-fixing string decoder issue for input sizes of a multiple of 5

2 files changed, 44 insertions, 32 deletions

diff --git a/src/util/strings.c b/src/util/strings.c
index e9b5b3c210..8bbc904bc2 100644
--- a/src/util/strings.c
+++ b/src/util/strings.c
@@ -817,7 +817,7 @@ GNUNET_STRINGS_data_to_string (const void *data, size_t size, char *out, size_t
  * @param enc the encoding
  * @param enclen number of characters in 'enc' (without 0-terminator, which can be missing)
  * @param out location where to store the decoded data
- * @param out_size sizeof the output buffer
+ * @param out_size size of the output buffer
  * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
  */
 int
@@ -831,31 +831,40 @@ GNUNET_STRINGS_string_to_data (const char *enc, size_t enclen,
   int ret;
   int shift;
   unsigned char *uout;
-  int encoded_len = out_size * 8;
+  unsigned int encoded_len = out_size * 8;
 
+  if (0 == enclen)
+  {
+    if (0 == out_size)
+      return GNUNET_OK;
+    return GNUNET_SYSERR;
+  }
   uout = out;
-  if (encoded_len % 5 > 0)
+  wpos = out_size;
+  rpos = enclen;
+  if ((encoded_len % 5) > 0)
   {
     vbit = encoded_len % 5; /* padding! */
     shift = 5 - vbit;
+    bits = (ret = getValue__ (enc[--rpos])) >> (5 - (encoded_len % 5));
   }
   else
   {
-    vbit = 0;
+    vbit = 5;
     shift = 0;
+    bits = (ret = getValue__ (enc[--rpos]));
   }
   if ((encoded_len + shift) / 5 != enclen)
     return GNUNET_SYSERR;
-
-  wpos = out_size;
-  rpos = enclen;
-  bits = (ret = getValue__ (enc[--rpos])) >> (5 - encoded_len % 5);
   if (-1 == ret)
     return GNUNET_SYSERR;
   while (wpos > 0)
   {
     if (0 == rpos)
+    {
+      GNUNET_break (0);
       return GNUNET_SYSERR;
+    }
     bits = ((ret = getValue__ (enc[--rpos])) << vbit) | bits;
     if (-1 == ret)
       return GNUNET_SYSERR;
diff --git a/src/util/test_strings_to_data.c b/src/util/test_strings_to_data.c
index d98cd85782..7397735583 100644
--- a/src/util/test_strings_to_data.c
+++ b/src/util/test_strings_to_data.c
@@ -30,30 +30,33 @@
 int
 main (int argc, char *argv[])
 {
-	GNUNET_log_setup ("util", "DEBUG", NULL);
-	char *conv;
-	char buf[255];
-	char *end;
-	struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded src;
-	struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded dest;
-
-	memset (&src, '\1', sizeof (src));
-	memset (&dest, '\2', sizeof (dest));
-
-	end = GNUNET_STRINGS_data_to_string (&src, sizeof (src), buf, sizeof (buf));
-	end[0] = '\0';
-	fprintf (stderr, "Key `%s'\n",buf);
-	GNUNET_assert (GNUNET_OK == GNUNET_CRYPTO_ecc_public_key_from_string (buf, strlen (buf), &dest));
-
-	conv = GNUNET_CRYPTO_ecc_public_key_to_string (&src);
-	GNUNET_assert (NULL != conv);
-	fprintf (stderr, "Key `%s'\n",conv);
-
-
-  GNUNET_assert (GNUNET_OK == GNUNET_STRINGS_string_to_data (conv, strlen (conv), (unsigned char *) &dest, sizeof (dest)));
-  GNUNET_assert (0 == memcmp (&src, &dest, sizeof (dest)));
-
-	return 0;
+  char buf[1024];
+  char *end;
+  char src[128];
+  char dst[128];
+  unsigned int i;
+  int ret = 0;
+  
+  GNUNET_log_setup ("util", "DEBUG", NULL);
+  for (i=0;i<sizeof(src);i++)
+  {
+    memset (src, i, sizeof (src));
+    memset (dst, i+1, sizeof (dst));
+
+    end = GNUNET_STRINGS_data_to_string (&src, i, buf, sizeof (buf));
+    end[0] = '\0';
+    if (GNUNET_OK != 
+	GNUNET_STRINGS_string_to_data (buf, strlen (buf), dst, i))
+    {
+      fprintf (stderr, "%u failed decode (%u bytes)\n", i, (unsigned int) strlen (buf));
+      ret = 1;
+    } else if (0 != memcmp (src, dst, i))
+    {
+      fprintf (stderr, "%u wrong decode (%u bytes)\n", i, (unsigned int) strlen (buf));
+      ret = 1;
+    }
+  }
+  return ret;
 }