| 1 |
/* |
| 2 |
* $Id: base64.h,v 1.1 2007-07-19 08:24:50 pippijn Exp $ |
| 3 |
*/ |
| 4 |
/* base64.h - base64 enc algorithm */ |
| 5 |
|
| 6 |
#ifndef BASE64_H |
| 7 |
#define BASE64_H |
| 8 |
|
| 9 |
#include <cstddef> |
| 10 |
|
| 11 |
namespace base64 |
| 12 |
{ |
| 13 |
class encoder |
| 14 |
{ |
| 15 |
enum step |
| 16 |
{ |
| 17 |
step_a, step_b, step_c |
| 18 |
}; |
| 19 |
|
| 20 |
struct state |
| 21 |
{ |
| 22 |
enum step step; |
| 23 |
char result; |
| 24 |
int stepcnt; |
| 25 |
}; |
| 26 |
|
| 27 |
static size_t enc_block (char const * const text, size_t inlen, char *code, state *st); |
| 28 |
static size_t enc_blockend (char *code, state *st); |
| 29 |
|
| 30 |
static size_t const CHARS_PER_LINE = 72; |
| 31 |
|
| 32 |
static char enc_value (char val) |
| 33 |
{ |
| 34 |
static char const * const enc = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| 35 |
if (val > 63) |
| 36 |
return '='; |
| 37 |
return enc[(size_t) val]; |
| 38 |
} |
| 39 |
|
| 40 |
state m_state; |
| 41 |
size_t m_bufsize; |
| 42 |
|
| 43 |
size_t enc_end (char *outtext) |
| 44 |
{ |
| 45 |
return enc_blockend (outtext, &m_state); |
| 46 |
} |
| 47 |
|
| 48 |
public: |
| 49 |
encoder (size_t bufsize = 4096) |
| 50 |
: m_bufsize (bufsize) |
| 51 |
{ |
| 52 |
} |
| 53 |
|
| 54 |
size_t encode (char val) |
| 55 |
{ |
| 56 |
return enc_value (val); |
| 57 |
} |
| 58 |
|
| 59 |
size_t encode (char const * const code, size_t const inlen, char *outtext) |
| 60 |
{ |
| 61 |
return enc_block (code, inlen, outtext, &m_state); |
| 62 |
} |
| 63 |
|
| 64 |
bool encode (char const * const code, size_t const inlen, char **outtext) |
| 65 |
{ |
| 66 |
size_t outlen = 1 + (((inlen + 2) / 3) * 4); |
| 67 |
if (inlen > outlen) |
| 68 |
{ |
| 69 |
*outtext = NULL; |
| 70 |
return 0; |
| 71 |
} |
| 72 |
|
| 73 |
*outtext = new char[outlen]; |
| 74 |
|
| 75 |
if (*outtext) |
| 76 |
encode (code, inlen, *outtext); |
| 77 |
|
| 78 |
return outlen - 1; |
| 79 |
} |
| 80 |
}; |
| 81 |
|
| 82 |
class decoder |
| 83 |
{ |
| 84 |
enum step |
| 85 |
{ |
| 86 |
step_a, step_b, step_c, step_d |
| 87 |
}; |
| 88 |
|
| 89 |
struct state |
| 90 |
{ |
| 91 |
enum step step; |
| 92 |
char plainchar; |
| 93 |
}; |
| 94 |
|
| 95 |
static size_t dec_block (char const * const code, size_t const inlen, char *outtext, state *st); |
| 96 |
|
| 97 |
static size_t dec_value (char val) |
| 98 |
{ |
| 99 |
static char const dec[] = { |
| 100 |
62, -1, -1, -1, 63, 52, 53, 54, 55, 56, |
| 101 |
57, 58, 59, 60, 61, -1, -1, -1, -2, -1, |
| 102 |
-1, -1, 0, 1, 2, 3, 4, 5, 6, 7, |
| 103 |
8, 9, 10, 11, 12, 13, 14, 15, 16, 17, |
| 104 |
18, 19, 20, 21, 22, 23, 24, 25, -1, -1, |
| 105 |
-1, -1, -1, -1, 26, 27, 28, 29, 30, 31, |
| 106 |
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, |
| 107 |
42, 43, 44, 45, 46, 47, 48, 49, 50, 51 |
| 108 |
}; |
| 109 |
|
| 110 |
static char const decsize = sizeof (dec); |
| 111 |
|
| 112 |
val -= 43; |
| 113 |
if (val < 0 || val > decsize) |
| 114 |
return -1; |
| 115 |
return dec[(size_t) val]; |
| 116 |
} |
| 117 |
|
| 118 |
state m_state; |
| 119 |
size_t m_bufsize; |
| 120 |
|
| 121 |
public: |
| 122 |
decoder (size_t bufsize = 4096) |
| 123 |
: m_bufsize (bufsize) |
| 124 |
{ |
| 125 |
} |
| 126 |
|
| 127 |
size_t decode (char val) |
| 128 |
{ |
| 129 |
return dec_value (val); |
| 130 |
} |
| 131 |
|
| 132 |
size_t decode (char const * const code, size_t const inlen, char *outtext) |
| 133 |
{ |
| 134 |
return dec_block (code, inlen, outtext, &m_state); |
| 135 |
} |
| 136 |
|
| 137 |
bool decode (char const * const code, size_t const inlen, char **outtext, size_t *outlen) |
| 138 |
{ |
| 139 |
size_t needlen = 3 * (inlen / 4) + 3; |
| 140 |
*outtext = new char[needlen]; |
| 141 |
if (!*outtext) |
| 142 |
return false; |
| 143 |
|
| 144 |
if (!decode (code, inlen, *outtext)) |
| 145 |
{ |
| 146 |
delete[] *outtext; |
| 147 |
*outtext = NULL; |
| 148 |
return false; |
| 149 |
} |
| 150 |
|
| 151 |
(*outtext)[needlen] = '\0'; |
| 152 |
if (outlen) |
| 153 |
*outlen = needlen; |
| 154 |
|
| 155 |
return true; |
| 156 |
} |
| 157 |
}; |
| 158 |
} // namespace base64 |
| 159 |
|
| 160 |
#endif // BASE64_H |