移动开发---DES加密解密

DES加密解密

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.security.Key;

import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.IvParameterSpec;

/**
 * Date: 2019/4/1
 * autor:Wayne
 */

public class DesUtils
{ // 密钥
//    private final static String secretKey = "my.oschina.net/penngo?#@" ;
    // 向量
    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 secretKey, 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 secretKey,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 String padding(String str) {
        byte[] oldByteArray;
        try {
            oldByteArray = str.getBytes("UTF8");
            int numberToPad = 8 - oldByteArray.length % 8;
            byte[] newByteArray = new byte[oldByteArray.length + numberToPad];
            System.arraycopy(oldByteArray, 0, newByteArray, 0,
                    oldByteArray.length);
            for (int i = oldByteArray.length; i < newByteArray.length; ++i) {
                newByteArray[i] = 0;
            }
            return new String(newByteArray, "UTF8");
        } catch (UnsupportedEncodingException e) {
            System.out.println("Crypter.padding UnsupportedEncodingException");
        }
        return null;
    }

    /**
     * Base64编码工具类
     *
     */
    public static class Base64 {
        private static final char [] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" .toCharArray();

        public static String encode( byte [] data) {
            int start = 0 ;
            int len = data.length;
            StringBuffer buf = new StringBuffer(data.length * 3 / 2 );

            int end = len - 3 ;
            int i = start;
            int n = 0 ;

            while (i <= end) {
                int d = (((( int ) data[i]) & 0x0ff ) << 16 ) | (((( int ) data[i + 1 ]) & 0x0ff ) << 8 ) | ((( int ) data[i + 2 ]) & 0x0ff );

                buf.append(legalChars[(d >> 18 ) & 63 ]);
                buf.append(legalChars[(d >> 12 ) & 63 ]);
                buf.append(legalChars[(d >> 6 ) & 63 ]);
                buf.append(legalChars[d & 63 ]);

                i += 3 ;

                if (n++ >= 14 ) {
                    n = 0 ;
                    buf.append( " " );
                }
            }

            if (i == start + len - 2 ) {
                int d = (((( int ) data[i]) & 0x0ff ) << 16 ) | (((( int ) data[i + 1 ]) & 255 ) << 8 );

                buf.append(legalChars[(d >> 18 ) & 63 ]);
                buf.append(legalChars[(d >> 12 ) & 63 ]);
                buf.append(legalChars[(d >> 6 ) & 63 ]);
                buf.append( "=" );
            } else if (i == start + len - 1 ) {
                int d = ((( int ) data[i]) & 0x0ff ) << 16 ;

                buf.append(legalChars[(d >> 18 ) & 63 ]);
                buf.append(legalChars[(d >> 12 ) & 63 ]);
                buf.append( "==" );
            }

            return buf.toString();
        }

        private static int decode( char c) {
            if (c >= 'A' && c <= 'Z' )
                return (( int ) c) - 65 ;
            else if (c >= 'a' && c <= 'z' )
                return (( int ) c) - 97 + 26 ;
            else if (c >= '0' && c <= '9' )
                return (( int ) c) - 48 + 26 + 26 ;
            else
                switch (c) {
                    case '+' :
                        return 62 ;
                    case '/' :
                        return 63 ;
                    case '=' :
                        return 0 ;
                    default :
                        throw new RuntimeException( "unexpected code: " + c);
                }
        }

        /**
         * Decodes the given Base64 encoded String to a new byte array. The byte array holding the decoded data is returned.
         */

        public static byte [] decode(String s) {

            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            try {
                decode(s, bos);
            } catch (IOException e) {
                throw new RuntimeException();
            }
            byte [] decodedBytes = bos.toByteArray();
            try {
                bos.close();
                bos = null ;
            } catch (IOException ex) {
                System.err.println( "Error while decoding BASE64: " + ex.toString());
            }
            return decodedBytes;
        }

        private static void decode(String s, OutputStream os) throws IOException {
            int i = 0 ;

            int len = s.length();

            while ( true ) {
                while (i < len && s.charAt(i) <= ' ' )
                    i++;

                if (i == len)
                    break ;

                int tri = (decode(s.charAt(i)) << 18 ) + (decode(s.charAt(i + 1 )) << 12 ) + (decode(s.charAt(i + 2 )) << 6 ) + (decode(s.charAt(i + 3 )));

                os.write((tri >> 16 ) & 255 );
                if (s.charAt(i + 2 ) == '=' )
                    break ;
                os.write((tri >> 8 ) & 255 );
                if (s.charAt(i + 3 ) == '=' )
                    break ;
                os.write(tri & 255 );

                i += 4 ;
            }
        }
    }

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

        String secretKey = "my.oschina.net/penngo?#@" ;

        String plainText = "来自http://my.oschina.net/penngo的博客";
        String encryptText = DesUtils.encode(secretKey,plainText);
        System.out.println(encryptText);
        System.out.println(DesUtils.decode(secretKey,encryptText));


    }
}

要是得到一个MD5值

 

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.Signature;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Date: 2019/4/1
 * autor:Wayne
 */

public class SignUtils {

    public static String getPackageSignInfo(Context context, String packageName) {
        try {
            PackageInfo pis = context.getPackageManager().
                    getPackageInfo(packageName, PackageManager.GET_SIGNATURES);
            Signature[] sigs = pis.signatures;
            String sig = new String(sigs[0].toChars());
            return sig;
        } catch (Exception e) {
            return "";
        }
    }

    public static String MD5Encode(String str) {
        try {
            byte[] digest = MessageDigest.getInstance("MD5").digest(str.getBytes());
            StringBuffer stringBuffer = new StringBuffer();
            for (byte b : digest) {
                String toHexString = Integer.toHexString(b & 255);
                if (toHexString.length() == 1) {
                    stringBuffer.append(0);
                }
                stringBuffer.append(toHexString);
            }
            return stringBuffer.toString();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return null;
        }
    }

最后：前端后端配合加解密

//请求得到加密的数据
String data= json.getString(data);
//md5值
String packageSignInfo = SignUtils.getPackageSignInfo(context, CommonUtils.getPackageName());
String md5 = SignUtils.MD5Encode(packageSignInfo);
//解密后的数据
String data=DesUtils.decode(md5,data);