DES加密（支持ARC与MRC）

DES加密（支持ARC与MRC）

源文件：

YXCrypto.h 与 YXCrypto.m

//

//  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

#endif

static 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 content

    NSData* bytes = [src dataUsingEncoding:NSUTF8StringEncoding];

    NSData* data = [shareInstance DesCryptWithOperation:kCCEncrypt

                                                  bytes:bytes

                                                    key:key];

    // format bytes to visible string

    char* pBuff = (char*)[data bytes];

    for (int i=; 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,

        , , , , , , ,    // :, ;, <, =, >, ?, @,

        0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,

    };

    // decode source content to bytes

    unsigned char* bytes = (unsigned char*)malloc((src.length+)*sizeof(unsigned char));

    [[src uppercaseString] getCString:(char*)bytes maxLength:src.length+ encoding:NSUTF8StringEncoding];

    unsigned char *p1 = bytes, *p2 = bytes;

    unsigned long n = src.length/;

    for (int i=; i<n; i++) {

        *p1 = _map_ch2hex[*p2-''] * 0x10 + _map_ch2hex[*(p2+)-''];

        p1++;

        p2+=;

    }

    NSData* data = [NSData dataWithBytes:bytes

                                  length:n];

    // decrypt source bytes

    NSData* dataOut = [shareInstance DesCryptWithOperation:kCCDecrypt

                                                     bytes:data

                                                       key:key];

    free(bytes);

    NSString* strRet = [[NSString alloc] initWithData:dataOut

                                             encoding: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 - );

    unsigned char *buffer = (unsigned char *)malloc(bufferSize*sizeof(unsigned char));

    memset((void*)buffer, , bufferSize);

    size_t numBytesCrypted = ;

    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

此类是用类方法，使用非常便利：