Base64Enc.cpp
上传用户:woshihumen
上传日期:2013-07-18
资源大小:484k
文件大小:4k
- /*
- * XMail by Davide Libenzi ( Intranet and Internet mail server )
- * Copyright (C) 1999,..,2004 Davide Libenzi
- *
- * 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
- *
- * Davide Libenzi <davidel@xmailserver.org>
- *
- */
- #include "SysInclude.h"
- #include "SysDep.h"
- #include "SvrDefines.h"
- #include "StrUtils.h"
- #include "BuffSock.h"
- #include "MiscUtils.h"
- #include "Base64Enc.h"
- #define OK (0)
- #define FAIL (-1)
- #define BUFOVER (-2)
- #define CHAR64(c) (((c) < 0 || (c) > 127) ? -1 : index_64[(c)])
- static char basis_64[] =
- "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????";
- static char index_64[128] = {
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
- 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
- -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
- 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
- -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
- 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1
- };
- int encode64(const char *_in, unsigned inlen, char *_out, unsigned outmax, unsigned *outlen)
- {
- const unsigned char *in = (const unsigned char *) _in;
- unsigned char *out = (unsigned char *) _out;
- unsigned char oval;
- char *blah;
- unsigned olen;
- olen = (inlen + 2) / 3 * 4;
- if (outlen)
- *outlen = olen;
- if (outmax < olen)
- return BUFOVER;
- blah = (char *) out;
- while (inlen >= 3) {
- /* user provided max buffer size; make sure we don't go over it */
- *out++ = basis_64[in[0] >> 2];
- *out++ = basis_64[((in[0] << 4) & 0x30) | (in[1] >> 4)];
- *out++ = basis_64[((in[1] << 2) & 0x3c) | (in[2] >> 6)];
- *out++ = basis_64[in[2] & 0x3f];
- in += 3;
- inlen -= 3;
- }
- if (inlen > 0) {
- /* user provided max buffer size; make sure we don't go over it */
- *out++ = basis_64[in[0] >> 2];
- oval = (in[0] << 4) & 0x30;
- if (inlen > 1)
- oval |= in[1] >> 4;
- *out++ = basis_64[oval];
- *out++ = (inlen < 2) ? '=' : basis_64[(in[1] << 2) & 0x3c];
- *out++ = '=';
- }
- if (olen < outmax)
- *out = ' ';
- return OK;
- }
- int decode64(const char *in, unsigned inlen, char *out, unsigned *outlen)
- {
- unsigned len = 0;
- unsigned lup;
- int c1;
- int c2;
- int c3;
- int c4;
- if (inlen >= 2 && in[0] == '+' && in[1] == ' ')
- in += 2, inlen -= 2;
- if (*in == ' ')
- return FAIL;
- for (lup = 0; lup < inlen / 4; lup++) {
- c1 = in[0];
- if (CHAR64(c1) == -1)
- return FAIL;
- c2 = in[1];
- if (CHAR64(c2) == -1)
- return FAIL;
- c3 = in[2];
- if (c3 != '=' && CHAR64(c3) == -1)
- return FAIL;
- c4 = in[3];
- if (c4 != '=' && CHAR64(c4) == -1)
- return FAIL;
- in += 4;
- *out++ = (CHAR64(c1) << 2) | (CHAR64(c2) >> 4);
- ++len;
- if (c3 != '=') {
- *out++ = ((CHAR64(c2) << 4) & 0xf0) | (CHAR64(c3) >> 2);
- ++len;
- if (c4 != '=') {
- *out++ = ((CHAR64(c3) << 6) & 0xc0) | CHAR64(c4);
- ++len;
- }
- }
- }
- *out = 0;
- *outlen = len;
- return OK;
- }