From 73c6cb8353355d5895b67252ac28489428263875 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Mon, 3 Nov 2008 16:36:15 +0000
Subject: [PATCH] Fix unit test failure related to intro point parsing.

svn:r17188
---
 ChangeLog            |  2 ++
 src/or/routerparse.c | 25 +++++++++++++++----------
 src/or/test.c        |  4 ++--
 3 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 4e8901f42f..ed1bb0de22 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -54,6 +54,8 @@ Changes in version 0.2.1.7-alpha - 2008-11-xx
       addresses.  Possible fix for bug 845 and bug 811.
     - Make the assert_circuit_ok() function work correctly on circuits that
       have already been marked for close.
+    - Fix read-off-the-end-of-string error in unit tests when decoding
+      introduction points.
 
 
 Changes in version 0.2.1.6-alpha - 2008-09-30
diff --git a/src/or/routerparse.c b/src/or/routerparse.c
index c6b7454966..d093b72220 100644
--- a/src/or/routerparse.c
+++ b/src/or/routerparse.c
@@ -3671,7 +3671,7 @@ rend_decrypt_introduction_points(char **ipos_decrypted,
         crypto_free_cipher_env(cipher);
         cipher = crypto_create_init_cipher(session_key, 0);
         len = ipos_encrypted_size - 2 - client_entries_len - CIPHER_IV_LEN;
-        dec = tor_malloc_zero(len);
+        dec = tor_malloc(len);
         declen = crypto_cipher_decrypt_with_iv(cipher, dec, len,
             ipos_encrypted + 2 + client_entries_len,
             ipos_encrypted_size - 2 - client_entries_len);
@@ -3681,7 +3681,7 @@ rend_decrypt_introduction_points(char **ipos_decrypted,
           tor_free(dec);
           return -1;
         }
-        if (strcmpstart(dec, "introduction-point ")) {
+        if (memcmpstart(dec, declen, "introduction-point ")) {
           log_warn(LD_REND, "Decrypted introduction points don't "
                             "look like we could parse them.");
           tor_free(dec);
@@ -3731,7 +3731,7 @@ rend_parse_introduction_points(rend_service_descriptor_t *parsed,
                                const char *intro_points_encoded,
                                size_t intro_points_encoded_size)
 {
-  const char **current_ipo;
+  const char *current_ipo, *end_of_intro_points;
   smartlist_t *tokens;
   directory_token_t *tok;
   rend_intro_point_t *intro;
@@ -3744,28 +3744,33 @@ rend_parse_introduction_points(rend_service_descriptor_t *parsed,
   tor_assert(intro_points_encoded);
   tor_assert(intro_points_encoded_size > 0);
   /* Consider one intro point after the other. */
-  current_ipo = &intro_points_encoded;
+  current_ipo = intro_points_encoded;
+  end_of_intro_points = intro_points_encoded + intro_points_encoded_size;
   tokens = smartlist_create();
   parsed->intro_nodes = smartlist_create();
   area = memarea_new(4096);
-  while (!strcmpstart(*current_ipo, "introduction-point ")) {
+
+  while (!memcmpstart(current_ipo, end_of_intro_points-current_ipo,
+                      "introduction-point ")) {
     /* Determine end of string. */
-    const char *eos = strstr(*current_ipo, "\nintroduction-point ");
+    const char *eos = tor_memstr(current_ipo, end_of_intro_points-current_ipo,
+                                 "\nintroduction-point ");
     if (!eos)
-      eos = *current_ipo+strlen(*current_ipo);
+      eos = end_of_intro_points;
     else
       eos = eos+1;
+    tor_assert(eos <= intro_points_encoded+intro_points_encoded_size);
     /* Free tokens and clear token list. */
     SMARTLIST_FOREACH(tokens, directory_token_t *, t, token_free(t));
     smartlist_clear(tokens);
     memarea_clear(area);
     /* Tokenize string. */
-    if (tokenize_string(area, *current_ipo, eos, tokens, ipo_token_table, 0)) {
-      log_warn(LD_REND, "Error tokenizing introduction point.");
+    if (tokenize_string(area, current_ipo, eos, tokens, ipo_token_table, 0)) {
+      log_warn(LD_REND, "Error tokenizing introduction point");
       goto err;
     }
     /* Advance to next introduction point, if available. */
-    *current_ipo = eos;
+    current_ipo = eos;
     /* Check minimum allowed length of introduction point. */
     if (smartlist_len(tokens) < 5) {
       log_warn(LD_REND, "Impossibly short introduction point.");
diff --git a/src/or/test.c b/src/or/test.c
index cf142d279a..c90a35db0b 100644
--- a/src/or/test.c
+++ b/src/or/test.c
@@ -4262,8 +4262,8 @@ test_rend_fns_v2(void)
   test_assert(parsed);
   test_memeq(((rend_encoded_v2_service_descriptor_t *)
              smartlist_get(descs, 0))->desc_id, parsed_desc_id, DIGEST_LEN);
-  test_assert(rend_parse_introduction_points(parsed, intro_points_encrypted,
-                                             intro_points_size) == 3);
+  test_eq(rend_parse_introduction_points(parsed, intro_points_encrypted,
+                                         intro_points_size), 3);
   test_assert(!crypto_pk_cmp_keys(generated->pk, parsed->pk));
   test_eq(parsed->timestamp, now);
   test_eq(parsed->version, 2);