Base64 and base16 decoding: Use *dst_length as output only.

ChangeLog

+2014-02-07  Niels Möller  <nisse@lysator.liu.se>
+
+	* base64-decode.c (base64_decode_update): Use *dst_length for
+	output only. Don't require callers to pass a sane value.
+	* base16-decode.c (base16_decode_update): Likewise.
+
 2014-02-06  Niels Möller  <nisse@lysator.liu.se>
 
 	* NEWS: List _set_key incompatibilities.

base16-decode.c

@@ -101,8 +101,6 @@ base16_decode_update(struct base16_decode_ctx *ctx,
   size_t done;
   size_t i;
 
-  assert(*dst_length >= BASE16_DECODE_LENGTH(src_length));
-  
   for (i = done = 0; i<src_length; i++)
     switch(base16_decode_single(ctx, dst + done, src[i]))
       {

base16.h

@@ -81,13 +81,9 @@ base16_decode_single(struct base16_decode_ctx *ctx,
 		     uint8_t src);
 
 /* Returns 1 on success, 0 on error. DST should point to an area of
- * size at least BASE16_DECODE_LENGTH(length), and for sanity
- * checking, *DST_LENGTH should be initialized to the size of that
- * area before the call. *DST_LENGTH is updated to the amount of
- * decoded output. */
+ * size at least BASE16_DECODE_LENGTH(length). The amount of data
+ * generated is returned in *DST_LENGTH. */
 
-/* Currently results in an assertion failure if *DST_LENGTH is
- * too small. FIXME: Return some error instead? */
 int
 base16_decode_update(struct base16_decode_ctx *ctx,
 		     size_t *dst_length,

base64-decode.c

@@ -122,8 +122,6 @@ base64_decode_update(struct base64_decode_ctx *ctx,
   size_t done;
   size_t i;
 
-  assert(*dst_length >= BASE64_DECODE_LENGTH(src_length));
-  
   for (i = 0, done = 0; i<src_length; i++)
     switch(base64_decode_single(ctx, dst + done, src[i]))
       {

base64.h

@@ -128,13 +128,8 @@ base64_decode_single(struct base64_decode_ctx *ctx,
 		     uint8_t src);
 
 /* Returns 1 on success, 0 on error. DST should point to an area of
- * size at least BASE64_DECODE_LENGTH(length), and for sanity
- * checking, *DST_LENGTH should be initialized to the size of that
- * area before the call. *DST_LENGTH is updated to the amount of
- * decoded output. */
-
-/* Currently results in an assertion failure if *DST_LENGTH is
- * too small. FIXME: Return some error instead? */
+ * size at least BASE64_DECODE_LENGTH(length). The amount of data
+ * generated is returned in *DST_LENGTH. */
 int
 base64_decode_update(struct base64_decode_ctx *ctx,
 		     size_t *dst_length,