/* * LumaQQ - Cross platform QQ client, special edition for Mac * * Copyright (C) 2007 luma <stubma@163.com> * * 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 */#import "NSData-Base64.h"@implementation NSData (Base64)const char alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";- (NSData*)base64Encode {	const unsigned char* data = (const unsigned char*)[self bytes];    int len = [self length];        NSMutableData* target = [NSMutableData dataWithLength: ((len - 1) / 3 + 1) * 4];    unsigned char* output = (unsigned char*)[target mutableBytes];        unsigned long val;    int quad, trip;        for(int i = 0, j = 0; i < len; i += 3, j += 4) {        quad = 0;        trip = 0;                val = data[i];        val <<= 8;                if((i + 1) < len) {            val |= data[i + 1];            trip = 1;        }        val <<= 8;                if((i + 2) < len) {            val |= data[i + 2];            quad = 1;        }                output[j + 3] = alphabet[(quad ? (val & 0x3f) : 64)];        val >>= 6;        output[j + 2] = alphabet[(trip ? (val & 0x3f) : 64)];        val >>= 6;        output[j + 1] = alphabet[val & 0x3f];        val >>= 6;        output[j] = alphabet[val];    }        return target;}- (NSData*)base64Decode {	const unsigned char* data = (const unsigned char*)[self bytes];    int len = [self length];        NSMutableData* target = [NSMutableData dataWithLength: (len / 4) * 3];    unsigned char* out = (unsigned char*)[target mutableBytes];        UInt32 val;        for(int i = 0, j = 0; i + 3 < len; i += 4, j += 3) {        val = 0;        for(int k = i; k < i + 4; k++) {            if(data[k] >= 'A' && data[k] <= 'Z') {                val <<= 6;                val += data[k] - 'A';            } else if(data[k] >= 'a' && data[k] <= 'z') {                val <<= 6;                val += data[k] - 'a' + 26;            } else if(data[k] >= '0' && data[k] <= '9') {                val <<= 6;                val += data[k] - '0' + 52;            } else if(data[k] == '+') {                val <<= 6;                val += 62;            } else if(data[k] == '/') {                val <<= 6;                val += 63;            } else {                val <<= 6;            }        }				val = EndianU32_NtoB(val);        memcpy(out + j, ((unsigned char*)(&val)) + 1, 3);    }		data = (const unsigned char*)[target bytes];	len = 0;	for(int i = [target length] - 1; i >= 0; i--, len++) {		if(data[i] != 0)			break;	}	return [NSData dataWithBytes:[target bytes] length:([target length] - len)];}@end