/* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */ /* See LICENSE for licensing information */ /* $Id$ */ #include "or.h" /* * * 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) { /* eof reached, kill it. */ log(LOG_DEBUG,"connection_or_process_inbuf(): conn reached eof. Closing."); return -1; } // 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(LOG_DEBUG,"connection_or_process_inbuf() called in state where I'm writing. Ignoring buf for now."); } return 0; } int connection_or_finished_flushing(connection_t *conn) { int e, len=sizeof(e); assert(conn && conn->type == CONN_TYPE_OR); switch(conn->state) { case OR_CONN_STATE_OP_CONNECTING: if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, &e, &len) < 0) { /* not yet */ if(errno != EINPROGRESS){ /* yuck. kill it. */ log(LOG_DEBUG,"connection_or_finished_flushing(): in-progress connect failed. Removing."); return -1; } else { return 0; /* no change, see if next time is better */ } } /* the connect has finished. */ log(LOG_DEBUG,"connection_or_finished_flushing() : OP connection to router %s:%u established.", conn->address,conn->port); return or_handshake_op_send_keys(conn); case OR_CONN_STATE_OP_SENDING_KEYS: return or_handshake_op_finished_sending_keys(conn); case OR_CONN_STATE_CLIENT_CONNECTING: if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, &e, &len) < 0) { /* not yet */ if(errno != EINPROGRESS){ /* yuck. kill it. */ log(LOG_DEBUG,"connection_or_finished_flushing(): in-progress connect failed. Removing."); return -1; } else { return 0; /* no change, see if next time is better */ } } /* the connect has finished. */ log(LOG_DEBUG,"connection_or_finished_flushing() : OR connection to router %s:%u established.", conn->address,conn->port); return or_handshake_client_send_auth(conn); case OR_CONN_STATE_CLIENT_SENDING_AUTH: log(LOG_DEBUG,"connection_or_finished_flushing(): 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(LOG_DEBUG,"connection_or_finished_flushing(): 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(LOG_DEBUG,"connection_or_finished_flushing(): server finished sending auth."); conn->state = OR_CONN_STATE_SERVER_NONCE_WAIT; connection_watch_events(conn, POLLIN); return 0; case OR_CONN_STATE_OPEN: /* FIXME down the road, we'll clear out circuits that are pending to close */ connection_stop_writing(conn); return 0; default: log(LOG_DEBUG,"Bug: connection_or_finished_flushing() called in unexpected state."); return 0; } return 0; } /*********************/ void connection_or_set_open(connection_t *conn) { conn->state = OR_CONN_STATE_OPEN; directory_set_dirty(); connection_init_timeval(conn); connection_watch_events(conn, POLLIN); } void conn_or_init_crypto(connection_t *conn) { //int x; unsigned char iv[16]; assert(conn); #if 0 printf("f_session_key: "); for(x=0;x<8;x++) { printf("%d ",conn->f_crypto->key[x]); } printf("\nb_session_key: "); for(x=0;x<8;x++) { printf("%d ",conn->b_crypto->key[x]); } printf("\n"); #endif 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 */ } /* helper function for connection_or_connect_as_or and _as_op. * returns NULL if the connection fails. If it succeeds, it sets * *result to 1 if connect() returned before completing, or to 2 * if it completed, and returns the new conn. */ connection_t *connection_or_connect(routerinfo_t *router, uint16_t port, int *result) { connection_t *conn; struct sockaddr_in router_addr; int s; 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; /* NOTE we store or_port here always */ 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; } fcntl(s, F_SETFL, O_NONBLOCK); /* set s to non-blocking */ memset((void *)&router_addr,0,sizeof(router_addr)); router_addr.sin_family = AF_INET; router_addr.sin_port = htons(port); router_addr.sin_addr.s_addr = htonl(router->addr); log(LOG_DEBUG,"connection_or_connect() : Trying to connect to %s:%u.",router->address,port); if(connect(s,(struct sockaddr *)&router_addr,sizeof(router_addr)) < 0){ if(errno != EINPROGRESS){ /* 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); /* writable indicates finish, readable indicates broken link */ *result = 1; /* 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,port); *result = 2; /* connection finished */ return(conn); } /* * * handshake for connecting to the op_port of an onion router * */ connection_t *connection_or_connect_as_op(routerinfo_t *router) { connection_t *conn; int result=0; /* so connection_or_connect() can tell us what happened */ assert(router); if(router_is_me(router->addr, router->or_port)) { /* this is me! don't connect to me. */ log(LOG_WARNING,"connection_or_connect_as_op(): You just asked me to connect to myself."); 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_or_connect(router, router->op_port, &result); if(!conn) return NULL; assert(result != 0); /* if conn is defined, then it must have set result */ /* now we know it succeeded */ if(result == 1) { conn->state = OR_CONN_STATE_OP_CONNECTING; return conn; } if(result == 2) { /* move to the next step in the handshake */ if(or_handshake_op_send_keys(conn) < 0) { connection_remove(conn); connection_free(conn); return NULL; } return conn; } return NULL; /* shouldn't get here; to keep gcc happy */ } int or_handshake_op_send_keys(connection_t *conn) { unsigned char message[36]; /* bandwidth(32bits), forward key(128bits), backward key(128bits) */ unsigned char cipher[128]; 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 3DES key."); return -1; } log(LOG_DEBUG,"or_handshake_op_send_keys() : Generated 3DES keys."); /* compose the message */ *(uint32_t *)message = htonl(conn->bandwidth); memcpy((void *)(message + 4), (void *)conn->f_crypto->key, 16); memcpy((void *)(message + 20), (void *)conn->b_crypto->key, 16); #if 0 printf("f_session_key: "); for(x=0;x<16;x++) { printf("%d ",conn->f_crypto->key[x]); } printf("\nb_session_key: "); for(x=0;x<16;x++) { printf("%d ",conn->b_crypto->key[x]); } printf("\n"); #endif /* encrypt with RSA */ if(crypto_pk_public_encrypt(conn->pkey, message, 36, 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, 128, 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); } 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; } /* * * auth handshake, as performed by OR *initiating* the connection * */ connection_t *connection_or_connect_as_or(routerinfo_t *router) { connection_t *conn; int result=0; /* so connection_or_connect() can tell us what happened */ 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_as_or(): This is me. Skipping."); return NULL; } conn = connection_or_connect(router, router->or_port, &result); if(!conn) return NULL; /* now we know it succeeded */ if(result == 1) { conn->state = OR_CONN_STATE_CLIENT_CONNECTING; return conn; } if(result == 2) { /* move to the next step in the handshake */ if(or_handshake_client_send_auth(conn) < 0) { connection_remove(conn); connection_free(conn); return NULL; } return conn; } return NULL; /* shouldn't get here; to keep gcc happy */ } int or_handshake_client_send_auth(connection_t *conn) { int retval; char buf[48]; char cipher[128]; 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 DES key."); return -1; } log(LOG_DEBUG,"or_handshake_client_send_auth() : Generated DES keys."); /* generate first message */ *(uint32_t*)buf = me.sin_addr.s_addr; /* local address, network order */ *(uint16_t*)(buf+4) = me.sin_port; /* local port, network order */ *(uint32_t*)(buf+6) = htonl(conn->addr); /* remote address */ *(uint16_t*)(buf+10) = htons(conn->port); /* remote port */ memcpy(buf+12,conn->f_crypto->key,16); /* keys */ memcpy(buf+28,conn->b_crypto->key,16); *(uint32_t *)(buf+44) = htonl(conn->bandwidth); /* max link utilisation */ log(LOG_DEBUG,"or_handshake_client_send_auth() : Generated first authentication message."); /* encrypt message */ retval = crypto_pk_public_encrypt(conn->pkey, buf, 48, 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, 128, 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; } int or_handshake_client_process_auth(connection_t *conn) { char buf[128]; /* only 56 of this is expected to be used */ char cipher[128]; uint32_t bandwidth; 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 */ if(connection_fetch_from_buf(cipher,128,conn) < 0) { return -1; } log(LOG_DEBUG,"or_handshake_client_process_auth() : Received auth."); /* decrypt response */ retval = crypto_pk_private_decrypt(getprivatekey(), 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 != 56) { 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."); /* update link info */ bandwidth = ntohl(*(uint32_t *)(buf+44)); if (conn->bandwidth > bandwidth) conn->bandwidth = bandwidth; /* reply is just local addr/port, remote addr/port, nonce */ memcpy(buf+12, buf+48, 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 * */ int or_handshake_server_process_auth(connection_t *conn) { int retval; char buf[128]; /* only 48 of this is expected to be used */ char cipher[128]; uint32_t addr; uint16_t port; uint32_t bandwidth; 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 */ if(connection_fetch_from_buf(cipher,128,conn) < 0) { return -1; } log(LOG_DEBUG,"or_handshake_server_process_auth() : Received auth."); /* decrypt response */ retval = crypto_pk_private_decrypt(getprivatekey(), 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; } else if (retval != 48) { log(LOG_ERR,"or_handshake_server_process_auth(): received an incorrect authentication request."); return -1; } log(LOG_DEBUG,"or_handshake_server_process_auth() : Decrypted authentication message."); /* identify the router */ addr = ntohl(*(uint32_t*)buf); /* save the IP address */ port = ntohs(*(uint16_t*)(buf+4)); /* 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+12); crypto_cipher_set_key(conn->f_crypto,buf+28); /* update link info */ bandwidth = ntohl(*(uint32_t *)(buf+44)); conn->bandwidth = router->bandwidth; if (conn->bandwidth > bandwidth) conn->bandwidth = bandwidth; /* copy all relevant info to conn */ conn->addr = router->addr, conn->port = router->or_port; conn->pkey = crypto_pk_dup_key(router->pkey); conn->address = strdup(router->address); /* generate a nonce */ retval = crypto_pseudo_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."); *(uint32_t *)(buf+44) = htonl(conn->bandwidth); /* send max link utilisation */ memcpy(buf+48,conn->nonce,8); /* append the nonce to the end of the message */ /* encrypt message */ retval = crypto_pk_public_encrypt(conn->pkey, buf, 56, 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; } 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 */ if(connection_fetch_from_buf(cipher,128,conn) < 0) { return -1; } log(LOG_DEBUG,"or_handshake_server_process_nonce() : Received auth."); /* decrypt response */ retval = crypto_pk_private_decrypt(getprivatekey(), 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 */ } /* ********************************** */ 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 from a router. Attempting to authenticate."); return connection_handle_listener_read(conn, CONN_TYPE_OR, OR_CONN_STATE_SERVER_AUTH_WAIT); } /* Local Variables: mode:c indent-tabs-mode:nil c-basic-offset:2 End: */