X-Git-Url: https://ruderich.org/simon/gitweb/?a=blobdiff_plain;f=src%2Fverify.c;h=6ea5f1b23d07f45be840f813035410129765d466;hb=c98db32cbc4a3f7e4b655aacfbc503639bb8379c;hp=63ca6da2d982a121d36cb8b6779e795ba0c72f30;hpb=a964f7f572ec43c2d2f143bdb4a467f1ea5dbc36;p=tlsproxy%2Ftlsproxy.git

diff --git a/src/verify.c b/src/verify.c
index 63ca6da..6ea5f1b 100644
--- a/src/verify.c
+++ b/src/verify.c
@@ -1,7 +1,7 @@
 /*
  * Verify established TLS connections.
  *
- * Copyright (C) 2011  Simon Ruderich
+ * Copyright (C) 2011-2013  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
@@ -26,9 +26,13 @@
 #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];
+    char path[TLSPROXY_MAX_PATH_LENGTH];
 
     size_t size;
     unsigned int status;
@@ -110,7 +114,7 @@ int verify_tls_connection(gnutls_session_t session, const char *hostname) {
     gnutls_x509_crt_deinit(cert);
 
     /* Open stored server certificate file. */
-    if (0 != server_certificate_path(&file, hostname, path, sizeof(path))) {
+    if (0 != server_certificate_file(&file, hostname, path, sizeof(path))) {
         LOG(LOG_DEBUG, "server certificate:\n%s", server_cert);
         return -1;
     }
@@ -152,35 +156,67 @@ int verify_tls_connection(gnutls_session_t session, const char *hostname) {
         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;
 }
 
-int server_certificate_path(FILE **file, const char *hostname,
-                            char *path, size_t size) {
+
+static int get_certificate_path(const char *format,
+        const char *hostname, char *buffer, size_t size) {
     int result;
 
     /* Hostname too long. */
-    if (size - strlen(STORED_SERVER_CERT_FORMAT) <= strlen(hostname)) {
+    if (size - strlen(format) <= strlen(hostname)) {
         LOG(LOG_WARNING,
-            "server_certificate_path(): hostname too long: '%s'",
+            "get_certificate_path(): hostname too long: '%s'",
             hostname);
         return -1;
     }
     /* Try to prevent path traversals in hostnames. */
     if (NULL != strstr(hostname, "..")) {
         LOG(LOG_WARNING,
-            "server_certificate_path(): possible path traversal: '%s'",
+            "get_certificate_path(): possible path traversal: '%s'",
             hostname);
         return -1;
     }
-    result = snprintf(path, size, STORED_SERVER_CERT_FORMAT, hostname);
+    /* Safe as format is no user input. */
+    result = snprintf(buffer, size, format, hostname);
     if (result < 0) {
-        LOG_PERROR(LOG_ERROR,
-                   "server_certificate_path(): snprintf failed");
+        LOG_PERROR(LOG_ERROR, "get_certificate_path(): snprintf failed");
         return -1;
     } else if ((size_t)result >= size) {
-        LOG(LOG_ERROR,
-            "server_certificate_path(): snprintf buffer too short");
+        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;
     }
 
@@ -189,11 +225,11 @@ int server_certificate_path(FILE **file, const char *hostname,
     if (NULL == *file) {
         if (global_passthrough_unknown) {
             LOG(LOG_DEBUG,
-                "server_certificate_path(): failed to open '%s': %s",
+                "server_certificate_file(): failed to open '%s': %s",
                 path, strerror(errno));
         } else {
             LOG(LOG_WARNING,
-                "server_certificate_path(): failed to open '%s': %s",
+                "server_certificate_file(): failed to open '%s': %s",
                 path, strerror(errno));
         }
         /* Couldn't open the file, special case. */