2 * tlsproxy is a TLS proxy for HTTPS which intercepts the connections and
3 * ensures the server certificate doesn't change. Normally this isn't detected
4 * if a trusted CA for the new server certificate is installed.
6 * Copyright (C) 2011 Simon Ruderich
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 #include "connection.h"
26 /* socket(), bind(), accept(), listen() */
27 #include <sys/types.h>
28 #include <sys/socket.h>
32 #include <arpa/inet.h>
43 GCRY_THREAD_OPTION_PTHREAD_IMPL;
46 /* Size of ringbuffer. */
47 #define RINGBUFFER_SIZE 10
49 /* Bit size of Diffie-Hellman key exchange parameters. */
53 /* For gnutls_*() functions. */
54 #define GNUTLS_ERROR_EXIT(error, message) \
55 if (GNUTLS_E_SUCCESS != error) { \
56 fprintf(stderr, "%s: %s\n", message, gnutls_strerror(error)); \
61 /* Server should shut down. Set by SIGINT handler. */
62 static volatile int done;
64 /* Number of threads. */
65 static size_t thread_count;
67 /* Synchronized ring buffer storing accept()ed client sockets. */
68 static int ringbuffer[RINGBUFFER_SIZE];
69 static int ringbuffer_read;
70 static int ringbuffer_write;
71 static SEM *ringbuffer_full; /* At least one element in the buffer? */
72 static SEM *ringbuffer_free; /* Space for another element in the buffer? */
73 static SEM *ringbuffer_lock; /* Read lock. */
76 static void sigint_handler(int signal);
78 static void parse_arguments(int argc, char **argv);
79 static void print_usage(const char *argv);
81 static void initialize_gnutls(void);
82 static void deinitialize_gnutls(void);
84 static void worker_thread(void);
87 int main(int argc, char **argv) {
89 int client_socket, server_socket;
90 struct sockaddr_in6 server_in;
95 struct sigaction action;
97 parse_arguments(argc, argv);
99 port = atoi(argv[argc - 1]);
100 if (0 >= port || 0xffff < port) {
101 print_usage(argv[0]);
102 fprintf(stderr, "\ninvalid port\n");
106 /* Setup our SIGINT signal handler which allows a "normal" termination of
108 sigemptyset(&action.sa_mask);
109 action.sa_handler = sigint_handler;
111 sigaction(SIGINT, &action, NULL);
112 /* Ignore SIGPIPEs. */
113 action.sa_handler = SIG_IGN;
114 sigaction(SIGPIPE, &action, NULL);
116 /* Initialize ring buffer. */
118 ringbuffer_write = 0;
119 ringbuffer_full = sem_init(0);
120 ringbuffer_free = sem_init(RINGBUFFER_SIZE);
121 ringbuffer_lock = sem_init(1);
122 if (NULL == ringbuffer_full
123 || NULL == ringbuffer_free
124 || NULL == ringbuffer_lock) {
125 perror("sem_init()");
131 /* Spawn worker threads to handle requests. */
132 threads = (pthread_t *)malloc(thread_count * sizeof(pthread_t));
133 if (NULL == threads) {
134 perror("thread malloc failed");
137 for (i = 0; i < thread_count; i++) {
141 result = pthread_create(&thread, NULL,
142 (void * (*)(void *))&worker_thread,
145 printf("failed to create worker thread: %s\n", strerror(result));
152 server_socket = socket(PF_INET6, SOCK_STREAM, 0);
153 if (-1 == server_socket) {
159 /* Fast rebinding for debug mode, could cause invalid packets. */
161 int socket_option = 1;
162 setsockopt(server_socket, SOL_SOCKET, SO_REUSEADDR,
163 &socket_option, sizeof(socket_option));
167 /* Bind to the listen socket. */
168 memset(&server_in, 0, sizeof(server_in));
169 server_in.sin6_family = AF_INET6; /* IPv6 (and IPv4) */
170 server_in.sin6_addr = in6addr_any; /* bind to any address */
171 server_in.sin6_port = htons((uint16_t)port); /* port to bind to */
172 if (-1 == bind(server_socket, (struct sockaddr *)&server_in,
173 sizeof(server_in))) {
177 /* And accept connections. */
178 if (-1 == listen(server_socket, 5)) {
183 if (LOG_DEBUG <= global_log_level) {
184 printf("Listening for connections on port %d.\n", port);
186 if (NULL != global_proxy_host && NULL != global_proxy_port) {
187 printf("Using proxy: %s:%s.\n", global_proxy_host,
193 /* Accept new connection. */
194 client_socket = accept(server_socket, NULL, NULL);
195 if (-1 == client_socket) {
200 /* No lock, we only have one producer! */
202 ringbuffer[ringbuffer_write] = client_socket;
203 ringbuffer_write = (ringbuffer_write + 1) % RINGBUFFER_SIZE;
207 close(server_socket);
209 /* Poison all threads and shut them down. */
210 for (i = 0; i < thread_count; i++) {
212 ringbuffer[ringbuffer_write] = -1; /* poison */
213 ringbuffer_write = (ringbuffer_write + 1) % RINGBUFFER_SIZE;
216 for (i = 0; i < thread_count; i++) {
217 errno = pthread_join(threads[i], NULL);
219 perror("pthread_join()");
224 free(ringbuffer_full);
225 free(ringbuffer_free);
226 free(ringbuffer_lock);
230 deinitialize_gnutls();
232 free(global_proxy_host);
233 free(global_proxy_port);
238 static void sigint_handler(int signal_number) {
244 static void parse_arguments(int argc, char **argv) {
247 /* Default values. */
250 global_log_level = LOG_DEBUG;
252 global_log_level = LOG_WARNING;
255 while (-1 != (option = getopt(argc, argv, "d:p:t:h?"))) {
258 if (0 > atoi(optarg)) {
259 print_usage(argv[0]);
260 fprintf(stderr, "\n-d positive number required\n");
263 global_log_level = atoi(optarg);
269 /* -p must have the format host:port. */
270 if (NULL == (position = strchr(optarg, ':'))
271 || position == optarg
272 || 0 == strlen(position + 1)
273 || 0 >= atoi(position + 1)
274 || 0xffff < atoi(position + 1)) {
275 print_usage(argv[0]);
276 fprintf(stderr, "\ninvalid -p, format host:port\n");
280 global_proxy_host = malloc((size_t)(position - optarg) + 1);
281 if (NULL == global_proxy_host) {
285 memcpy(global_proxy_host, optarg, (size_t)(position - optarg));
286 global_proxy_host[position - optarg] = '\0';
288 global_proxy_port = malloc(strlen(position + 1) + 1);
289 if (NULL == global_proxy_port) {
293 strcpy(global_proxy_port, position + 1);
298 if (0 >= atoi(optarg)) {
299 print_usage(argv[0]);
300 fprintf(stderr, "\n-t positive number required\n");
303 thread_count = (size_t)atoi(optarg);
308 print_usage(argv[0]);
313 if (optind >= argc) {
314 print_usage(argv[0]);
315 fprintf(stderr, "\nport missing\n");
319 static void print_usage(const char *argv) {
320 fprintf(stderr, "Usage: %s [-d level] [-p host:port] [-t count] port\n",
322 fprintf(stderr, "\n");
323 fprintf(stderr, "-d debug level: 0=errors only, 2=debug [default: 1]\n");
324 fprintf(stderr, "-p proxy hostname and port\n");
325 fprintf(stderr, "-t number of threads [default: 10]\n");
328 static void initialize_gnutls(void) {
330 gcry_error_t error = 0;
332 /* Thread safe setup. Must be called before gnutls_global_init(). */
333 error = gcry_control(GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
335 fprintf(stderr, "gcry_control(): %s/%s\n", gcry_strsource(error),
336 gcry_strerror(error));
339 /* Prevent usage of blocking /dev/random. */
340 error = gcry_control(GCRYCTL_ENABLE_QUICK_RANDOM, 0);
342 fprintf(stderr, "gcry_control(): %s/%s\n", gcry_strsource(error),
343 gcry_strerror(error));
347 /* Initialize GnuTLS. */
348 result = gnutls_global_init();
349 GNUTLS_ERROR_EXIT(result, "gnutls_global_init()");
351 /* Setup GnuTLS cipher suites. */
352 result = gnutls_priority_init(&tls_priority_cache, "NORMAL", NULL);
353 GNUTLS_ERROR_EXIT(result, "gnutls_priority_init()");
355 /* Generate Diffie-Hellman parameters. */
356 result = gnutls_dh_params_init(&tls_dh_params);
357 GNUTLS_ERROR_EXIT(result, "gnutls_dh_params_init()");
358 result = gnutls_dh_params_generate2(tls_dh_params, DH_SIZE);
359 GNUTLS_ERROR_EXIT(result, "gnutls_dh_params_generate2()");
361 static void deinitialize_gnutls(void) {
362 gnutls_dh_params_deinit(tls_dh_params);
363 gnutls_priority_deinit(tls_priority_cache);
365 gnutls_global_deinit();
368 static void worker_thread(void) {
372 /* Get next element from ring buffer. */
375 client_socket = ringbuffer[ringbuffer_read];
376 ringbuffer_read = (ringbuffer_read + 1) % RINGBUFFER_SIZE;
380 /* Negative value indicates we should shut down our thread. */
381 if (0 > client_socket) {
385 handle_connection(client_socket);