Applied patch from Dan Egnor improving the base64 code.

* base64.h (BASE64_ENCODE_LENGTH): New macro.
(struct base64_ctx): New context struct, for decoding.
(BASE64_DECODE_LENGTH): New macro.
* base64.c (base64_decode_init): New function.
(base64_decode_update): New function, replacing base64_decode.
Takes a struct base64_ctx argument.
* nettle-meta.h: Updated nettle_armor, and related typedefs and
macros.
* testsuite/testutils.c (test_armor): Updated.
* configure.in: Use AC_PREREQ(2.50).

Rev: src/nettle/testsuite/testutils.c:1.9

testsuite/testutils.c

@@ -228,11 +228,12 @@ test_armor(const struct nettle_armor *armor,
            const uint8_t *data,
            const uint8_t *ascii)
 {
+  void *ctx = alloca(armor->context_size);
   uint8_t *buffer = alloca(1 + strlen(ascii));
   uint8_t *check = alloca(1 + data_length);
 
-  memset(buffer, 0, 1 + strlen(ascii));
-  memset(check, 0, 1 + data_length);
+  memset(buffer, 0x33, 1 + strlen(ascii));
+  memset(check, 0x55, 1 + data_length);
 
   if (strlen(ascii) != armor->encode(buffer, data_length, data))
     FAIL();
@@ -240,16 +241,17 @@ test_armor(const struct nettle_armor *armor,
   if (!MEMEQ(strlen(ascii), buffer, ascii))
     FAIL();
 
-  if (buffer[strlen(ascii)])
+  if (0x33 != buffer[strlen(ascii)])
     FAIL();  
 
-  if (data_length != armor->decode(check, strlen(ascii), buffer))
+  armor->decode_init(ctx);
+  if (data_length != armor->decode_update(ctx, check, strlen(ascii), buffer))
     FAIL();
 
   if (!MEMEQ(data_length, check, data))
     FAIL();
 
-  if (check[data_length])
+  if (0x55 != check[data_length])
     FAIL();
 }