Amos Jeffries <[email protected]> writes:
> The attached patch implements a proposed API/ABI extension adding
> support for RFC 4648 section 5 "Base 64 Encoding with URL and Filename
> Safe Alphabet"
Thanks. I have some comments below. Also, testcases are essential (and I
suspect that the definition of base64_encode_group is not really
accepted by the compiler).
> For the standardized alphabets external code simply calls the init()
> function relevant to the alphabet it is needing to encode/decode with.
> The library internally uses the context to select which lookup table to
> use for later base64 function calls.
Or we could introduce a generalized init function, if that need arises.
> -#define ENCODE(x) (encode_table[0x3F & (x)])
> +#define ENCODE(x) (ctx->alphabet[0x3F & (x)])
I think
#define ENCODE(alphabet, x) ((alphabet)[0x3F & (x)])
is better, not relying on "ctx" variable being defined where the macro
is used.
> void
> base64_encode_raw(uint8_t *dst, size_t length, const uint8_t *src)
> {
> + struct base64_encode_ctx ctx;
> + base64_encode_init(&ctx);
> + _base64_encode_raw(&cxt, dst, length, src);
> +}
I think it would be better to let _base64_encode_raw take the alphabet
as an argument. base64_encode_raw would then be simply
void
base64_encode_raw(uint8_t *dst, size_t length, const uint8_t *src)
{
_base64_encode_raw(default_encode_table, dst, length, src);
}
> void
> base64_encode_group(uint8_t *dst, uint32_t group)
> {
> + struct base64_encode ctx;
> + base64_encode_init(&ctx);
> +
> *dst++ = ENCODE(group >> 18);
> *dst++ = ENCODE(group >> 12);
> *dst++ = ENCODE(group >> 6);
> @@ -144,6 +111,7 @@ void
And similarly here, I think it would be better to not use any ctx
struct, and instead do
*dst++ = ENCODE(default_encode_table, group >> 18);
*dst++ = ENCODE(default_encode_table, group >> 12);
*dst++ = ENCODE(default_encode_table, group >> 6);
(And this function is of questionable utility...)
Regards,
/Niels
--
Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26.
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