//
//  YXCrypto.h
//  用秘钥给字符串加密或者解密
//
//  Created by YouXian on 14-11-16.
//  Copyright (c) 2014年 YouXian. All rights reserved.
//

#import <Foundation/Foundation.h>@interface YXCrypto : NSObject/*!* 给字符串加密*/
+ (NSString *)DesEncryptString:(NSString*)src WithKey:(NSString *)key;/*!* 给字符串解密*/
+ (NSString *)DesDecryptString:(NSString*)src WithKey:(NSString *)key;@end

//
//  YXCrypto.m
//  用秘钥给字符串加密或者解密
//
//  Created by YouXian on 14-11-16.
//  Copyright (c) 2014年 YouXian. All rights reserved.
//

#import "YXCrypto.h"
#import <CommonCrypto/CommonCryptor.h>#if __has_feature(objc_arc)
// ARC
#define Auto_Release(obj)
#define Safe_Release(obj)
#else
// 非ARC
#define Auto_Release(obj) [obj autorelease]
#define Safe_Release(obj) [obj release]; obj = nil
#endifstatic YXCrypto *shareInstance = nil;@implementation YXCrypto/*!* 给字符串加密*/
+ (NSString *)DesEncryptString:(NSString*)src WithKey:(NSString *)key {NSString* strRet = @"";if (shareInstance == nil){shareInstance = [[YXCrypto alloc] init];}// encrypt source contentNSData* bytes = [src dataUsingEncoding:NSUTF8StringEncoding];NSData* data = [shareInstance DesCryptWithOperation:kCCEncryptbytes:byteskey:key];// format bytes to visible stringchar* pBuff = (char*)[data bytes];for (int i=0; i<data.length; i++) {strRet = [strRet stringByAppendingFormat:@"%02X", pBuff[i]& 0xFF];}return strRet;
}/*!* 给字符串解密*/
+ (NSString *)DesDecryptString:(NSString*)src WithKey:(NSString *)key
{if (shareInstance == nil){shareInstance = [[YXCrypto alloc] init];}static unsigned char _map_ch2hex[] ={0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,0, 0, 0, 0, 0, 0, 0,    // :, ;, <, =, >, ?, @,0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,};// decode source content to bytesunsigned char* bytes = (unsigned char*)malloc((src.length+1)*sizeof(unsigned char));[[src uppercaseString] getCString:(char*)bytes maxLength:src.length+1 encoding:NSUTF8StringEncoding];unsigned char *p1 = bytes, *p2 = bytes;unsigned long n = src.length/2;for (int i=0; i<n; i++) {*p1 = _map_ch2hex[*p2-'0'] * 0x10 + _map_ch2hex[*(p2+1)-'0'];p1++;p2+=2;}NSData* data = [NSData dataWithBytes:byteslength:n];// decrypt source bytesNSData* dataOut = [shareInstance DesCryptWithOperation:kCCDecryptbytes:datakey:key];free(bytes);NSString* strRet = [[NSString alloc] initWithData:dataOutencoding:NSUTF8StringEncoding];Auto_Release(strRet);return strRet;
}- (NSData *)DesCryptWithOperation:(CCOperation)operation bytes:(NSData*)bytes key:(NSString *)key {NSUInteger dataLength = [bytes length];size_t bufferSize = ([bytes length] + kCCBlockSizeDES) & ~(kCCBlockSizeDES - 1);unsigned char *buffer = (unsigned char *)malloc(bufferSize*sizeof(unsigned char));memset((void*)buffer, 0, bufferSize);size_t numBytesCrypted = 0;CCCryptorStatus cryptStatus = CCCrypt(operation,kCCAlgorithmDES,kCCOptionPKCS7Padding | kCCOptionECBMode,(void const*)[key UTF8String],kCCKeySizeDES,NULL,[bytes bytes], dataLength,(void*)buffer, bufferSize,&numBytesCrypted);NSData* dataRet = nil;if (cryptStatus == kCCSuccess) {dataRet = [[NSData alloc] initWithBytes:buffer length:numBytesCrypted];Auto_Release(dataRet);}free(buffer);return dataRet;
}@end