From: Guus Sliepen Date: Sun, 3 Jul 2011 13:59:49 +0000 (+0200) Subject: Use PRF. X-Git-Tag: release-1.1pre2~36 X-Git-Url: https://git.tinc-vpn.org/git/browse?a=commitdiff_plain;h=82f00ea07bffc10985ccb1a15723e6daa0ab4969;p=tinc Use PRF. --- diff --git a/src/openssl/prf.c b/src/openssl/prf.c index 2830d609..59e8a3aa 100644 --- 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) { 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)) diff --git a/src/protocol_key.c b/src/protocol_key.c index f52e8961..8bbb6ad4 100644 --- a/src/protocol_key.c +++ b/src/protocol_key.c @@ -29,6 +29,7 @@ #include "net.h" #include "netutl.h" #include "node.h" +#include "prf.h" #include "protocol.h" #include "utils.h" #include "xalloc.h" @@ -311,25 +312,27 @@ bool ans_key_h(connection_t *c, char *request) { /* Update our crypto end */ - char *mykey; size_t mykeylen = cipher_keylength(&myself->incipher); keylen = cipher_keylength(&from->outcipher); - if(ECDH_SHARED_SIZE < mykeylen) { - logger(LOG_ERR, "ECDH key too short for cipher of MYSELF!"); - return false; - } - + char *mykey; + char *seed = NULL; + if(strcmp(myself->name, from->name) < 0) { logger(LOG_DEBUG, "Using left half of shared secret"); - mykey = shared; - memcpy(key, shared + ECDH_SHARED_SIZE - keylen, keylen); + mykey = key; + xasprintf(&seed, "tinc key expansion %s %s", myself->name, from->name); } else { logger(LOG_DEBUG, "Using right half of shared secret"); - mykey = shared + ECDH_SHARED_SIZE - mykeylen; - memcpy(key, shared, keylen); + mykey = key + keylen; + xasprintf(&seed, "tinc key expansion %s %s", from->name, myself->name); } + if(!prf(shared, ECDH_SHARED_SIZE, seed, strlen(seed), key, keylen + mykeylen)) + return false; + + free(seed); + cipher_open_by_nid(&from->incipher, cipher_get_nid(&myself->incipher)); digest_open_by_nid(&from->indigest, digest_get_nid(&myself->indigest), digest_length(&myself->indigest)); from->incompression = myself->incompression; @@ -343,17 +346,8 @@ bool ans_key_h(connection_t *c, char *request) { if(replaywin) memset(from->late, 0, replaywin); - bin2hex(shared, hex, ECDH_SHARED_SIZE); - hex[ECDH_SHARED_SIZE * 2] = 0; - logger(LOG_DEBUG, "Shared secret was %s", hex); - - bin2hex(mykey, hex, mykeylen); - hex[mykeylen * 2] = 0; - logger(LOG_DEBUG, "My part is: %s (%d)", hex, mykeylen); - - bin2hex(key, hex, keylen); - hex[keylen * 2] = 0; - logger(LOG_DEBUG, "His part is: %s (%d)", hex, keylen); + if(strcmp(myself->name, from->name) < 0) + memmove(key, key + mykeylen, keylen); } else { keylen = strlen(key) / 2; hex2bin(key, key, keylen);