数据签名标准算法-DSA (Digital signature Algorithm DSA)-白红宇

数据签名标准算法-DSA (Digital signature Algorithm DSA)

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发布时间：2019-06-29

本文共 2624 字，大约阅读时间需要 8 分钟。

　　　　　　　　支持的算法有： SHA1withDSA 224 , 256 , 384, 512

public abstract class DSACoderSignature {    private static final String PRIVATE_KEY = "RSAPrivate_Key";    private static final String PUBLIC_KEY = "RSAPublic_key";    private static final int KEY_SIZE = 1024;    private static final String KEY_ALGORITHM = "DSA";    private static final String SIGNATURE_ALGORITHM = "SHA1withDSA";    public static byte[] getprivateKey(Map
      
        keyMap) throws Exception {        Key key = (Key) keyMap.get(PRIVATE_KEY);        return key.getEncoded();    }    public static byte[] getPublicKey(Map
       
         keyMap) throws Exception {        Key key = (Key) keyMap.get(PUBLIC_KEY);        return key.getEncoded();    }        /**     *  生产公私钥 保存到Map里面     * @return     * @throws Exception     */    public static Map
        
          initKey() throws Exception {        Map
         
           keyMap = new HashMap
          
           (2);        KeyPairGenerator keyPaiGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);        keyPaiGen.initialize(KEY_SIZE);        KeyPair pair = keyPaiGen.generateKeyPair();        DSAPublicKey publicKey = (DSAPublicKey) pair.getPublic();        DSAPrivateKey privateKey = (DSAPrivateKey) pair.getPrivate();        keyMap.put(PUBLIC_KEY, publicKey);        keyMap.put(PRIVATE_KEY, privateKey);        return keyMap;    }    /**     * 用私钥生产数字签名，     * @param data     * @param privateKey     * @return     * @throws Exception     */    public static byte[] sign(byte[] data, byte[] privateKey) throws Exception {        PKCS8EncodedKeySpec pkc = new PKCS8EncodedKeySpec(privateKey);        KeyFactory keyfactory = KeyFactory.getInstance(KEY_ALGORITHM);        PrivateKey prikey = keyfactory.generatePrivate(pkc);        Signature sig = Signature.getInstance(SIGNATURE_ALGORITHM);        sig.initSign(prikey);        sig.update(data);        return sig.sign();    }        /**     * 用公钥decryption，检验私钥encryption的正确性，     * @param data     * @param publicKey     * @param signs  私钥生产的encryption数字证书     * @return     * @throws Exception     */    public static boolean verify(byte[] data, byte[] publicKey, byte[] signs) throws Exception {        X509EncodedKeySpec pkc= new X509EncodedKeySpec(publicKey);        KeyFactory keyfactory = KeyFactory.getInstance(KEY_ALGORITHM);        PublicKey pubkey = keyfactory.generatePublic(pkc);        Signature sig = Signature.getInstance(SIGNATURE_ALGORITHM);        sig.initVerify(pubkey);        sig.update(data);        return sig.verify(signs);    }}