* should be a good limit to make processing simpler. */
#define MAX_REQUEST_LINE 4096
+/* Paths to necessary TLS files: the CA and the server key. */
+#define PROXY_CA_FILE "proxy-ca.pem"
+#define PROXY_KEY_FILE "proxy-key.pem"
+
/* Helper macro for LOG/LOG_PERROR. Print file/line number if compiled with
* debug output. */
#ifdef DEBUG
log_message(level, "%s: %s", message, strerror(errno))
+static int initialize_tls_session_client(int peer_socket,
+ const char *hostname,
+ gnutls_session_t *session,
+ gnutls_certificate_credentials_t *x509_cred);
+static int initialize_tls_session_server(int peer_socket,
+ gnutls_session_t *session,
+ gnutls_certificate_credentials_t *x509_cred);
+
static int read_http_request(FILE *client_fd, char *request, size_t length);
static void send_bad_request(FILE *client_fd);
static void send_forwarding_failure(FILE *client_fd);
+#if 0
static void transfer_data(int client, int server);
static int read_from_write_to(int from, int to);
+#endif
+static void transfer_data_tls(int client, int server,
+ gnutls_session_t client_session,
+ gnutls_session_t server_session);
+static int read_from_write_to_tls(gnutls_session_t from, gnutls_session_t to);
static int connect_to_host(const char *hostname, const char *port);
int version_minor;
int result;
+ /* client_x509_cred is used when talking to the client (acting as a TSL
+ * server), server_x509_cred is used when talking to the server (acting as
+ * a TSL client). */
+ gnutls_certificate_credentials_t client_x509_cred, server_x509_cred;
+
+ gnutls_session_t client_session, server_session;
+ /* initialize_tls_session_*() called? - used for goto out */
+ int client_session_init, server_session_init;
+ /* gnutls_handshake() called? - used for goto out */
+ int client_session_started, server_session_started;
+
LOG(LOG_DEBUG, "new connection");
server_socket = -1;
client_fd = NULL;
server_fd = NULL;
+ client_session_init = 0;
+ server_session_init = 0;
+ client_session_started = 0;
+ server_session_started = 0;
client_fd = fdopen(client_socket, "a+");
if (NULL == client_fd) {
fprintf(client_fd, "\r\n");
fflush(client_fd);
- /* And transfer all data between client and server transparently. */
- transfer_data(client_socket, server_socket);
+ /* Initialize TLS server credentials to talk to the client. */
+ result = initialize_tls_session_client(client_socket, host,
+ &client_session,
+ &client_x509_cred);
+ if (0 != result) {
+ LOG(LOG_WARNING, "initialize_tls_session_client() failed");
+ send_forwarding_failure(client_fd);
+ goto out;
+ }
+ client_session_init = 1;
+
+ LOG(LOG_DEBUG, "starting client TLS handshake");
+
+ /* Try to establish TLS handshake between client and us. */
+ result = gnutls_handshake(client_session);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_WARNING, "client TLS handshake failed: %s",
+ gnutls_strerror(result));
+ send_forwarding_failure(client_fd);
+ goto out;
+ }
+ client_session_started = 1;
+
+ LOG(LOG_DEBUG, "client TLS handshake finished");
+
+ result = initialize_tls_session_server(server_socket, &server_session,
+ &server_x509_cred);
+ /* Initialize TLS client credentials to talk to the server. */
+ if (0 != result) {
+ LOG(LOG_WARNING, "initialize_tls_session_server() failed");
+ send_forwarding_failure(client_fd);
+ goto out;
+ }
+ server_session_init = 1;
+
+ LOG(LOG_DEBUG, "starting server TLS handshake");
+
+ /* Try to establish TLS handshake between us and server. */
+ result = gnutls_handshake(server_session);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_WARNING, "server TLS handshake failed: %s",
+ gnutls_strerror(result));
+ send_forwarding_failure(client_fd);
+ goto out;
+ }
+ server_session_started = 1;
+
+ LOG(LOG_DEBUG, "server TLS handshake finished, transferring data");
+
+ /* FIXME: verify server's fingerprint */
+
+ /* Proxy data between client and server until one suite is done (EOF or
+ * error). */
+ transfer_data_tls(client_socket, server_socket,
+ client_session, server_session);
+
+ LOG(LOG_DEBUG, "finished transferring data");
out:
+ /* Close TLS sessions if necessary. */
+ if (0 != server_session_started) {
+ gnutls_bye(server_session, GNUTLS_SHUT_WR);
+ }
+ if (0 != client_session_started) {
+ gnutls_bye(client_session, GNUTLS_SHUT_WR);
+ }
+ if (0 != server_session_init) {
+ gnutls_deinit(server_session);
+ gnutls_certificate_free_credentials(server_x509_cred);
+ }
+ if (0 != client_session_init) {
+ gnutls_deinit(client_session);
+ gnutls_certificate_free_cas(client_x509_cred);
+ gnutls_certificate_free_keys(client_x509_cred);
+ gnutls_certificate_free_credentials(client_x509_cred);
+ }
+
/* Close connection to server/proxy. */
if (NULL != server_fd) {
fclose(server_fd);
LOG(LOG_DEBUG, "connection finished");
}
+
+static int initialize_tls_session_client(int peer_socket,
+ const char *hostname,
+ gnutls_session_t *session,
+ gnutls_certificate_credentials_t *x509_cred) {
+ int result;
+ char path[1024];
+ /* The server certificate for the given hostname is stored in
+ * "./certificate-hostname-proxy.pem". */
+#define PATH_FORMAT "./certificate-%s-proxy.pem"
+
+ /* Hostname too long. */
+ if (sizeof(path) - strlen(PATH_FORMAT) <= strlen(hostname)) {
+ LOG(LOG_WARNING,
+ "initialize_tls_session_client(): hostname too long: '%s'",
+ hostname);
+ return -1;
+ }
+ /* Try to prevent path traversals in hostnames. */
+ if (NULL != strstr(hostname, "..")) {
+ LOG(LOG_WARNING,
+ "initialize_tls_session_client(): possible path traversal: '%s'",
+ hostname);
+ return -1;
+ }
+ snprintf(path, sizeof(path), PATH_FORMAT, hostname);
+#undef PATH_FORMAT
+
+ result = gnutls_certificate_allocate_credentials(x509_cred);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_client(): \
+gnutls_certificate_allocate_credentials(): %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+
+ /* Load proxy CA file, this CA "list" is send to the client. */
+ result = gnutls_certificate_set_x509_trust_file(*x509_cred,
+ PROXY_CA_FILE,
+ GNUTLS_X509_FMT_PEM);
+ if (0 >= result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_client(): can't read CA file: '%s'",
+ PROXY_CA_FILE);
+ return -1;
+ }
+ /* And certificate for this website and proxy's private key. */
+ result = gnutls_certificate_set_x509_key_file(*x509_cred,
+ path, PROXY_KEY_FILE,
+ GNUTLS_X509_FMT_PEM);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_client(): \
+can't read server certificate ('%s') or key file ('%s'): %s",
+ path, PROXY_KEY_FILE, gnutls_strerror(result));
+ /* Could be a missing certificate. */
+ return -2;
+ }
+
+ gnutls_certificate_set_dh_params(*x509_cred, tls_dh_params);
+
+ result = gnutls_init(session, GNUTLS_SERVER);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_client(): gnutls_init(): %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+ result = gnutls_priority_set(*session, tls_priority_cache);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_client(): gnutls_priority_set(): %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+ result = gnutls_credentials_set(*session,
+ GNUTLS_CRD_CERTIFICATE, *x509_cred);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_client(): gnutls_credentials_set(): %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+
+ gnutls_transport_set_ptr(*session, (gnutls_transport_ptr_t)peer_socket);
+
+ return 0;
+}
+static int initialize_tls_session_server(int peer_socket,
+ gnutls_session_t *session,
+ gnutls_certificate_credentials_t *x509_cred) {
+ int result;
+
+ result = gnutls_certificate_allocate_credentials(x509_cred);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_server(): \
+gnutls_certificate_allocate_credentials(): %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+
+ result = gnutls_init(session, GNUTLS_CLIENT);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_server(): gnutls_init(): %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+ gnutls_priority_set(*session, tls_priority_cache);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_server(): gnutls_priority_set(): %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+ result = gnutls_credentials_set(*session,
+ GNUTLS_CRD_CERTIFICATE, *x509_cred);
+ if (GNUTLS_E_SUCCESS != result) {
+ LOG(LOG_ERROR,
+ "initialize_tls_session_server(): gnutls_credentials_set(): %s",
+ gnutls_strerror(result));
+ return -1;
+ }
+
+ gnutls_transport_set_ptr(*session, (gnutls_transport_ptr_t)peer_socket);
+
+ return 0;
+}
+
+
/* Read HTTP request line and headers (ignored).
*
* On success 0 is returned, -1 on client error, -2 on unexpected EOF.
}
+#if 0
/* Transfer data between client and server sockets until one closes the
* connection. */
static void transfer_data(int client, int server) {
return 0;
}
+#endif
+
+/* Transfer data between client and server TLS connection until one closes the
+ * connection. */
+static void transfer_data_tls(int client, int server,
+ gnutls_session_t client_session,
+ gnutls_session_t server_session) {
+ 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;
+
+ for (;;) {
+ int result = poll(fds, 2, -1 /* no timeout */);
+ if (result < 0) {
+ LOG_PERROR(LOG_ERROR, "transfer_data(): poll()");
+ return;
+ }
+
+ /* Data available from client. */
+ if (fds[0].revents & POLLIN || fds[0].revents & POLLPRI) {
+ if (0 != read_from_write_to_tls(client_session, server_session)) {
+ /* EOF (or other error) */
+ break;
+ }
+ }
+ /* Data available from server. */
+ if (fds[1].revents & POLLIN || fds[1].revents & POLLPRI) {
+ if (0 != read_from_write_to_tls(server_session, client_session)) {
+ /* 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) {
+ break;
+ }
+ }
+}
+
+/* Read available data from session from and write to session to. */
+static int read_from_write_to_tls(gnutls_session_t from,
+ gnutls_session_t to) {
+ size_t size;
+ ssize_t size_read;
+ ssize_t size_written;
+ char buffer[16384];
+
+ /* Get maximum possible buffer size. */
+ size = gnutls_record_get_max_size(from);
+ LOG(LOG_DEBUG, "read_from_write_to_tls(): suggested buffer size: %ld",
+ (long int)size);
+ if (size > gnutls_record_get_max_size(to)) {
+ size = gnutls_record_get_max_size(to);
+ }
+ if (size > sizeof(buffer)) {
+ size = sizeof(buffer);
+ }
+ LOG(LOG_DEBUG, "read_from_write_to_tls(): used buffer size: %ld",
+ (long int)size);
+
+ size_read = gnutls_record_recv(from, buffer, size);
+ if (0 > size_read) {
+ LOG(LOG_WARNING, "read_from_write_to_tls(): gnutls_record_recv(): %s",
+ gnutls_strerror((int)size_read));
+ return -1;
+ }
+ /* EOF */
+ if (0 == size_read) {
+ return -1;
+ }
+
+ size_written = gnutls_record_send(to, buffer, (size_t)size_read);
+ if (0 > size_written) {
+ LOG(LOG_WARNING, "read_from_write_to_tls(): gnutls_record_send(): %s",
+ gnutls_strerror((int)size_written));
+ return -1;
+ }
+ if (size_read != size_written) {
+ LOG(LOG_ERROR, "read_from_write_to_tls(): only written %ld of %ld bytes!",
+ (long int)size_written, (long int)size_read);
+ return -1;
+ }
+
+ return 0;
+}
static int connect_to_host(const char *hostname, const char *port) {
/* 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
+
/* 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 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);
return EXIT_FAILURE;
}
+ initialize_gnutls();
+
/* Spawn worker threads to handle requests. */
threads = (pthread_t *)malloc(thread_count * sizeof(pthread_t));
if (NULL == threads) {
free(threads);
+ deinitialize_gnutls();
+
free(global_proxy_host);
free(global_proxy_port);
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;
ruderich.org/simon / tlsproxy / tlsproxy.git / commitdiff