This commit is contained in:
Guus Sliepen 2011-07-03 15:59:49 +02:00
parent feb3f22fff
commit 82f00ea07b
2 changed files with 17 additions and 23 deletions

View file

@ -22,14 +22,14 @@
#include "digest.h" #include "digest.h"
#include "prf.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. 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, char *secret, size_t secretlen, char *seed, size_t seedlen, char *out, ssize_t outlen) {
digest_t digest; digest_t digest;
if(!digest_open_by_nid(&digest, nid, 0)) if(!digest_open_by_nid(&digest, nid, -1))
return false; return false;
if(!digest_set_key(&digest, secret, secretlen)) if(!digest_set_key(&digest, secret, secretlen))

View file

@ -29,6 +29,7 @@
#include "net.h" #include "net.h"
#include "netutl.h" #include "netutl.h"
#include "node.h" #include "node.h"
#include "prf.h"
#include "protocol.h" #include "protocol.h"
#include "utils.h" #include "utils.h"
#include "xalloc.h" #include "xalloc.h"
@ -311,25 +312,27 @@ bool ans_key_h(connection_t *c, char *request) {
/* Update our crypto end */ /* Update our crypto end */
char *mykey;
size_t mykeylen = cipher_keylength(&myself->incipher); size_t mykeylen = cipher_keylength(&myself->incipher);
keylen = cipher_keylength(&from->outcipher); keylen = cipher_keylength(&from->outcipher);
if(ECDH_SHARED_SIZE < mykeylen) { char *mykey;
logger(LOG_ERR, "ECDH key too short for cipher of MYSELF!"); char *seed = NULL;
return false;
}
if(strcmp(myself->name, from->name) < 0) { if(strcmp(myself->name, from->name) < 0) {
logger(LOG_DEBUG, "Using left half of shared secret"); logger(LOG_DEBUG, "Using left half of shared secret");
mykey = shared; mykey = key;
memcpy(key, shared + ECDH_SHARED_SIZE - keylen, keylen); xasprintf(&seed, "tinc key expansion %s %s", myself->name, from->name);
} else { } else {
logger(LOG_DEBUG, "Using right half of shared secret"); logger(LOG_DEBUG, "Using right half of shared secret");
mykey = shared + ECDH_SHARED_SIZE - mykeylen; mykey = key + keylen;
memcpy(key, shared, 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)); 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)); digest_open_by_nid(&from->indigest, digest_get_nid(&myself->indigest), digest_length(&myself->indigest));
from->incompression = myself->incompression; from->incompression = myself->incompression;
@ -343,17 +346,8 @@ bool ans_key_h(connection_t *c, char *request) {
if(replaywin) if(replaywin)
memset(from->late, 0, replaywin); memset(from->late, 0, replaywin);
bin2hex(shared, hex, ECDH_SHARED_SIZE); if(strcmp(myself->name, from->name) < 0)
hex[ECDH_SHARED_SIZE * 2] = 0; memmove(key, key + mykeylen, keylen);
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);
} else { } else {
keylen = strlen(key) / 2; keylen = strlen(key) / 2;
hex2bin(key, key, keylen); hex2bin(key, key, keylen);