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pippijn |
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/* |
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pippijn |
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* $Id: base64.h,v 1.1 2007-07-19 08:24:50 pippijn Exp $ |
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pippijn |
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*/ |
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/* base64.h - base64 enc algorithm */ |
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#ifndef BASE64_H |
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#define BASE64_H |
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#include <cstddef> |
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namespace base64 |
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{ |
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class encoder |
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{ |
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enum step |
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{ |
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step_a, step_b, step_c |
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}; |
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struct state |
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{ |
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enum step step; |
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char result; |
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int stepcnt; |
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}; |
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static size_t enc_block (char const * const text, size_t inlen, char *code, state *st); |
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static size_t enc_blockend (char *code, state *st); |
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static size_t const CHARS_PER_LINE = 72; |
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static char enc_value (char val) |
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{ |
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static char const * const enc = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
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if (val > 63) |
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return '='; |
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return enc[(size_t) val]; |
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} |
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state m_state; |
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size_t m_bufsize; |
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size_t enc_end (char *outtext) |
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{ |
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return enc_blockend (outtext, &m_state); |
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} |
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public: |
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encoder (size_t bufsize = 4096) |
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: m_bufsize (bufsize) |
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{ |
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} |
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size_t encode (char val) |
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{ |
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return enc_value (val); |
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} |
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size_t encode (char const * const code, size_t const inlen, char *outtext) |
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{ |
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return enc_block (code, inlen, outtext, &m_state); |
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} |
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bool encode (char const * const code, size_t const inlen, char **outtext) |
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{ |
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size_t outlen = 1 + (((inlen + 2) / 3) * 4); |
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if (inlen > outlen) |
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{ |
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*outtext = NULL; |
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return 0; |
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} |
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*outtext = new char[outlen]; |
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if (*outtext) |
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encode (code, inlen, *outtext); |
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return outlen - 1; |
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} |
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}; |
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class decoder |
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{ |
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enum step |
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{ |
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step_a, step_b, step_c, step_d |
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}; |
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struct state |
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{ |
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enum step step; |
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char plainchar; |
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}; |
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static size_t dec_block (char const * const code, size_t const inlen, char *outtext, state *st); |
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static size_t dec_value (char val) |
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{ |
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static char const dec[] = { |
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62, -1, -1, -1, 63, 52, 53, 54, 55, 56, |
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57, 58, 59, 60, 61, -1, -1, -1, -2, -1, |
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-1, -1, 0, 1, 2, 3, 4, 5, 6, 7, |
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8, 9, 10, 11, 12, 13, 14, 15, 16, 17, |
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18, 19, 20, 21, 22, 23, 24, 25, -1, -1, |
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-1, -1, -1, -1, 26, 27, 28, 29, 30, 31, |
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32, 33, 34, 35, 36, 37, 38, 39, 40, 41, |
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42, 43, 44, 45, 46, 47, 48, 49, 50, 51 |
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}; |
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static char const decsize = sizeof (dec); |
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val -= 43; |
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if (val < 0 || val > decsize) |
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return -1; |
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return dec[(size_t) val]; |
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} |
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state m_state; |
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size_t m_bufsize; |
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public: |
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decoder (size_t bufsize = 4096) |
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: m_bufsize (bufsize) |
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{ |
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} |
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size_t decode (char val) |
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{ |
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return dec_value (val); |
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} |
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size_t decode (char const * const code, size_t const inlen, char *outtext) |
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{ |
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return dec_block (code, inlen, outtext, &m_state); |
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} |
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bool decode (char const * const code, size_t const inlen, char **outtext, size_t *outlen) |
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{ |
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size_t needlen = 3 * (inlen / 4) + 3; |
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*outtext = new char[needlen]; |
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if (!*outtext) |
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return false; |
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if (!decode (code, inlen, *outtext)) |
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{ |
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delete[] *outtext; |
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*outtext = NULL; |
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return false; |
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} |
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(*outtext)[needlen] = '\0'; |
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if (outlen) |
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*outlen = needlen; |
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return true; |
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} |
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}; |
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} // namespace base64 |
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#endif // BASE64_H |