iOS DES ECB模式对称加密解密

    最近忙于android和iOS的项目，写完了android的DES 的ECB模式加密解密（相关连接：http://blog.csdn.net/vipa1888/article/details/8086037），又回到了Ios上面，因为本人也是最近今年开始研究ios的，所以Ios上面好多东西都不懂，进过了半年的研究，终于吧ios的DES 的ECB模式对称加密解密搞定了，本人遇到的问题很严重的问题，网上写的好多16进制数转化位字节都有问题的，经过本人研究发现他们有一个地方写错了，导致解密后的NSString 位null，我的代码已经修复了这个问题，下面贴出源代码供大家参考：

首先贴出加密类的头文件：

////  DesUtil.h//  Author:spring sky//  QQ:840950105//  Email:[e-mail]//#import <Foundation/Foundation.h>@interface DesUtil : NSObject/** DES加密 */+(NSString *) encryptUseDES:(NSString *)plainText key:(NSString *)key;/** DES解密 */+(NSString *) decryptUseDES:(NSString *)plainText key:(NSString *)key;@end

加密类的实现类：

////  DesUtil.m//  Author:spring sky//  QQ:840950105//  Email:[e-mail]//#import "DesUtil.h"#import <CommonCrypto/CommonCryptor.h>#import "ConverUtil.h"@implementation DesUtilstatic Byte iv[] = {1,2,3,4,5,6,7,8};/* DES加密 */+(NSString *) encryptUseDES:(NSString *)clearText key:(NSString *)key{    NSString *ciphertext = nil;    NSData *textData = [clearText dataUsingEncoding:NSUTF8StringEncoding];    NSUInteger dataLength = [clearText length];    unsigned char buffer[1024];    memset(buffer, 0, sizeof(char));    size_t numBytesEncrypted = 0;            CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,                                          kCCOptionECBMode,                                          [key UTF8String], kCCKeySizeDES,                                          iv,                                          [textData bytes], dataLength,                                          buffer, 1024,                                          &numBytesEncrypted);    if (cryptStatus == kCCSuccess) {        NSLog(@"DES加密成功");        NSData *data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];        Byte* bb = (Byte*)[data bytes];        ciphertext = [ConverUtil parseByteArray2HexString:bb];    }else{        NSLog(@"DES加密失败");    }    return ciphertext;}/** DES解密 */+(NSString *) decryptUseDES:(NSString *)plainText key:(NSString *)key{    NSString *cleartext = nil;    NSData *textData = [ConverUtil parseHexToByteArray:plainText];    NSUInteger dataLength = [textData length];    unsigned char buffer[1024];    memset(buffer, 0, sizeof(char));    size_t numBytesEncrypted = 0;            CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,                                          kCCOptionECBMode,                                          [key UTF8String], kCCKeySizeDES,                                          iv,                                          [textData bytes], dataLength,                                          buffer, 1024,                                          &numBytesEncrypted);    if (cryptStatus == kCCSuccess) {        NSLog(@"DES解密成功");        NSData *data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];        cleartext = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];    }else{        NSLog(@"DES解密失败");    }    return cleartext;}@end

下面是转码类，主要是16进制和字节的转化 

头文件：

////  ConverUtil.h//  Author:spring sky//  QQ:840950105//  Email:[e-mail]//#import <Foundation/Foundation.h>@interface ConverUtil : NSObject/** 64编码 */+(NSString *)base64Encoding:(NSData*) text;/** 字节转化为16进制数 */+(NSString *) parseByte2HexString:(Byte *) bytes;/** 字节数组转化16进制数 */+(NSString *) parseByteArray2HexString:(Byte[]) bytes;/* 将16进制数据转化成NSData 数组 */+(NSData*) parseHexToByteArray:(NSString*) hexString;@end

实现类：

////  ConverUtil.m//  Author:spring sky//  QQ:840950105//  Email:[e-mail]//#import "ConverUtil.h"@implementation ConverUtilstatic const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";/** 64编码 */+(NSString *)base64Encoding:(NSData*) text{    if (text.length == 0)        return @"";        char *characters = malloc(text.length*3/2);        if (characters == NULL)        return @"";        int end = text.length - 3;    int index = 0;    int charCount = 0;    int n = 0;        while (index <= end) {        int d = (((int)(((char *)[text bytes])[index]) & 0x0ff) << 16)        | (((int)(((char *)[text bytes])[index + 1]) & 0x0ff) << 8)        | ((int)(((char *)[text bytes])[index + 2]) & 0x0ff);                characters[charCount++] = encodingTable[(d >> 18) & 63];        characters[charCount++] = encodingTable[(d >> 12) & 63];        characters[charCount++] = encodingTable[(d >> 6) & 63];        characters[charCount++] = encodingTable[d & 63];                index += 3;                if(n++ >= 14)        {            n = 0;            characters[charCount++] = ' ';        }    }        if(index == text.length - 2)    {        int d = (((int)(((char *)[text bytes])[index]) & 0x0ff) << 16)        | (((int)(((char *)[text bytes])[index + 1]) & 255) << 8);        characters[charCount++] = encodingTable[(d >> 18) & 63];        characters[charCount++] = encodingTable[(d >> 12) & 63];        characters[charCount++] = encodingTable[(d >> 6) & 63];        characters[charCount++] = '=';    }    else if(index == text.length - 1)    {        int d = ((int)(((char *)[text bytes])[index]) & 0x0ff) << 16;        characters[charCount++] = encodingTable[(d >> 18) & 63];        characters[charCount++] = encodingTable[(d >> 12) & 63];        characters[charCount++] = '=';        characters[charCount++] = '=';    }    NSString * rtnStr = [[NSString alloc] initWithBytesNoCopy:characters length:charCount encoding:NSUTF8StringEncoding freeWhenDone:YES];    return rtnStr;}/** 字节转化为16进制数 */+(NSString *) parseByte2HexString:(Byte *) bytes{    NSMutableString *hexStr = [[NSMutableString alloc]init];    int i = 0;    if(bytes)    {        while (bytes[i] != '\0')        {            NSString *hexByte = [NSString stringWithFormat:@"%x",bytes[i] & 0xff];///16进制数            if([hexByte length]==1)                [hexStr appendFormat:@"0%@", hexByte];            else                [hexStr appendFormat:@"%@", hexByte];                        i++;        }    }    NSLog(@"bytes 的16进制数为:%@",hexStr);    return hexStr;}/** 字节数组转化16进制数 */+(NSString *) parseByteArray2HexString:(Byte[]) bytes{    NSMutableString *hexStr = [[NSMutableString alloc]init];    int i = 0;    if(bytes)    {        while (bytes[i] != '\0')        {            NSString *hexByte = [NSString stringWithFormat:@"%x",bytes[i] & 0xff];///16进制数            if([hexByte length]==1)                [hexStr appendFormat:@"0%@", hexByte];            else                [hexStr appendFormat:@"%@", hexByte];                        i++;        }    }    NSLog(@"bytes 的16进制数为:%@",hexStr);    return [hexStr uppercaseString];}/* 将16进制数据转化成NSData 数组 */+(NSData*) parseHexToByteArray:(NSString*) hexString{    int j=0;    Byte bytes[hexString.length];     for(int i=0;i<[hexString length];i++)    {        int int_ch;  /// 两位16进制数转化后的10进制数        unichar hex_char1 = [hexString characterAtIndex:i]; ////两位16进制数中的第一位(高位*16)        int int_ch1;        if(hex_char1 >= '0' && hex_char1 <='9')            int_ch1 = (hex_char1-48)*16;   //// 0 的Ascll - 48        else if(hex_char1 >= 'A' && hex_char1 <='F')            int_ch1 = (hex_char1-55)*16; //// A 的Ascll - 65        else            int_ch1 = (hex_char1-87)*16; //// a 的Ascll - 97        i++;        unichar hex_char2 = [hexString characterAtIndex:i]; ///两位16进制数中的第二位(低位)        int int_ch2;        if(hex_char2 >= '0' && hex_char2 <='9')            int_ch2 = (hex_char2-48); //// 0 的Ascll - 48        else if(hex_char2 >= 'A' && hex_char1 <='F')            int_ch2 = hex_char2-55; //// A 的Ascll - 65        else            int_ch2 = hex_char2-87; //// a 的Ascll - 97                int_ch = int_ch1+int_ch2;        bytes[j] = int_ch;  ///将转化后的数放入Byte数组里        j++;    }    NSData *newData = [[NSData alloc] initWithBytes:bytes length:hexString.length/2];    NSLog(@"newData=%@",newData);    return newData;}@end

测试结果：

2012-10-18 19:58:41.592 [3356:707]明文 = 1PALMPAY   key = 12345678

2012-10-18 19:58:41.599 [3356:707] DES加密成功

2012-10-18 19:58:41.601 [3356:707] bytes的16进制数为:0be9d717b1478b32

2012-10-18 19:58:41.603 [3356:707]加密后的数据：0BE9D717B1478B32

2012-10-18 19:58:41.604 [3356:707] newData=<0be9d717 b1478b32>

2012-10-18 19:58:41.607 [3356:707] DES解密成功

2012-10-18 19:58:41.608 [3356:707]解密后的数据：1PALMPAY

本人的工作内容主要是银行金融方面，所以经常会使用到各种的加密解密，如果有需要帮助的朋友可以联系我，如果我能搞定的，一定尽力而已！

欢迎转载，但是必须保留版权！