Examples of java.security.AlgorithmParameterGenerator

java.security.AlgorithmParameterGenerator
The AlgorithmParameterGenerator class is used to generate a set of parameters to be used with a certain algorithm. Parameter generators are constructed using the getInstance factory methods (static methods that return instances of a given class).
The object that will generate the parameters can be initialized in two different ways: in an algorithm-independent manner, or in an algorithm-specific manner:
- The algorithm-independent approach uses the fact that all parameter generators share the concept of a "size" and a source of randomness. The measure of size is universally shared by all algorithm parameters, though it is interpreted differently for different algorithms. For example, in the case of parameters for the DSA algorithm, "size" corresponds to the size of the prime modulus (in bits). When using this approach, algorithm-specific parameter generation values - if any - default to some standard values, unless they can be derived from the specified size.
- The other approach initializes a parameter generator object using algorithm-specific semantics, which are represented by a set of algorithm-specific parameter generation values. To generate Diffie-Hellman system parameters, for example, the parameter generation values usually consist of the size of the prime modulus and the size of the random exponent, both specified in number of bits.
In case the client does not explicitly initialize the AlgorithmParameterGenerator (via a call to an init method), each provider must supply (and document) a default initialization. For example, the Sun provider uses a default modulus prime size of 1024 bits for the generation of DSA parameters. @author Jan Luehe @version 1.43, 04/21/06 @see AlgorithmParameters @see java.security.spec.AlgorithmParameterSpec @since 1.2

            // Test bug with ElGamal P size != 0 mod 8 (don't use these sizes at home!)
            SecureRandom random = new SecureRandom();
            for (int pSize = 257; pSize < 264; ++pSize)
            {
                // Generate some parameters of the given size
                AlgorithmParameterGenerator a = AlgorithmParameterGenerator.getInstance("ElGamal", "BC");
                a.init(pSize, new SecureRandom());
                AlgorithmParameters params = a.generateParameters();


                DHParameterSpec elP = (DHParameterSpec)params.getParameterSpec(DHParameterSpec.class);
                KeyPairGenerator keyGen = KeyPairGenerator.getInstance("ElGamal", "BC");


                keyGen.initialize(elP);

View Full Code Here

  private void init() 
    throws NoSuchAlgorithmException, 
           InvalidAlgorithmParameterException, 
           InvalidParameterSpecException,
           InvalidKeySpecException  {
    AlgorithmParameterGenerator pgen = AlgorithmParameterGenerator.getInstance("DH");
    pgen.init(512);
    AlgorithmParameters params = pgen.generateParameters();
    DHParameterSpec dhspec = (DHParameterSpec)params.getParameterSpec(DHParameterSpec.class);
    KeyPairGenerator keypairgen = KeyPairGenerator.getInstance("DH");
    keypairgen.initialize(dhspec);   
    keyPair = keypairgen.generateKeyPair();
    p = dhspec.getP();

View Full Code Here


    private void testRandom(
        int         size)
        throws Exception
    {
        AlgorithmParameterGenerator a = AlgorithmParameterGenerator.getInstance("DH", "BC");
        a.init(size, new SecureRandom());
        AlgorithmParameters params = a.generateParameters();


        byte[] encodeParams = params.getEncoded();


        AlgorithmParameters a2 = AlgorithmParameters.getInstance("DH", "BC");
        a2.init(encodeParams);

View Full Code Here

               GeneralSecurityException 
    {
        
        String s = "1.2.840.113549.3.2";
        
        AlgorithmParameterGenerator algorithmparametergenerator = AlgorithmParameterGenerator.getInstance(s);
        AlgorithmParameters algorithmparameters = algorithmparametergenerator.generateParameters();
        ByteArrayInputStream bytearrayinputstream = new ByteArrayInputStream(algorithmparameters.getEncoded("ASN.1"));
        ASN1InputStream asn1inputstream = new ASN1InputStream(bytearrayinputstream);
        DERObject derobject = asn1inputstream.readObject();
        KeyGenerator keygenerator = KeyGenerator.getInstance(s);
        keygenerator.init(128);

View Full Code Here

    protected AlgorithmParameters generateParameters(String encryptionOID, SecretKey encKey, String encProvider)
        throws NoSuchProviderException, CMSException
    {
        try
        {
            AlgorithmParameterGenerator pGen = AlgorithmParameterGenerator.getInstance(encryptionOID, encProvider);


            if (encryptionOID.equals(RC2_CBC))
            {
                byte[]  iv = new byte[8];


                //
                // mix in a bit extra...
                //
                rand.setSeed(System.currentTimeMillis());


                rand.nextBytes(iv);


                try
                {
                    pGen.init(new RC2ParameterSpec(encKey.getEncoded().length * 8, iv), rand);
                }
                catch (InvalidAlgorithmParameterException e)
                {
                    throw new CMSException("parameters generation error: " + e, e);
                }
            }


            return pGen.generateParameters();
        }
        catch (NoSuchAlgorithmException e)
        {
            return null;
        }

View Full Code Here

        return buf.toString();
    }


    private void init() throws NoSuchAlgorithmException, InvalidAlgorithmParameterException,
        InvalidParameterSpecException, InvalidKeySpecException {
        AlgorithmParameterGenerator pgen = AlgorithmParameterGenerator.getInstance("DH");
        pgen.init(512);
        AlgorithmParameters params = pgen.generateParameters();
        DHParameterSpec dhspec = (DHParameterSpec)params.getParameterSpec(DHParameterSpec.class);
        KeyPairGenerator keypairgen = KeyPairGenerator.getInstance("DH");
        keypairgen.initialize(dhspec);
        keyPair = keypairgen.generateKeyPair();
        p = dhspec.getP();

View Full Code Here

               GeneralSecurityException
    {


        String s = "1.2.840.113549.3.2";


        AlgorithmParameterGenerator algorithmparametergenerator = AlgorithmParameterGenerator.getInstance(s);
        AlgorithmParameters algorithmparameters = algorithmparametergenerator.generateParameters();
        ByteArrayInputStream bytearrayinputstream = new ByteArrayInputStream(algorithmparameters.getEncoded("ASN.1"));
        ASN1InputStream asn1inputstream = new ASN1InputStream(bytearrayinputstream);
        DERObject derobject = asn1inputstream.readObject();
        KeyGenerator keygenerator = KeyGenerator.getInstance(s);
        keygenerator.init(128);

View Full Code Here

    }


    private void testParameters()
        throws Exception
    {
        AlgorithmParameterGenerator a = AlgorithmParameterGenerator.getInstance("DSA", "BC");
        a.init(512, random);
        AlgorithmParameters params = a.generateParameters();
        
        byte[] encodeParams = params.getEncoded();
        
        AlgorithmParameters a2 = AlgorithmParameters.getInstance("DSA", "BC");
        a2.init(encodeParams);

View Full Code Here

0 1 2 3 4

TOP

Related Classes of java.security.AlgorithmParameterGenerator

com.itextpdf.text.pdf.PdfPublicKeySecurityHandler

com.lowagie.text.pdf.PdfPublicKeySecurityHandler

erki.talk.DHKeyExchange

gnu.java.lang.CPStringBuilder

gnu.testlet.java.security.AlgorithmParameterGenerator.getInstance14

hudson.cli.Connection

io.apigee.trireme.core.modules.crypto.DHImpl

org.apache.abdera.security.util.DHContext

org.apache.abdera.security.util.servlet.DHContext

org.apache.harmony.security.tests.java.security.AlgorithmParameterGenerator3Test

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.