Coverage Report

Created: 2024-11-25 06:29

/src/nettle/base64-decode.c
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Count
Source (jump to first uncovered line)
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/* base64-encode.c
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   Copyright (C) 2002 Niels Möller
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   This file is part of GNU Nettle.
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   GNU Nettle is free software: you can redistribute it and/or
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   modify it under the terms of either:
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     * the GNU Lesser General Public License as published by the Free
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       Software Foundation; either version 3 of the License, or (at your
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       option) any later version.
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   or
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     * the GNU General Public License as published by the Free
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       Software Foundation; either version 2 of the License, or (at your
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       option) any later version.
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   or both in parallel, as here.
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   GNU Nettle is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   General Public License for more details.
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   You should have received copies of the GNU General Public License and
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   the GNU Lesser General Public License along with this program.  If
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   not, see http://www.gnu.org/licenses/.
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*/
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#if HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <assert.h>
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#include <stdlib.h>
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#include "base64.h"
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0
#define TABLE_INVALID -1
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0
#define TABLE_SPACE -2
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8.13k
#define TABLE_END -3
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void
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base64_decode_init(struct base64_decode_ctx *ctx)
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12.1k
{
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  static const signed char base64_decode_table[0x100] =
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    {
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      /* White space is HT, VT, FF, CR, LF and SPC */
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -2, -2, -2, -1, -1, 
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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      -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
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      52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -3, -1, -1,
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      -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
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      15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
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      -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
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      41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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    };
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  ctx->word = ctx->bits = ctx->padding = 0;
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  ctx->table = base64_decode_table;
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}
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int
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base64_decode_single(struct base64_decode_ctx *ctx,
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         uint8_t *dst,
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         char src)
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14.1M
{
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  int data = ctx->table[(uint8_t) src];
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  switch(data)
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14.1M
    {
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    default:
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      assert(data >= 0 && data < 0x40);
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      if (ctx->padding)
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0
  return -1;
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      ctx->word = ctx->word << 6 | data;
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      ctx->bits += 6;
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      if (ctx->bits >= 8)
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10.6M
  {
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    ctx->bits -= 8;
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    dst[0] = ctx->word >> ctx->bits;
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    return 1;
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  }
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3.54M
      else return 0;
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0
    case TABLE_INVALID:
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0
      return -1;
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0
    case TABLE_SPACE:
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0
      return 0;
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    case TABLE_END:
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      /* There can be at most two padding characters. */
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      if (!ctx->bits || ctx->padding > 2)
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0
  return -1;
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      if (ctx->word & ( (1<<ctx->bits) - 1))
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  /* We shouldn't have any leftover bits */
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  return -1;
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      ctx->padding++;
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      ctx->bits -= 2;
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      return 0;
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14.1M
    }
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}
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int
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base64_decode_update(struct base64_decode_ctx *ctx,
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         size_t *dst_length,
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         uint8_t *dst,
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         size_t src_length,
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         const char *src)
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12.1k
{
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  size_t done;
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  size_t i;
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  for (i = 0, done = 0; i<src_length; i++)
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    switch(base64_decode_single(ctx, dst + done, src[i]))
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      {
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0
      case -1:
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0
  return 0;
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      case 1:
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  done++;
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  /* Fall through */
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      case 0:
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  break;
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0
      default:
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0
  abort();
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      }
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  assert(done <= BASE64_DECODE_LENGTH(src_length));
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  *dst_length = done;
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  return 1;
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}
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int
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base64_decode_final(struct base64_decode_ctx *ctx)
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12.1k
{
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  return ctx->bits == 0;
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}