Examples of KeyPairGenerator

java.security.KeyPairGenerator
The KeyPairGenerator class is used to generate pairs of public and private keys. Key pair generators are constructed using the getInstance factory methods (static methods that return instances of a given class).
A Key pair generator for a particular algorithm creates a public/private key pair that can be used with this algorithm. It also associates algorithm-specific parameters with each of the generated keys.
There are two ways to generate a key pair: in an algorithm-independent manner, and in an algorithm-specific manner. The only difference between the two is the initialization of the object:
- Algorithm-Independent Initialization
  All key pair generators share the concepts of a keysize and a source of randomness. The keysize is interpreted differently for different algorithms (e.g., in the case of the DSA algorithm, the keysize corresponds to the length of the modulus). There is an {@link #initialize(int,java.security.SecureRandom) initialize}method in this KeyPairGenerator class that takes these two universally shared types of arguments. There is also one that takes just a keysize argument, and uses the SecureRandom implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness is used.)
  Since no other parameters are specified when you call the above algorithm-independent initialize methods, it is up to the provider what to do about the algorithm-specific parameters (if any) to be associated with each of the keys.
  If the algorithm is the DSA algorithm, and the keysize (modulus size) is 512, 768, or 1024, then the Sun provider uses a set of precomputed values for the p, q, and g parameters. If the modulus size is not one of the above values, the Sun provider creates a new set of parameters. Other providers might have precomputed parameter sets for more than just the three modulus sizes mentioned above. Still others might not have a list of precomputed parameters at all and instead always create new parameter sets.
- Algorithm-Specific Initialization
  For situations where a set of algorithm-specific parameters already exists (e.g., so-called community parameters in DSA), there are two {@link #initialize(java.security.spec.AlgorithmParameterSpec) initialize} methods that have an AlgorithmParameterSpecargument. One also has a SecureRandom argument, while the the other uses the SecureRandom implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness is used.)
In case the client does not explicitly initialize the KeyPairGenerator (via a call to an initialize method), each provider must supply (and document) a default initialization. For example, the Sun provider uses a default modulus size (keysize) of 1024 bits.
Note that this class is abstract and extends from KeyPairGeneratorSpi for historical reasons. Application developers should only take notice of the methods defined in this KeyPairGenerator class; all the methods in the superclass are intended for cryptographic service providers who wish to supply their own implementations of key pair generators. @author Benjamin Renaud @version 1.59, 04/21/06 @see java.security.spec.AlgorithmParameterSpec

Examples of java.security.KeyPairGenerator

                        "ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml");
        DocumentBuilder builder = XMLUtils.createDocumentBuilder(false);
        Document document = builder.parse(sourceDocument);
        
        // Set up the Key
        KeyPairGenerator rsaKeygen = KeyPairGenerator.getInstance("RSA");
        KeyPair kp = rsaKeygen.generateKeyPair();
        PrivateKey priv = kp.getPrivate();
        PublicKey pub = kp.getPublic();


        // Generate a traffic key
        KeyGenerator keygen = KeyGenerator.getInstance("AES");

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Examples of java.security.KeyPairGenerator

                        "ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml");
        DocumentBuilder builder = XMLUtils.createDocumentBuilder(false);
        Document document = builder.parse(sourceDocument);


        // Set up the Key
        KeyPairGenerator rsaKeygen = KeyPairGenerator.getInstance("RSA");
        KeyPair kp = rsaKeygen.generateKeyPair();
        PrivateKey priv = kp.getPrivate();
        PublicKey pub = kp.getPublic();


        // Generate a traffic key
        KeyGenerator keygen = KeyGenerator.getInstance("AES");

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Examples of java.security.KeyPairGenerator

        cipher.init(Cipher.DECRYPT_MODE, key);
        return cipher.doFinal(inpBytes);
    }


    public static KeyPair generateKeyPair() throws NoSuchAlgorithmException {
        KeyPairGenerator kpg = KeyPairGenerator.getInstance(algorithm);
        kpg.initialize(2048, new SecureRandom());


        return kpg.generateKeyPair();
    }

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Examples of java.security.KeyPairGenerator


        if (side) {
            AlgorithmParameterGenerator paramGen = AlgorithmParameterGenerator.getInstance("DH");
            paramGen.init(512);


            KeyPairGenerator dh = KeyPairGenerator.getInstance("DH");
            dh.initialize(paramGen.generateParameters().getParameterSpec(DHParameterSpec.class));
            keyPair = dh.generateKeyPair();


            // send a half and get a half
            writeKey(keyPair.getPublic());
            otherHalf = KeyFactory.getInstance("DH").generatePublic(readKey());
        } else {
            otherHalf = KeyFactory.getInstance("DH").generatePublic(readKey());


            KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("DH");
            keyPairGen.initialize(((DHPublicKey) otherHalf).getParams());
            keyPair = keyPairGen.generateKeyPair();


            // send a half and get a half
            writeKey(keyPair.getPublic());
        }

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Examples of java.security.KeyPairGenerator

    public void setUpKeys(String algorithm, int keylength) throws Exception {
        keyPair = getKeyPair(algorithm, keylength);
    }


    public static KeyPair getKeyPair(String algorithm, int keylength) {
        KeyPairGenerator keyGen;
        try {
            keyGen = KeyPairGenerator.getInstance(algorithm);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
        keyGen.initialize(keylength, new SecureRandom());
        return keyGen.generateKeyPair();
    }

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Examples of java.security.KeyPairGenerator

    public void setUpKeys(String algorithm, int keylength) throws Exception {
        keyPair = getKeyPair(algorithm, keylength);
    }


    public static KeyPair getKeyPair(String algorithm, int keylength) {
        KeyPairGenerator keyGen;
        try {
            keyGen = KeyPairGenerator.getInstance(algorithm);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
        keyGen.initialize(keylength, new SecureRandom());
        return keyGen.generateKeyPair();
    }

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Examples of java.security.KeyPairGenerator

    public void setUpKeys(String algorithm, int keylength) throws Exception {
        keyPair = getKeyPair(algorithm, keylength);
    }


    public static KeyPair getKeyPair(String algorithm, int keylength) {
        KeyPairGenerator keyGen;
        try {
            keyGen = KeyPairGenerator.getInstance(algorithm);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
        keyGen.initialize(keylength, new SecureRandom());
        return keyGen.generateKeyPair();
    }

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Examples of java.security.KeyPairGenerator

      return data;
    }
  }


  public static KeyPair generateKeyPair(String algorithm, int keysize) {
    KeyPairGenerator generator;
    try {
      generator = KeyPairGenerator.getInstance(algorithm);
    } catch (NoSuchAlgorithmException e) {
      throw new IllegalStateException("Error loading crypto provider", e);
    }
    generator.initialize(keysize);
    KeyPair keyPair = generator.generateKeyPair();
    return keyPair;


  }

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Examples of java.security.KeyPairGenerator

      IoUtils.safeClose(pemWriter);
    }
  }


  public static KeyPair generateKeyPair(String algorithm, Integer keySize) throws OpsException {
    KeyPairGenerator generator;
    try {
      generator = KeyPairGenerator.getInstance(algorithm);
    } catch (NoSuchAlgorithmException e) {
      throw new OpsException("Error building keypair generator: " + algorithm, e);
    }
    if (keySize != null) {
      generator.initialize(keySize);
    }
    return generator.generateKeyPair();
  }

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Examples of java.security.KeyPairGenerator

    public static KeyPair genKeyPair(KeyPairType type) {
        if(type.equals(KeyPairType.DSA)){
            throw new UnsupportedTypeException(type);
        }
        try {
            KeyPairGenerator kg = KeyPairGenerator.getInstance(type.alg);
            kg.initialize(type.spec);
            return kg.generateKeyPair();
        } catch (NoSuchAlgorithmException e) {
            throw new Error(e); // Impossible?
        } catch (InvalidAlgorithmParameterException e) {
            throw new Error(e); // Impossible?
        }

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