Base64 Encoding/Decoding
pjproject-2.10\pjlib-util\include\pjlib-util\base64.h
/* $Id$ */ /* * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifndef __PJLIB_UTIL_BASE64_H__ #define __PJLIB_UTIL_BASE64_H__ /** * @file base64.h * @brief Base64 encoding and decoding */ #include <pjlib-util/types.h> PJ_BEGIN_DECL /** * @defgroup PJLIB_UTIL_BASE64 Base64 Encoding/Decoding * @ingroup PJLIB_UTIL_ENCRYPTION * @{ * This module implements base64 encoding and decoding. */ /** * Helper macro to calculate the approximate length required for base256 to * base64 conversion. */ #define PJ_BASE256_TO_BASE64_LEN(len) (len * 4 / 3 + 3) /** * Helper macro to calculate the approximage length required for base64 to * base256 conversion. */ #define PJ_BASE64_TO_BASE256_LEN(len) (len * 3 / 4) /** * Encode a buffer into base64 encoding. * * @param input The input buffer. * @param in_len Size of the input buffer. * @param output Output buffer. Caller must allocate this buffer with * the appropriate size. * @param out_len On entry, it specifies the length of the output buffer. * Upon return, this will be filled with the actual * length of the output buffer. * * @return PJ_SUCCESS on success. */ PJ_DECL(pj_status_t) pj_base64_encode(const pj_uint8_t *input, int in_len, char *output, int *out_len); /** * Decode base64 string. * * @param input Input string. * @param out Buffer to store the output. Caller must allocate * this buffer with the appropriate size. * @param out_len On entry, it specifies the length of the output buffer. * Upon return, this will be filled with the actual * length of the output. */ PJ_DECL(pj_status_t) pj_base64_decode(const pj_str_t *input, pj_uint8_t *out, int *out_len); /** * @} */ PJ_END_DECL #endif /* __PJLIB_UTIL_BASE64_H__ */
pjproject-2.10\pjlib-util\src\pjlib-util\base64.c
/* $Id$ */ /* * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <pjlib-util/base64.h> #include <pj/assert.h> #include <pj/errno.h> #define INV -1 #define PADDING '=' static const char base64_char[] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' }; static int base256_char(char c) { if (c >= 'A' && c <= 'Z') return (c - 'A'); else if (c >= 'a' && c <= 'z') return (c - 'a' + 26); else if (c >= '0' && c <= '9') return (c - '0' + 52); else if (c == '+') return (62); else if (c == '/') return (63); else { /* It *may* happen on bad input, so this is not a good idea. * pj_assert(!"Should not happen as '=' should have been filtered"); */ return INV; } } static void base256to64(pj_uint8_t c1, pj_uint8_t c2, pj_uint8_t c3, int padding, char *output) { *output++ = base64_char[c1>>2]; *output++ = base64_char[((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4)]; switch (padding) { case 0: *output++ = base64_char[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)]; *output = base64_char[c3 & 0x3F]; break; case 1: *output++ = base64_char[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)]; *output = PADDING; break; case 2: default: *output++ = PADDING; *output = PADDING; break; } } PJ_DEF(pj_status_t) pj_base64_encode(const pj_uint8_t *input, int in_len, char *output, int *out_len) { const pj_uint8_t *pi = input; pj_uint8_t c1, c2, c3; int i = 0; char *po = output; PJ_ASSERT_RETURN(input && output && out_len, PJ_EINVAL); PJ_ASSERT_RETURN(*out_len >= PJ_BASE256_TO_BASE64_LEN(in_len), PJ_ETOOSMALL); while (i < in_len) { c1 = *pi++; ++i; if (i == in_len) { base256to64(c1, 0, 0, 2, po); po += 4; break; } else { c2 = *pi++; ++i; if (i == in_len) { base256to64(c1, c2, 0, 1, po); po += 4; break; } else { c3 = *pi++; ++i; base256to64(c1, c2, c3, 0, po); } } po += 4; } *out_len = (int)(po - output); return PJ_SUCCESS; } PJ_DEF(pj_status_t) pj_base64_decode(const pj_str_t *input, pj_uint8_t *out, int *out_len) { const char *buf; int len; int i, j, k; int c[4]; PJ_ASSERT_RETURN(input && out && out_len, PJ_EINVAL); buf = input->ptr; len = (int)input->slen; while (len && buf[len-1] == '=') --len; PJ_ASSERT_RETURN(*out_len >= PJ_BASE64_TO_BASE256_LEN(len), PJ_ETOOSMALL); for (i=0, j=0; i<len; ) { /* Fill up c, silently ignoring invalid characters */ for (k=0; k<4 && i<len; ++k) { do { c[k] = base256_char(buf[i++]); } while (c[k]==INV && i<len); } if (k<4) { if (k > 1) { out[j++] = (pj_uint8_t)((c[0]<<2) | ((c[1] & 0x30)>>4)); if (k > 2) { out[j++] = (pj_uint8_t) (((c[1] & 0x0F)<<4) | ((c[2] & 0x3C)>>2)); } } break; } out[j++] = (pj_uint8_t)((c[0]<<2) | ((c[1] & 0x30)>>4)); out[j++] = (pj_uint8_t)(((c[1] & 0x0F)<<4) | ((c[2] & 0x3C)>>2)); out[j++] = (pj_uint8_t)(((c[2] & 0x03)<<6) | (c[3] & 0x3F)); } pj_assert(j <= *out_len); *out_len = j; return PJ_SUCCESS; }
