一、DES加密和解密

一、DES加密和解密

原文:http://www.jb51.net/article/51879.htm  还有其他文章

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package com.itjh.javaUtil;
 
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
 
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
 
/**
 * DES加密和解密。
 *
 * @author 宋立君
 * @date 2014年07月03日
 */
public class DESUtil {
 
    /** 安全密钥 */
    private String keyData = "ABCDEFGHIJKLMNOPQRSTWXYZabcdefghijklmnopqrstwxyz0123456789-_.";
 
    /**
     * 功能:构造
     *
     * @author 宋立君
     * @date 2014年07月03日
     */
    public DESUtil() {
    }
 
    /**
     * 功能:构造
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param keyData
     *  key
     */
    public DESUtil(String key) {
        this.keyData = key;
    }
 
    /**
     * 功能:加密 (UTF-8)
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param source
     *  源字符串
     * @param charSet
     *  编码
     * @return String
     * @throws UnsupportedEncodingException
     *  编码异常
     */
    public String encrypt(String source) throws UnsupportedEncodingException {
        return encrypt(source, "UTF-8");
    }
 
    /**
     *
     * 功能:解密 (UTF-8)
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param encryptedData
     *  被加密后的字符串
     * @return String
     * @throws UnsupportedEncodingException
     *  编码异常
     */
    public String decrypt(String encryptedData)
            throws UnsupportedEncodingException {
        return decrypt(encryptedData, "UTF-8");
    }
 
    /**
     * 功能:加密
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param source
     *  源字符串
     * @param charSet
     *  编码
     * @return String
     * @throws UnsupportedEncodingException
     *  编码异常
     */
    public String encrypt(String source, String charSet)
            throws UnsupportedEncodingException {
        String encrypt = null;
        byte[] ret = encrypt(source.getBytes(charSet));
        encrypt = new String(Base64.encode(ret));
        return encrypt;
    }
 
    /**
     *
     * 功能:解密
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param encryptedData
     *  被加密后的字符串
     * @param charSet
     *  编码
     * @return String
     * @throws UnsupportedEncodingException
     *  编码异常
     */
    public String decrypt(String encryptedData, String charSet)
            throws UnsupportedEncodingException {
        String descryptedData = null;
        byte[] ret = descrypt(Base64.decode(encryptedData.toCharArray()));
        descryptedData = new String(ret, charSet);
        return descryptedData;
    }
 
    /**
     * 加密数据 用生成的密钥加密原始数据
     *
     * @param primaryData
     *  原始数据
     * @return byte[]
     * @author 宋立君
     * @date 2014年07月03日
     */
    private byte[] encrypt(byte[] primaryData) {
 
        /** 取得安全密钥 */
        byte rawKeyData[] = getKey();
 
        /** DES算法要求有一个可信任的随机数源 */
        SecureRandom sr = new SecureRandom();
 
        /** 使用原始密钥数据创建DESKeySpec对象 */
        DESKeySpec dks = null;
        try {
            dks = new DESKeySpec(keyData.getBytes());
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        }
 
        /** 创建一个密钥工厂 */
        SecretKeyFactory keyFactory = null;
        try {
            keyFactory = SecretKeyFactory.getInstance("DES");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
 
        /** 用密钥工厂把DESKeySpec转换成一个SecretKey对象 */
        SecretKey key = null;
        try {
            key = keyFactory.generateSecret(dks);
        } catch (InvalidKeySpecException e) {
            e.printStackTrace();
        }
 
        /** Cipher对象实际完成加密操作 */
        Cipher cipher = null;
        try {
            cipher = Cipher.getInstance("DES");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        }
 
        /** 用密钥初始化Cipher对象 */
        try {
            cipher.init(Cipher.ENCRYPT_MODE, key, sr);
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        }
 
        /** 正式执行加密操作 */
        byte encryptedData[] = null;
        try {
            encryptedData = cipher.doFinal(primaryData);
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
 
        /** 返回加密数据 */
        return encryptedData;
    }
 
    /**
     * 用密钥解密数据
     *
     * @param encryptedData
     *  加密后的数据
     * @return byte[]
     * @author 宋立君
     * @date 2014年07月03日
     */
    private byte[] descrypt(byte[] encryptedData) {
 
        /** DES算法要求有一个可信任的随机数源 */
        SecureRandom sr = new SecureRandom();
 
        /** 取得安全密钥 */
        byte rawKeyData[] = getKey();
 
        /** 使用原始密钥数据创建DESKeySpec对象 */
        DESKeySpec dks = null;
        try {
            dks = new DESKeySpec(keyData.getBytes());
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        }
 
        /** 创建一个密钥工厂 */
        SecretKeyFactory keyFactory = null;
        try {
            keyFactory = SecretKeyFactory.getInstance("DES");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
 
        /** 用密钥工厂把DESKeySpec转换成一个SecretKey对象 */
        SecretKey key = null;
        try {
            key = keyFactory.generateSecret(dks);
        } catch (InvalidKeySpecException e) {
            e.printStackTrace();
        }
 
        /** Cipher对象实际完成加密操作 */
        Cipher cipher = null;
        try {
            cipher = Cipher.getInstance("DES");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        }
 
        /** 用密钥初始化Cipher对象 */
        try {
            cipher.init(Cipher.DECRYPT_MODE, key, sr);
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        }
 
        /** 正式执行解密操作 */
        byte decryptedData[] = null;
        try {
            decryptedData = cipher.doFinal(encryptedData);
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
 
        return decryptedData;
    }
 
    /**
     * 取得安全密钥 此方法作废,因为每次key生成都不一样导致解密加密用的密钥都不一样, 从而导致Given final block not
     * properly padded错误.
     *
     * @return byte数组
     * @author 宋立君
     * @date 2014年07月03日
     */
    private byte[] getKey() {
 
        /** DES算法要求有一个可信任的随机数源 */
        SecureRandom sr = new SecureRandom();
 
        /** 为我们选择的DES算法生成一个密钥生成器对象 */
        KeyGenerator kg = null;
        try {
            kg = KeyGenerator.getInstance("DES");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        kg.init(sr);
 
        /** 生成密钥工具类 */
        SecretKey key = kg.generateKey();
 
        /** 生成密钥byte数组 */
        byte rawKeyData[] = key.getEncoded();
 
        return rawKeyData;
    }
 
}

二、Base64加密和解密

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package com.itjh.javaUtil;
 
import java.io.*;
 
/**
 * Base64 编码和解码。
 *
 * @author 宋立君
 * @date 2014年07月03日
 */
public class Base64 {
 
    public Base64() {
    }
 
    /**
     * 功能:编码字符串
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param data
     *  源字符串
     * @return String
     */
    public static String encode(String data) {
        return new String(encode(data.getBytes()));
    }
 
    /**
     * 功能:解码字符串
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param data
     *  源字符串
     * @return String
     */
    public static String decode(String data) {
        return new String(decode(data.toCharArray()));
    }
 
    /**
     * 功能:编码byte[]
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param data
     *  源
     * @return char[]
     */
    public static char[] encode(byte[] data) {
        char[] out = new char[((data.length + 2) / 3) * 4];
        for (int i = 0, index = 0; i < data.length; i += 3, index += 4) {
            boolean quad = false;
            boolean trip = false;
 
            int val = (0xFF & (int) data[i]);
            val <<= 8;
            if ((i + 1) < data.length) {
                val |= (0xFF & (int) data[i + 1]);
                trip = true;
            }
            val <<= 8;
            if ((i + 2) < data.length) {
                val |= (0xFF & (int) data[i + 2]);
                quad = true;
            }
            out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)];
            val >>= 6;
            out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)];
            val >>= 6;
            out[index + 1] = alphabet[val & 0x3F];
            val >>= 6;
            out[index + 0] = alphabet[val & 0x3F];
        }
        return out;
    }
 
    /**
     * 功能:解码
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param data
     *  编码后的字符数组
     * @return byte[]
     */
    public static byte[] decode(char[] data) {
 
        int tempLen = data.length;
        for (int ix = 0; ix < data.length; ix++) {
            if ((data[ix] > 255) || codes[data[ix]] < 0) {
                --tempLen; // ignore non-valid chars and padding
            }
        }
        // calculate required length:
        // -- 3 bytes for every 4 valid base64 chars
        // -- plus 2 bytes if there are 3 extra base64 chars,
        // or plus 1 byte if there are 2 extra.
 
        int len = (tempLen / 4) * 3;
        if ((tempLen % 4) == 3) {
            len += 2;
        }
        if ((tempLen % 4) == 2) {
            len += 1;
 
        }
        byte[] out = new byte[len];
 
        int shift = 0; // # of excess bits stored in accum
        int accum = 0; // excess bits
        int index = 0;
 
        // we now go through the entire array (NOT using the 'tempLen' value)
        for (int ix = 0; ix < data.length; ix++) {
            int value = (data[ix] > 255) ? -1 : codes[data[ix]];
 
            if (value >= 0) { // skip over non-code
                accum <<= 6; // bits shift up by 6 each time thru
                shift += 6; // loop, with new bits being put in
                accum |= value; // at the bottom.
                if (shift >= 8) { // whenever there are 8 or more shifted in,
                    shift -= 8; // write them out (from the top, leaving any
                    out[index++] = // excess at the bottom for next iteration.
                    (byte) ((accum >> shift) & 0xff);
                }
            }
        }
 
        // if there is STILL something wrong we just have to throw up now!
        if (index != out.length) {
            throw new Error("Miscalculated data length (wrote " + index
                    + " instead of " + out.length + ")");
        }
 
        return out;
    }
 
    /**
     * 功能:编码文件
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param file
     *  源文件
     */
    public static void encode(File file) throws IOException {
        if (!file.exists()) {
            System.exit(0);
        }
 
        else {
            byte[] decoded = readBytes(file);
            char[] encoded = encode(decoded);
            writeChars(file, encoded);
        }
        file = null;
    }
 
    /**
     * 功能:解码文件。
     *
     * @author 宋立君
     * @date 2014年07月03日
     * @param file
     *  源文件
     * @throws IOException
     */
    public static void decode(File file) throws IOException {
        if (!file.exists()) {
            System.exit(0);
        } else {
            char[] encoded = readChars(file);
            byte[] decoded = decode(encoded);
            writeBytes(file, decoded);
        }
        file = null;
    }
 
    //
    // code characters for values 0..63
    //
    private static char[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
            .toCharArray();
 
    //
    // lookup table for converting base64 characters to value in range 0..63
    //
    private static byte[] codes = new byte[256];
    static {
        for (int i = 0; i < 256; i++) {
            codes[i] = -1;
            // LoggerUtil.debug(i + "&" + codes[i] + " ");
        }
        for (int i = 'A'; i <= 'Z'; i++) {
            codes[i] = (byte) (i - 'A');
            // LoggerUtil.debug(i + "&" + codes[i] + " ");
        }
 
        for (int i = 'a'; i <= 'z'; i++) {
            codes[i] = (byte) (26 + i - 'a');
            // LoggerUtil.debug(i + "&" + codes[i] + " ");
        }
        for (int i = '0'; i <= '9'; i++) {
            codes[i] = (byte) (52 + i - '0');
            // LoggerUtil.debug(i + "&" + codes[i] + " ");
        }
        codes['+'] = 62;
        codes['/'] = 63;
    }
 
    private static byte[] readBytes(File file) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] b = null;
        InputStream fis = null;
        InputStream is = null;
        try {
            fis = new FileInputStream(file);
            is = new BufferedInputStream(fis);
            int count = 0;
            byte[] buf = new byte[16384];
            while ((count = is.read(buf)) != -1) {
                if (count > 0) {
                    baos.write(buf, 0, count);
                }
            }
            b = baos.toByteArray();
 
        } finally {
            try {
                if (fis != null)
                    fis.close();
                if (is != null)
                    is.close();
                if (baos != null)
                    baos.close();
            } catch (Exception e) {
                System.out.println(e);
            }
        }
 
        return b;
    }
 
    private static char[] readChars(File file) throws IOException {
        CharArrayWriter caw = new CharArrayWriter();
        Reader fr = null;
        Reader in = null;
        try {
            fr = new FileReader(file);
            in = new BufferedReader(fr);
            int count = 0;
            char[] buf = new char[16384];
            while ((count = in.read(buf)) != -1) {
                if (count > 0) {
                    caw.write(buf, 0, count);
                }
            }
 
        } finally {
            try {
                if (caw != null)
                    caw.close();
                if (in != null)
                    in.close();
                if (fr != null)
                    fr.close();
            } catch (Exception e) {
                System.out.println(e);
            }
        }
 
        return caw.toCharArray();
    }
 
    private static void writeBytes(File file, byte[] data) throws IOException {
        OutputStream fos = null;
        OutputStream os = null;
        try {
            fos = new FileOutputStream(file);
            os = new BufferedOutputStream(fos);
            os.write(data);
 
        } finally {
            try {
                if (os != null)
                    os.close();
                if (fos != null)
                    fos.close();
            } catch (Exception e) {
                System.out.println(e);
            }
        }
    }
 
    private static void writeChars(File file, char[] data) throws IOException {
        Writer fos = null;
        Writer os = null;
        try {
            fos = new FileWriter(file);
            os = new BufferedWriter(fos);
            os.write(data);
 
        } finally {
            try {
                if (os != null)
                    os.close();
                if (fos != null)
                    fos.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
 
    // /////////////////////////////////////////////////
    // end of test code.
    // /////////////////////////////////////////////////
 
}

posted on 2017-12-22 09:58  admingy  阅读(119)  评论(0编辑  收藏  举报

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