#include "tlsproxy.h"
#include "connection.h"
+#include "verify.h"
/* close() */
#include <unistd.h>
#include <poll.h>
/* errno */
#include <errno.h>
-/* va_*() */
-#include <stdarg.h>
-/* pthread_*() */
-#include <pthread.h>
/* Maximum line of a HTTP request line. Longer request lines are aborted with
* 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
-#define LOG_PRINT_LOCATION fprintf(stdout, "%s:%-3d ", __FILE__, __LINE__);
-#else
-#define LOG_PRINT_LOCATION
-#endif
-/* Call log_message() and print current file and line number. */
-#define LOG \
- LOG_PRINT_LOCATION \
- log_message
-/* perror() replacement with debug level support. */
-#define LOG_PERROR(level, message) \
- LOG_PRINT_LOCATION \
- log_message(level, "%s: %s", message, strerror(errno))
+/* Format string used to send HTTP/1.0 error responses to the client.
+ *
+ * %s is used 4 times, first three are the error code (no %n$s!), the last is
+ * the message. */
+#define HTTP_RESPONSE_FORMAT "HTTP/1.0 %s\r\n\
+Content-Type: text/html; charset=US-ASCII\r\n\
+\r\n\
+<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\n\
+<html>\n\
+<head><title>%s</title></head>\n\
+<body>\n\
+<h1>%s</h1>\n\
+<p>%s</p>\n\
+</body>\n\
+</html>\n"
static int initialize_tls_session_client(int peer_socket,
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);
+static void tls_send_invalid_cert_message(gnutls_session_t session);
-#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 parse_request(const char *buffer, char *host, char *port,
int *version_minor);
-static void log_message(int level, const char *format, ...);
-
void handle_connection(int client_socket) {
int server_socket;
int client_session_init, server_session_init;
/* gnutls_handshake() called? - used for goto out */
int client_session_started, server_session_started;
+ /* Validation failed? If yes we need to send the special "invalid"
+ * certificate. */
+ int validation_failed;
LOG(LOG_DEBUG, "new connection");
server_session_init = 0;
client_session_started = 0;
server_session_started = 0;
+ validation_failed = 0;
client_fd = fdopen(client_socket, "a+");
if (NULL == client_fd) {
LOG(LOG_DEBUG, "connection to server established");
- /* 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);
+ /* If the -u option is used and we don't know this hostname's server
+ * certificate then just pass through the connection and let the client
+ * verify the server certificate. */
+ if (global_passthrough_unknown) {
+ char path[1024];
+ FILE *file = NULL;
- /* 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;
+ if (-2 == server_certificate_path(&file, host, path, sizeof(path))) {
+ /* 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);
- LOG(LOG_DEBUG, "starting client TLS handshake");
+ LOG(LOG_DEBUG, "transferring data");
- /* 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;
+ /* Proxy data between client and server until one suite is done
+ * (EOF or error). */
+ transfer_data(client_socket, server_socket);
- LOG(LOG_DEBUG, "client TLS handshake finished");
+ LOG(LOG_DEBUG, "finished transferring data");
+
+ goto out;
+ }
+ /* server_certificate_path() may open the file, close it. */
+ if (NULL != file) {
+ fclose(file);
+ }
+ }
result = initialize_tls_session_server(server_socket, &server_session,
&server_x509_cred);
}
server_session_started = 1;
- LOG(LOG_DEBUG, "server TLS handshake finished, transferring data");
+ LOG(LOG_DEBUG, "server TLS handshake finished");
+
+ /* Make sure the server certificate is valid and known. */
+ if (0 != verify_tls_connection(server_session, host)) {
+ LOG(LOG_ERROR, "server certificate validation failed!");
+ /* We send the error message over our TLS connection to the client,
+ * but with an invalid certificate. */
+ validation_failed = 1;
+ }
+
+ /* Initialize TLS server credentials to talk to the client. */
+ result = initialize_tls_session_client(client_socket,
+ /* use special host if the server
+ * certificate was invalid */
+ (validation_failed) ? "invalid"
+ : 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;
+
+ /* 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);
- /* FIXME: verify server's fingerprint */
+ 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");
+
+ /* Tell the client that the verification failed. Shouldn't be necessary as
+ * the client should terminate the connection because he received the
+ * invalid certificate but better be sure. */
+ if (validation_failed) {
+ tls_send_invalid_cert_message(client_session);
+ goto out;
+ }
+
+ LOG(LOG_DEBUG, "transferring TLS data");
/* 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");
+ LOG(LOG_DEBUG, "finished transferring TLS data");
out:
- /* Close TLS sessions if necessary. */
+ /* Close TLS sessions if necessary. Use GNUTLS_SHUT_RDWR so the data is
+ * reliable transmitted. */
if (0 != server_session_started) {
- gnutls_bye(server_session, GNUTLS_SHUT_WR);
+ gnutls_bye(server_session, GNUTLS_SHUT_RDWR);
}
if (0 != client_session_started) {
- gnutls_bye(client_session, GNUTLS_SHUT_WR);
+ gnutls_bye(client_session, GNUTLS_SHUT_RDWR);
}
if (0 != server_session_init) {
gnutls_deinit(server_session);
gnutls_session_t *session,
gnutls_certificate_credentials_t *x509_cred) {
int result;
+ int use_invalid_cert;
char path[1024];
- /* The server certificate for the given hostname is stored in
- * "./certificate-hostname-proxy.pem". */
-#define PATH_FORMAT "./certificate-%s-proxy.pem"
+
+ /* The "invalid" hostname is special. If it's used we send an invalid
+ * certificate to let the client know something is wrong. */
+ use_invalid_cert = 0 == strcmp(hostname, "invalid");
/* Hostname too long. */
- if (sizeof(path) - strlen(PATH_FORMAT) <= strlen(hostname)) {
+ if (sizeof(path) - strlen(PROXY_SERVER_CERT_FORMAT) <= strlen(hostname)) {
LOG(LOG_WARNING,
"initialize_tls_session_client(): hostname too long: '%s'",
hostname);
hostname);
return -1;
}
- snprintf(path, sizeof(path), PATH_FORMAT, hostname);
-#undef PATH_FORMAT
+ snprintf(path, sizeof(path), PROXY_SERVER_CERT_FORMAT, hostname);
result = gnutls_certificate_allocate_credentials(x509_cred);
if (GNUTLS_E_SUCCESS != result) {
}
/* 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 (!use_invalid_cert) {
+ result = gnutls_certificate_set_x509_trust_file(*x509_cred,
+ PROXY_CA_FILE,
+ GNUTLS_X509_FMT_PEM);
+ /* If the invalid hostname was specified do nothing, we use a self-signed
+ * certificate in this case. */
+ } else {
+ result = 1;
+ }
if (0 >= result) {
LOG(LOG_ERROR,
"initialize_tls_session_client(): can't read CA file: '%s'",
PROXY_CA_FILE);
+ gnutls_certificate_free_credentials(*x509_cred);
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 (!use_invalid_cert) {
+ result = gnutls_certificate_set_x509_key_file(*x509_cred,
+ path, PROXY_KEY_FILE,
+ GNUTLS_X509_FMT_PEM);
+ /* If the invalid hostname was specified load our special "invalid"
+ * certificate. */
+ } else {
+ result = gnutls_certificate_set_x509_key_file(*x509_cred,
+ PROXY_INVALID_CERT_FILE,
+ 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));
+ gnutls_certificate_free_credentials(*x509_cred);
/* Could be a missing certificate. */
return -2;
}
LOG(LOG_ERROR,
"initialize_tls_session_client(): gnutls_init(): %s",
gnutls_strerror(result));
+ gnutls_certificate_free_credentials(*x509_cred);
return -1;
}
result = gnutls_priority_set(*session, tls_priority_cache);
LOG(LOG_ERROR,
"initialize_tls_session_client(): gnutls_priority_set(): %s",
gnutls_strerror(result));
+ gnutls_deinit(*session);
+ gnutls_certificate_free_credentials(*x509_cred);
return -1;
}
result = gnutls_credentials_set(*session,
LOG(LOG_ERROR,
"initialize_tls_session_client(): gnutls_credentials_set(): %s",
gnutls_strerror(result));
+ gnutls_deinit(*session);
+ gnutls_certificate_free_credentials(*x509_cred);
return -1;
}
LOG(LOG_ERROR,
"initialize_tls_session_server(): gnutls_init(): %s",
gnutls_strerror(result));
+ gnutls_certificate_free_credentials(*x509_cred);
return -1;
}
gnutls_priority_set(*session, tls_priority_cache);
LOG(LOG_ERROR,
"initialize_tls_session_server(): gnutls_priority_set(): %s",
gnutls_strerror(result));
+ gnutls_deinit(*session);
+ gnutls_certificate_free_credentials(*x509_cred);
return -1;
}
result = gnutls_credentials_set(*session,
LOG(LOG_ERROR,
"initialize_tls_session_server(): gnutls_credentials_set(): %s",
gnutls_strerror(result));
+ gnutls_deinit(*session);
+ gnutls_certificate_free_credentials(*x509_cred);
return -1;
}
}
static void send_bad_request(FILE *client_fd) {
- fprintf(client_fd, "HTTP/1.0 400 Bad Request\r\n");
- fprintf(client_fd, "\r\n");
+#define RESPONSE_ERROR "400 Bad Request"
+#define RESPONSE_MSG "Your browser sent an invalid request."
+ fprintf(client_fd, HTTP_RESPONSE_FORMAT,
+ RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_ERROR,
+ RESPONSE_MSG);
+#undef RESPONSE_ERROR
+#undef RESPONSE_MSG
}
static void send_forwarding_failure(FILE *client_fd) {
- fprintf(client_fd, "HTTP/1.0 503 Forwarding failure\r\n");
- fprintf(client_fd, "\r\n");
+#define RESPONSE_ERROR "503 Forwarding failure"
+#define RESPONSE_MSG "Failed to connect to server, check logs."
+ fprintf(client_fd, HTTP_RESPONSE_FORMAT,
+ RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_ERROR,
+ RESPONSE_MSG);
+#undef RESPONSE_ERROR
+#undef RESPONSE_MSG
+}
+static void tls_send_invalid_cert_message(gnutls_session_t session) {
+#define RESPONSE_ERROR "500 Internal Server Error"
+#define RESPONSE_MSG "Server certificate validation failed, check logs."
+
+ char buffer[sizeof(HTTP_RESPONSE_FORMAT) - 1 /* '\0' */
+ - 4 * 2 /* four %s */
+ + (sizeof(RESPONSE_ERROR) - 1 /* '\0' */) * 3
+ + sizeof(RESPONSE_MSG) - 1 /* '\0' */
+ + 1 /* '\0' */];
+
+ snprintf(buffer, sizeof(buffer),
+ HTTP_RESPONSE_FORMAT,
+ RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_MSG);
+
+ gnutls_record_send(session, buffer, sizeof(buffer) - 1);
+ /* don't send trailing '\0' */
+#undef RESPONSE_ERROR
+#undef RESPONSE_MSG
}
-#if 0
/* Transfer data between client and server sockets until one closes the
* connection. */
static void transfer_data(int client, int server) {
ssize_t size_written;
char buffer[4096];
+ LOG(LOG_DEBUG, "read_from_write_to(): %d -> %d", from, to);
+
size_read = read(from, buffer, sizeof(buffer));
if (0 > size_read) {
LOG_PERROR(LOG_WARNING, "read_from_write_to(): read()");
return 0;
}
-#endif
/* Transfer data between client and server TLS connection until one closes the
* connection. */
return 0;
}
-
-
-static void log_message(int level, const char *format, ...) {
- va_list ap;
- const char *level_string;
-
- if (global_log_level < level) {
- return;
- }
-
- switch (level) {
- case LOG_ERROR: level_string = "ERROR"; break;
- case LOG_WARNING: level_string = "WARN "; break;
- case LOG_DEBUG: level_string = "DEBUG"; break;
- default: level_string = "UNKNOWN";
- }
-
- va_start(ap, format);
- fprintf(stdout, "[%s] [%d] ", level_string, (int)pthread_self());
- vfprintf(stdout, format, ap);
- fprintf(stdout, "\n");
- va_end(ap);
-}
ruderich.org/simon / tlsproxy / tlsproxy.git / blobdiff