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android平台上AES,DES加解密及问题

2024-08-10 15:20:37   217人阅读

在使用java进行AES加密的时候，会用到如下方法： SecureRandom sr = SecureRandom.getInstance("SHA1PRNG"); 
但是在android4.2以上进行加密、解密时，会报类似badPadding的异常，但是把该代码替换成一下方法则一切都OK。 SecureRandom sr = SecureRandom.getInstance("SHA1PRNG", "Crypto"); 
AES加密算法：

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import java.security.SecureRandom;
 
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
 
public class AESUtil {
 
    public static String encrypt(String seed, String cleartext)
            throws Exception {
        byte[] rawKey = getRawKey(seed.getBytes());
        byte[] result = encrypt(rawKey, cleartext.getBytes());
        return toHex(result);
    }
 
    public static String decrypt(String seed, String encrypted)
            throws Exception {
        byte[] rawKey = getRawKey(seed.getBytes());
        byte[] enc = toByte(encrypted);
        byte[] result = decrypt(rawKey, enc);
        return new String(result);
    }
 
    private static byte[] getRawKey(byte[] seed) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
//      SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
        SecureRandom sr = SecureRandom.getInstance("SHA1PRNG", "Crypto");
        sr.setSeed(seed);
        kgen.init(128, sr); // 192 and 256 bits may not be available
        SecretKey skey = kgen.generateKey();
        byte[] raw = skey.getEncoded();
        return raw;
    }
 
    private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
        byte[] encrypted = cipher.doFinal(clear);
        return encrypted;
    }
 
    private static byte[] decrypt(byte[] raw, byte[] encrypted)
            throws Exception {
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, skeySpec);
        byte[] decrypted = cipher.doFinal(encrypted);
        return decrypted;
    }
 
    public static String toHex(String txt) {
        return toHex(txt.getBytes());
    }
 
    public static String fromHex(String hex) {
        return new String(toByte(hex));
    }
 
    public static byte[] toByte(String hexString) {
        int len = hexString.length()/2;
        byte[] result = new byte[len];
        for (int i = 0; i < len; i++)
            result[i] = Integer.valueOf(hexString.substring(2*i, 2*i+2), 16).byteValue();
        return result;
    }
 
    public static String toHex(byte[] buf) {
        if (buf == null)
            return "";
        StringBuffer result = new StringBuffer(2*buf.length);
        for (int i = 0; i < buf.length; i++) {
            appendHex(result, buf[i]);
        }
        return result.toString();
    }
 
    private final static String HEX = "0123456789ABCDEF";
 
    private static void appendHex(StringBuffer sb, byte b) {
         sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
    }
}


DES加密算法

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import java.io.UnsupportedEncodingException;
import java.security.Key;
import java.util.Locale;
 
import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.IvParameterSpec;
 
/**
 * DES加密
 *
 * @author houjinyun
 *
 */
public class DesUtils {
 
    private static final String KEY = "********************";
     
    /**
     * 对字符串进行DES3加密
     *
     * @param str
     * @return 加密后的字符串，若失败则返回null
     */
    public static String encode(String str) {
        try {
            byte[] key = KEY.getBytes("UTF-8");
            byte[] data = http://www.mamicode.com/str.getBytes("UTF-8");
            byte[] encodedData = http://www.mamicode.com/des3EncodeECB(key, data);
            return byte2HexString(encodedData);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }      
        return null;
    }
 
    public static String decode(String str) {
        try {
            byte[] key = KEY.getBytes("UTF-8");
            byte[] data = http://www.mamicode.com/hexString2Byte(str);
            byte[] decodedData = http://www.mamicode.com/des3DecodeECB(key, data);
            return new String(decodedData, "UTF-8");
        } catch(Exception e) {
            e.printStackTrace();
        }
        return null;
    }
     
    /**
     * ECB加密,不要IV
     *
     * @param key
     *            密钥
     * @param data
     *            明文
     * @return Base64编码的密文
     * @throws Exception
     */
    public static byte[] des3EncodeECB(byte[] key, byte[] data)
            throws Exception {
        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);
        Cipher cipher = Cipher.getInstance("desede" + "/ECB/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, deskey);
        byte[] bOut = cipher.doFinal(data);
        return bOut;
    }
 
    /**
     * ECB解密,不要IV
     *
     * @param key
     *            密钥
     * @param data
     *            Base64编码的密文
     * @return 明文
     * @throws Exception
     */
    public static byte[] ees3DecodeECB(byte[] key, byte[] data)
            throws Exception {
        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);
        Cipher cipher = Cipher.getInstance("desede" + "/ECB/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, deskey);
        byte[] bOut = cipher.doFinal(data);
        return bOut;
    }
 
    /**
     * CBC加密
     *
     * @param key
     *            密钥
     * @param keyiv
     *            IV
     * @param data
     *            明文
     * @return Base64编码的密文
     * @throws Exception
     */
    public static byte[] des3EncodeCBC(byte[] key, byte[] keyiv, byte[] data)
            throws Exception {
        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);
        Cipher cipher = Cipher.getInstance("desede" + "/CBC/PKCS5Padding");
        IvParameterSpec ips = new IvParameterSpec(keyiv);
        cipher.init(Cipher.ENCRYPT_MODE, deskey, ips);
        byte[] bOut = cipher.doFinal(data);
        return bOut;
    }
 
    /**
     * CBC解密
     *
     * @param key
     *            密钥
     * @param keyiv
     *            IV
     * @param data
     *            Base64编码的密文
     * @return 明文
     * @throws Exception
     */
    public static byte[] des3DecodeCBC(byte[] key, byte[] keyiv, byte[] data)
            throws Exception {
        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);
 
        Cipher cipher = Cipher.getInstance("desede" + "/CBC/PKCS5Padding");
        IvParameterSpec ips = new IvParameterSpec(keyiv);
        cipher.init(Cipher.DECRYPT_MODE, deskey, ips);
        byte[] bOut = cipher.doFinal(data);
        return bOut;
    }
 
    public static byte[] des3DecodeECB(byte[] key, byte[] data)
            throws Exception {
        Key deskey = null;
        DESedeKeySpec spec = new DESedeKeySpec(key);
        SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
        deskey = keyfactory.generateSecret(spec);
        Cipher cipher = Cipher.getInstance("desede" + "/ECB/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, deskey);
        byte[] bOut = cipher.doFinal(data);
        return bOut;
    }
     
    private static String byte2HexString(byte[] b) {
        String a = "";
        for (int i = 0; i < b.length; i++) {
            String hex = Integer.toHexString(b[i] & 0xFF)
                    .toUpperCase(Locale.US);
            if (hex.length() == 1) {
                hex = ‘0‘ + hex;
            }
            a = a + hex;
        }
        return a;
    }
 
    private static byte[] hexString2Byte(String str) {
        if (str == null)
            return null;
        str = str.trim();
        int len = str.length();
        if (len == 0 || len % 2 == 1)
            return null;
        byte[] b = new byte[len / 2];
        try {
            for (int i = 0; i < str.length(); i += 2) {
                b[i / 2] = (byte) Integer.decode("0x" + str.substring(i, i + 2)).intValue();
            }
            return b;
        } catch (Exception e) {
            return null;
        }
    }
     
}
 

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android平台上AES,DES加解密及问题


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