Start of "Simple Peer-To-Peer Security" protocol.

[tinc] / src / openssl / prf.c

diff --git a/src/openssl/prf.c b/src/openssl/prf.c
index 2830d60..648a157 100644 (file)
--- a/src/openssl/prf.c
+++ b/src/openssl/prf.c
@@ -22,14 +22,14 @@
 #include "digest.h"
 #include "prf.h"
 
-/* Generate key material from a master secret and a seed, based on RFC 2246.
+/* Generate key material from a master secret and a seed, based on RFC 4346 section 5.
    We use SHA512 and Whirlpool 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 +65,12 @@ 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) {
+bool prf(const 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. */
 
        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 + 1) / 2, seed, seedlen, out, outlen)
+               && prf_xor(NID_whirlpool, secret + secretlen / 2, (secretlen + 1) / 2, seed, seedlen, out, outlen);
 }