/* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */ /* See LICENSE for licensing information */ /* $Id$ */ #include "or.h" extern or_options_t options; /* command-line and config-file options */ #ifndef USE_TLS static int or_handshake_op_send_keys(connection_t *conn); static int or_handshake_op_finished_sending_keys(connection_t *conn); static int or_handshake_client_process_auth(connection_t *conn); static int or_handshake_client_send_auth(connection_t *conn); static int or_handshake_server_process_auth(connection_t *conn); static int or_handshake_server_process_nonce(connection_t *conn); static void conn_or_init_crypto(connection_t *conn); #endif static void connection_or_set_open(connection_t *conn); /* * * these two functions are the main ways 'in' to connection_or * */ int connection_or_process_inbuf(connection_t *conn) { assert(conn && conn->type == CONN_TYPE_OR); if(conn->inbuf_reached_eof) { log_fn(LOG_DEBUG,"conn reached eof. Closing."); return -1; } #ifdef USE_TLS assert(conn->state == OR_CONN_STATE_OPEN); return connection_process_cell_from_inbuf(conn); #else // log(LOG_DEBUG,"connection_or_process_inbuf(): state %d.",conn->state); switch(conn->state) { case OR_CONN_STATE_CLIENT_AUTH_WAIT: return or_handshake_client_process_auth(conn); case OR_CONN_STATE_SERVER_AUTH_WAIT: return or_handshake_server_process_auth(conn); case OR_CONN_STATE_SERVER_NONCE_WAIT: return or_handshake_server_process_nonce(conn); case OR_CONN_STATE_OPEN: return connection_process_cell_from_inbuf(conn); default: log_fn(LOG_DEBUG,"called in state where I'm writing. Ignoring buf for now."); } return 0; #endif } int connection_or_finished_flushing(connection_t *conn) { int e, len=sizeof(e); assert(conn && conn->type == CONN_TYPE_OR); switch(conn->state) { #ifndef USE_TLS case OR_CONN_STATE_OP_SENDING_KEYS: return or_handshake_op_finished_sending_keys(conn); case OR_CONN_STATE_CLIENT_CONNECTING: #else case OR_CONN_STATE_CONNECTING: #endif if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, (void*)&e, &len) < 0) { /* not yet */ if(!ERRNO_CONN_EINPROGRESS(errno)){ /* yuck. kill it. */ log_fn(LOG_DEBUG,"in-progress connect failed. Removing."); return -1; } else { return 0; /* no change, see if next time is better */ } } /* the connect has finished. */ log_fn(LOG_DEBUG,"OR connection to router %s:%u established.", conn->address,conn->port); #ifdef USE_TLS call TLS new, and start the TLS handshake #else if(options.OnionRouter) return or_handshake_client_send_auth(conn); else return or_handshake_op_send_keys(conn); case OR_CONN_STATE_CLIENT_SENDING_AUTH: log_fn(LOG_DEBUG,"client finished sending auth."); conn->state = OR_CONN_STATE_CLIENT_AUTH_WAIT; connection_watch_events(conn, POLLIN); return 0; case OR_CONN_STATE_CLIENT_SENDING_NONCE: log_fn(LOG_DEBUG,"client finished sending nonce."); conn_or_init_crypto(conn); connection_or_set_open(conn); return connection_process_inbuf(conn); /* in case there's anything waiting on it */ case OR_CONN_STATE_SERVER_SENDING_AUTH: log_fn(LOG_DEBUG,"server finished sending auth."); conn->state = OR_CONN_STATE_SERVER_NONCE_WAIT; connection_watch_events(conn, POLLIN); return 0; #endif case OR_CONN_STATE_OPEN: connection_stop_writing(conn); return 0; default: log_fn(LOG_ERR,"BUG: called in unexpected state."); return 0; } } /*********************/ connection_t *connection_or_connect(routerinfo_t *router) { connection_t *conn; struct sockaddr_in router_addr; int s; assert(router); if(router_is_me(router->addr, router->or_port)) { /* this is me! don't connect to me. */ log(LOG_DEBUG,"connection_or_connect(): This is me. Skipping."); return NULL; } /* this function should never be called if we're already connected to router, but */ /* check first to be sure */ conn = connection_exact_get_by_addr_port(router->addr,router->or_port); if(conn) return conn; conn = connection_new(CONN_TYPE_OR); if(!conn) { return NULL; } /* set up conn so it's got all the data we need to remember */ conn->addr = router->addr; conn->port = router->or_port; conn->bandwidth = router->bandwidth; conn->pkey = crypto_pk_dup_key(router->pkey); conn->address = strdup(router->address); s=socket(PF_INET,SOCK_STREAM,IPPROTO_TCP); if (s < 0) { log(LOG_ERR,"Error creating network socket."); connection_free(conn); return NULL; } set_socket_nonblocking(s); memset((void *)&router_addr,0,sizeof(router_addr)); router_addr.sin_family = AF_INET; router_addr.sin_port = htons(router->or_port); router_addr.sin_addr.s_addr = htonl(router->addr); log(LOG_DEBUG,"connection_or_connect() : Trying to connect to %s:%u.",router->address,router->or_port); if(connect(s,(struct sockaddr *)&router_addr,sizeof(router_addr)) < 0){ if(!ERRNO_CONN_EINPROGRESS(errno)) { /* yuck. kill it. */ connection_free(conn); return NULL; } else { /* it's in progress. set state appropriately and return. */ conn->s = s; if(connection_add(conn) < 0) { /* no space, forget it */ connection_free(conn); return NULL; } log(LOG_DEBUG,"connection_or_connect() : connect in progress."); connection_watch_events(conn, POLLIN | POLLOUT | POLLERR); /* writable indicates finish, readable indicates broken link, error indicates broken link on windows */ conn->state = OR_CONN_STATE_CLIENT_CONNECTING; return conn; } } /* it succeeded. we're connected. */ conn->s = s; if(connection_add(conn) < 0) { /* no space, forget it */ connection_free(conn); return NULL; } log(LOG_DEBUG,"connection_or_connect() : Connection to router %s:%u established.", router->address, router->or_port); if((options.OnionRouter && or_handshake_client_send_auth(conn) >= 0) || (!options.OnionRouter && or_handshake_op_send_keys(conn) >= 0)) return conn; /* success! */ /* failure */ connection_remove(conn); connection_free(conn); return NULL; } /* ********************************** */ int connection_or_create_listener(struct sockaddr_in *bindaddr) { log(LOG_DEBUG,"connection_create_or_listener starting"); return connection_create_listener(bindaddr, CONN_TYPE_OR_LISTENER); } int connection_or_handle_listener_read(connection_t *conn) { log(LOG_NOTICE,"OR: Received a connection request. Attempting to authenticate."); return connection_handle_listener_read(conn, CONN_TYPE_OR, OR_CONN_STATE_SERVER_AUTH_WAIT); } /* ***************** */ /* Helper functions to implement handshaking */ #define FLAGS_LEN 2 #define KEY_LEN 16 #define ADDR_LEN 4 #define PORT_LEN 2 #define PKEY_LEN 128 static int or_handshake_op_send_keys(connection_t *conn) { unsigned char message[FLAGS_LEN + KEY_LEN + KEY_LEN]; unsigned char cipher[PKEY_LEN]; int retval; assert(conn && conn->type == CONN_TYPE_OR); conn->bandwidth = DEFAULT_BANDWIDTH_OP; /* generate random keys */ if(crypto_cipher_generate_key(conn->f_crypto) || crypto_cipher_generate_key(conn->b_crypto)) { log(LOG_ERR,"Cannot generate a secure symmetric key."); return -1; } log(LOG_DEBUG,"or_handshake_op_send_keys() : Generated symmetric keys."); /* compose the message */ *(uint16_t *)(message) = htons(HANDSHAKE_AS_OP); memcpy((void *)(message+FLAGS_LEN), (void *)conn->f_crypto->key, 16); memcpy((void *)(message+FLAGS_LEN+KEY_LEN), (void *)conn->b_crypto->key, 16); /* encrypt with RSA */ if(crypto_pk_public_encrypt(conn->pkey, message, sizeof(message), cipher, RSA_PKCS1_PADDING) < 0) { log(LOG_ERR,"or_handshake_op_send_keys(): Public key encryption failed."); return -1; } log(LOG_DEBUG,"or_handshake_op_send_keys() : Encrypted authentication message."); /* send message */ if(connection_write_to_buf(cipher, PKEY_LEN, conn) < 0) { log(LOG_DEBUG,"or_handshake_op_send_keys(): my outbuf is full. Oops."); return -1; } retval = connection_flush_buf(conn); if(retval < 0) { log(LOG_DEBUG,"or_handshake_op_send_keys(): bad socket while flushing."); return -1; } if(retval > 0) { /* still stuff on the buffer. */ conn->state = OR_CONN_STATE_OP_SENDING_KEYS; connection_watch_events(conn, POLLOUT | POLLIN); return 0; } /* it finished sending */ log(LOG_DEBUG,"or_handshake_op_send_keys(): Finished sending authentication message."); return or_handshake_op_finished_sending_keys(conn); } static int or_handshake_op_finished_sending_keys(connection_t *conn) { /* do crypto initialization, etc */ conn_or_init_crypto(conn); connection_or_set_open(conn); circuit_n_conn_open(conn); /* send the pending onion(s) */ return 0; } static int or_handshake_client_send_auth(connection_t *conn) { int retval; char buf[FLAGS_LEN+ADDR_LEN+PORT_LEN+ADDR_LEN+ PORT_LEN+KEY_LEN+KEY_LEN]; char cipher[PKEY_LEN]; struct sockaddr_in me; /* my router identity */ assert(conn); if(learn_my_address(&me) < 0) return -1; /* generate random keys */ if(crypto_cipher_generate_key(conn->f_crypto) || crypto_cipher_generate_key(conn->b_crypto)) { log(LOG_ERR,"Cannot generate a secure symmetric key."); return -1; } log(LOG_DEBUG,"or_handshake_client_send_auth() : Generated symmetric keys."); /* generate first message */ *(uint16_t*)buf = htons(HANDSHAKE_AS_OR); *(uint32_t*)(buf+FLAGS_LEN) = me.sin_addr.s_addr; /* local address, network order */ *(uint16_t*)(buf+FLAGS_LEN+ADDR_LEN) = me.sin_port; /* local port, network order */ *(uint32_t*)(buf+FLAGS_LEN+ADDR_LEN+PORT_LEN) = htonl(conn->addr); /* remote address */ *(uint16_t*)(buf+FLAGS_LEN+ADDR_LEN+PORT_LEN+ADDR_LEN) = htons(conn->port); /* remote port */ memcpy(buf+FLAGS_LEN+ADDR_LEN+PORT_LEN+ADDR_LEN+PORT_LEN, conn->f_crypto->key,16); /* keys */ memcpy(buf+FLAGS_LEN+ADDR_LEN+PORT_LEN+ADDR_LEN+PORT_LEN+KEY_LEN, conn->b_crypto->key,16); log(LOG_DEBUG,"or_handshake_client_send_auth() : Generated first authentication message."); /* encrypt message */ retval = crypto_pk_public_encrypt(conn->pkey, buf, sizeof(buf), cipher,RSA_PKCS1_PADDING); if (retval == -1) /* error */ { log(LOG_ERR,"Public-key encryption failed during authentication to %s:%u.",conn->address,conn->port); log(LOG_DEBUG,"or_handshake_client_send_auth() : Reason : %s.",crypto_perror()); return -1; } log(LOG_DEBUG,"or_handshake_client_send_auth() : Encrypted authentication message."); /* send message */ if(connection_write_to_buf(cipher, PKEY_LEN, conn) < 0) { log(LOG_DEBUG,"or_handshake_client_send_auth(): my outbuf is full. Oops."); return -1; } retval = connection_flush_buf(conn); if(retval < 0) { log(LOG_DEBUG,"or_handshake_client_send_auth(): bad socket while flushing."); return -1; } if(retval > 0) { /* still stuff on the buffer. */ conn->state = OR_CONN_STATE_CLIENT_SENDING_AUTH; connection_watch_events(conn, POLLOUT | POLLIN); return 0; } /* it finished sending */ log(LOG_DEBUG,"or_handshake_client_send_auth(): Finished sending authentication message."); conn->state = OR_CONN_STATE_CLIENT_AUTH_WAIT; connection_watch_events(conn, POLLIN); return 0; } static int or_handshake_client_process_auth(connection_t *conn) { char buf[128]; /* only 52 of this is expected to be used */ char cipher[128]; int retval; struct sockaddr_in me; /* my router identity */ assert(conn); if(learn_my_address(&me) < 0) return -1; if(conn->inbuf_datalen < 128) /* entire response available? */ return 0; /* not yet */ connection_fetch_from_buf(cipher,128,conn); log(LOG_DEBUG,"or_handshake_client_process_auth() : Received auth."); /* decrypt response */ retval = crypto_pk_private_decrypt(get_privatekey(), cipher, 128, buf, RSA_PKCS1_PADDING); if (retval == -1) { log(LOG_ERR,"Public-key decryption failed during authentication to %s:%u.", conn->address,conn->port); log(LOG_DEBUG,"or_handshake_client_process_auth() : Reason : %s.", crypto_perror()); return -1; } else if (retval != 52) { log(LOG_ERR,"client_process_auth: incorrect response from router %s:%u.", conn->address,conn->port); return -1; } log(LOG_DEBUG,"or_handshake_client_process_auth() : Decrypted response."); /* check validity */ if ( (*(uint32_t*)buf != me.sin_addr.s_addr) || /* local address, network order */ (*(uint16_t*)(buf+4) != me.sin_port) || /* local port, network order */ (ntohl(*(uint32_t*)(buf+6)) != conn->addr) || /* remote address */ (ntohs(*(uint16_t*)(buf+10)) != conn->port) ) { /* remote port */ log(LOG_ERR,"client_process_auth: Router %s:%u: bad address info.", conn->address,conn->port); return -1; } if ( (memcmp(conn->f_crypto->key, buf+12, 16)) || /* keys */ (memcmp(conn->b_crypto->key, buf+28, 16)) ) { log(LOG_ERR,"client_process_auth: Router %s:%u: bad key info.",conn->address,conn->port); return -1; } log(LOG_DEBUG,"or_handshake_client_process_auth() : Response valid."); /* reply is just local addr/port, remote addr/port, nonce */ memcpy(buf+12, buf+44, 8); /* encrypt reply */ retval = crypto_pk_public_encrypt(conn->pkey, buf, 20, cipher,RSA_PKCS1_PADDING); if (retval == -1) /* error */ { log(LOG_ERR,"Public-key encryption failed during authentication to %s:%u.",conn->address,conn->port); log(LOG_DEBUG,"or_handshake_client_process_auth() : Reason : %s.",crypto_perror()); return -1; } /* send the message */ if(connection_write_to_buf(cipher, 128, conn) < 0) { log(LOG_DEBUG,"or_handshake_client_process_auth(): my outbuf is full. Oops."); return -1; } retval = connection_flush_buf(conn); if(retval < 0) { log(LOG_DEBUG,"or_handshake_client_process_auth(): bad socket while flushing."); return -1; } if(retval > 0) { /* still stuff on the buffer. */ conn->state = OR_CONN_STATE_CLIENT_SENDING_NONCE; connection_watch_events(conn, POLLOUT | POLLIN); /* return(connection_process_inbuf(conn)); process the rest of the inbuf */ return 0; } /* it finished sending */ log(LOG_DEBUG,"or_handshake_client_process_auth(): Finished sending nonce."); conn_or_init_crypto(conn); connection_or_set_open(conn); return connection_process_inbuf(conn); /* process the rest of the inbuf */ } /* * * auth handshake, as performed by OR *receiving* the connection * */ static int or_handshake_server_process_auth(connection_t *conn) { int retval; char buf[128]; /* 50 of this is expected to be used for OR, 38 for OP */ char cipher[128]; unsigned char iv[16]; uint32_t addr; uint16_t port; routerinfo_t *router; assert(conn); log(LOG_DEBUG,"or_handshake_server_process_auth() entered."); if(conn->inbuf_datalen < 128) /* entire response available? */ return 0; /* not yet */ connection_fetch_from_buf(cipher,128,conn); log(LOG_DEBUG,"or_handshake_server_process_auth() : Received auth."); /* decrypt response */ retval = crypto_pk_private_decrypt(get_privatekey(), cipher, 128, buf, RSA_PKCS1_PADDING); if (retval == -1) { log(LOG_ERR,"or_handshake_server_process_auth: Public-key decryption failed."); log(LOG_DEBUG,"or_handshake_server_process_auth() : Reason : %s.", crypto_perror()); return -1; } if (retval == 46) { log(LOG_DEBUG,"or_handshake_server_process_auth(): Decrypted OR-style auth message."); if(ntohs(*(uint16_t*)buf) != HANDSHAKE_AS_OR) { log(LOG_DEBUG,"or_handshake_server_process_auth(): ...but wasn't labelled OR. Dropping."); return -1; } /* identify the router */ addr = ntohl(*(uint32_t*)(buf+2)); /* save the IP address */ port = ntohs(*(uint16_t*)(buf+6)); /* save the port */ router = router_get_by_addr_port(addr,port); if (!router) { log(LOG_DEBUG,"or_handshake_server_process_auth() : unknown router '%s:%d'. Will drop.", conn->address, port); return -1; } log(LOG_DEBUG,"or_handshake_server_process_auth() : Router identified as %s:%u.", router->address,router->or_port); if(connection_exact_get_by_addr_port(addr,port)) { log(LOG_DEBUG,"or_handshake_server_process_auth(): That router is already connected. Dropping."); return -1; } /* save keys */ crypto_cipher_set_key(conn->b_crypto,buf+14); crypto_cipher_set_key(conn->f_crypto,buf+30); conn->bandwidth = router->bandwidth; /* copy all relevant info to conn */ conn->addr = router->addr, conn->port = router->or_port; conn->pkey = crypto_pk_dup_key(router->pkey); if(conn->address) free(conn->address); conn->address = strdup(router->address); /* generate a nonce */ retval = crypto_rand(8, conn->nonce); if (retval) { /* error */ log(LOG_ERR,"Cannot generate a nonce."); return -1; } log(LOG_DEBUG,"or_handshake_server_process_auth(): Nonce generated."); memmove(buf, buf+2, 44); memcpy(buf+44,conn->nonce,8); /* append the nonce to the end of the message */ /* encrypt message */ retval = crypto_pk_public_encrypt(conn->pkey, buf, 52, cipher,RSA_PKCS1_PADDING); if (retval == -1) { /* error */ log(LOG_ERR,"Public-key encryption failed during authentication to %s:%u.",conn->address,conn->port); log(LOG_DEBUG,"or_handshake_server_process_auth() : Reason : %s.",crypto_perror()); return -1; } log(LOG_DEBUG,"or_handshake_server_process_auth() : Reply encrypted."); /* send message */ if(connection_write_to_buf(cipher, 128, conn) < 0) { log(LOG_DEBUG,"or_handshake_server_process_auth(): my outbuf is full. Oops."); return -1; } retval = connection_flush_buf(conn); if(retval < 0) { log(LOG_DEBUG,"or_handshake_server_process_auth(): bad socket while flushing."); return -1; } if(retval > 0) { /* still stuff on the buffer. */ conn->state = OR_CONN_STATE_SERVER_SENDING_AUTH; connection_watch_events(conn, POLLOUT | POLLIN); return 0; } /* it finished sending */ log(LOG_DEBUG,"or_handshake_server_process_auth(): Finished sending auth."); conn->state = OR_CONN_STATE_SERVER_NONCE_WAIT; connection_watch_events(conn, POLLIN); return 0; } if(retval == 34) { log(LOG_DEBUG,"or_handshake_server_process_auth(): Decrypted OP-style auth message."); if(ntohs(*(uint16_t*)buf) != HANDSHAKE_AS_OP) { log(LOG_DEBUG,"or_handshake_server_process_auth(): ...but wasn't labelled OP. Dropping."); return -1; } crypto_cipher_set_key(conn->b_crypto, buf+2); crypto_cipher_set_key(conn->f_crypto, buf+18); memset(iv, 0, 16); crypto_cipher_set_iv(conn->b_crypto, iv); crypto_cipher_set_iv(conn->f_crypto, iv); crypto_cipher_encrypt_init_cipher(conn->b_crypto); crypto_cipher_decrypt_init_cipher(conn->f_crypto); conn->state = OR_CONN_STATE_OPEN; connection_watch_events(conn, POLLIN); return connection_process_inbuf(conn); /* in case they sent some cells along with the keys */ } log(LOG_ERR,"or_handshake_server_process_auth(): received an incorrect authentication request."); return -1; } static int or_handshake_server_process_nonce(connection_t *conn) { char buf[128]; char cipher[128]; int retval; struct sockaddr_in me; /* my router identity */ assert(conn); if(learn_my_address(&me) < 0) return -1; if(conn->inbuf_datalen < 128) /* entire response available? */ return 0; /* not yet */ connection_fetch_from_buf(cipher,128,conn); log(LOG_DEBUG,"or_handshake_server_process_nonce() : Received auth."); /* decrypt response */ retval = crypto_pk_private_decrypt(get_privatekey(), cipher, 128, buf,RSA_PKCS1_PADDING); if (retval == -1) { log(LOG_ERR,"Public-key decryption failed during authentication to %s:%u.", conn->address,conn->port); log(LOG_DEBUG,"or_handshake_server_process_nonce() : Reason : %s.", crypto_perror()); return -1; } else if (retval != 20) { log(LOG_ERR,"server_process_nonce: incorrect response from router %s:%u.", conn->address,conn->port); return -1; } log(LOG_DEBUG,"or_handshake_server_process_nonce() : Response decrypted."); /* check validity */ if ((ntohl(*(uint32_t*)buf) != conn->addr) || /* remote address */ (ntohs(*(uint16_t*)(buf+4)) != conn->port) || /* remote port */ (*(uint32_t*)(buf+6) != me.sin_addr.s_addr) || /* local address, network order */ (*(uint16_t*)(buf+10) != me.sin_port) || /* local port, network order */ (memcmp(conn->nonce,buf+12,8))) /* nonce */ { log(LOG_ERR,"server_process_nonce: Router %s:%u gave bad response.",conn->address,conn->port); return -1; } log(LOG_DEBUG,"or_handshake_server_process_nonce() : Response valid. Authentication complete."); conn_or_init_crypto(conn); connection_or_set_open(conn); return connection_process_inbuf(conn); /* process the rest of the inbuf */ } /*********************/ static void connection_or_set_open(connection_t *conn) { conn->state = OR_CONN_STATE_OPEN; directory_set_dirty(); connection_watch_events(conn, POLLIN); } #ifndef USE_TLS static void conn_or_init_crypto(connection_t *conn) { //int x; unsigned char iv[16]; assert(conn); memset((void *)iv, 0, 16); crypto_cipher_set_iv(conn->f_crypto, iv); crypto_cipher_set_iv(conn->b_crypto, iv); crypto_cipher_encrypt_init_cipher(conn->f_crypto); crypto_cipher_decrypt_init_cipher(conn->b_crypto); /* always encrypt with f, always decrypt with b */ } #endif /* Local Variables: mode:c indent-tabs-mode:nil c-basic-offset:2 End: */