along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: protocol.c,v 1.28.4.80 2001/02/25 16:34:19 guus Exp $
+ $Id: protocol.c,v 1.28.4.82 2001/02/26 11:37:20 guus Exp $
*/
#include "config.h"
int send_id(connection_t *cl)
{
-cp
- cl->allow_request = CHALLENGE;
cp
return send_request(cl, "%d %s %d %lx %hd", ID, myself->name, myself->protocol_version, myself->options, myself->port);
}
cl->port = port;
avl_insert_node(connection_tree, node);
- /* Read in the public key, so that we can send a challenge */
+ /* Read in the public key, so that we can send a metakey */
if(read_rsa_public_key(cl))
return -1;
+ cl->allow_request = METAKEY;
cp
- return send_challenge(cl);
+ return send_metakey(cl);
}
int send_challenge(connection_t *cl)
char *buffer;
int len, x;
cp
+ /* CHECKME: what is most reasonable value for len? */
+
len = RSA_size(cl->rsa_key);
/* Allocate buffers for the challenge */
RAND_bytes(cl->hischallenge, len);
- cl->hischallenge[0] &= 0x7F; /* Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
cp
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(cl->hischallenge, buffer, len);
- buffer[len*2] = '\0';
- syslog(LOG_DEBUG, _("Generated random challenge (unencrypted): %s"), buffer);
- }
+ /* Convert to hex */
- /* Encrypt the random data */
-
- if(RSA_public_encrypt(len, cl->hischallenge, buffer, cl->rsa_key, RSA_NO_PADDING) != len) /* NO_PADDING because the message size equals the RSA key size and it is totally random */
- {
- syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname);
- free(buffer);
- return -1;
- }
-cp
- /* Convert the encrypted random data to a hexadecimal formatted string */
-
- bin2hex(buffer, buffer, len);
+ bin2hex(cl->hischallenge, buffer, len);
buffer[len*2] = '\0';
+
cp
/* Send the challenge */
- cl->allow_request = CHAL_REPLY;
x = send_request(cl, "%d %s", CHALLENGE, buffer);
free(buffer);
cp
/* Convert the challenge from hexadecimal back to binary */
- hex2bin(buffer,buffer,len);
+ hex2bin(buffer,cl->mychallenge,len);
- /* Decrypt the challenge */
-
- if(RSA_private_decrypt(len, buffer, cl->mychallenge, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */
- {
- syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(cl->mychallenge, buffer, len);
- buffer[len*2] = '\0';
- syslog(LOG_DEBUG, _("Received random challenge (unencrypted): %s"), buffer);
- }
+ cl->allow_request = CHAL_REPLY;
/* Rest is done by send_chal_reply() */
cp
/* Send the reply */
- if(cl->status.outgoing)
- cl->allow_request = ID;
- else
- cl->allow_request = METAKEY;
-
cp
return send_request(cl, "%d %s", CHAL_REPLY, hash);
}
return -1;
}
-
/* Identity has now been positively verified.
- If we are accepting this new connection, then send our identity,
- if we are making this connecting, acknowledge.
+ ack_h() handles the rest from now on.
*/
cp
- if(cl->status.outgoing)
- return send_metakey(cl);
- else
- return send_id(cl);
+ return ack_h(cl);
}
int send_metakey(connection_t *cl)
RAND_bytes(cl->cipher_outkey, len);
- cl->cipher_outkey[0] &= 0x7F; /* FIXME: Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
-
+ cl->cipher_outkey[0] &= 0x0F; /* Make sure that the random data is smaller than the modulus of the RSA key */
+
if(debug_lvl >= DEBUG_SCARY_THINGS)
{
bin2hex(cl->cipher_outkey, buffer, len);
/* Send the meta key */
- if(cl->status.outgoing)
- cl->allow_request = METAKEY;
- else
- cl->allow_request = ACK;
-
x = send_request(cl, "%d %s", METAKEY, buffer);
free(buffer);
- EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(), cl->cipher_outkey, cl->cipher_outkey + EVP_bf_cfb()->key_len);
+ /* Further outgoing requests are encrypted with the key we just generated */
+
+ EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(),
+ cl->cipher_outkey + len - EVP_bf_cfb()->key_len,
+ cl->cipher_outkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len);
+
+ cl->status.encryptout = 1;
cp
return x;
}
syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer);
}
- EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), cl->cipher_inkey, cl->cipher_inkey + EVP_bf_cfb()->key_len);
-
-cp
- if(cl->status.outgoing)
- return send_ack(cl);
- else
- return send_metakey(cl);
-}
+ /* All incoming requests will now be encrypted. */
-int send_ack(connection_t *cl)
-{
- int x;
-cp
- if(cl->status.outgoing)
- cl->allow_request = ACK;
+ EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(),
+ cl->cipher_inkey + len - EVP_bf_cfb()->key_len,
+ cl->cipher_inkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len);
+
+ cl->status.decryptin = 1;
- x = send_request(cl, "%d", ACK);
- cl->status.encryptout = 1;
+ cl->allow_request = CHALLENGE;
cp
- return x;
+ return send_challenge(cl);
}
int ack_h(connection_t *cl)
cl->allow_request = ALL;
cl->status.active = 1;
- cl->status.decryptin = 1;
cl->nexthop = cl;
cl->cipher_pkttype = EVP_bf_cbc();
cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname);
cp
- if(!cl->status.outgoing)
- send_ack(cl);
-
/* Check some options */
if((cfg = get_config_val(cl->config, config_indirectdata)))
/* Jumptable for the request handlers */
int (*request_handlers[])(connection_t*) = {
- id_h, challenge_h, chal_reply_h, metakey_h, ack_h,
+ id_h, metakey_h, challenge_h, chal_reply_h,
status_h, error_h, termreq_h,
ping_h, pong_h,
add_host_h, del_host_h,
/* Request names */
char (*request_name[]) = {
- "ID", "CHALLENGE", "CHAL_REPLY", "METAKEY", "ACK",
+ "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY",
"STATUS", "ERROR", "TERMREQ",
"PING", "PONG",
"ADD_HOST", "DEL_HOST",
projects / tinc / blobdiff