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Viewing changes to libtomcrypt/base64_decode.c

  • Committer: Bazaar Package Importer
  • Author(s): Matt Johnston
  • Date: 2005-12-08 19:20:21 UTC
  • mfrom: (1.2.2 upstream)
  • Revision ID: james.westby@ubuntu.com-20051208192021-nyp9rwnt77nsg6ty
Tags: 0.47-1
* New upstream release.
* SECURITY: Fix incorrect buffer sizing.

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libtomcrypt/base64_decode.c
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis
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 *
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 * LibTomCrypt is a library that provides various cryptographic
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 * algorithms in a highly modular and flexible manner.
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 *
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 * The library is free for all purposes without any express
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 * guarantee it works.
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 *
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 * Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org
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 */
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/* compliant base64 code donated by Wayne Scott (wscott@bitmover.com) */
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#include "mycrypt.h"
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#ifdef BASE64
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static const unsigned char map[256] = {
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255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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255, 255, 255, 255, 255, 255, 255,  62, 255, 255, 255,  63,
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 52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255,
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255, 254, 255, 255, 255,   0,   1,   2,   3,   4,   5,   6,
24
 
  7,   8,   9,  10,  11,  12,  13,  14,  15,  16,  17,  18,
25
 
 19,  20,  21,  22,  23,  24,  25, 255, 255, 255, 255, 255,
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255,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,
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 37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
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 49,  50,  51, 255, 255, 255, 255, 255, 255, 255, 255, 255,
29
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
30
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
31
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
32
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
33
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
34
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
35
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
36
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
37
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
38
 
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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255, 255, 255, 255 };
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int base64_decode(const unsigned char *in,  unsigned long len, 
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                        unsigned char *out, unsigned long *outlen)
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{
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   unsigned long t, x, y, z;
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   unsigned char c;
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   int           g;
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   _ARGCHK(in     != NULL);
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   _ARGCHK(out    != NULL);
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   _ARGCHK(outlen != NULL);
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   g = 3;
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   for (x = y = z = t = 0; x < len; x++) {
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       c = map[in[x]&0xFF];
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       if (c == 255) continue;
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       if (c == 254) { c = 0; g--; }
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       t = (t<<6)|c;
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       if (++y == 4) {
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          if (z + g > *outlen) { 
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             return CRYPT_BUFFER_OVERFLOW; 
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          }
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          out[z++] = (unsigned char)((t>>16)&255);
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          if (g > 1) out[z++] = (unsigned char)((t>>8)&255);
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          if (g > 2) out[z++] = (unsigned char)(t&255);
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          y = t = 0;
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       }
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   }
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   if (y != 0) {
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       return CRYPT_INVALID_PACKET;
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   }
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   *outlen = z;
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   return CRYPT_OK;
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}
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#endif
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