ECDSA算法教程对字符串进行签名

你能帮我找一个简单的教程，讲解如何在java中使用ECDSA算法对字符串进行签名。 但是没有使用任何像bouncycastle这样的第三方库。 只是JDK 7.我发现很难搜索一个简单的例子，我是密码学的新手。

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import java.io.*; import java.security.*; public class GenSig { /** * @param args the command line arguments */ public static void main(String[] args) { /* * Generate a DSA signature */ try { /* * Generate a key pair */ KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA", "SUN"); SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN"); keyGen.initialize(1024, random); KeyPair pair = keyGen.generateKeyPair(); PrivateKey priv = pair.getPrivate(); PublicKey pub = pair.getPublic(); /* * Create a Signature object and initialize it with the private key */ Signature dsa = Signature.getInstance("SHA1withDSA", "SUN"); dsa.initSign(priv); String str = "This is string to sign"; byte[] strByte = str.getBytes(); dsa.update(strByte); /* * Now that all the data to be signed has been read in, generate a * signature for it */ byte[] realSig = dsa.sign(); System.out.println("Signature: " + new String(realSig)); } catch (Exception e) { System.err.println("Caught exception " + e.toString()); } } } 

如何修改ECDSA？

Answer 1

以下是基于您的示例的小示例。

 import java.math.BigInteger; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import java.security.SecureRandom; import java.security.Signature; public class ECDSAExample { public static void main(String[] args) throws Exception { /* * Generate an ECDSA signature */ /* * Generate a key pair */ KeyPairGenerator keyGen = KeyPairGenerator.getInstance("EC"); SecureRandom random = SecureRandom.getInstance("SHA1PRNG"); keyGen.initialize(256, random); KeyPair pair = keyGen.generateKeyPair(); PrivateKey priv = pair.getPrivate(); PublicKey pub = pair.getPublic(); /* * Create a Signature object and initialize it with the private key */ Signature dsa = Signature.getInstance("SHA1withECDSA"); dsa.initSign(priv); String str = "This is string to sign"; byte[] strByte = str.getBytes("UTF-8"); dsa.update(strByte); /* * Now that all the data to be signed has been read in, generate a * signature for it */ byte[] realSig = dsa.sign(); System.out.println("Signature: " + new BigInteger(1, realSig).toString(16)); } } 

Answer 2

 @Override public byte[] sign(PrivateKey privateKey, String message) throws Exception { Signature signature = Signature.getInstance("SHA1withECDSA"); signature.initSign(privateKey); signature.update(message.getBytes()); return signature.sign(); } @Override public boolean verify(PublicKey publicKey, byte[] signed, String message) throws Exception { Signature signature = Signature.getInstance("SHA1withECDSA"); signature.initVerify(publicKey); signature.update(message.getBytes()); return signature.verify(signed); } 

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 public class ECCCipherTest { private final KeyPairGenerator keygen; public ECCCipherTest() throws NoSuchProviderException, NoSuchAlgorithmException, InvalidAlgorithmParameterException { Security.addProvider(new BouncyCastleProvider()); this.keygen = KeyPairGenerator.getInstance("ECDSA", "BC"); keygen.initialize(new ECGenParameterSpec("brainpoolP384r1")); } @Test public void ECC_CipherTest_1() throws Exception { String message = "hello world"; ICipher cipher = new ECCCipher(); KeyPair keyPair = keygen.generateKeyPair(); byte[] encrypted = cipher.sign(keyPair.getPrivate(), message); Assert.assertTrue(cipher.verify(keyPair.getPublic(), encrypted, message)); } 

}

这是我项目中的一个小代码片段。 这个对我有用。 我还包括一个junit测试; 希望这会有所帮助。

以防有人想知道我们如何加载私钥和pubkey :(注意：privKey是表示java中BigInteger的字节数组，而pubKey是二进制格式的曲线点）

  @Override public PrivateKey generatePrivateKey(byte[] keyBin) throws InvalidKeySpecException, NoSuchAlgorithmException { ECNamedCurveParameterSpec spec = ECNamedCurveTable.getParameterSpec("secp256k1"); KeyFactory kf = KeyFactory.getInstance("ECDSA", new BouncyCastleProvider()); ECNamedCurveSpec params = new ECNamedCurveSpec("secp256k1", spec.getCurve(), spec.getG(), spec.getN()); ECPrivateKeySpec privKeySpec = new ECPrivateKeySpec(new BigInteger(keyBin), params); return kf.generatePrivate(privKeySpec); } @Override public PublicKey generatePublicKey(byte[] keyBin) throws InvalidKeySpecException, NoSuchAlgorithmException { ECNamedCurveParameterSpec spec = ECNamedCurveTable.getParameterSpec("secp256k1"); KeyFactory kf = KeyFactory.getInstance("ECDSA", new BouncyCastleProvider()); ECNamedCurveSpec params = new ECNamedCurveSpec("secp256k1", spec.getCurve(), spec.getG(), spec.getN()); ECPoint point = ECPointUtil.decodePoint(params.getCurve(), keyBin); ECPublicKeySpec pubKeySpec = new ECPublicKeySpec(point, params); return kf.generatePublic(pubKeySpec); }