X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fopenssl%2Fprf.c;h=4412529621abc3bd36c44f94be3b170ee94b0c6e;hb=d917c8cb6b69475d568ccbe82389b9f2b3eb5e80;hp=2830d609a0c5cb2bba35ef3d5405f314a79a3efd;hpb=feb3f22fffa2620b9b11a509ce51ff9fa3be9418;p=tinc

diff --git a/src/openssl/prf.c b/src/openssl/prf.c
index 2830d609..44125296 100644
--- a/src/openssl/prf.c
+++ b/src/openssl/prf.c
@@ -19,17 +19,19 @@
 
 #include "system.h"
 
+#include <openssl/obj_mac.h>
+
 #include "digest.h"
 #include "prf.h"
 
-/* Generate key material from a master secret and a seed, based on RFC 2246.
-   We use SHA512 and Whirlpool instead of MD5 and SHA1.
+/* Generate key material from a master secret and a seed, based on RFC 4346 section 5.
+   We use SHA512 instead of MD5 and SHA1.
  */
 
-static bool prf_xor(int nid, char *secret, size_t secretlen, char *seed, size_t seedlen, char *out, ssize_t outlen) {
+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;
-	
-	if(!digest_open_by_nid(&digest, nid, 0))
+
+	if(!digest_open_by_nid(&digest, nid, -1))
 		return false;
 
 	if(!digest_set_key(&digest, secret, secretlen))
@@ -65,12 +67,9 @@ static bool prf_xor(int nid, char *secret, size_t secretlen, char *seed, size_t
 	return true;
 }
 
-bool prf(char *secret, size_t secretlen, char *seed, size_t seedlen, char *out, size_t outlen) {
-	/* Split secret in half, generate outlen bits with two different hash algorithms,
-	   and XOR the results. */
-
+bool prf(const char *secret, size_t secretlen, char *seed, size_t seedlen, char *out, size_t outlen) {
+	/* This construction allows us to easily switch back to a scheme where the PRF is calculated using two different digest algorithms. */
 	memset(out, 0, outlen);
 
-	return prf_xor(NID_sha512, secret, secretlen / 2, seed, seedlen, out, outlen)
-		&& prf_xor(NID_whirlpool, secret, secretlen / 2, seed, seedlen, out, outlen);
+	return prf_xor(NID_sha512, secret, secretlen, seed, seedlen, out, outlen);
 }