C语言实现base64编码，base64解码
jopen
9年前
C语言实现base64编码，base64解码。
char *base64_encode(char *binData, char *base64, int binLength) { int i = 0; int j = 0; int current = 0; for (i = 0; i < binLength; i += 3) { //获取第一个6位 current = (*(binData+i) >> 2) & 0x3F; *(base64 + j++) = base64char[current]; //获取第二个6位的前两位 current = (*(binData+i) << 4) & 0x30; //如果只有一个字符，那么需要做特殊处理 if (binLength <= (i+1)) { *(base64 + j++) = base64char[current]; *(base64 + j++) = '='; *(base64 + j++) = '='; break; } //获取第二个6位的后四位 current |= (*(binData+i+1) >> 4 ) & 0xf; *(base64 + j++) = base64char[current]; //获取第三个6位的前四位 current = (*(binData+i+1) << 2 ) & 0x3c; if (binLength <= (i+2)) { *(base64 + j++) = base64char[current]; *(base64 + j++) = '='; break; } //获取第三个6位的后两位 current |= (*(binData+i+2) >> 6) & 0x03; *(base64 + j++) = base64char[current]; //获取第四个6位 current = *(binData+i+2) & 0x3F; *(base64 + j++) = base64char[current]; } *(base64+j) = '\0'; return base64; } char *base64_decode(char const *base64Str, char *debase64Str, int encodeStrLen) { int i = 0; int j = 0; int k = 0; char temp[4] = ""; for (i = 0; i < encodeStrLen; i += 4) { for (j = 0; j < 64 ; j++) { if (*(base64Str + i) == base64char[j]) { temp[0] = j; } } for (j = 0; j < 64 ; j++) { if (*(base64Str + i + 1) == base64char[j]) { temp[1] = j; } } for (j = 0; j < 64 ; j++) { if (*(base64Str + i + 2) == base64char[j]) { temp[2] = j; } } for (j = 0; j < 64 ; j++) { if (*(base64Str + i + 3) == base64char[j]) { temp[3] = j; } } *(debase64Str + k++) = ((temp[0] << 2) & 0xFC) | ((temp[1]>>4) & 0x03); if ( *(base64Str + i + 2) == '=' ) break; *(debase64Str + k++) = ((temp[1] << 4) & 0xF0) | ((temp[2]>>2) & 0x0F); if ( *(base64Str + i + 3) == '=' ) break; *(debase64Str + k++) = ((temp[2] << 6) & 0xF0) | (temp[3] & 0x3F); } return debase64Str; }