+++ /dev/null
-/* base64.c
- *
- * Base64 "ASCII armor" codec.
- */
-
-/* nettle, low-level cryptographics library
- *
- * Copyright (C) 2002 Niels Möller, Dan Egnor
- *
- * The nettle library is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation; either version 2.1 of the License, or (at your
- * option) any later version.
- *
- * The nettle library is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
- * License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with the nettle library; see the file COPYING.LIB. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-#include "base64.h"
-
-#include <assert.h>
-#include <stdlib.h>
-
-#define TABLE_INVALID -1
-#define TABLE_SPACE -2
-#define TABLE_END -3
-
-static const uint8_t encode_table[64] =
- "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
- "abcdefghijklmnopqrstuvwxyz"
- "0123456789+/";
-
-static const signed char decode_table[256] =
-{
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -1, -1, -2, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
- 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -3, -1, -1,
- -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
- 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
- -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
- 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-};
-
-#define ENCODE(x) (encode_table[0x3F & (x)])
-
-void
-base64_encode_group(uint8_t *dst, uint32_t group)
-{
- *dst++ = ENCODE(group >> 18);
- *dst++ = ENCODE(group >> 12);
- *dst++ = ENCODE(group >> 6);
- *dst++ = ENCODE(group);
-}
-
-unsigned
-base64_encode(uint8_t *dst,
- unsigned src_length,
- const uint8_t *src)
-{
- unsigned dst_length = BASE64_ENCODE_LENGTH(src_length);
- const uint8_t *in = src + src_length;
- uint8_t *out = dst + dst_length;
- unsigned left_over = src_length % 3;
-
- if (left_over)
- {
- in -= left_over;
- *--out = '=';
- switch(left_over)
- {
- case 1:
- *--out = '=';
- *--out = ENCODE(in[0] << 4);
- break;
-
- case 2:
- *--out = ENCODE( in[1] << 2);
- *--out = ENCODE((in[0] << 4) | (in[1] >> 4));
- break;
-
- default:
- abort();
- }
- *--out = ENCODE(in[0] >> 2);
- }
-
- while (in > src)
- {
- in -= 3;
- *--out = ENCODE( in[2]);
- *--out = ENCODE((in[1] << 2) | (in[2] >> 6));
- *--out = ENCODE((in[0] << 4) | (in[1] >> 4));
- *--out = ENCODE( in[0] >> 2);
- }
-
- assert(out == dst);
-
- return dst_length;
-}
-
-void
-base64_decode_init(struct base64_ctx *ctx)
-{
- ctx->shift = 10;
- ctx->accum = 0;
-}
-
-unsigned
-base64_decode_update(struct base64_ctx *ctx,
- uint8_t *dst,
- unsigned src_length,
- const uint8_t *src)
-{
- uint8_t *out = dst;
-
- for (;;)
- {
- int data;
- if (src_length == 0) return out - dst;
- data = decode_table[*src];
- switch (data)
- {
- default:
- ctx->accum |= data << ctx->shift;
- ctx->shift -= 6;
- if (ctx->shift <= 2)
- {
- *out++ = ctx->accum >> 8;
- ctx->accum <<= 8;
- ctx->shift += 8;
- }
- /* Fall through */
- case TABLE_INVALID:
- case TABLE_SPACE:
- case TABLE_END:
- /* FIXME: Silently ignores any invalid characters.
- * We need to detect and return errors, in some way. */
- ++src;
- --src_length;
- }
- }
-}