/*
- * 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
*
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <stdlib.h>
-#include <stdio.h>
+#include "tlsproxy.h"
+#include "sem.h"
+#include "connection.h"
+
/* socket(), bind(), accept(), listen() */
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
/* htons() */
#include <arpa/inet.h>
-/* getaddrinfo() */
-#include <netdb.h>
-/* strncmp() */
-#include <string.h>
/* sigaction() */
#include <signal.h>
-/* poll() */
-#include <poll.h>
+/* errno */
+#include <errno.h>
+/* pthread_*() */
+#include <pthread.h>
+
+/* For GnuTLS. */
+#include <gcrypt.h>
+
+GCRY_THREAD_OPTION_PTHREAD_IMPL;
+
+
+/* Size of ringbuffer. */
+#define RINGBUFFER_SIZE 10
-#include <config.h>
+/* Bit size of Diffie-Hellman key exchange parameters. */
+#define DH_SIZE 1024
-/* Maximum line of the request line. Longer request lines are aborted with an
- * error. The standard doesn't specify a maximum line length but this should
- * be a good limit to make processing simpler. */
-#define MAX_REQUEST_LINE 4096
+/* 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;
-/* Proxy hostname and port if specified on the command line. */
-static char *use_proxy_host;
-static char *use_proxy_port;
+/* 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 int ringbuffer_write;
+static SEM *ringbuffer_full; /* At least one element in the buffer? */
+static SEM *ringbuffer_free; /* Space for another element in the buffer? */
+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 handle_connection(int socket);
-static int read_http_request(FILE *client_fd, char *request, size_t length);
-static void send_close_bad_request(FILE *client_fd);
-static void send_close_forwarding_failure(FILE *client_fd);
-
-static void transfer_data(int client, int server);
-static int read_from_write_to(int from, int to);
+static void initialize_gnutls(void);
+static void deinitialize_gnutls(void);
-static int connect_to_host(const char *hostname, const char *port);
-
-static int parse_request(const char *buffer, char *host, char *port,
- int *version_minor);
+static void worker_thread(void);
int main(int argc, char **argv) {
int port;
int client_socket, server_socket;
+#ifdef USE_IPV4_ONLY
+ struct sockaddr_in server_in;
+#else
struct sockaddr_in6 server_in;
+#endif
+
+ size_t i;
+ pthread_t *threads;
struct sigaction action;
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;
+ ringbuffer_write = 0;
+ ringbuffer_full = sem_init(0);
+ ringbuffer_free = sem_init(RINGBUFFER_SIZE);
+ ringbuffer_lock = sem_init(1);
+ if (NULL == ringbuffer_full
+ || NULL == ringbuffer_free
+ || NULL == ringbuffer_lock) {
+ perror("sem_init()");
+ return EXIT_FAILURE;
+ }
+
+ initialize_gnutls();
+ /* Spawn worker threads to handle requests. */
+ threads = (pthread_t *)malloc(thread_count * sizeof(pthread_t));
+ if (NULL == threads) {
+ perror("thread malloc failed");
+ return EXIT_FAILURE;
+ }
+ for (i = 0; i < thread_count; i++) {
+ int result;
+ pthread_t thread;
+
+ result = pthread_create(&thread, NULL,
+ (void * (*)(void *))&worker_thread,
+ NULL);
+ if (0 != result) {
+ fprintf(stderr, "failed to create worker thread: %s\n",
+ strerror(result));
+ return EXIT_FAILURE;
+ }
+
+ threads[i] = thread;
+ }
+
+#ifdef USE_IPV4_ONLY
+ server_socket = socket(PF_INET, SOCK_STREAM, 0);
+#else
server_socket = socket(PF_INET6, SOCK_STREAM, 0);
+#endif
if (-1 == server_socket) {
perror("socket()");
return EXIT_FAILURE;
}
-#ifdef DEBUG
/* Fast rebinding for debug mode, could cause invalid packets. */
- {
+ if (LOG_DEBUG <= global_log_level) {
int socket_option = 1;
setsockopt(server_socket, SOL_SOCKET, SO_REUSEADDR,
&socket_option, sizeof(socket_option));
}
-#endif
/* Bind to the listen socket. */
memset(&server_in, 0, sizeof(server_in));
+#ifdef USE_IPV4_ONLY
+ server_in.sin_family = AF_INET; /* IPv4 only */
+ server_in.sin_addr.s_addr = htonl(INADDR_ANY); /* bind to any address */
+ server_in.sin_port = htons((uint16_t)port); /* port to bind to */
+#else
server_in.sin6_family = AF_INET6; /* IPv6 (and IPv4) */
server_in.sin6_addr = in6addr_any; /* bind to any address */
server_in.sin6_port = htons((uint16_t)port); /* port to bind to */
+#endif
if (-1 == bind(server_socket, (struct sockaddr *)&server_in,
sizeof(server_in))) {
perror("bind()");
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. */
break;
}
- handle_connection(client_socket);
+ /* No lock, we only have one producer! */
+ P(ringbuffer_free);
+ ringbuffer[ringbuffer_write] = client_socket;
+ ringbuffer_write = (ringbuffer_write + 1) % RINGBUFFER_SIZE;
+ V(ringbuffer_full);
}
close(server_socket);
- free(use_proxy_host);
- free(use_proxy_port);
+ /* Poison all threads and shut them down. */
+ for (i = 0; i < thread_count; i++) {
+ P(ringbuffer_free);
+ ringbuffer[ringbuffer_write] = -1; /* poison */
+ ringbuffer_write = (ringbuffer_write + 1) % RINGBUFFER_SIZE;
+ V(ringbuffer_full);
+ }
+ for (i = 0; i < thread_count; i++) {
+ errno = pthread_join(threads[i], NULL);
+ if (0 != errno) {
+ perror("pthread_join()");
+ continue;
+ }
+ }
+
+ free(ringbuffer_full);
+ free(ringbuffer_free);
+ free(ringbuffer_lock);
+
+ free(threads);
+
+ 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;
- while (-1 != (option = getopt(argc, argv, "p:h?"))) {
+ /* Default values. */
+ thread_count = 10;
+#ifdef DEBUG
+ global_log_level = LOG_DEBUG;
+#else
+ global_log_level = LOG_WARNING;
+#endif
+ global_passthrough_unknown = 0;
+
+ while (-1 != (option = getopt(argc, argv, "d:p:t:uh?"))) {
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)) {
+ print_usage(argv[0]);
+ fprintf(stderr, "\n-t positive number required\n");
+ exit(EXIT_FAILURE);
+ }
+ thread_count = (size_t)atoi(optarg);
+ break;
+ }
+ case 'u': {
+ global_passthrough_unknown = 1;
+ break;
+ }
case 'h':
default: /* '?' */
print_usage(argv[0]);
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] [-u] 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");
+ fprintf(stderr, "-u passthrough connection if no certificate is stored \
+[default: error]\n");
+ fprintf(stderr, " WARNING: might be a security problem!\n");
}
-static void handle_connection(int client_socket) {
- int server_socket;
- FILE *client_fd, *server_fd;
-
- char buffer[MAX_REQUEST_LINE];
- char host[MAX_REQUEST_LINE];
- char port[5 + 1];
-
- int version_minor;
+static void initialize_gnutls(void) {
int result;
+ gcry_error_t error = 0;
- client_fd = fdopen(client_socket, "a+");
- if (NULL == client_fd) {
- perror("fdopen()");
- close(client_socket);
- return;
- }
-
-#ifdef DEBUG
- printf("New connection:\n");
-#endif
-
- /* Read request line (CONNECT ..) and headers (they are discarded). */
- result = read_http_request(client_fd, buffer, sizeof(buffer));
- if (result == -1) {
- /* Read error. */
- return;
- } else if (result == -2) {
- /* EOF */
- send_close_bad_request(client_fd);
- return;
- }
-
-#ifdef DEBUG
- printf(" request: %s", buffer);
-#endif
-
- if (0 != parse_request(buffer, host, port, &version_minor)) {
- send_close_bad_request(client_fd);
-#ifdef DEBUG
- printf(" bad request\n");
-#endif
- return;
- }
-
-#ifdef DEBUG
- printf(" %s:%s (HTTP 1.%d)\n", host, port, version_minor);
-#endif
-
- /* Connect to proxy server or directly to server. */
- if (NULL != use_proxy_host && NULL != use_proxy_port) {
- server_socket = connect_to_host(use_proxy_host, use_proxy_port);
- } else {
- server_socket = connect_to_host(host, port);
- }
-
- if (-1 == server_socket) {
- send_close_forwarding_failure(client_fd);
- return;
- }
- server_fd = fdopen(server_socket, "a+");
- if (NULL == server_fd) {
- send_close_forwarding_failure(client_fd);
- return;
+ /* 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);
}
-
- /* Connect to proxy if requested (command line option). */
- if (NULL != use_proxy_host && NULL != use_proxy_port) {
- fprintf(server_fd, "CONNECT %s:%s HTTP/1.0\r\n", host, port);
- fprintf(server_fd, "\r\n");
-
- /* Read response line from proxy server. */
- result = read_http_request(server_fd, buffer, sizeof(buffer));
- if (result == -1) {
- /* Read error. */
- send_close_forwarding_failure(client_fd);
- return;
- } else if (result == -2) {
- /* EOF */
- fclose(server_fd);
- send_close_forwarding_failure(client_fd);
- return;
- }
-
- /* Check response of proxy server. */
- if (0 != strncmp(buffer, "HTTP/1.0 200", 12)) {
-#ifdef DEBUG
- printf(" bad proxy response\n");
-#endif
- fclose(server_fd);
- send_close_forwarding_failure(client_fd);
- return;
- }
+ /* 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);
}
-#ifdef DEBUG
- printf(" connection to server established\n");
-#endif
-
- /* We've established a connection, tell the client. */
- fprintf(client_fd, "HTTP/1.0 200 Connection established\r\n");
- fprintf(client_fd, "\r\n");
- fflush(client_fd);
+ /* Initialize GnuTLS. */
+ result = gnutls_global_init();
+ GNUTLS_ERROR_EXIT(result, "gnutls_global_init()");
- /* And transfer all data between client and server transparently. */
- transfer_data(client_socket, server_socket);
+ /* Setup GnuTLS cipher suites. */
+ result = gnutls_priority_init(&tls_priority_cache, "NORMAL", NULL);
+ GNUTLS_ERROR_EXIT(result, "gnutls_priority_init()");
- fclose(client_fd);
- fclose(server_fd);
+ /* 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);
-/* Read HTTP request line and headers (ignored).
- *
- * On success 0 is returned, -1 on client error (we close client descriptor in
- * this case), -2 on unexpected EOF.
- */
-static int read_http_request(FILE *client_fd, char *request, size_t length) {
- char buffer[MAX_REQUEST_LINE];
-
- if (NULL == fgets(request, (int)length, client_fd)) {
- if (ferror(client_fd)) {
- perror("fgets(), request");
- fclose(client_fd);
- return -1;
- }
-
- return -2;
- }
-
- while (NULL != fgets(buffer, MAX_REQUEST_LINE, client_fd)) {
- /* End of header. */
- if (0 == strcmp(buffer, "\n") || 0 == strcmp(buffer, "\r\n")) {
- break;
- }
- }
- if (ferror(client_fd)) {
- perror("fgets(), header");
- fclose(client_fd);
- return -1;
- }
-
- return 0;
-}
-
-static void send_close_bad_request(FILE *client_fd) {
- fprintf(client_fd, "HTTP/1.0 400 Bad Request\r\n");
- fprintf(client_fd, "\r\n");
- fclose(client_fd);
-}
-static void send_close_forwarding_failure(FILE *client_fd) {
- fprintf(client_fd, "HTTP/1.0 503 Forwarding failure\r\n");
- fprintf(client_fd, "\r\n");
- fclose(client_fd);
+ gnutls_global_deinit();
}
-
-/* Transfer data between client and server sockets until one closes the
- * connection. */
-static void transfer_data(int client, int server) {
- struct pollfd fds[2];
- fds[0].fd = client;
- fds[0].events = POLLIN | POLLPRI | POLLHUP | POLLERR;
- fds[0].revents = 0;
- fds[1].fd = server;
- fds[1].events = POLLIN | POLLPRI | POLLHUP | POLLERR;
- fds[1].revents = 0;
+static void worker_thread(void) {
+ int client_socket;
for (;;) {
- int result = poll(fds, 2, -1 /* no timeout */);
- if (result < 0) {
- perror("poll()");
- return;
- }
-
- /* Data available from client. */
- if (fds[0].revents & POLLIN || fds[0].revents & POLLPRI) {
- if (0 != read_from_write_to(client, server)) {
- /* EOF (or other error) */
- break;
- }
- }
- /* Data available from server. */
- if (fds[1].revents & POLLIN || fds[1].revents & POLLPRI) {
- if (0 != read_from_write_to(server, client)) {
- /* EOF (or other error) */
- break;
- }
- }
-
- /* Client closed connection. */
- if (fds[0].revents & POLLERR || fds[0].revents & POLLHUP) {
- break;
- }
- /* Server closed connection. */
- if (fds[1].revents & POLLERR || fds[1].revents & POLLHUP) {
+ /* Get next element from ring buffer. */
+ P(ringbuffer_full);
+ P(ringbuffer_lock);
+ client_socket = ringbuffer[ringbuffer_read];
+ ringbuffer_read = (ringbuffer_read + 1) % RINGBUFFER_SIZE;
+ V(ringbuffer_lock);
+ V(ringbuffer_free);
+
+ /* Negative value indicates we should shut down our thread. */
+ if (0 > client_socket) {
break;
}
- }
-}
-
-/* Read available data from socket from and write it to socket to. At maximum
- * 4096 bytes are read/written. */
-static int read_from_write_to(int from, int to) {
- ssize_t size_read;
- ssize_t size_written;
- char buffer[4096];
-
- size_read = read(from, buffer, sizeof(buffer));
- if (0 > size_read) {
- perror("read()");
- return -1;
- }
- /* EOF */
- if (0 == size_read) {
- return -1;
- }
-
- size_written = write(to, buffer, (size_t)size_read);
- if (0 > size_written) {
- perror("write()");
- return -1;
- }
- if (size_read != size_written) {
- printf("only written %ld of %ld bytes!\n", (long int)size_read,
- (long int)size_written);
- return -1;
- }
-
- return 0;
-}
-
-
-static int connect_to_host(const char *hostname, const char *port) {
- struct addrinfo gai_hints;
- struct addrinfo *gai_result;
- int gai_return;
-
- int server_socket;
- struct addrinfo *server;
-
- if (NULL == hostname || NULL == port) {
- return -1;
- }
-
- /* Get IP of hostname server. */
- memset(&gai_hints, 0, sizeof(gai_hints));
- gai_hints.ai_family = AF_UNSPEC;
- gai_hints.ai_socktype = SOCK_STREAM;
- gai_hints.ai_protocol = 0;
- gai_hints.ai_flags = AI_NUMERICSERV /* given port is numeric */
- | AI_ADDRCONFIG /* supported by this computer */
- | AI_V4MAPPED; /* support IPv4 through IPv6 */
- gai_return = getaddrinfo(hostname, port, &gai_hints, &gai_result);
- if (0 != gai_return) {
- perror("getaddrinfo()");
- return -1;
- }
-
- /* Now try to connect to each server returned by getaddrinfo(), use the
- * first successful connect. */
- for (server = gai_result; NULL != server; server = server->ai_next) {
- server_socket = socket(server->ai_family,
- server->ai_socktype,
- server->ai_protocol);
- if (-1 == server_socket) {
- perror("socket(), trying next");
- continue;
- }
-
- if (-1 != connect(server_socket, server->ai_addr,
- server->ai_addrlen)) {
- break;
- }
- perror("connect(), trying next");
-
- close(server_socket);
- }
- /* Make sure we free the result from getaddrinfo(). */
- freeaddrinfo(gai_result);
-
- if (NULL == server) {
- fprintf(stderr, "no server found, aborting\n");
- return -1;
- }
-
- return server_socket;
-}
-
-/* Parse HTTP CONNECT request string and save its parameters.
- *
- * The following format is expected: "CONNECT host:port HTTP/1.y".
- *
- * request and host must have the same size! port must be at least 6 bytes
- * long (5 + '\0').
- */
-static int parse_request(const char *request, char *host, char *port,
- int *version_minor) {
- int port_unused; /* just used to verify the port is numeric */
- char *position;
-
- /* scanf() doesn't check spaces. */
- if (0 != strncmp(request, "CONNECT ", 8)) {
- return -1;
- }
- /* Check request and extract data, "host:port" is not yet separated. */
- if (2 != sscanf(request, "CONNECT %s HTTP/1.%d",
- host, version_minor)) {
- return -1;
- }
- /* Make sure ":port" is there. */
- if (NULL == (position = strchr(host, ':'))) {
- return -1;
- }
- /* Make sure port is numeric. */
- if (1 != sscanf(position + 1, "%d", &port_unused)) {
- return -1;
+ handle_connection(client_socket);
}
- /* Store it in *port. */
- strncpy(port, position + 1, 5);
- port[5] = '\0';
- /* And remove port from host. */
- *position = '\0';
-
- return 0;
}
ruderich.org/simon / tlsproxy / tlsproxy.git / blobdiff