////  Base64.h//  Copyright (c) 2014年 grant. All rights reserved.//#import <Foundation/Foundation.h>@interface Based64 : NSObject//Base64加密+ (NSString *) encodeBase64WithString:(NSString *)strData;+ (NSString *) encodeBase64WithData:(NSData *)objData;//Based64解密+ (NSData *) decodeBase64WithString:(NSString *)strBase64;@end

////  Base64.m//  Copyright (c) 2014年 grant. All rights reserved.//#import "Base64.h"static const char _bas64EncodingTable[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";static const short _base64DecodingTable[256] = {    -2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1, -2, -1, -1, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,    -1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 62, -2, -2, -2, 63,    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -2, -2, -2, -2, -2, -2,    -2,  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, -2, -2, -2, -2, -2,    -2, 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, -2, -2, -2, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2};@implementation Base64+ (NSString *)encodeBase64WithString:(NSString *)strData {    return [Based64 encodeBase64WithData:[strData dataUsingEncoding:NSUTF8StringEncoding]];}+ (NSString *)encodeBase64WithData:(NSData *)objData {    const unsigned char * objRawData =http://www.mamicode.com/ [objData bytes];    char * objPointer;    char * strResult;        int intLength = [objData length];    if (intLength == 0) return nil;        strResult = (char *)calloc(((intLength + 2) / 3) * 4, sizeof(char));    objPointer = strResult;        while(intLength > 2) {        *objPointer++ = _bas64EncodingTable[objRawData[0] >> 2];        *objPointer++ = _bas64EncodingTable[((objRawData[0] & 0x03) << 4) + (objRawData[1] >> 4)];        *objPointer++ = _bas64EncodingTable[((objRawData[1] & 0x0f) << 2) + (objRawData[2] >> 6)];        *objPointer++ = _bas64EncodingTable[objRawData[2] & 0x3f];                objRawData += 3;        intLength -= 3;    }        if (intLength != 0) {        *objPointer++ = _bas64EncodingTable[objRawData[0] >> 2];        if (intLength > 1) {            *objPointer++ = _bas64EncodingTable[((objRawData[0] & 0x03) << 4) + (objRawData[1] >> 4)];            *objPointer++ = _bas64EncodingTable[(objRawData[1] & 0x0f) << 2];            *objPointer++ = ‘=‘;        } else {            *objPointer++ = _bas64EncodingTable[(objRawData[0] & 0x03) << 4];            *objPointer++ = ‘=‘;            *objPointer++ = ‘=‘;        }    }        *objPointer = ‘\0‘;        return[NSString stringWithCString:strResult encoding:NSASCIIStringEncoding];}+ (NSData *)decodeBase64WithString:(NSString *)strBase64 {    const char* objPointer = [strBase64 cStringUsingEncoding:NSASCIIStringEncoding];    int intLength = strlen(objPointer);    int intCurrent;    int i = 0, j = 0, k;        unsigned char * objResult;    objResult = calloc(intLength, sizeof(char));        while ( ((intCurrent = *objPointer++) != ‘\0‘) && (intLength-- > 0) ) {        if (intCurrent == ‘=‘) {            if (*objPointer != ‘=‘ && ((i % 4) == 1)) {// || (intLength > 0)) {                free(objResult);                return nil;            }            continue;        }                intCurrent = _base64DecodingTable[intCurrent];        if (intCurrent == -1) {            continue;        } else if (intCurrent == -2) {            free(objResult);            return nil;        }                switch (i % 4) {            case 0:                objResult[j] = intCurrent << 2;                break;                            case 1:                objResult[j++] |= intCurrent >> 4;                objResult[j] = (intCurrent & 0x0f) << 4;                break;                            case 2:                objResult[j++] |= intCurrent >>2;                objResult[j] = (intCurrent & 0x03) << 6;                break;                            case 3:                objResult[j++] |= intCurrent;                break;        }        i++;    }        k = j;    if (intCurrent == ‘=‘) {        switch (i % 4) {            case 1:                free(objResult);                return nil;            case 2:                k++;            case 3:                objResult[k] = 0;        }    }        NSData * objData =http://www.mamicode.com/ [[NSData alloc] initWithBytes:objResult length:j] ;    free(objResult);    return objData;}@end