo_bytes() returns 0 if bytes are not cryptographically strong
X-Git-Tag: 5.1.0dr2~19
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=324b90cc46e3af52731fa98eb947e412ab56a2f5;p=thirdparty%2Fstrongswan.git

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.
---

diff --git a/src/libstrongswan/plugins/openssl/openssl_rng.c b/src/libstrongswan/plugins/openssl/openssl_rng.c
index 10db6293a3..815cf4f0c1 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,