Base64 C源码

#include "StdAfx.h" #include "Base64.h" char base64EncodeChars[65] ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";//编码后的字符集 int base64DecodeChars[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 };//对应ASICC字符的位置 char* base64encode(LPCTSTR str) { //加密 char Out[260]={0}; int i = 0, len = strlen(str); char c1, c2, c3; while (i < len) { c1 = str[i++] & 0xff; if (i == len) { sprintf(Out,"%s%c",Out,base64EncodeChars[c1 >> 2]); sprintf(Out,"%s%c",Out,base64EncodeChars[(c1 & 0x3) << 4]); sprintf(Out,"%s==",Out); break; } c2 = str[i++]; if (i == len) { sprintf(Out,"%s%c",Out,base64EncodeChars[c1 >> 2]); sprintf(Out,"%s%c",Out,base64EncodeChars[((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4)]); sprintf(Out,"%s%c",Out,base64EncodeChars[(c2 & 0xF) << 2]); sprintf(Out,"%s==",Out); break; } c3 = str[i++]; sprintf(Out,"%s%c",Out,base64EncodeChars[c1 >> 2]); sprintf(Out,"%s%c",Out,base64EncodeChars[((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4)]); sprintf(Out,"%s%c",Out,base64EncodeChars[((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6)]); sprintf(Out,"%s%c",Out,base64EncodeChars[c3 & 0x3F]); } return &(*Out); } char* utf16to8(LPCTSTR str) { char Out[260] ={0}; int i, len; char c;//char为16位Unicode字符,范围0~0xffff, len = strlen(str); for (i = 0; i < len; i++) {//根据字符的不同范围分别转化 c = str[i]; if ((c >= 0x0001) && (c <= 0x007F)) { sprintf(Out,"%s%c",Out,str[i]); } else if (c > 0x07FF) { sprintf(Out,"%s%c",Out,(0xE0 | ((c >> 12) & 0x0F))); sprintf(Out,"%s%c",Out,(0xE0 | ((c >> 12) & 0x0F))); sprintf(Out,"%s%c",Out,(0x80 | ((c >> 6) & 0x3F))); sprintf(Out,"%s%c",Out,(0x80 | ((c >> 0) & 0x3F))); } else { sprintf(Out,"%s%c",Out,(0xC0 | ((c >> 6) & 0x1F))); sprintf(Out,"%s%c",Out,(0x80 | ((c >> 0) & 0x3F))); } } return &(*Out); } char* base64decode(LPCTSTR str) {//解密 int c1, c2, c3, c4; int i=0, len; char Out[260]={0}; len = strlen(str); while (i < len) { do { c1 = base64DecodeChars[str[i++] & 0xff]; } while (i < len && c1 == -1); if (c1 == -1) break; do { c2 = base64DecodeChars[str[i++] & 0xff]; } while (i < len && c2 == -1); if (c2 == -1) break; sprintf(Out,"%s%c",Out,((c1 << 2) | ((c2 & 0x30) >> 4))); do { c3 = str[i++] & 0xff; if (c3 == 61) return Out; c3 = base64DecodeChars[c3]; } while (i < len && c3 == -1); if (c3 == -1) break; sprintf(Out,"%s%c",Out,((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2)); do { c4 = str[i++] & 0xff; if (c4 == 61) return Out; c4 = base64DecodeChars[c4]; } while (i < len && c4 == -1); if (c4 == -1) break; sprintf(Out,"%s%c",Out,((c3 & 0x03) << 6) | c4); } return &(*Out); } char* utf8to16(LPCTSTR str) { char Out[260]={0}; int i=0, len; char c, char2, char3; len = strlen(str); while (i < len) { c = str[i++]; switch (c >> 4) { case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: sprintf(Out,"%s%c",Out,str[i - 1]); break; case 12: case 13: char2 = str[i++]; sprintf(Out,"%s%c",Out,(((c & 0x1F) << 6) | (char2 & 0x3F))); break; case 14: char2 = str[i++]; char3 = str[i++]; sprintf(Out,"%s%c",Out,(((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0))); break; } } return &(*Out); }