Example usage for java.security MessageDigest getInstance

Introduction

In this page you can find the example usage for java.security MessageDigest getInstance.

Prototype

public static MessageDigest getInstance(String algorithm, Provider provider) throws NoSuchAlgorithmException 

Source Link

Document

Returns a MessageDigest object that implements the specified digest algorithm.

Usage

From source file:Main.java

public static void main(String[] args) throws Exception {
    //Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    DHParameterSpec dhParams = new DHParameterSpec(p512, g512);
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DH", "BC");

    keyGen.initialize(dhParams, new SecureRandom());

    KeyAgreement aKeyAgree = KeyAgreement.getInstance("DH", "BC");
    KeyPair aPair = keyGen.generateKeyPair();
    KeyAgreement bKeyAgree = KeyAgreement.getInstance("DH", "BC");
    KeyPair bPair = keyGen.generateKeyPair();

    aKeyAgree.init(aPair.getPrivate());/* www  . j av  a  2 s . com*/
    bKeyAgree.init(bPair.getPrivate());

    aKeyAgree.doPhase(bPair.getPublic(), true);
    bKeyAgree.doPhase(aPair.getPublic(), true);

    MessageDigest hash = MessageDigest.getInstance("SHA1", "BC");
    System.out.println(new String(hash.digest(aKeyAgree.generateSecret())));
    System.out.println(new String(hash.digest(bKeyAgree.generateSecret())));
}

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From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    DHParameterSpec dhParams = new DHParameterSpec(p512, g512);
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DH", "BC");

    keyGen.initialize(dhParams, new SecureRandom());

    KeyAgreement aKeyAgree = KeyAgreement.getInstance("DH", "BC");
    KeyPair aPair = keyGen.generateKeyPair();
    KeyAgreement bKeyAgree = KeyAgreement.getInstance("DH", "BC");
    KeyPair bPair = keyGen.generateKeyPair();

    aKeyAgree.init(aPair.getPrivate());/*  ww  w  . j a v  a 2 s  . co  m*/
    bKeyAgree.init(bPair.getPrivate());

    aKeyAgree.doPhase(bPair.getPublic(), true);
    bKeyAgree.doPhase(aPair.getPublic(), true);

    MessageDigest hash = MessageDigest.getInstance("SHA1", "BC");
    System.out.println(new String(hash.digest(aKeyAgree.generateSecret())));
    System.out.println(new String(hash.digest(bKeyAgree.generateSecret())));
}

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From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA", "BC");
    keyGen.initialize(512, new SecureRandom());
    KeyPair keyPair = keyGen.generateKeyPair();

    Signature signature = Signature.getInstance("SHA256withRSA", "BC");
    signature.initSign(keyPair.getPrivate());

    byte[] message = "abc".getBytes();
    signature.update(message);//from  ww w .j  av a 2  s. com

    byte[] sigBytes = signature.sign();
    Cipher cipher = Cipher.getInstance("RSA/None/PKCS1Padding", "BC");
    cipher.init(Cipher.DECRYPT_MODE, keyPair.getPublic());

    byte[] decSig = cipher.doFinal(sigBytes);
    ASN1InputStream aIn = new ASN1InputStream(decSig);
    ASN1Sequence seq = (ASN1Sequence) aIn.readObject();

    System.out.println(ASN1Dump.dumpAsString(seq));

    MessageDigest hash = MessageDigest.getInstance("SHA-256", "BC");
    hash.update(message);

    ASN1OctetString sigHash = (ASN1OctetString) seq.getObjectAt(1);
    System.out.println(MessageDigest.isEqual(hash.digest(), sigHash.getOctets()));
}

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From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("ECDH", "BC");
    EllipticCurve curve = new EllipticCurve(
            new ECFieldFp(new BigInteger("fffffffffffffffffffffffffffffffeffffffffffffffff", 16)),
            new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16),
            new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16));

    ECParameterSpec ecSpec = new ECParameterSpec(curve,
            new ECPoint(new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16),
                    new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16)),
            new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16), 1);

    keyGen.initialize(ecSpec, new SecureRandom());

    KeyAgreement aKeyAgree = KeyAgreement.getInstance("ECDH", "BC");
    KeyPair aPair = keyGen.generateKeyPair();
    KeyAgreement bKeyAgree = KeyAgreement.getInstance("ECDH", "BC");
    KeyPair bPair = keyGen.generateKeyPair();

    aKeyAgree.init(aPair.getPrivate());/*from  w  w  w .j a v a 2  s  .  c  o  m*/
    bKeyAgree.init(bPair.getPrivate());

    aKeyAgree.doPhase(bPair.getPublic(), true);
    bKeyAgree.doPhase(aPair.getPublic(), true);

    MessageDigest hash = MessageDigest.getInstance("SHA1", "BC");

    System.out.println(new String(hash.digest(aKeyAgree.generateSecret())));
    System.out.println(new String(hash.digest(bKeyAgree.generateSecret())));
}

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From source file:MainClass.java

public static void main(String[] args) throws Exception {
    // Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("ECDH", "BC");
    EllipticCurve curve = new EllipticCurve(
            new ECFieldFp(new BigInteger("fffffffffffffffffffffffffffffffeffffffffffffffff", 16)),
            new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16),
            new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16));

    ECParameterSpec ecSpec = new ECParameterSpec(curve,
            new ECPoint(new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16),
                    new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16)),
            new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16), 1);

    keyGen.initialize(ecSpec, new SecureRandom());

    KeyAgreement aKeyAgree = KeyAgreement.getInstance("ECDH", "BC");
    KeyPair aPair = keyGen.generateKeyPair();
    KeyAgreement bKeyAgree = KeyAgreement.getInstance("ECDH", "BC");
    KeyPair bPair = keyGen.generateKeyPair();

    aKeyAgree.init(aPair.getPrivate());//from  w  w w  . j  a v  a  2s. co  m
    bKeyAgree.init(bPair.getPrivate());

    aKeyAgree.doPhase(bPair.getPublic(), true);
    bKeyAgree.doPhase(aPair.getPublic(), true);

    MessageDigest hash = MessageDigest.getInstance("SHA1", "BC");

    System.out.println(new String(hash.digest(aKeyAgree.generateSecret())));
    System.out.println(new String(hash.digest(bKeyAgree.generateSecret())));
}

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