Strip '\r' characters when reading text files on Unix.

This patch ensures that we strip "\r" characters on both Windows as well
as Unix when we read text files. This should prevent the issue where
some Tor state files have been moved from a Windows machine, and thus
contains CRLF line ending, to a Unix machine where only \n is needed.

We add a test-case to ensure that we handle this properly on all our
platforms.

See: https://bugs.torproject.org/tpo/core/tor/33781

1 files changed, 49 insertions, 0 deletions

diff --git a/src/test/test_util.c b/src/test/test_util.c
index 3a0eb15157..06ea8191a2 100644
--- a/src/test/test_util.c
+++ b/src/test/test_util.c
@@ -173,6 +173,54 @@ test_util_read_file_eof_zero_bytes(void *arg)
   test_util_read_until_eof_impl("tor_test_fifo_empty", 0, 10000);
 }
 
+static void
+test_util_read_file_endlines(void *arg)
+{
+  (void)arg;
+
+  char *fname = NULL;
+  char *read_content = NULL;
+  int r = -1;
+
+  /* Write a file that contains both \n and \r\n as line ending. */
+  const char *file_content = "foo bar\n"
+                             "foo bar baz\r\n"
+                             "foo bar\r\n";
+
+  const char *expected_file_content = "foo bar\n"
+                                      "foo bar baz\n"
+                                      "foo bar\n";
+
+  fname = tor_strdup(get_fname("file_with_crlf_ending"));
+
+  r = write_bytes_to_file(fname, file_content, strlen(file_content), 1);
+  tt_int_op(r, OP_EQ, 0);
+
+  /* Read the file in text mode: we strip \r's from the files on both Windows
+   * and UNIX. */
+  read_content = read_file_to_str(fname, 0, NULL);
+
+  tt_ptr_op(read_content, OP_NE, NULL);
+  tt_int_op(strlen(read_content), OP_EQ, strlen(expected_file_content));
+  tt_str_op(read_content, OP_EQ, expected_file_content);
+
+  tor_free(read_content);
+
+  /* Read the file in binary mode: we should preserve the \r here. */
+  read_content = read_file_to_str(fname, RFTS_BIN, NULL);
+
+  tt_ptr_op(read_content, OP_NE, NULL);
+  tt_int_op(strlen(read_content), OP_EQ, strlen(file_content));
+  tt_str_op(read_content, OP_EQ, file_content);
+
+  tor_free(read_content);
+
+ done:
+  unlink(fname);
+  tor_free(fname);
+  tor_free(read_content);
+}
+
 /* Test the basic expected behaviour for write_chunks_to_file.
  * NOTE: This will need to be updated if we ever change the tempfile location
  * or extension */
@@ -6508,6 +6556,7 @@ struct testcase_t util_tests[] = {
   UTIL_TEST(read_file_eof_two_loops, 0),
   UTIL_TEST(read_file_eof_two_loops_b, 0),
   UTIL_TEST(read_file_eof_zero_bytes, 0),
+  UTIL_TEST(read_file_endlines, 0),
   UTIL_TEST(write_chunks_to_file, 0),
   UTIL_TEST(mathlog, 0),
   UTIL_TEST(fraction, 0),