三重Des对称加密在Android、Ios 和Java 平台的实现

2022-12-19 21:41:06

引言

如今手机app五彩缤纷，确保手机用户的数据安全是开发人员必须掌握的技巧，下面通过实例介绍DES在android、ios、java平台的使用方法；

DES加密是目前最常用的对称加密方式，性能优于非对称加密（RSA），是手机app请求数据加密的优先选择。

DES简介：

DES全称为Data Encryption Standard，即数据加密标准，是一种使用密钥加密的块算法，算法的入口参数有三个:Key、Data、Mode。

Key：为7个字节共56位,是DES算法的工作密钥;

Data：为8个字节64位,是要被加密或被解密的数据;

Mode：为DES的工作方式,有两种:加密或解密。

3DES简介：

3DES（或称为Triple DES）是三重数据加密算法（TDEA，Triple Data Encryption Algorithm）块密码的通称。它相当于是对每个数据块应用三次DES加密算法。由于计算机运算能力的增强，原版DES密码的密钥长度变得容易被暴力破解；3DES即是设计用来提供一种相对简单的方法，即通过增加DES的密钥长度来避免类似的攻击，而不是设计一种全新的块密码算法。因此比起最初的DES，3DES更为安全。

加密实例：

java版

package com.v1.linxun.portal.utils;

import java.security.Key;

import javax.crypto.Cipher;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESedeKeySpec;

import javax.crypto.spec.IvParameterSpec;

/**

* 3DES加密工具类

public class Des3Util {

// 密钥长度不得小于24

private final static String secretKey = "123456789012345678901234" ;

// 向量可有可无终端后台也要约定

private final static String iv = "01234567";

// 加解密统一使用的编码方式

private final static String encoding = "utf-8";

/**

* 3DES加密

* @param plainText

* 普通文本

* @return

* @throws Exception

public static String encode(String plainText) throws Exception {

Key deskey = null;

DESedeKeySpec spec = new DESedeKeySpec(secretKey .getBytes());

SecretKeyFactory keyfactory = SecretKeyFactory.getInstance( "desede");

deskey = keyfactory.generateSecret( spec);

Cipher cipher = Cipher.getInstance( "desede/CBC/PKCS5Padding");

IvParameterSpec ips = new IvParameterSpec( iv.getBytes());

cipher.init(Cipher. ENCRYPT_MODE, deskey, ips);

byte[] encryptData = cipher.doFinal( plainText.getBytes( encoding));

return Base64. encode( encryptData);

}

/**

* 3DES解密

* @param encryptText

* 加密文本

* @return

* @throws Exception

public static String decode(String encryptText) throws Exception {

Key deskey = null;

DESedeKeySpec spec = new DESedeKeySpec( secretKey.getBytes());

SecretKeyFactory keyfactory = SecretKeyFactory.getInstance( "desede");

deskey = keyfactory. generateSecret( spec);

Cipher cipher = Cipher.getInstance( "desede/CBC/PKCS5Padding" );

IvParameterSpec ips = new IvParameterSpec( iv.getBytes());

cipher. init(Cipher. DECRYPT_MODE, deskey, ips);

byte[] decryptData = cipher. doFinal(Base64. decode(encryptText ));

return new String( decryptData, encoding);

}

public static void main(String args[]) throws Exception{

String str = "你好" ;

System. out.println( "----加密前-----：" + str );

String encodeStr = Des3Util. encode( str);

System. out.println( "----加密后-----：" + encodeStr );

System. out.println( "----解密后-----：" + Des3Util.decode( encodeStr));

}

Android版：

package com.inn.test;

import java.security.Key;

import javax.crypto.Cipher;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESedeKeySpec;

import javax.crypto.spec.IvParameterSpec;

import android.util.Base64;

/**

* Android 3DES加密工具类

public class AndroidDes3Util {

// 密钥长度不得小于24

private final static String secretKey = "123456789012345678901234" ;

// 向量可有可无终端后台也要约定

private final static String iv = "01234567" ;

// 加解密统一使用的编码方式

private final static String encoding = "utf-8" ;

/**

* 3DES加密

* @param plainText

* 普通文本

* @return

* @throws Exception

public static String encode(String plainText) throws Exception {

Key deskey = null ;

DESedeKeySpec spec = new DESedeKeySpec(secretKey .getBytes());

SecretKeyFactory keyfactory = SecretKeyFactory.getInstance( "desede");

deskey = keyfactory.generateSecret(spec);

Cipher cipher = Cipher.getInstance( "desede/CBC/PKCS5Padding");

IvParameterSpec ips = new IvParameterSpec( iv.getBytes());

cipher.init(Cipher. ENCRYPT_MODE , deskey, ips);

byte [] encryptData = cipher.doFinal(plainText.getBytes(encoding ));

return Base64.encodeToString(encryptData,Base64. DEFAULT );

}

/**

* 3DES解密

* @param encryptText

* 加密文本

* @return

* @throws Exception

public static String decode(String encryptText) throws Exception {

Key deskey = null ;

DESedeKeySpec spec = new DESedeKeySpec( secretKey.getBytes());

SecretKeyFactory keyfactory = SecretKeyFactory.getInstance( "desede" );

deskey = keyfactory. generateSecret(spec);

Cipher cipher = Cipher.getInstance( "desede/CBC/PKCS5Padding" );

IvParameterSpec ips = new IvParameterSpec( iv.getBytes());

cipher. init(Cipher. DECRYPT_MODE, deskey, ips);

byte [] decryptData = cipher.doFinal(Base64. decode(encryptText, Base64. DEFAULT));

return new String (decryptData, encoding);

}

IOS版：

#import <Foundation/Foundation.h>

@interface DES3EncryptUtil : NSObject

// 加密方法
+ (NSString*)encrypt:(NSString*)plainText;

// 解密方法
+ (NSString*)decrypt:(NSString*)encryptText;

@end

#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonCryptor.h>
#import "MyBase64.h"

//秘钥
#define gkey @"xiangchao@qq.comrnnchina"
//向量
#define gIv @"01234567"

@implementation DES3EncryptUtil : NSObject

// 加密方法
+ (NSString*)encrypt:(NSString*)plainText {
    NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];
    size_t plainTextBufferSize = [data length];
    const void *vplainText = (const void *)[data bytes];

    CCCryptorStatus ccStatus;
    uint8_t *bufferPtr = NULL;
    size_t bufferPtrSize = 0;
    size_t movedBytes = 0;

    bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
    bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
    memset((void *)bufferPtr, 0x0, bufferPtrSize);

    const void *vkey = (const void *) [gkey UTF8String];
    const void *vinitVec = (const void *) [gIv UTF8String];

    ccStatus = CCCrypt(kCCEncrypt,
                       kCCAlgorithm3DES,
                       kCCOptionPKCS7Padding,
                       vkey,
                       kCCKeySize3DES,
                       vinitVec,
                       vplainText,
                       plainTextBufferSize,
                       (void *)bufferPtr,
                       bufferPtrSize,
                       &movedBytes);

    NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes];
    NSString *result = [MyBase64 base64EncodedStringFrom:myData];
    return result;
}

// 解密方法
+ (NSString*)decrypt:(NSString*)encryptText {
    NSData *encryptData = [MyBase64 dataWithBase64EncodedString:encryptText];
    size_t plainTextBufferSize = [encryptData length];
    const void *vplainText = [encryptData bytes];

    CCCryptorStatus ccStatus;
    uint8_t *bufferPtr = NULL;
    size_t bufferPtrSize = 0;
    size_t movedBytes = 0;

    bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
    bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
    memset((void *)bufferPtr, 0x0, bufferPtrSize);

    const void *vkey = (const void *) [gkey UTF8String];
    const void *vinitVec = (const void *) [gIv UTF8String];

    ccStatus = CCCrypt(kCCDecrypt,
                       kCCAlgorithm3DES,
                       kCCOptionPKCS7Padding,
                       vkey,
                       kCCKeySize3DES,
                       vinitVec,
                       vplainText,
                       plainTextBufferSize,
                       (void *)bufferPtr,
                       bufferPtrSize,
                       &movedBytes);

    NSString *result = [[NSString alloc] initWithData:[NSData dataWithBytes:(const void *)bufferPtr
                                                                     length:(NSUInteger)movedBytes] encoding:NSUTF8StringEncoding] ;
    return result;
}

@end

IOS加密工具中会将加密后的密文转化程Base64的字符串，用到了Base64编码工具，如下

#import <Foundation/Foundation.h>

#define __BASE64( text ) [CommonFunc base64StringFromText:text]
#define __TEXT( base64 ) [CommonFunc textFromBase64String:base64]

@interface MyBase64 : NSObject

/******************************************************************************
函数名称 : + (NSString *)base64StringFromText:(NSString *)text
函数描述 : 将文本转换为base64格式字符串
输入参数 : (NSString *)text 文本
输出参数 : N/A
返回参数 : (NSString *) base64格式字符串
备注信息 :
******************************************************************************/
+ (NSString *)base64StringFromText:(NSString *)text;

/******************************************************************************
函数名称 : + (NSString *)textFromBase64String:(NSString *)base64
函数描述 : 将base64格式字符串转换为文本
输入参数 : (NSString *)base64 base64格式字符串
输出参数 : N/A
返回参数 : (NSString *) 文本
备注信息 :
******************************************************************************/
+ (NSString *)textFromBase64String:(NSString *)base64;

@end

#import "MyBase64.h"

//引入IOS自带密码库
#import <CommonCrypto/CommonCryptor.h>

//空字符串
#define LocalStr_None @""

static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

@implementation MyBase64 : NSObject

+ (NSString *)base64StringFromText:(NSString *)text
{
    if (text && ![text isEqualToString:LocalStr_None]) {
        //取项目的bundleIdentifier作为KEY 改动了此处
        //NSString *key = [[NSBundle mainBundle] bundleIdentifier];
        NSData *data = [text dataUsingEncoding:NSUTF8StringEncoding];
        //IOS 自带DES加密 Begin 改动了此处
        //data = [self DESEncrypt:data WithKey:key];
        //IOS 自带DES加密 End
        return [self base64EncodedStringFrom:data];
    }
    else {
        return LocalStr_None;
    }
}

+ (NSString *)textFromBase64String:(NSString *)base64
{
    if (base64 && ![base64 isEqualToString:LocalStr_None]) {
        //取项目的bundleIdentifier作为KEY   改动了此处
        //NSString *key = [[NSBundle mainBundle] bundleIdentifier];
        NSData *data = [self dataWithBase64EncodedString:base64];
        //IOS 自带DES解密 Begin    改动了此处
        //data = [self DESDecrypt:data WithKey:key];
        //IOS 自带DES加密 End
        return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    }
    else {
        return LocalStr_None;
    }
}

/******************************************************************************
函数名称 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
函数描述 : 文本数据进行DES加密
输入参数 : (NSData *)data
(NSString *)key
输出参数 : N/A
返回参数 : (NSData *)
备注信息 : 此函数不可用于过长文本
******************************************************************************/
+ (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
{
    char keyPtr[kCCKeySizeAES256+1];
    bzero(keyPtr, sizeof(keyPtr));

    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

    NSUInteger dataLength = [data length];

    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);

    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCBlockSizeDES,
                                          NULL,
                                          [data bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
    }

    free(buffer);
    return nil;
}

/******************************************************************************
函数名称 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
函数描述 : 文本数据进行DES解密
输入参数 : (NSData *)data
(NSString *)key
输出参数 : N/A
返回参数 : (NSData *)
备注信息 : 此函数不可用于过长文本
******************************************************************************/
+ (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key
{
    char keyPtr[kCCKeySizeAES256+1];
    bzero(keyPtr, sizeof(keyPtr));

    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

    NSUInteger dataLength = [data length];

    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);

    size_t numBytesDecrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCBlockSizeDES,
                                          NULL,
                                          [data bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesDecrypted);

    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
    }

    free(buffer);
    return nil;
}

/******************************************************************************
函数名称 : + (NSData *)dataWithBase64EncodedString:(NSString *)string
函数描述 : base64格式字符串转换为文本数据
输入参数 : (NSString *)string
输出参数 : N/A
返回参数 : (NSData *)
备注信息 :
******************************************************************************/
+ (NSData *)dataWithBase64EncodedString:(NSString *)string
{
    if (string == nil)
        [NSException raise:NSInvalidArgumentException format:nil];
    if ([string length] == 0)
        return [NSData data];

    static char *decodingTable = NULL;
    if (decodingTable == NULL)
    {
        decodingTable = malloc(256);
        if (decodingTable == NULL)
            return nil;
        memset(decodingTable, CHAR_MAX, 256);
        NSUInteger i;
        for (i = 0; i < 64; i++)
            decodingTable[(short)encodingTable[i]] = i;
    }

    const char *characters = [string cStringUsingEncoding:NSASCIIStringEncoding];
    if (characters == NULL)     // Not an ASCII string!
        return nil;
    char *bytes = malloc((([string length] + 3) / 4) * 3);
    if (bytes == NULL)
        return nil;
    NSUInteger length = 0;

    NSUInteger i = 0;
    while (YES)
    {
        char buffer[4];
        short bufferLength;
        for (bufferLength = 0; bufferLength < 4; i++)
        {
            if (characters[i] == '\0')
                break;
            if (isspace(characters[i]) || characters[i] == '=')
                continue;
            buffer[bufferLength] = decodingTable[(short)characters[i]];
            if (buffer[bufferLength++] == CHAR_MAX)      // Illegal character!
            {
                free(bytes);
                return nil;
            }
        }

        if (bufferLength == 0)
            break;
        if (bufferLength == 1)      // At least two characters are needed to produce one byte!
        {
            free(bytes);
            return nil;
        }

        // Decode the characters in the buffer to bytes.
        bytes[length++] = (buffer[0] << 2) | (buffer[1] >> 4);
        if (bufferLength > 2)
            bytes[length++] = (buffer[1] << 4) | (buffer[2] >> 2);
        if (bufferLength > 3)
            bytes[length++] = (buffer[2] << 6) | buffer[3];
    }

    bytes = realloc(bytes, length);
    return [NSData dataWithBytesNoCopy:bytes length:length];
}

/******************************************************************************
函数名称 : + (NSString *)base64EncodedStringFrom:(NSData *)data
函数描述 : 文本数据转换为base64格式字符串
输入参数 : (NSData *)data
输出参数 : N/A
返回参数 : (NSString *)
备注信息 :
******************************************************************************/
+ (NSString *)base64EncodedStringFrom:(NSData *)data
{
    if ([data length] == 0)
        return @"";

    char *characters = malloc((([data length] + 2) / 3) * 4);
    if (characters == NULL)
        return nil;
    NSUInteger length = 0;

    NSUInteger i = 0;
    while (i < [data length])
    {
        char buffer[3] = {0,0,0};
        short bufferLength = 0;
        while (bufferLength < 3 && i < [data length])
            buffer[bufferLength++] = ((char *)[data bytes])[i++];

        // Encode the bytes in the buffer to four characters, including padding "=" characters if necessary.
        characters[length++] = encodingTable[(buffer[0] & 0xFC) >> 2];
        characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];
        if (bufferLength > 1)
            characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];
        else characters[length++] = '=';
        if (bufferLength > 2)
            characters[length++] = encodingTable[buffer[2] & 0x3F];
        else characters[length++] = '=';
    }

    return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];
}

@end

到此为止，三平台的加密已经全部结束，代码可以直接使用。

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