/*
* Verify established TLS connections.
*
- * Copyright (C) 2011 Simon Ruderich
+ * Copyright (C) 2011-2012 Simon Ruderich
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#include <gnutls/x509.h>
+static int get_certificate_path(const char *format,
+ const char *hostname, char *buffer, size_t size);
+
+
int verify_tls_connection(gnutls_session_t session, const char *hostname) {
int result;
char path[1024];
gnutls_x509_crt_deinit(cert);
return -1;
}
- /* We got the certificate as PEM, free it. */
+ /* We got the certificate as PEM, free the crt struct. */
gnutls_x509_crt_deinit(cert);
- /* Hostname too long. */
- if (sizeof(path) - strlen(STORED_SERVER_CERT_FORMAT) <= strlen(hostname)) {
- LOG(LOG_WARNING,
- "verify_tls_connection(): hostname too long: '%s'",
- hostname);
- return -1;
- }
- /* Try to prevent path traversals in hostnames. */
- if (NULL != strstr(hostname, "..")) {
- LOG(LOG_WARNING,
- "verify_tls_connection(): possible path traversal: '%s'",
- hostname);
- return -1;
- }
- snprintf(path, sizeof(path), STORED_SERVER_CERT_FORMAT, hostname);
-
- /* Open the stored certificate file. */
- file = fopen(path, "rb");
- if (NULL == file) {
- LOG(LOG_WARNING,
- "verify_tls_connection(): failed to open '%s': %s",
- path, strerror(errno));
+ /* Open stored server certificate file. */
+ if (0 != server_certificate_file(&file, hostname, path, sizeof(path))) {
+ LOG(LOG_DEBUG, "server certificate:\n%s", server_cert);
return -1;
}
size += strlen(buffer);
/* Make sure the buffer is big enough. */
if (sizeof(stored_cert) <= size) {
- LOG(LOG_WARNING, "verify_tls_connection(): '%s' too big",
- path);
+ LOG(LOG_WARNING, "verify_tls_connection(): '%s' too big", path);
fclose(file);
+
+ LOG(LOG_DEBUG, "server certificate:\n%s", server_cert);
return -1;
}
LOG(LOG_WARNING,
"verify_tls_connection(): failed to read from '%s': %s",
path, strerror(errno));
+
+ LOG(LOG_DEBUG, "server certificate:\n%s", server_cert);
return -1;
}
fclose(file);
LOG(LOG_ERROR,
"verify_tls_connection(): server certificate changed!",
path, strerror(errno));
+
+ LOG(LOG_WARNING, "server certificate:\n%s", server_cert);
+ return -2;
+ }
+
+ /* Check that the proxy certificate file exists and is readable for this
+ * domain. This ensures we send an "invalid" certificate even if the proxy
+ * certificate doesn't exist. */
+ if (0 != proxy_certificate_path(hostname, path, sizeof(path))) {
+ return -1;
+ }
+ file = fopen(path, "r");
+ if (NULL == file) {
+ LOG(LOG_WARNING,
+ "verify_tls_connection(): proxy certificate doesn't exist: '%s'",
+ path);
+ return -1;
+ }
+ fclose(file);
+
+ return 0;
+}
+
+
+static int get_certificate_path(const char *format,
+ const char *hostname, char *buffer, size_t size) {
+ int result;
+
+ /* Hostname too long. */
+ if (size - strlen(format) <= strlen(hostname)) {
+ LOG(LOG_WARNING,
+ "get_certificate_path(): hostname too long: '%s'",
+ hostname);
+ return -1;
+ }
+ /* Try to prevent path traversals in hostnames. */
+ if (NULL != strstr(hostname, "..")) {
+ LOG(LOG_WARNING,
+ "get_certificate_path(): possible path traversal: '%s'",
+ hostname);
+ return -1;
+ }
+ /* Safe as format is no user input. */
+ result = snprintf(buffer, size, format, hostname);
+ if (result < 0) {
+ LOG_PERROR(LOG_ERROR, "get_certificate_path(): snprintf failed");
+ return -1;
+ } else if ((size_t)result >= size) {
+ LOG(LOG_ERROR, "get_certificate_path(): snprintf buffer too short");
+ return -1;
+ }
+
+ return 0;
+}
+
+int proxy_certificate_path(const char *hostname, char *path, size_t size) {
+ return get_certificate_path(PROXY_SERVER_CERT_FORMAT,
+ hostname, path, size);
+}
+
+int server_certificate_file(FILE **file, const char *hostname,
+ char *path, size_t size) {
+ if (0 != get_certificate_path(STORED_SERVER_CERT_FORMAT,
+ hostname, path, size)) {
+ LOG_PERROR(LOG_ERROR,
+ "server_certificate_file(): failed to get path");
+ return -1;
+ }
+
+ /* Open the stored certificate file. */
+ *file = fopen(path, "rb");
+ if (NULL == *file) {
+ if (global_passthrough_unknown) {
+ LOG(LOG_DEBUG,
+ "server_certificate_file(): failed to open '%s': %s",
+ path, strerror(errno));
+ } else {
+ LOG(LOG_WARNING,
+ "server_certificate_file(): failed to open '%s': %s",
+ path, strerror(errno));
+ }
+ /* Couldn't open the file, special case. */
return -2;
}