1 files changed, 64 insertions, 120 deletions

diff --git a/src/common/util.c b/src/common/util.c
index 71b77e20fa..db160fdf0a 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -20,7 +20,6 @@
 #define UTIL_PRIVATE
 #include "util.h"
 #include "torlog.h"
-#undef log
 #include "crypto.h"
 #include "torint.h"
 #include "container.h"
@@ -337,8 +336,8 @@ tor_log_mallinfo(int severity)
  * ===== */
 
 /**
- * Returns the natural logarithm of d base 2.  We define this wrapper here so
- * as to make it easier not to conflict with Tor's log() macro.
+ * Returns the natural logarithm of d base e.  We defined this wrapper here so
+ * to avoid conflicts with old versions of tor_log(), which were named log().
  */
 double
 tor_mathlog(double d)
@@ -1191,119 +1190,10 @@ escaped(const char *s)
   return escaped_val_;
 }
 
-/** Rudimentary string wrapping code: given a un-wrapped <b>string</b> (no
- * newlines!), break the string into newline-terminated lines of no more than
- * <b>width</b> characters long (not counting newline) and insert them into
- * <b>out</b> in order.  Precede the first line with prefix0, and subsequent
- * lines with prefixRest.
- */
-/* This uses a stupid greedy wrapping algorithm right now:
- *  - For each line:
- *    - Try to fit as much stuff as possible, but break on a space.
- *    - If the first "word" of the line will extend beyond the allowable
- *      width, break the word at the end of the width.
- */
-void
-wrap_string(smartlist_t *out, const char *string, size_t width,
-            const char *prefix0, const char *prefixRest)
-{
-  size_t p0Len, pRestLen, pCurLen;
-  const char *eos, *prefixCur;
-  tor_assert(out);
-  tor_assert(string);
-  tor_assert(width);
-  if (!prefix0)
-    prefix0 = "";
-  if (!prefixRest)
-    prefixRest = "";
-
-  p0Len = strlen(prefix0);
-  pRestLen = strlen(prefixRest);
-  tor_assert(width > p0Len && width > pRestLen);
-  eos = strchr(string, '\0');
-  tor_assert(eos);
-  pCurLen = p0Len;
-  prefixCur = prefix0;
-
-  while ((eos-string)+pCurLen > width) {
-    const char *eol = string + width - pCurLen;
-    while (eol > string && *eol != ' ')
-      --eol;
-    /* eol is now the last space that can fit, or the start of the string. */
-    if (eol > string) {
-      size_t line_len = (eol-string) + pCurLen + 2;
-      char *line = tor_malloc(line_len);
-      memcpy(line, prefixCur, pCurLen);
-      memcpy(line+pCurLen, string, eol-string);
-      line[line_len-2] = '\n';
-      line[line_len-1] = '\0';
-      smartlist_add(out, line);
-      string = eol + 1;
-    } else {
-      size_t line_len = width + 2;
-      char *line = tor_malloc(line_len);
-      memcpy(line, prefixCur, pCurLen);
-      memcpy(line+pCurLen, string, width - pCurLen);
-      line[line_len-2] = '\n';
-      line[line_len-1] = '\0';
-      smartlist_add(out, line);
-      string += width-pCurLen;
-    }
-    prefixCur = prefixRest;
-    pCurLen = pRestLen;
-  }
-
-  if (string < eos) {
-    size_t line_len = (eos-string) + pCurLen + 2;
-    char *line = tor_malloc(line_len);
-    memcpy(line, prefixCur, pCurLen);
-    memcpy(line+pCurLen, string, eos-string);
-    line[line_len-2] = '\n';
-    line[line_len-1] = '\0';
-    smartlist_add(out, line);
-  }
-}
-
 /* =====
  * Time
  * ===== */
 
-/**
- * Converts struct timeval to a double value.
- * Preserves microsecond precision, but just barely.
- * Error is approx +/- 0.1 usec when dealing with epoch values.
- */
-double
-tv_to_double(const struct timeval *tv)
-{
-  double conv = tv->tv_sec;
-  conv += tv->tv_usec/1000000.0;
-  return conv;
-}
-
-/**
- * Converts timeval to milliseconds.
- */
-int64_t
-tv_to_msec(const struct timeval *tv)
-{
-  int64_t conv = ((int64_t)tv->tv_sec)*1000L;
-  /* Round ghetto-style */
-  conv += ((int64_t)tv->tv_usec+500)/1000L;
-  return conv;
-}
-
-/**
- * Converts timeval to microseconds.
- */
-int64_t
-tv_to_usec(const struct timeval *tv)
-{
-  int64_t conv = ((int64_t)tv->tv_sec)*1000000L;
-  conv += tv->tv_usec;
-  return conv;
-}
-
 /** Return the number of microseconds elapsed between *start and *end.
  */
 long
@@ -2389,8 +2279,10 @@ read_file_to_str(const char *filename, int flags, struct stat *stat_out)
   }
 #endif
 
-  if ((uint64_t)(statbuf.st_size)+1 >= SIZE_T_CEILING)
+  if ((uint64_t)(statbuf.st_size)+1 >= SIZE_T_CEILING) {
+    close(fd);
     return NULL;
+  }
 
   string = tor_malloc((size_t)(statbuf.st_size+1));
 
@@ -2550,10 +2442,13 @@ unescape_string(const char *s, char **result, size_t *size_out)
  * key portion and *<b>value_out</b> to a new string holding the value portion
  * of the line, and return a pointer to the start of the next line.  If we run
  * out of data, return a pointer to the end of the string.  If we encounter an
- * error, return NULL.
+ * error, return NULL and set *<b>err_out</b> (if provided) to an error
+ * message.
  */
 const char *
-parse_config_line_from_str(const char *line, char **key_out, char **value_out)
+parse_config_line_from_str_verbose(const char *line, char **key_out,
+                                   char **value_out,
+                                   const char **err_out)
 {
   /* I believe the file format here is supposed to be:
      FILE = (EMPTYLINE | LINE)* (EMPTYLASTLINE | LASTLINE)?
@@ -2627,12 +2522,18 @@ parse_config_line_from_str(const char *line, char **key_out, char **value_out)
 
   /* Find the end of the line. */
   if (*line == '\"') { // XXX No continuation handling is done here
-    if (!(line = unescape_string(line, value_out, NULL)))
-       return NULL;
+    if (!(line = unescape_string(line, value_out, NULL))) {
+      if (err_out)
+        *err_out = "Invalid escape sequence in quoted string";
+      return NULL;
+    }
     while (*line == ' ' || *line == '\t')
       ++line;
-    if (*line && *line != '#' && *line != '\n')
+    if (*line && *line != '#' && *line != '\n') {
+      if (err_out)
+        *err_out = "Excess data after quoted string";
       return NULL;
+    }
   } else {
     /* Look for the end of the line. */
     while (*line && *line != '\n' && (*line != '#' || continuation)) {
@@ -3847,12 +3748,13 @@ tor_spawn_background(const char *const filename, const char **argv,
   child_state = CHILD_STATE_MAXFD;
 
 #ifdef _SC_OPEN_MAX
-  if (-1 != max_fd) {
+  if (-1 == max_fd) {
     max_fd = (int) sysconf(_SC_OPEN_MAX);
-    if (max_fd == -1)
+    if (max_fd == -1) {
       max_fd = DEFAULT_MAX_FD;
       log_warn(LD_GENERAL,
                "Cannot find maximum file descriptor, assuming %d", max_fd);
+    }
   }
 #else
   max_fd = DEFAULT_MAX_FD;
@@ -5009,3 +4911,45 @@ tor_check_port_forwarding(const char *filename,
   }
 }
 
+/** Initialize the insecure RNG <b>rng</b> from a seed value <b>seed</b>. */
+void
+tor_init_weak_random(tor_weak_rng_t *rng, unsigned seed)
+{
+  rng->state = (uint32_t)(seed & 0x7fffffff);
+}
+
+/** Return a randomly chosen value in the range 0..TOR_WEAK_RANDOM_MAX based
+ * on the RNG state of <b>rng</b>.  This entropy will not be cryptographically
+ * strong; do not rely on it for anything an adversary should not be able to
+ * predict. */
+int32_t
+tor_weak_random(tor_weak_rng_t *rng)
+{
+  /* Here's a linear congruential generator. OpenBSD and glibc use these
+   * parameters; they aren't too bad, and should have maximal period over the
+   * range 0..INT32_MAX. We don't want to use the platform rand() or random(),
+   * since some platforms have bad weak RNGs that only return values in the
+   * range 0..INT16_MAX, which just isn't enough. */
+  rng->state = (rng->state * 1103515245 + 12345) & 0x7fffffff;
+  return (int32_t) rng->state;
+}
+
+/** Return a random number in the range [0 , <b>top</b>). {That is, the range
+ * of integers i such that 0 <= i < top.}  Chooses uniformly.  Requires that
+ * top is greater than 0. This randomness is not cryptographically strong; do
+ * not rely on it for anything an adversary should not be able to predict. */
+int32_t
+tor_weak_random_range(tor_weak_rng_t *rng, int32_t top)
+{
+  /* We don't want to just do tor_weak_random() % top, since random() is often
+   * implemented with an LCG whose modulus is a power of 2, and those are
+   * cyclic in their low-order bits. */
+  int divisor, result;
+  tor_assert(top > 0);
+  divisor = TOR_WEAK_RANDOM_MAX / top;
+  do {
+    result = (int32_t)(tor_weak_random(rng) / divisor);
+  } while (result >= top);
+  return result;
+}
+