Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
wine-mirror
GitHub Repository: wine-mirror/wine
 Path: blob/master/libs/tomcrypt/src/misc/base64/base64_decode.c
5972 views
1
/* LibTomCrypt, modular cryptographic library -- Tom St Denis

2
 *

3
 * LibTomCrypt is a library that provides various cryptographic

4
 * algorithms in a highly modular and flexible manner.

5
 *

6
 * The library is free for all purposes without any express

7
 * guarantee it works.

8
 */

9
#include "tomcrypt.h"

10


11
/**

12
  @file base64_decode.c

13
  Compliant base64 code donated by Wayne Scott ([email protected])

14
  base64 URL Safe variant (RFC 4648 section 5) by Karel Miko

15
*/

16


17


18
#if defined(LTC_BASE64) || defined (LTC_BASE64_URL)

19


20
#if defined(LTC_BASE64)

21
static const unsigned char map_base64[256] = {

22
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

23
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

24
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

25
255, 255, 255, 255, 255, 255, 255,  62, 255, 255, 255,  63,

26
 52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255,

27
255, 254, 255, 255, 255,   0,   1,   2,   3,   4,   5,   6,

28
  7,   8,   9,  10,  11,  12,  13,  14,  15,  16,  17,  18,

29
 19,  20,  21,  22,  23,  24,  25, 255, 255, 255, 255, 255,

30
255,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,

31
 37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,  48,

32
 49,  50,  51, 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,

39
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

40
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

41
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

42
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

43
255, 255, 255, 255 };

44
#endif /* LTC_BASE64 */

45


46
static const unsigned char map_base64url[] = {

47
#if defined(LTC_BASE64_URL)

48
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

49
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

50
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

51
255, 255, 255, 255, 255, 255, 255, 255, 255,  62, 255, 255,

52
 52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255,

53
255, 254, 255, 255, 255,   0,   1,   2,   3,   4,   5,   6,

54
  7,   8,   9,  10,  11,  12,  13,  14,  15,  16,  17,  18,

55
 19,  20,  21,  22,  23,  24,  25, 255, 255, 255, 255,  63,

56
255,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,

57
 37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,  48,

58
 49,  50,  51, 255, 255, 255, 255, 255, 255, 255, 255, 255,

59
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

60
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

61
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

62
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

63
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

64
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

65
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

66
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

67
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

68
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

69
255, 255, 255, 255

70
#endif /* LTC_BASE64_URL */

71
};

72


73
enum {

74
   relaxed = 0,

75
   strict = 1

76
};

77


78
static int _base64_decode_internal(const unsigned char *in,  unsigned long inlen,

79
                                 unsigned char *out, unsigned long *outlen,

80
                           const unsigned char *map, int is_strict)

81
{

82
   unsigned long t, x, y, z;

83
   unsigned char c;

84
   int           g;

85


86
   LTC_ARGCHK(in     != NULL);

87
   LTC_ARGCHK(out    != NULL);

88
   LTC_ARGCHK(outlen != NULL);

89


90
   g = 0; /* '=' counter */

91
   for (x = y = z = t = 0; x < inlen; x++) {

92
       c = map[in[x]&0xFF];

93
       if (c == 254) {

94
          g++;

95
          continue;

96
       }

97
       else if (is_strict && g > 0) {

98
          /* we only allow '=' to be at the end */

99
          return CRYPT_INVALID_PACKET;

100
       }

101
       if (c == 255) {

102
          if (is_strict)

103
             return CRYPT_INVALID_PACKET;

104
          else

105
             continue;

106
       }

107


108
       t = (t<<6)|c;

109


110
       if (++y == 4) {

111
          if (z + 3 > *outlen) return CRYPT_BUFFER_OVERFLOW;

112
          out[z++] = (unsigned char)((t>>16)&255);

113
          out[z++] = (unsigned char)((t>>8)&255);

114
          out[z++] = (unsigned char)(t&255);

115
          y = t = 0;

116
       }

117
   }

118


119
   if (y != 0) {

120
      if (y == 1) return CRYPT_INVALID_PACKET;

121
      if ((y + g) != 4 && is_strict && map != map_base64url) return CRYPT_INVALID_PACKET;

122
      t = t << (6 * (4 - y));

123
      if (z + y - 1 > *outlen) return CRYPT_BUFFER_OVERFLOW;

124
      if (y >= 2) out[z++] = (unsigned char) ((t >> 16) & 255);

125
      if (y == 3) out[z++] = (unsigned char) ((t >> 8) & 255);

126
   }

127
   *outlen = z;

128
   return CRYPT_OK;

129
}

130


131
#if defined(LTC_BASE64)

132
/**

133
   Relaxed base64 decode a block of memory

134
   @param in       The base64 data to decode

135
   @param inlen    The length of the base64 data

136
   @param out      [out] The destination of the binary decoded data

137
   @param outlen   [in/out] The max size and resulting size of the decoded data

138
   @return CRYPT_OK if successful

139
*/

140
int base64_decode(const unsigned char *in,  unsigned long inlen,

141
                        unsigned char *out, unsigned long *outlen)

142
{

143
    return _base64_decode_internal(in, inlen, out, outlen, map_base64, relaxed);

144
}

145


146
/**

147
   Strict base64 decode a block of memory

148
   @param in       The base64 data to decode

149
   @param inlen    The length of the base64 data

150
   @param out      [out] The destination of the binary decoded data

151
   @param outlen   [in/out] The max size and resulting size of the decoded data

152
   @return CRYPT_OK if successful

153
*/

154
int base64_strict_decode(const unsigned char *in,  unsigned long inlen,

155
                        unsigned char *out, unsigned long *outlen)

156
{

157
   return _base64_decode_internal(in, inlen, out, outlen, map_base64, strict);

158
}

159
#endif /* LTC_BASE64 */

160


161
#if defined(LTC_BASE64_URL)

162
/**

163
   Relaxed base64 (URL Safe, RFC 4648 section 5) decode a block of memory

164
   @param in       The base64 data to decode

165
   @param inlen    The length of the base64 data

166
   @param out      [out] The destination of the binary decoded data

167
   @param outlen   [in/out] The max size and resulting size of the decoded data

168
   @return CRYPT_OK if successful

169
*/

170
int base64url_decode(const unsigned char *in,  unsigned long inlen,

171
                           unsigned char *out, unsigned long *outlen)

172
{

173
    return _base64_decode_internal(in, inlen, out, outlen, map_base64url, relaxed);

174
}

175


176
/**

177
   Strict base64 (URL Safe, RFC 4648 section 5) decode a block of memory

178
   @param in       The base64 data to decode

179
   @param inlen    The length of the base64 data

180
   @param out      [out] The destination of the binary decoded data

181
   @param outlen   [in/out] The max size and resulting size of the decoded data

182
   @return CRYPT_OK if successful

183
*/

184
int base64url_strict_decode(const unsigned char *in,  unsigned long inlen,

185
                           unsigned char *out, unsigned long *outlen)

186
{

187
    return _base64_decode_internal(in, inlen, out, outlen, map_base64url, strict);

188
}

189
#endif /* LTC_BASE64_URL */

190


191
#endif

192


193