/*
- * tlsproxy is a transparent TLS proxy for HTTPS connections.
+ * tlsproxy is a TLS proxy for HTTPS which intercepts the connections and
+ * ensures the server certificate doesn't change. Normally this isn't detected
+ * if a trusted CA for the new server certificate is installed.
*
* Copyright (C) 2011 Simon Ruderich
*
/* pthread_*() */
#include <pthread.h>
+/* For GnuTLS. */
+#include <gcrypt.h>
+
+GCRY_THREAD_OPTION_PTHREAD_IMPL;
+
+
/* Size of ringbuffer. */
#define RINGBUFFER_SIZE 10
+/* Bit size of Diffie-Hellman key exchange parameters. */
+#define DH_SIZE 1024
+
+
+/* For gnutls_*() functions. */
+#define GNUTLS_ERROR_EXIT(error, message) \
+ if (GNUTLS_E_SUCCESS != error) { \
+ fprintf(stderr, "%s: %s\n", message, gnutls_strerror(error)); \
+ exit(EXIT_FAILURE); \
+ }
+
/* Server should shut down. Set by SIGINT handler. */
static volatile int done;
/* Number of threads. */
static size_t thread_count;
+
/* Synchronized ring buffer storing accept()ed client sockets. */
static int ringbuffer[RINGBUFFER_SIZE];
static int ringbuffer_read;
static SEM *ringbuffer_lock; /* Read lock. */
+#ifdef DEBUG
static void sigint_handler(int signal);
+#endif
static void parse_arguments(int argc, char **argv);
static void print_usage(const char *argv);
+static void initialize_gnutls(void);
+static void deinitialize_gnutls(void);
+
static void worker_thread(void);
port = atoi(argv[argc - 1]);
if (0 >= port || 0xffff < port) {
print_usage(argv[0]);
- fprintf(stderr, "\ninvalid port");
+ fprintf(stderr, "\ninvalid port\n");
return EXIT_FAILURE;
}
/* Setup our SIGINT signal handler which allows a "normal" termination of
- * the server. */
+ * the server in DEBUG mode. */
sigemptyset(&action.sa_mask);
- action.sa_handler = sigint_handler;
action.sa_flags = 0;
+#ifdef DEBUG
+ action.sa_handler = sigint_handler;
sigaction(SIGINT, &action, NULL);
+#endif
+ /* Ignore SIGPIPEs. */
+ action.sa_handler = SIG_IGN;
+ sigaction(SIGPIPE, &action, NULL);
/* Initialize ring buffer. */
ringbuffer_read = 0;
return EXIT_FAILURE;
}
+ initialize_gnutls();
+
/* Spawn worker threads to handle requests. */
threads = (pthread_t *)malloc(thread_count * sizeof(pthread_t));
if (NULL == threads) {
(void * (*)(void *))&worker_thread,
NULL);
if (0 != result) {
- printf("failed to create worker thread: %s\n", strerror(result));
+ fprintf(stderr, "failed to create worker thread: %s\n",
+ strerror(result));
return EXIT_FAILURE;
}
return EXIT_FAILURE;
}
-#ifdef DEBUG
- printf("Listening for connections on port %d.\n", port);
+ if (LOG_DEBUG <= global_log_level) {
+ printf("Listening for connections on port %d.\n", port);
- if (NULL != use_proxy_host && NULL != use_proxy_port) {
- printf("Using proxy: %s:%s.\n", use_proxy_host, use_proxy_port);
+ if (NULL != global_proxy_host && NULL != global_proxy_port) {
+ printf("Using proxy: %s:%s.\n", global_proxy_host,
+ global_proxy_port);
+ }
}
-#endif
while (!done) {
/* Accept new connection. */
free(threads);
- free(use_proxy_host);
- free(use_proxy_port);
+ deinitialize_gnutls();
+
+ free(global_proxy_host);
+ free(global_proxy_port);
return EXIT_FAILURE;
}
+#ifdef DEBUG
static void sigint_handler(int signal_number) {
(void)signal_number;
done = 1;
}
+#endif
static void parse_arguments(int argc, char **argv) {
int option;
/* Default values. */
thread_count = 10;
+#ifdef DEBUG
+ global_log_level = LOG_DEBUG;
+#else
+ global_log_level = LOG_WARNING;
+#endif
- while (-1 != (option = getopt(argc, argv, "p:t:h?"))) {
+ while (-1 != (option = getopt(argc, argv, "d:p:t:h?"))) {
switch (option) {
+ case 'd': {
+ if (0 > atoi(optarg)) {
+ print_usage(argv[0]);
+ fprintf(stderr, "\n-d positive number required\n");
+ exit(EXIT_FAILURE);
+ }
+ global_log_level = atoi(optarg);
+ break;
+ }
case 'p': {
char *position;
|| 0 == strlen(position + 1)
|| 0 >= atoi(position + 1)
|| 0xffff < atoi(position + 1)) {
- fprintf(stderr, "-p host:port\n");
+ print_usage(argv[0]);
+ fprintf(stderr, "\ninvalid -p, format host:port\n");
exit(EXIT_FAILURE);
}
- use_proxy_host = malloc((size_t)(position - optarg) + 1);
- if (NULL == use_proxy_host) {
+ global_proxy_host = malloc((size_t)(position - optarg) + 1);
+ if (NULL == global_proxy_host) {
perror("malloc()");
exit(EXIT_FAILURE);
}
- memcpy(use_proxy_host, optarg, (size_t)(position - optarg));
- use_proxy_host[position - optarg] = '\0';
+ memcpy(global_proxy_host, optarg, (size_t)(position - optarg));
+ global_proxy_host[position - optarg] = '\0';
- use_proxy_port = malloc(strlen(position + 1) + 1);
- if (NULL == use_proxy_port) {
+ global_proxy_port = malloc(strlen(position + 1) + 1);
+ if (NULL == global_proxy_port) {
perror("malloc()");
exit(EXIT_FAILURE);
}
- strcpy(use_proxy_port, position + 1);
+ strcpy(global_proxy_port, position + 1);
break;
}
case 't': {
if (0 >= atoi(optarg)) {
- fprintf(stderr, "-t positive number required\n");
+ print_usage(argv[0]);
+ fprintf(stderr, "\n-t positive number required\n");
exit(EXIT_FAILURE);
}
thread_count = (size_t)atoi(optarg);
if (optind >= argc) {
print_usage(argv[0]);
+ fprintf(stderr, "\nport missing\n");
exit(EXIT_FAILURE);
}
}
static void print_usage(const char *argv) {
- fprintf(stderr, "Usage: %s [-p host:port] port\n", argv);
+ fprintf(stderr, "Usage: %s [-d level] [-p host:port] [-t count] port\n",
+ argv);
fprintf(stderr, "\n");
+ fprintf(stderr, "-d debug level: 0=errors only, 2=debug [default: 1]\n");
fprintf(stderr, "-p proxy hostname and port\n");
fprintf(stderr, "-t number of threads [default: 10]\n");
}
+static void initialize_gnutls(void) {
+ int result;
+ gcry_error_t error = 0;
+
+ /* Thread safe setup. Must be called before gnutls_global_init(). */
+ error = gcry_control(GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
+ if (error) {
+ fprintf(stderr, "gcry_control(): %s/%s\n", gcry_strsource(error),
+ gcry_strerror(error));
+ exit(EXIT_FAILURE);
+ }
+ /* Prevent usage of blocking /dev/random. */
+ error = gcry_control(GCRYCTL_ENABLE_QUICK_RANDOM, 0);
+ if (error) {
+ fprintf(stderr, "gcry_control(): %s/%s\n", gcry_strsource(error),
+ gcry_strerror(error));
+ exit(EXIT_FAILURE);
+ }
+
+ /* Initialize GnuTLS. */
+ result = gnutls_global_init();
+ GNUTLS_ERROR_EXIT(result, "gnutls_global_init()");
+
+ /* Setup GnuTLS cipher suites. */
+ result = gnutls_priority_init(&tls_priority_cache, "NORMAL", NULL);
+ GNUTLS_ERROR_EXIT(result, "gnutls_priority_init()");
+
+ /* Generate Diffie-Hellman parameters. */
+ result = gnutls_dh_params_init(&tls_dh_params);
+ GNUTLS_ERROR_EXIT(result, "gnutls_dh_params_init()");
+ result = gnutls_dh_params_generate2(tls_dh_params, DH_SIZE);
+ GNUTLS_ERROR_EXIT(result, "gnutls_dh_params_generate2()");
+}
+static void deinitialize_gnutls(void) {
+ gnutls_dh_params_deinit(tls_dh_params);
+ gnutls_priority_deinit(tls_priority_cache);
+
+ gnutls_global_deinit();
+}
+
static void worker_thread(void) {
int client_socket;
V(ringbuffer_free);
/* Negative value indicates we should shut down our thread. */
- if (client_socket < 0) {
+ if (0 > client_socket) {
break;
}