From fec279a9c54ec8a13bd1ba4c7bec0d2a15454992 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Tue, 12 Jul 2011 23:43:12 +0200 Subject: [PATCH] Make use of the improved hex and base64 functions. Also, use base64 for all EC related data, it is shorter and easy to distinguish from the legacy protocol. --- src/control.c | 1 - src/protocol_auth.c | 67 ++++++++++++++++++--------------------------- src/protocol_key.c | 11 ++------ 3 files changed, 29 insertions(+), 50 deletions(-) diff --git a/src/control.c b/src/control.c index bcafc09f..7f46a709 100644 --- a/src/control.c +++ b/src/control.c @@ -134,7 +134,6 @@ bool control_h(connection_t *c, char *request) { bool init_control(void) { randomize(controlcookie, sizeof controlcookie / 2); bin2hex(controlcookie, controlcookie, sizeof controlcookie / 2); - controlcookie[sizeof controlcookie - 1] = 0; FILE *f = fopen(pidfilename, "w"); if(!f) { diff --git a/src/protocol_auth.c b/src/protocol_auth.c index 21a4b7e1..41911e42 100644 --- a/src/protocol_auth.c +++ b/src/protocol_auth.c @@ -143,24 +143,19 @@ bool send_metakey_ec(connection_t *c) { size_t siglen = ecdsa_size(&myself->connection->ecdsa); - char key[ECDH_SIZE]; - char sig[siglen]; + char key[(ECDH_SIZE + siglen) * 2 + 1]; // TODO: include nonce? Use relevant parts of SSH or TLS protocol if(!ecdh_generate_public(&c->ecdh, key)) return false; - if(!ecdsa_sign(&myself->connection->ecdsa, key, ECDH_SIZE, sig)) + if(!ecdsa_sign(&myself->connection->ecdsa, key, ECDH_SIZE, key + ECDH_SIZE)) return false; - char out[MAX_STRING_SIZE]; - - bin2hex(key, out, ECDH_SIZE); - bin2hex(sig, out + ECDH_SIZE * 2, siglen); - out[(ECDH_SIZE + siglen) * 2] = 0; + b64encode(key, key, ECDH_SIZE + siglen); - bool result = send_request(c, "%d %s", METAKEY, out); + bool result = send_request(c, "%d %s", METAKEY, key); } bool send_metakey(connection_t *c) { @@ -198,7 +193,6 @@ bool send_metakey(connection_t *c) { ifdebug(SCARY_THINGS) { bin2hex(key, hexkey, len); - hexkey[len * 2] = '\0'; logger(LOG_DEBUG, "Generated random meta key (unencrypted): %s", hexkey); } @@ -217,7 +211,6 @@ bool send_metakey(connection_t *c) { /* Convert the encrypted random data to a hexadecimal formatted string */ bin2hex(enckey, hexkey, len); - hexkey[len * 2] = '\0'; /* Send the meta key */ @@ -232,31 +225,29 @@ bool send_metakey(connection_t *c) { static bool metakey_ec_h(connection_t *c, const char *request) { size_t siglen = ecdsa_size(&c->ecdsa); - char in[MAX_STRING_SIZE]; char key[MAX_STRING_SIZE]; char sig[siglen]; logger(LOG_DEBUG, "Got ECDH metakey from %s", c->name); - if(sscanf(request, "%*d " MAX_STRING, in) != 1) { + if(sscanf(request, "%*d " MAX_STRING, key) != 1) { logger(LOG_ERR, "Got bad %s from %s (%s)", "METAKEY", c->name, c->hostname); return false; } - if(strlen(in) != (ECDH_SIZE + siglen) * 2) { - logger(LOG_ERR, "Possible intruder %s (%s): %s %d != %d", c->name, c->hostname, "wrong keylength", strlen(in) / 2, (ECDH_SIZE + siglen)); + int inlen = b64decode(key, key, sizeof key); + + if(inlen != (ECDH_SIZE + siglen)) { + logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong keylength"); return false; } - hex2bin(in, key, ECDH_SIZE); - hex2bin(in + ECDH_SIZE * 2, sig, siglen); - - if(!ecdsa_verify(&c->ecdsa, key, ECDH_SIZE, sig)) { + if(!ecdsa_verify(&c->ecdsa, key, ECDH_SIZE, key + ECDH_SIZE)) { logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "invalid ECDSA signature"); return false; } - char shared[ECDH_SHARED_SIZE * 2 + 1]; + char shared[ECDH_SHARED_SIZE]; if(!ecdh_compute_shared(&c->ecdh, key, shared)) return false; @@ -294,10 +285,6 @@ static bool metakey_ec_h(connection_t *c, const char *request) { free(seed); - bin2hex(shared, shared, ECDH_SHARED_SIZE); - shared[ECDH_SHARED_SIZE * 2] = 0; - logger(LOG_DEBUG, "Shared secret is %s", shared); - cipher_set_key(&c->incipher, mykey, true); digest_set_key(&c->indigest, mykey + mykeylen, mykeylen); @@ -326,17 +313,17 @@ bool metakey_h(connection_t *c, char *request) { return false; } + /* Convert the challenge from hexadecimal back to binary */ + + int inlen = hex2bin(hexkey, enckey, sizeof enckey); + /* Check if the length of the meta key is all right */ - if(strlen(hexkey) != len * 2) { + if(inlen != len) { logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong keylength"); return false; } - /* Convert the challenge from hexadecimal back to binary */ - - hex2bin(hexkey, enckey, len); - /* Decrypt the meta key */ if(!rsa_private_decrypt(&myself->connection->rsa, enckey, len, key)) { @@ -346,7 +333,6 @@ bool metakey_h(connection_t *c, char *request) { ifdebug(SCARY_THINGS) { bin2hex(key, hexkey, len); - hexkey[len * 2] = '\0'; logger(LOG_DEBUG, "Received random meta key (unencrypted): %s", hexkey); } @@ -383,7 +369,6 @@ bool send_challenge(connection_t *c) { /* Convert to hex */ bin2hex(c->hischallenge, buffer, len); - buffer[len * 2] = '\0'; /* Send the challenge */ @@ -401,17 +386,17 @@ bool challenge_h(connection_t *c, char *request) { return false; } + /* Convert the challenge from hexadecimal back to binary */ + + int inlen = hex2bin(buffer, buffer, sizeof buffer); + /* Check if the length of the challenge is all right */ - if(strlen(buffer) != len * 2) { + if(inlen != len) { logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge length"); return false; } - /* Convert the challenge from hexadecimal back to binary */ - - hex2bin(buffer, buffer, len); - c->allow_request = CHAL_REPLY; /* Calculate the hash from the challenge we received */ @@ -421,7 +406,6 @@ bool challenge_h(connection_t *c, char *request) { /* Convert the hash to a hexadecimal formatted string */ bin2hex(digest, buffer, digestlen); - buffer[digestlen * 2] = '\0'; /* Send the reply */ @@ -437,16 +421,17 @@ bool chal_reply_h(connection_t *c, char *request) { return false; } + /* Convert the hash to binary format */ + + int inlen = hex2bin(hishash, hishash, sizeof hishash); + /* Check if the length of the hash is all right */ - if(strlen(hishash) != digest_length(&c->outdigest) * 2) { + if(inlen != digest_length(&c->outdigest)) { logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge reply length"); return false; } - /* Convert the hash to binary format */ - - hex2bin(hishash, hishash, digest_length(&c->outdigest)); /* Verify the hash */ diff --git a/src/protocol_key.c b/src/protocol_key.c index 0ae95681..fc3707ae 100644 --- a/src/protocol_key.c +++ b/src/protocol_key.c @@ -149,8 +149,7 @@ bool send_ans_key_ecdh(node_t *to) { ecdh_generate_public(&to->ecdh, key); - bin2hex(key, key, ECDH_SIZE); - key[ECDH_SIZE * 2] = '\0'; + b64encode(key, key, ECDH_SIZE); return send_request(to->nexthop->connection, "%d %s %s ECDH:%s %d %d %zu %d", ANS_KEY, myself->name, to->name, key, @@ -176,7 +175,6 @@ bool send_ans_key(node_t *to) { digest_set_key(&to->indigest, key, keylen); bin2hex(key, key, keylen); - key[keylen * 2] = '\0'; // Reset sequence number and late packet window mykeyused = true; @@ -281,7 +279,7 @@ bool ans_key_h(connection_t *c, char *request) { /* ECDH or old-style key exchange? */ if(experimental && !strncmp(key, "ECDH:", 5)) { - keylen = (strlen(key) - 5) / 2; + int keylen = b64decode(key + 5, key + 5, sizeof key - 5); if(keylen != ECDH_SIZE) { logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname); @@ -300,8 +298,6 @@ bool ans_key_h(connection_t *c, char *request) { } char shared[ECDH_SHARED_SIZE * 2 + 1]; - char hex[ECDH_SHARED_SIZE * 2 + 1]; - hex2bin(key + 5, key + 5, keylen); if(!ecdh_compute_shared(&from->ecdh, key + 5, shared)) return false; @@ -349,8 +345,7 @@ bool ans_key_h(connection_t *c, char *request) { if(strcmp(myself->name, from->name) < 0) memmove(key, key + mykeylen * 2, hiskeylen * 2); } else { - keylen = strlen(key) / 2; - hex2bin(key, key, keylen); + keylen = hex2bin(key, key, sizeof key); if(keylen != cipher_keylength(&from->outcipher)) { logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname); -- 2.20.1