Imported gnutls based branch.
[tinc] / src / protocol_auth.c
index 1b8794d..497d43f 100644 (file)
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: protocol_auth.c,v 1.1.4.23 2003/07/12 17:41:47 guus Exp $
+    $Id: protocol_auth.c,v 1.1.4.34 2003/12/22 11:04:16 guus Exp $
 */
 
-#include "config.h"
-
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <stdarg.h>
-#include <errno.h>
-
-#include <utils.h>
-#include <xalloc.h>
-#include <avl_tree.h>
+#include "system.h"
 
-#include <openssl/sha.h>
-#include <openssl/rand.h>
-#include <openssl/evp.h>
+#include <gnutls/gnutls.h>
+#include <gnutls/x509.h>
 
+#include "avl_tree.h"
 #include "conf.h"
-#include "net.h"
-#include "netutl.h"
-#include "protocol.h"
-#include "meta.h"
 #include "connection.h"
-#include "node.h"
 #include "edge.h"
 #include "graph.h"
 #include "logger.h"
+#include "net.h"
+#include "netutl.h"
+#include "node.h"
+#include "protocol.h"
+#include "utils.h"
+#include "xalloc.h"
 
-#include "system.h"
-
-int send_id(connection_t *c)
-{
-       cp();
-
-       return send_request(c, "%d %s %d", ID, myself->connection->name,
-                                               myself->connection->protocol_version);
-}
-
-int id_h(connection_t *c)
+bool send_ack(connection_t *c)
 {
-       char name[MAX_STRING_SIZE];
-       int bla;
+       char buf[MAX_STRING_SIZE];
+       size_t len;
+       gnutls_x509_crt cert;
+       const gnutls_datum *cert_list;
+       int cert_list_size = 0, result;
+       char *p, *name;
+
+       cert_list = gnutls_certificate_get_peers(c->session, &cert_list_size);
+
+       if (!cert_list || !cert_list_size) {
+               logger(LOG_ERR, _("No certificates from %s"), c->hostname);
+               return false;
+       }
 
-       cp();
+       len = sizeof buf;
+       gnutls_x509_crt_init(&cert);
+       result = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER)
+               ?: gnutls_x509_crt_get_dn(cert, buf, &len);
 
-       if(sscanf(c->buffer, "%*d " MAX_STRING " %d", name, &c->protocol_version) != 2) {
-               logger(LOG_ERR, _("Got bad %s from %s (%s)"), "ID", c->name,
-                          c->hostname);
-               return -1;
+       if(result) {
+               logger(LOG_ERR, _("Error importing certificate from %s: %s"), c->hostname, gnutls_strerror(errno));
+               gnutls_x509_crt_deinit(cert);
+               return false;
        }
 
-       /* Check if identity is a valid name */
-
-       if(check_id(name)) {
-               logger(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ID", c->name,
-                          c->hostname, "invalid name");
-               return -1;
+       name = strstr(buf, "CN=");
+       if(!name) {
+               logger(LOG_ERR, _("No name in certificate from %s"), c->hostname);
+               gnutls_x509_crt_deinit(cert);
+               return false;
        }
+       name += 3;
+       for(p = name; *p && *p != ','; p++);
+       *p = '\0';
 
-       /* If we set c->name in advance, make sure we are connected to the right host */
+       if(!check_id(name)) {
+               logger(LOG_ERR, _("Invalid name from %s"), c->hostname);
+               return false;
+       }
 
        if(c->name) {
                if(strcmp(c->name, name)) {
-                       logger(LOG_ERR, _("Peer %s is %s instead of %s"), c->hostname, name,
-                                  c->name);
-                       return -1;
+                       logger(LOG_ERR, _("Peer %s is %s instead of %s"), c->hostname, name, c->hostname);
+                       return false;
                }
-       } else
+       } else {
                c->name = xstrdup(name);
-
-       /* Check if version matches */
-
-       if(c->protocol_version != myself->connection->protocol_version) {
-               logger(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"),
-                          c->name, c->hostname, c->protocol_version);
-               return -1;
        }
-
-       if(bypass_security) {
-               if(!c->config_tree)
-                       init_configuration(&c->config_tree);
-               c->allow_request = ACK;
-               return send_ack(c);
+       
+       result = gnutls_certificate_verify_peers(c->session);
+
+       if(result) {
+               if(result & GNUTLS_CERT_INVALID)
+                       logger(LOG_ERR, _("Certificate from %s (%s) invalid"), c->name, c->hostname);
+               if(result & GNUTLS_CERT_REVOKED)
+                       logger(LOG_ERR, _("Certificate from %s (%s) revoked"), c->name, c->hostname);
+               if(result & GNUTLS_CERT_SIGNER_NOT_FOUND)
+                       logger(LOG_ERR, _("Certificate from %s (%s) has no known signer"), c->name, c->hostname);
+               if(result & GNUTLS_CERT_SIGNER_NOT_CA)
+                       logger(LOG_ERR, _("Certificate from %s (%s) has no CA as signer"), c->name, c->hostname);
        }
-
+       
        if(!c->config_tree) {
                init_configuration(&c->config_tree);
 
-               bla = read_connection_config(c);
-
-               if(bla) {
+               if(!read_connection_config(c)) {
                        logger(LOG_ERR, _("Peer %s had unknown identity (%s)"), c->hostname,
                                   c->name);
-                       return -1;
-               }
-       }
-
-       if(read_rsa_public_key(c)) {
-               return -1;
-       }
-
-       /* Check some options */
-
-       if((get_config_bool(lookup_config(c->config_tree, "IndirectData"), &bla) && bla) || myself->options & OPTION_INDIRECT)
-               c->options |= OPTION_INDIRECT;
-
-       if((get_config_bool(lookup_config(c->config_tree, "TCPOnly"), &bla) && bla) || myself->options & OPTION_TCPONLY)
-               c->options |= OPTION_TCPONLY | OPTION_INDIRECT;
-
-       c->allow_request = METAKEY;
-
-       return send_metakey(c);
-}
-
-int send_metakey(connection_t *c)
-{
-       char buffer[MAX_STRING_SIZE];
-       int len, x;
-
-       cp();
-
-       len = RSA_size(c->rsa_key);
-
-       /* Allocate buffers for the meta key */
-
-       if(!c->outkey)
-               c->outkey = xmalloc(len);
-
-       if(!c->outctx)
-               c->outctx = xmalloc_and_zero(sizeof(*c->outctx));
-       cp();
-       /* Copy random data to the buffer */
-
-       RAND_bytes(c->outkey, len);
-
-       /* The message we send must be smaller than the modulus of the RSA key.
-          By definition, for a key of k bits, the following formula holds:
-
-          2^(k-1) <= modulus < 2^(k)
-
-          Where ^ means "to the power of", not "xor".
-          This means that to be sure, we must choose our message < 2^(k-1).
-          This can be done by setting the most significant bit to zero.
-        */
-
-       c->outkey[0] &= 0x7F;
-
-       ifdebug(SCARY_THINGS) {
-               bin2hex(c->outkey, buffer, len);
-               buffer[len * 2] = '\0';
-               logger(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"),
-                          buffer);
-       }
-
-       /* Encrypt the random data
-
-          We do not use one of the PKCS padding schemes here.
-          This is allowed, because we encrypt a totally random string
-          with a length equal to that of the modulus of the RSA key.
-        */
-
-       if(RSA_public_encrypt(len, c->outkey, buffer, c->rsa_key, RSA_NO_PADDING) != len) {
-               logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"),
-                          c->name, c->hostname);
-               return -1;
-       }
-
-       /* Convert the encrypted random data to a hexadecimal formatted string */
-
-       bin2hex(buffer, buffer, len);
-       buffer[len * 2] = '\0';
-
-       /* Send the meta key */
-
-       x = send_request(c, "%d %d %d %d %d %s", METAKEY,
-                                        c->outcipher ? c->outcipher->nid : 0,
-                                        c->outdigest ? c->outdigest->type : 0, c->outmaclength,
-                                        c->outcompression, buffer);
-
-       /* Further outgoing requests are encrypted with the key we just generated */
-
-       if(c->outcipher) {
-               EVP_EncryptInit(c->outctx, c->outcipher,
-                                               c->outkey + len - c->outcipher->key_len,
-                                               c->outkey + len - c->outcipher->key_len -
-                                               c->outcipher->iv_len);
-
-               c->status.encryptout = 1;
-       }
-
-       return x;
-}
-
-int metakey_h(connection_t *c)
-{
-       char buffer[MAX_STRING_SIZE];
-       int cipher, digest, maclength, compression;
-       int len;
-
-       cp();
-
-       if(sscanf(c->buffer, "%*d %d %d %d %d " MAX_STRING, &cipher, &digest, &maclength, &compression, buffer) != 5) {
-               logger(LOG_ERR, _("Got bad %s from %s (%s)"), "METAKEY", c->name,
-                          c->hostname);
-               return -1;
-       }
-
-       len = RSA_size(myself->connection->rsa_key);
-
-       /* Check if the length of the meta key is all right */
-
-       if(strlen(buffer) != len * 2) {
-               logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong keylength");
-               return -1;
-       }
-
-       /* Allocate buffers for the meta key */
-
-       if(!c->inkey)
-               c->inkey = xmalloc(len);
-
-       if(!c->inctx)
-               c->inctx = xmalloc_and_zero(sizeof(*c->inctx));
-
-       /* Convert the challenge from hexadecimal back to binary */
-
-       hex2bin(buffer, buffer, len);
-
-       /* Decrypt the meta key */
-
-       if(RSA_private_decrypt(len, buffer, c->inkey, myself->connection->rsa_key, RSA_NO_PADDING) != len) {    /* See challenge() */
-               logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"),
-                          c->name, c->hostname);
-               return -1;
-       }
-
-       ifdebug(SCARY_THINGS) {
-               bin2hex(c->inkey, buffer, len);
-               buffer[len * 2] = '\0';
-               logger(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer);
-       }
-
-       /* All incoming requests will now be encrypted. */
-
-       /* Check and lookup cipher and digest algorithms */
-
-       if(cipher) {
-               c->incipher = EVP_get_cipherbynid(cipher);
-               
-               if(!c->incipher) {
-                       logger(LOG_ERR, _("%s (%s) uses unknown cipher!"), c->name, c->hostname);
-                       return -1;
-               }
-
-               EVP_DecryptInit(c->inctx, c->incipher,
-                                               c->inkey + len - c->incipher->key_len,
-                                               c->inkey + len - c->incipher->key_len -
-                                               c->incipher->iv_len);
-
-               c->status.decryptin = 1;
-       } else {
-               c->incipher = NULL;
-       }
-
-       c->inmaclength = maclength;
-
-       if(digest) {
-               c->indigest = EVP_get_digestbynid(digest);
-
-               if(!c->indigest) {
-                       logger(LOG_ERR, _("Node %s (%s) uses unknown digest!"), c->name, c->hostname);
-                       return -1;
+                       return false;
                }
-
-               if(c->inmaclength > c->indigest->md_size || c->inmaclength < 0) {
-                       logger(LOG_ERR, _("%s (%s) uses bogus MAC length!"), c->name, c->hostname);
-                       return -1;
-               }
-       } else {
-               c->indigest = NULL;
-       }
-
-       c->incompression = compression;
-
-       c->allow_request = CHALLENGE;
-
-       return send_challenge(c);
-}
-
-int send_challenge(connection_t *c)
-{
-       char buffer[MAX_STRING_SIZE];
-       int len, x;
-
-       cp();
-
-       /* CHECKME: what is most reasonable value for len? */
-
-       len = RSA_size(c->rsa_key);
-
-       /* Allocate buffers for the challenge */
-
-       if(!c->hischallenge)
-               c->hischallenge = xmalloc(len);
-
-       /* Copy random data to the buffer */
-
-       RAND_bytes(c->hischallenge, len);
-
-       /* Convert to hex */
-
-       bin2hex(c->hischallenge, buffer, len);
-       buffer[len * 2] = '\0';
-
-       /* Send the challenge */
-
-       x = send_request(c, "%d %s", CHALLENGE, buffer);
-
-       return x;
-}
-
-int challenge_h(connection_t *c)
-{
-       char buffer[MAX_STRING_SIZE];
-       int len;
-
-       cp();
-
-       if(sscanf(c->buffer, "%*d " MAX_STRING, buffer) != 1) {
-               logger(LOG_ERR, _("Got bad %s from %s (%s)"), "CHALLENGE", c->name,
-                          c->hostname);
-               return -1;
        }
 
-       len = RSA_size(myself->connection->rsa_key);
-
-       /* Check if the length of the challenge is all right */
-
-       if(strlen(buffer) != len * 2) {
-               logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name,
-                          c->hostname, "wrong challenge length");
-               return -1;
-       }
-
-       /* Allocate buffers for the challenge */
-
-       if(!c->mychallenge)
-               c->mychallenge = xmalloc(len);
-
-       /* Convert the challenge from hexadecimal back to binary */
-
-       hex2bin(buffer, c->mychallenge, len);
-
-       c->allow_request = CHAL_REPLY;
-
-       /* Rest is done by send_chal_reply() */
-
-       return send_chal_reply(c);
-}
-
-int send_chal_reply(connection_t *c)
-{
-       char hash[EVP_MAX_MD_SIZE * 2 + 1];
-       EVP_MD_CTX ctx;
-
-       cp();
-
-       /* Calculate the hash from the challenge we received */
-
-       EVP_DigestInit(&ctx, c->indigest);
-       EVP_DigestUpdate(&ctx, c->mychallenge,
-                                        RSA_size(myself->connection->rsa_key));
-       EVP_DigestFinal(&ctx, hash, NULL);
-
-       /* Convert the hash to a hexadecimal formatted string */
-
-       bin2hex(hash, hash, c->indigest->md_size);
-       hash[c->indigest->md_size * 2] = '\0';
-
-       /* Send the reply */
-
-       return send_request(c, "%d %s", CHAL_REPLY, hash);
-}
-
-int chal_reply_h(connection_t *c)
-{
-       char hishash[MAX_STRING_SIZE];
-       char myhash[EVP_MAX_MD_SIZE];
-       EVP_MD_CTX ctx;
-
-       cp();
-
-       if(sscanf(c->buffer, "%*d " MAX_STRING, hishash) != 1) {
-               logger(LOG_ERR, _("Got bad %s from %s (%s)"), "CHAL_REPLY", c->name,
-                          c->hostname);
-               return -1;
-       }
-
-       /* Check if the length of the hash is all right */
-
-       if(strlen(hishash) != c->outdigest->md_size * 2) {
-               logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name,
-                          c->hostname, _("wrong challenge reply length"));
-               return -1;
-       }
-
-       /* Convert the hash to binary format */
-
-       hex2bin(hishash, hishash, c->outdigest->md_size);
-
-       /* Calculate the hash from the challenge we sent */
-
-       EVP_DigestInit(&ctx, c->outdigest);
-       EVP_DigestUpdate(&ctx, c->hischallenge, RSA_size(c->rsa_key));
-       EVP_DigestFinal(&ctx, myhash, NULL);
-
-       /* Verify the incoming hash with the calculated hash */
-
-       if(memcmp(hishash, myhash, c->outdigest->md_size)) {
-               logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name,
-                          c->hostname, _("wrong challenge reply"));
-
-               ifdebug(SCARY_THINGS) {
-                       bin2hex(myhash, hishash, SHA_DIGEST_LENGTH);
-                       hishash[SHA_DIGEST_LENGTH * 2] = '\0';
-                       logger(LOG_DEBUG, _("Expected challenge reply: %s"), hishash);
-               }
-
-               return -1;
-       }
-
-       /* Identity has now been positively verified.
-          Send an acknowledgement with the rest of the information needed.
-        */
-
-       c->allow_request = ACK;
-
-       return send_ack(c);
-}
-
-int send_ack(connection_t *c)
-{
        /* ACK message contains rest of the information the other end needs
           to create node_t and edge_t structures. */
 
-       int x;
        struct timeval now;
+       bool choice;
 
        cp();
 
        /* Estimate weight */
 
        gettimeofday(&now, NULL);
-       c->estimated_weight =
-               (now.tv_sec - c->start.tv_sec) * 1000 + (now.tv_usec -
-                                                                                                c->start.tv_usec) / 1000;
-       x = send_request(c, "%d %s %d %lx", ACK, myport, c->estimated_weight,
-                                        c->options);
+       c->estimated_weight = (now.tv_sec - c->start.tv_sec) * 1000 + (now.tv_usec - c->start.tv_usec) / 1000;
+
+       /* Check some options */
+
+       if((get_config_bool(lookup_config(c->config_tree, "IndirectData"), &choice) && choice) || myself->options & OPTION_INDIRECT)
+               c->options |= OPTION_INDIRECT;
+
+       if((get_config_bool(lookup_config(c->config_tree, "TCPOnly"), &choice) && choice) || myself->options & OPTION_TCPONLY)
+               c->options |= OPTION_TCPONLY | OPTION_INDIRECT;
 
-       return x;
+       if((get_config_bool(lookup_config(c->config_tree, "PMTUDiscovery"), &choice) && choice) || myself->options & OPTION_PMTU_DISCOVERY)
+               c->options |= OPTION_PMTU_DISCOVERY;
+
+       get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight);
+
+       return send_request(c, "%d %s %d %lx", ACK, myport, c->estimated_weight, c->options);
 }
 
 static void send_everything(connection_t *c)
@@ -490,26 +150,35 @@ static void send_everything(connection_t *c)
 
        /* Send all known subnets and edges */
 
+       if(tunnelserver) {
+               for(node = myself->subnet_tree->head; node; node = node->next) {
+                       s = node->data;
+                       send_add_subnet(c, s);
+               }
+
+               return;
+       }
+
        for(node = node_tree->head; node; node = node->next) {
-               n = (node_t *) node->data;
+               n = node->data;
 
                for(node2 = n->subnet_tree->head; node2; node2 = node2->next) {
-                       s = (subnet_t *) node2->data;
+                       s = node2->data;
                        send_add_subnet(c, s);
                }
 
                for(node2 = n->edge_tree->head; node2; node2 = node2->next) {
-                       e = (edge_t *) node2->data;
+                       e = node2->data;
                        send_add_edge(c, e);
                }
        }
 }
 
-int ack_h(connection_t *c)
+bool ack_h(connection_t *c)
 {
        char hisport[MAX_STRING_SIZE];
        char *hisaddress, *dummy;
-       int weight;
+       int weight, mtu;
        long int options;
        node_t *n;
 
@@ -518,7 +187,7 @@ int ack_h(connection_t *c)
        if(sscanf(c->buffer, "%*d " MAX_STRING " %d %lx", hisport, &weight, &options) != 3) {
                logger(LOG_ERR, _("Got bad %s from %s (%s)"), "ACK", c->name,
                           c->hostname);
-               return -1;
+               return false;
        }
 
        /* Check if we already have a node_t for him */
@@ -534,7 +203,7 @@ int ack_h(connection_t *c)
                        /* Oh dear, we already have a connection to this node. */
                        ifdebug(CONNECTIONS) logger(LOG_DEBUG, _("Established a second connection with %s (%s), closing old connection"),
                                           n->name, n->hostname);
-                       terminate_connection(n->connection, 0);
+                       terminate_connection(n->connection, false);
                        /* Run graph algorithm to purge key and make sure up/down scripts are rerun with new IP addresses and stuff */
                        graph();
                }
@@ -544,10 +213,16 @@ int ack_h(connection_t *c)
        c->node = n;
        c->options |= options;
 
+       if(get_config_int(lookup_config(c->config_tree, "PMTU"), &mtu) && mtu < n->mtu)
+               n->mtu = mtu;
+
+       if(get_config_int(lookup_config(myself->connection->config_tree, "PMTU"), &mtu) && mtu < n->mtu)
+               n->mtu = mtu;
+
        /* Activate this connection */
 
        c->allow_request = ALL;
-       c->status.active = 1;
+       c->status.active = true;
 
        ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection with %s (%s) activated"), c->name,
                           c->hostname);
@@ -574,11 +249,14 @@ int ack_h(connection_t *c)
 
        /* Notify everyone of the new edge */
 
-       send_add_edge(broadcast, c->edge);
+       if(tunnelserver)
+               send_add_edge(c, c->edge);
+       else
+               send_add_edge(broadcast, c->edge);
 
        /* Run MST and SSSP algorithms */
 
        graph();
 
-       return 0;
+       return true;
 }