sun.security.jca.GetInstance.Instance Java Examples

private static KeyPairGenerator getInstance(Instance instance,
        String algorithm) {
    KeyPairGenerator kpg;
    if (instance.impl instanceof KeyPairGenerator) {
        kpg = (KeyPairGenerator)instance.impl;
    } else {
        KeyPairGeneratorSpi spi = (KeyPairGeneratorSpi)instance.impl;
        kpg = new Delegate(spi, algorithm);
    }
    kpg.provider = instance.provider;

    if (!skipDebug && pdebug != null) {
        pdebug.println("KeyPairGenerator." + algorithm +
            " algorithm from: " + kpg.provider.getName());
    }

    return kpg;
}
 

static Instance getInstance(String type, Class<?> clazz, String algorithm)
        throws NoSuchAlgorithmException {
    List<Service> services = GetInstance.getServices(type, algorithm);
    NoSuchAlgorithmException failure = null;
    for (Service s : services) {
        if (canUseProvider(s.getProvider()) == false) {
            // allow only signed providers
            continue;
        }
        try {
            Instance instance = GetInstance.getInstance(s, clazz);
            return instance;
        } catch (NoSuchAlgorithmException e) {
            failure = e;
        }
    }
    throw new NoSuchAlgorithmException("Algorithm " + algorithm
            + " not available", failure);
}
 

static Instance getInstance(String type, Class<?> clazz, String algorithm)
        throws NoSuchAlgorithmException {
    List<Service> services = GetInstance.getServices(type, algorithm);
    NoSuchAlgorithmException failure = null;
    for (Service s : services) {
        if (canUseProvider(s.getProvider()) == false) {
            // allow only signed providers
            continue;
        }
        try {
            Instance instance = GetInstance.getInstance(s, clazz);
            return instance;
        } catch (NoSuchAlgorithmException e) {
            failure = e;
        }
    }
    throw new NoSuchAlgorithmException("Algorithm " + algorithm
            + " not available", failure);
}
 

private static KeyPairGenerator getInstance(Instance instance,
        String algorithm) {
    KeyPairGenerator kpg;
    if (instance.impl instanceof KeyPairGenerator) {
        kpg = (KeyPairGenerator)instance.impl;
    } else {
        KeyPairGeneratorSpi spi = (KeyPairGeneratorSpi)instance.impl;
        kpg = new Delegate(spi, algorithm);
    }
    kpg.provider = instance.provider;

    if (!skipDebug && pdebug != null) {
        pdebug.println("KeyPairGenerator." + algorithm +
            " algorithm from: " + kpg.provider.getName());
    }

    return kpg;
}
 

private static Signature getInstanceRSA(Provider p)
        throws NoSuchAlgorithmException {
    // try Signature first
    Service s = p.getService("Signature", RSA_SIGNATURE);
    if (s != null) {
        Instance instance = GetInstance.getInstance(s, SignatureSpi.class);
        return getInstance(instance, RSA_SIGNATURE);
    }
    // check Cipher
    try {
        Cipher c = Cipher.getInstance(RSA_CIPHER, p);
        return new Delegate(new CipherAdapter(c), RSA_SIGNATURE);
    } catch (GeneralSecurityException e) {
        // throw Signature style exception message to avoid confusion,
        // but append Cipher exception as cause
        throw new NoSuchAlgorithmException("no such algorithm: "
            + RSA_SIGNATURE + " for provider " + p.getName(), e);
    }
}
 

/**
 * Returns a <code>TransformService</code> that supports the specified
 * algorithm URI (ex: {@link Transform#XPATH2}) and mechanism type
 * (ex: DOM) as supplied by the specified provider. Note that the specified
 * <code>Provider</code> object does not have to be registered in the
 * provider list.
 *
 * @param algorithm the URI of the algorithm
 * @param mechanismType the type of the XML processing mechanism and
 *   representation
 * @param provider the <code>Provider</code> object
 * @return a new <code>TransformService</code>
 * @throws NullPointerException if <code>provider</code>,
 *   <code>algorithm</code>, or <code>mechanismType</code> is
 *   <code>null</code>
 * @throws NoSuchAlgorithmException if a <code>TransformService</code>
 *   implementation for the specified algorithm and mechanism type is not
 *   available from the specified <code>Provider</code> object
 * @see Provider
 */
public static TransformService getInstance
    (String algorithm, String mechanismType, Provider provider)
    throws NoSuchAlgorithmException {
    if (mechanismType == null || algorithm == null || provider == null) {
        throw new NullPointerException();
    }

    boolean dom = false;
    if (mechanismType.equals("DOM")) {
        dom = true;
    }
    Service s = GetInstance.getService
        ("TransformService", algorithm, provider);
    String value = s.getAttribute("MechanismType");
    if ((value == null && dom) ||
        (value != null && value.equals(mechanismType))) {
        Instance instance = GetInstance.getInstance(s, null);
        TransformService ts = (TransformService) instance.impl;
        ts.algorithm = algorithm;
        ts.mechanism = mechanismType;
        ts.provider = instance.provider;
        return ts;
    }
    throw new NoSuchAlgorithmException
        (algorithm + " algorithm and " + mechanismType
             + " mechanism not available");
}
 

static Instance getInstance(String type, Class<?> clazz, String algorithm,
        String provider) throws NoSuchAlgorithmException,
        NoSuchProviderException {
    Service s = GetInstance.getService(type, algorithm, provider);
    Exception ve = getVerificationResult(s.getProvider());
    if (ve != null) {
        String msg = "JCE cannot authenticate the provider " + provider;
        throw (NoSuchProviderException)
                            new NoSuchProviderException(msg).initCause(ve);
    }
    return GetInstance.getInstance(s, clazz);
}
 

private static Signature getInstance(Instance instance, String algorithm) {
    Signature sig;
    if (instance.impl instanceof Signature) {
        sig = (Signature)instance.impl;
        sig.algorithm = algorithm;
    } else {
        SignatureSpi spi = (SignatureSpi)instance.impl;
        sig = new Delegate(spi, algorithm);
    }
    sig.provider = instance.provider;
    return sig;
}
 

static Instance getInstance(String type, Class<?> clazz, String algorithm,
        Provider provider) throws NoSuchAlgorithmException {
    Service s = GetInstance.getService(type, algorithm, provider);
    Exception ve = JceSecurity.getVerificationResult(provider);
    if (ve != null) {
        String msg = "JCE cannot authenticate the provider "
            + provider.getName();
        throw new SecurityException(msg, ve);
    }
    return GetInstance.getInstance(s, clazz);
}
 

/**
 * Returns a <code>TransformService</code> that supports the specified
 * algorithm URI (ex: {@link Transform#XPATH2}) and mechanism type
 * (ex: DOM) as supplied by the specified provider. Note that the specified
 * <code>Provider</code> object does not have to be registered in the
 * provider list.
 *
 * @param algorithm the URI of the algorithm
 * @param mechanismType the type of the XML processing mechanism and
 *   representation
 * @param provider the <code>Provider</code> object
 * @return a new <code>TransformService</code>
 * @throws NullPointerException if <code>provider</code>,
 *   <code>algorithm</code>, or <code>mechanismType</code> is
 *   <code>null</code>
 * @throws NoSuchAlgorithmException if a <code>TransformService</code>
 *   implementation for the specified algorithm and mechanism type is not
 *   available from the specified <code>Provider</code> object
 * @see Provider
 */
public static TransformService getInstance
    (String algorithm, String mechanismType, Provider provider)
    throws NoSuchAlgorithmException {
    if (mechanismType == null || algorithm == null || provider == null) {
        throw new NullPointerException();
    }

    boolean dom = false;
    if (mechanismType.equals("DOM")) {
        dom = true;
    }
    Service s = GetInstance.getService
        ("TransformService", algorithm, provider);
    String value = s.getAttribute("MechanismType");
    if ((value == null && dom) ||
        (value != null && value.equals(mechanismType))) {
        Instance instance = GetInstance.getInstance(s, null);
        TransformService ts = (TransformService) instance.impl;
        ts.algorithm = algorithm;
        ts.mechanism = mechanismType;
        ts.provider = instance.provider;
        return ts;
    }
    throw new NoSuchAlgorithmException
        (algorithm + " algorithm and " + mechanismType
             + " mechanism not available");
}
 

/**
 * Returns a Signature object that implements the specified signature
 * algorithm.
 *
 * <p> This method traverses the list of registered security Providers,
 * starting with the most preferred Provider.
 * A new Signature object encapsulating the
 * SignatureSpi implementation from the first
 * Provider that supports the specified algorithm is returned.
 *
 * <p> Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param algorithm the standard name of the algorithm requested.
 * See the Signature section in the <a href=
 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Signature">
 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
 * for information about standard algorithm names.
 *
 * @return the new Signature object.
 *
 * @exception NoSuchAlgorithmException if no Provider supports a
 *          Signature implementation for the
 *          specified algorithm.
 *
 * @see Provider
 */
public static Signature getInstance(String algorithm)
        throws NoSuchAlgorithmException {
    List<Service> list;
    if (algorithm.equalsIgnoreCase(RSA_SIGNATURE)) {
        list = GetInstance.getServices(rsaIds);
    } else {
        list = GetInstance.getServices("Signature", algorithm);
    }
    Iterator<Service> t = list.iterator();
    if (t.hasNext() == false) {
        throw new NoSuchAlgorithmException
            (algorithm + " Signature not available");
    }
    // try services until we find an Spi or a working Signature subclass
    NoSuchAlgorithmException failure;
    do {
        Service s = t.next();
        if (isSpi(s)) {
            return new Delegate(s, t, algorithm);
        } else {
            // must be a subclass of Signature, disable dynamic selection
            try {
                Instance instance =
                    GetInstance.getInstance(s, SignatureSpi.class);
                return getInstance(instance, algorithm);
            } catch (NoSuchAlgorithmException e) {
                failure = e;
            }
        }
    } while (t.hasNext());
    throw failure;
}
 

/**
 * Returns a <code>TransformService</code> that supports the specified
 * algorithm URI (ex: {@link Transform#XPATH2}) and mechanism type
 * (ex: DOM) as supplied by the specified provider. The specified provider
 * must be registered in the security provider list.
 *
 * <p>Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param algorithm the URI of the algorithm
 * @param mechanismType the type of the XML processing mechanism and
 *   representation
 * @param provider the string name of the provider
 * @return a new <code>TransformService</code>
 * @throws NoSuchProviderException if the specified provider is not
 *   registered in the security provider list
 * @throws NullPointerException if <code>provider</code>,
 *   <code>mechanismType</code>, or <code>algorithm</code> is
 *   <code>null</code>
 * @throws NoSuchAlgorithmException if a <code>TransformService</code>
 *   implementation for the specified algorithm and mechanism type is not
 *   available from the specified provider
 * @see Provider
 */
public static TransformService getInstance
    (String algorithm, String mechanismType, String provider)
    throws NoSuchAlgorithmException, NoSuchProviderException {
    if (mechanismType == null || algorithm == null || provider == null) {
        throw new NullPointerException();
    } else if (provider.length() == 0) {
        throw new NoSuchProviderException();
    }
    boolean dom = false;
    if (mechanismType.equals("DOM")) {
        dom = true;
    }
    Service s = GetInstance.getService
        ("TransformService", algorithm, provider);
    String value = s.getAttribute("MechanismType");
    if ((value == null && dom) ||
        (value != null && value.equals(mechanismType))) {
        Instance instance = GetInstance.getInstance(s, null);
        TransformService ts = (TransformService) instance.impl;
        ts.algorithm = algorithm;
        ts.mechanism = mechanismType;
        ts.provider = instance.provider;
        return ts;
    }
    throw new NoSuchAlgorithmException
        (algorithm + " algorithm and " + mechanismType
             + " mechanism not available");
}
 

Delegate(Instance instance, Iterator<Service> serviceIterator,
        String algorithm) {
    super(algorithm);
    spi = (KeyPairGeneratorSpi)instance.impl;
    provider = instance.provider;
    this.serviceIterator = serviceIterator;
    initType = I_NONE;

    if (!skipDebug && pdebug != null) {
        pdebug.println("KeyPairGenerator." + algorithm +
            " algorithm from: " + provider.getName());
    }
}
 

/**
 * Returns a KeyPairGenerator object that generates public/private
 * key pairs for the specified algorithm.
 *
 * <p> This method traverses the list of registered security Providers,
 * starting with the most preferred Provider.
 * A new KeyPairGenerator object encapsulating the
 * KeyPairGeneratorSpi implementation from the first
 * Provider that supports the specified algorithm is returned.
 *
 * <p> Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param algorithm the standard string name of the algorithm.
 * See the KeyPairGenerator section in the <a href=
 * "{@docRoot}/../technotes/guides/security/StandardNames.html#KeyPairGenerator">
 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
 * for information about standard algorithm names.
 *
 * @return the new KeyPairGenerator object.
 *
 * @exception NoSuchAlgorithmException if no Provider supports a
 *          KeyPairGeneratorSpi implementation for the
 *          specified algorithm.
 *
 * @see Provider
 */
public static KeyPairGenerator getInstance(String algorithm)
        throws NoSuchAlgorithmException {
    List<Service> list =
            GetInstance.getServices("KeyPairGenerator", algorithm);
    Iterator<Service> t = list.iterator();
    if (t.hasNext() == false) {
        throw new NoSuchAlgorithmException
            (algorithm + " KeyPairGenerator not available");
    }
    // find a working Spi or KeyPairGenerator subclass
    NoSuchAlgorithmException failure = null;
    do {
        Service s = t.next();
        try {
            Instance instance =
                GetInstance.getInstance(s, KeyPairGeneratorSpi.class);
            if (instance.impl instanceof KeyPairGenerator) {
                return getInstance(instance, algorithm);
            } else {
                return new Delegate(instance, t, algorithm);
            }
        } catch (NoSuchAlgorithmException e) {
            if (failure == null) {
                failure = e;
            }
        }
    } while (t.hasNext());
    throw failure;
}
 

/**
 * Returns a <code>TransformService</code> that supports the specified
 * algorithm URI (ex: {@link Transform#XPATH2}) and mechanism type
 * (ex: DOM).
 *
 * <p>This method uses the standard JCA provider lookup mechanism to
 * locate and instantiate a <code>TransformService</code> implementation
 * of the desired algorithm and <code>MechanismType</code> service
 * attribute. It traverses the list of registered security
 * <code>Provider</code>s, starting with the most preferred
 * <code>Provider</code>. A new <code>TransformService</code> object
 * from the first <code>Provider</code> that supports the specified
 * algorithm and mechanism type is returned.
 *
 * <p> Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param algorithm the URI of the algorithm
 * @param mechanismType the type of the XML processing mechanism and
 *   representation
 * @return a new <code>TransformService</code>
 * @throws NullPointerException if <code>algorithm</code> or
 *   <code>mechanismType</code> is  <code>null</code>
 * @throws NoSuchAlgorithmException if no <code>Provider</code> supports a
 *   <code>TransformService</code> implementation for the specified
 *   algorithm and mechanism type
 * @see Provider
 */
public static TransformService getInstance
    (String algorithm, String mechanismType)
    throws NoSuchAlgorithmException {
    if (mechanismType == null || algorithm == null) {
        throw new NullPointerException();
    }
    boolean dom = false;
    if (mechanismType.equals("DOM")) {
        dom = true;
    }
    List<Service> services = GetInstance.getServices("TransformService", algorithm);
    for (Iterator<Service> t = services.iterator(); t.hasNext(); ) {
        Service s = t.next();
        String value = s.getAttribute("MechanismType");
        if ((value == null && dom) ||
            (value != null && value.equals(mechanismType))) {
            Instance instance = GetInstance.getInstance(s, null);
            TransformService ts = (TransformService) instance.impl;
            ts.algorithm = algorithm;
            ts.mechanism = mechanismType;
            ts.provider = instance.provider;
            return ts;
        }
    }
    throw new NoSuchAlgorithmException
        (algorithm + " algorithm and " + mechanismType
             + " mechanism not available");
}
 

/**
 * Returns a <code>TransformService</code> that supports the specified
 * algorithm URI (ex: {@link Transform#XPATH2}) and mechanism type
 * (ex: DOM) as supplied by the specified provider. Note that the specified
 * <code>Provider</code> object does not have to be registered in the
 * provider list.
 *
 * @param algorithm the URI of the algorithm
 * @param mechanismType the type of the XML processing mechanism and
 *   representation
 * @param provider the <code>Provider</code> object
 * @return a new <code>TransformService</code>
 * @throws NullPointerException if <code>provider</code>,
 *   <code>algorithm</code>, or <code>mechanismType</code> is
 *   <code>null</code>
 * @throws NoSuchAlgorithmException if a <code>TransformService</code>
 *   implementation for the specified algorithm and mechanism type is not
 *   available from the specified <code>Provider</code> object
 * @see Provider
 */
public static TransformService getInstance
    (String algorithm, String mechanismType, Provider provider)
    throws NoSuchAlgorithmException {
    if (mechanismType == null || algorithm == null || provider == null) {
        throw new NullPointerException();
    }

    boolean dom = false;
    if (mechanismType.equals("DOM")) {
        dom = true;
    }
    Service s = GetInstance.getService
        ("TransformService", algorithm, provider);
    String value = s.getAttribute("MechanismType");
    if ((value == null && dom) ||
        (value != null && value.equals(mechanismType))) {
        Instance instance = GetInstance.getInstance(s, null);
        TransformService ts = (TransformService) instance.impl;
        ts.algorithm = algorithm;
        ts.mechanism = mechanismType;
        ts.provider = instance.provider;
        return ts;
    }
    throw new NoSuchAlgorithmException
        (algorithm + " algorithm and " + mechanismType
             + " mechanism not available");
}
 

/**
 * Returns a <code>TransformService</code> that supports the specified
 * algorithm URI (ex: {@link Transform#XPATH2}) and mechanism type
 * (ex: DOM) as supplied by the specified provider. The specified provider
 * must be registered in the security provider list.
 *
 * <p>Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param algorithm the URI of the algorithm
 * @param mechanismType the type of the XML processing mechanism and
 *   representation
 * @param provider the string name of the provider
 * @return a new <code>TransformService</code>
 * @throws NoSuchProviderException if the specified provider is not
 *   registered in the security provider list
 * @throws NullPointerException if <code>provider</code>,
 *   <code>mechanismType</code>, or <code>algorithm</code> is
 *   <code>null</code>
 * @throws NoSuchAlgorithmException if a <code>TransformService</code>
 *   implementation for the specified algorithm and mechanism type is not
 *   available from the specified provider
 * @see Provider
 */
public static TransformService getInstance
    (String algorithm, String mechanismType, String provider)
    throws NoSuchAlgorithmException, NoSuchProviderException {
    if (mechanismType == null || algorithm == null || provider == null) {
        throw new NullPointerException();
    } else if (provider.length() == 0) {
        throw new NoSuchProviderException();
    }
    boolean dom = false;
    if (mechanismType.equals("DOM")) {
        dom = true;
    }
    Service s = GetInstance.getService
        ("TransformService", algorithm, provider);
    String value = s.getAttribute("MechanismType");
    if ((value == null && dom) ||
        (value != null && value.equals(mechanismType))) {
        Instance instance = GetInstance.getInstance(s, null);
        TransformService ts = (TransformService) instance.impl;
        ts.algorithm = algorithm;
        ts.mechanism = mechanismType;
        ts.provider = instance.provider;
        return ts;
    }
    throw new NoSuchAlgorithmException
        (algorithm + " algorithm and " + mechanismType
             + " mechanism not available");
}
 

/**
 * Returns a Signature object that implements the specified signature
 * algorithm.
 *
 * <p> This method traverses the list of registered security Providers,
 * starting with the most preferred Provider.
 * A new Signature object encapsulating the
 * SignatureSpi implementation from the first
 * Provider that supports the specified algorithm is returned.
 *
 * <p> Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param algorithm the standard name of the algorithm requested.
 * See the Signature section in the <a href=
 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Signature">
 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
 * for information about standard algorithm names.
 *
 * @return the new Signature object.
 *
 * @exception NoSuchAlgorithmException if no Provider supports a
 *          Signature implementation for the
 *          specified algorithm.
 *
 * @see Provider
 */
public static Signature getInstance(String algorithm)
        throws NoSuchAlgorithmException {
    List<Service> list;
    if (algorithm.equalsIgnoreCase(RSA_SIGNATURE)) {
        list = GetInstance.getServices(rsaIds);
    } else {
        list = GetInstance.getServices("Signature", algorithm);
    }
    Iterator<Service> t = list.iterator();
    if (t.hasNext() == false) {
        throw new NoSuchAlgorithmException
            (algorithm + " Signature not available");
    }
    // try services until we find an Spi or a working Signature subclass
    NoSuchAlgorithmException failure;
    do {
        Service s = t.next();
        if (isSpi(s)) {
            return new Delegate(s, t, algorithm);
        } else {
            // must be a subclass of Signature, disable dynamic selection
            try {
                Instance instance =
                    GetInstance.getInstance(s, SignatureSpi.class);
                return getInstance(instance, algorithm);
            } catch (NoSuchAlgorithmException e) {
                failure = e;
            }
        }
    } while (t.hasNext());
    throw failure;
}
 

private static Signature getInstance(Instance instance, String algorithm) {
    Signature sig;
    if (instance.impl instanceof Signature) {
        sig = (Signature)instance.impl;
        sig.algorithm = algorithm;
    } else {
        SignatureSpi spi = (SignatureSpi)instance.impl;
        sig = new Delegate(spi, algorithm);
    }
    sig.provider = instance.provider;
    return sig;
}
 

/**
 * Returns a <code>TransformService</code> that supports the specified
 * algorithm URI (ex: {@link Transform#XPATH2}) and mechanism type
 * (ex: DOM).
 *
 * <p>This method uses the standard JCA provider lookup mechanism to
 * locate and instantiate a <code>TransformService</code> implementation
 * of the desired algorithm and <code>MechanismType</code> service
 * attribute. It traverses the list of registered security
 * <code>Provider</code>s, starting with the most preferred
 * <code>Provider</code>. A new <code>TransformService</code> object
 * from the first <code>Provider</code> that supports the specified
 * algorithm and mechanism type is returned.
 *
 * <p> Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param algorithm the URI of the algorithm
 * @param mechanismType the type of the XML processing mechanism and
 *   representation
 * @return a new <code>TransformService</code>
 * @throws NullPointerException if <code>algorithm</code> or
 *   <code>mechanismType</code> is  <code>null</code>
 * @throws NoSuchAlgorithmException if no <code>Provider</code> supports a
 *   <code>TransformService</code> implementation for the specified
 *   algorithm and mechanism type
 * @see Provider
 */
public static TransformService getInstance
    (String algorithm, String mechanismType)
    throws NoSuchAlgorithmException {
    if (mechanismType == null || algorithm == null) {
        throw new NullPointerException();
    }
    boolean dom = false;
    if (mechanismType.equals("DOM")) {
        dom = true;
    }
    List<Service> services = GetInstance.getServices("TransformService", algorithm);
    for (Iterator<Service> t = services.iterator(); t.hasNext(); ) {
        Service s = t.next();
        String value = s.getAttribute("MechanismType");
        if ((value == null && dom) ||
            (value != null && value.equals(mechanismType))) {
            Instance instance = GetInstance.getInstance(s, null);
            TransformService ts = (TransformService) instance.impl;
            ts.algorithm = algorithm;
            ts.mechanism = mechanismType;
            ts.provider = instance.provider;
            return ts;
        }
    }
    throw new NoSuchAlgorithmException
        (algorithm + " algorithm and " + mechanismType
             + " mechanism not available");
}
 

/**
 * Returns a <code>KeyInfoFactory</code> that supports the
 * requested XML processing mechanism and representation type (ex: "DOM"),
 * as supplied by the specified provider. The specified provider must be
 * registered in the security provider list.
 *
 * <p>Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @param provider the string name of the provider
 * @return a new <code>KeyInfoFactory</code>
 * @throws NoSuchProviderException if the specified provider is not
 *    registered in the security provider list
 * @throws NullPointerException if <code>mechanismType</code> or
 *    <code>provider</code> are <code>null</code>
 * @throws NoSuchMechanismException if a <code>KeyInfoFactory</code>
 *    implementation for the specified mechanism is not available from the
 *    specified provider
 * @see Provider
 */
public static KeyInfoFactory getInstance(String mechanismType,
    String provider) throws NoSuchProviderException {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    } else if (provider == null) {
        throw new NullPointerException("provider cannot be null");
    } else if (provider.length() == 0) {
        throw new NoSuchProviderException();
    }

    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("KeyInfoFactory", null, mechanismType, provider);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    KeyInfoFactory factory = (KeyInfoFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}
 

/**
 * Returns an <code>XMLSignatureFactory</code> that supports the
 * requested XML processing mechanism and representation type (ex: "DOM"),
 * as supplied by the specified provider. The specified provider must be
 * registered in the security provider list.
 *
 * <p>Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @param provider the string name of the provider
 * @return a new <code>XMLSignatureFactory</code>
 * @throws NoSuchProviderException if the specified provider is not
 *    registered in the security provider list
 * @throws NullPointerException if <code>provider</code> or
 *    <code>mechanismType</code> is <code>null</code>
 * @throws NoSuchMechanismException if an <code>XMLSignatureFactory</code>
 *    implementation for the specified mechanism is not
 *    available from the specified provider
 * @see Provider
 */
public static XMLSignatureFactory getInstance(String mechanismType,
    String provider) throws NoSuchProviderException {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    } else if (provider == null) {
        throw new NullPointerException("provider cannot be null");
    } else if (provider.length() == 0) {
        throw new NoSuchProviderException();
    }

    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("XMLSignatureFactory", null, mechanismType, provider);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    XMLSignatureFactory factory = (XMLSignatureFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}
 

/**
 * Returns a <code>KeyInfoFactory</code> that supports the
 * requested XML processing mechanism and representation type (ex: "DOM"),
 * as supplied by the specified provider. Note that the specified
 * <code>Provider</code> object does not have to be registered in the
 * provider list.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @param provider the <code>Provider</code> object
 * @return a new <code>KeyInfoFactory</code>
 * @throws NullPointerException if <code>mechanismType</code> or
 *    <code>provider</code> are <code>null</code>
 * @throws NoSuchMechanismException if a <code>KeyInfoFactory</code>
 *    implementation for the specified mechanism is not available from the
 *    specified <code>Provider</code> object
 * @see Provider
 */
public static KeyInfoFactory getInstance(String mechanismType,
    Provider provider) {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    } else if (provider == null) {
        throw new NullPointerException("provider cannot be null");
    }

    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("KeyInfoFactory", null, mechanismType, provider);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    KeyInfoFactory factory = (KeyInfoFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}
 

/**
 * Returns an <code>XMLSignatureFactory</code> that supports the
 * requested XML processing mechanism and representation type (ex: "DOM"),
 * as supplied by the specified provider. Note that the specified
 * <code>Provider</code> object does not have to be registered in the
 * provider list.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @param provider the <code>Provider</code> object
 * @return a new <code>XMLSignatureFactory</code>
 * @throws NullPointerException if <code>provider</code> or
 *    <code>mechanismType</code> is <code>null</code>
 * @throws NoSuchMechanismException if an <code>XMLSignatureFactory</code>
 *   implementation for the specified mechanism is not available
 *   from the specified <code>Provider</code> object
 * @see Provider
 */
public static XMLSignatureFactory getInstance(String mechanismType,
    Provider provider) {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    } else if (provider == null) {
        throw new NullPointerException("provider cannot be null");
    }

    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("XMLSignatureFactory", null, mechanismType, provider);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    XMLSignatureFactory factory = (XMLSignatureFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}
 

/**
 * Returns an <code>XMLSignatureFactory</code> that supports the
 * requested XML processing mechanism and representation type (ex: "DOM"),
 * as supplied by the specified provider. Note that the specified
 * <code>Provider</code> object does not have to be registered in the
 * provider list.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @param provider the <code>Provider</code> object
 * @return a new <code>XMLSignatureFactory</code>
 * @throws NullPointerException if <code>provider</code> or
 *    <code>mechanismType</code> is <code>null</code>
 * @throws NoSuchMechanismException if an <code>XMLSignatureFactory</code>
 *   implementation for the specified mechanism is not available
 *   from the specified <code>Provider</code> object
 * @see Provider
 */
public static XMLSignatureFactory getInstance(String mechanismType,
    Provider provider) {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    } else if (provider == null) {
        throw new NullPointerException("provider cannot be null");
    }

    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("XMLSignatureFactory", null, mechanismType, provider);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    XMLSignatureFactory factory = (XMLSignatureFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}
 

/**
 * Returns an <code>XMLSignatureFactory</code> that supports the
 * requested XML processing mechanism and representation type (ex: "DOM"),
 * as supplied by the specified provider. The specified provider must be
 * registered in the security provider list.
 *
 * <p>Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @param provider the string name of the provider
 * @return a new <code>XMLSignatureFactory</code>
 * @throws NoSuchProviderException if the specified provider is not
 *    registered in the security provider list
 * @throws NullPointerException if <code>provider</code> or
 *    <code>mechanismType</code> is <code>null</code>
 * @throws NoSuchMechanismException if an <code>XMLSignatureFactory</code>
 *    implementation for the specified mechanism is not
 *    available from the specified provider
 * @see Provider
 */
public static XMLSignatureFactory getInstance(String mechanismType,
    String provider) throws NoSuchProviderException {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    } else if (provider == null) {
        throw new NullPointerException("provider cannot be null");
    } else if (provider.length() == 0) {
        throw new NoSuchProviderException();
    }

    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("XMLSignatureFactory", null, mechanismType, provider);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    XMLSignatureFactory factory = (XMLSignatureFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}
 

/**
 * Returns a <code>KeyInfoFactory</code> that supports the
 * specified XML processing mechanism and representation type (ex: "DOM").
 *
 * <p>This method uses the standard JCA provider lookup mechanism to
 * locate and instantiate a <code>KeyInfoFactory</code> implementation of
 * the desired mechanism type. It traverses the list of registered security
 * <code>Provider</code>s, starting with the most preferred
 * <code>Provider</code>. A new <code>KeyInfoFactory</code> object
 * from the first <code>Provider</code> that supports the specified
 * mechanism is returned.
 *
 * <p> Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @return a new <code>KeyInfoFactory</code>
 * @throws NullPointerException if <code>mechanismType</code> is
 *    <code>null</code>
 * @throws NoSuchMechanismException if no <code>Provider</code> supports a
 *    <code>KeyInfoFactory</code> implementation for the specified mechanism
 * @see Provider
 */
public static KeyInfoFactory getInstance(String mechanismType) {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    }
    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("KeyInfoFactory", null, mechanismType);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    KeyInfoFactory factory = (KeyInfoFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}
 

/**
 * Returns a Signature object that implements the specified signature
 * algorithm.
 *
 * <p> A new Signature object encapsulating the
 * SignatureSpi implementation from the specified provider
 * is returned.  The specified provider must be registered
 * in the security provider list.
 *
 * <p> Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param algorithm the name of the algorithm requested.
 * See the Signature section in the <a href=
 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Signature">
 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
 * for information about standard algorithm names.
 *
 * @param provider the name of the provider.
 *
 * @return the new Signature object.
 *
 * @exception NoSuchAlgorithmException if a SignatureSpi
 *          implementation for the specified algorithm is not
 *          available from the specified provider.
 *
 * @exception NoSuchProviderException if the specified provider is not
 *          registered in the security provider list.
 *
 * @exception IllegalArgumentException if the provider name is null
 *          or empty.
 *
 * @see Provider
 */
public static Signature getInstance(String algorithm, String provider)
        throws NoSuchAlgorithmException, NoSuchProviderException {
    if (algorithm.equalsIgnoreCase(RSA_SIGNATURE)) {
        // exception compatibility with existing code
        if ((provider == null) || (provider.length() == 0)) {
            throw new IllegalArgumentException("missing provider");
        }
        Provider p = Security.getProvider(provider);
        if (p == null) {
            throw new NoSuchProviderException
                ("no such provider: " + provider);
        }
        return getInstanceRSA(p);
    }
    Instance instance = GetInstance.getInstance
            ("Signature", SignatureSpi.class, algorithm, provider);
    return getInstance(instance, algorithm);
}
 

/**
 * Returns a <code>KeyInfoFactory</code> that supports the
 * requested XML processing mechanism and representation type (ex: "DOM"),
 * as supplied by the specified provider. The specified provider must be
 * registered in the security provider list.
 *
 * <p>Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @param provider the string name of the provider
 * @return a new <code>KeyInfoFactory</code>
 * @throws NoSuchProviderException if the specified provider is not
 *    registered in the security provider list
 * @throws NullPointerException if <code>mechanismType</code> or
 *    <code>provider</code> are <code>null</code>
 * @throws NoSuchMechanismException if a <code>KeyInfoFactory</code>
 *    implementation for the specified mechanism is not available from the
 *    specified provider
 * @see Provider
 */
public static KeyInfoFactory getInstance(String mechanismType,
    String provider) throws NoSuchProviderException {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    } else if (provider == null) {
        throw new NullPointerException("provider cannot be null");
    } else if (provider.length() == 0) {
        throw new NoSuchProviderException();
    }

    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("KeyInfoFactory", null, mechanismType, provider);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    KeyInfoFactory factory = (KeyInfoFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}
 

/**
 * Returns an <code>XMLSignatureFactory</code> that supports the
 * specified XML processing mechanism and representation type (ex: "DOM").
 *
 * <p>This method uses the standard JCA provider lookup mechanism to
 * locate and instantiate an <code>XMLSignatureFactory</code>
 * implementation of the desired mechanism type. It traverses the list of
 * registered security <code>Provider</code>s, starting with the most
 * preferred <code>Provider</code>.  A new <code>XMLSignatureFactory</code>
 * object from the first <code>Provider</code> that supports the specified
 * mechanism is returned.
 *
 * <p>Note that the list of registered providers may be retrieved via
 * the {@link Security#getProviders() Security.getProviders()} method.
 *
 * @param mechanismType the type of the XML processing mechanism and
 *    representation. See the <a
 *    href="../../../../../technotes/guides/security/xmldsig/overview.html#Service Provider">
 *    Service Providers</a> section of the API overview for a list of
 *    standard mechanism types.
 * @return a new <code>XMLSignatureFactory</code>
 * @throws NullPointerException if <code>mechanismType</code> is
 *    <code>null</code>
 * @throws NoSuchMechanismException if no <code>Provider</code> supports an
 *    <code>XMLSignatureFactory</code> implementation for the specified
 *    mechanism
 * @see Provider
 */
public static XMLSignatureFactory getInstance(String mechanismType) {
    if (mechanismType == null) {
        throw new NullPointerException("mechanismType cannot be null");
    }
    Instance instance;
    try {
        instance = GetInstance.getInstance
            ("XMLSignatureFactory", null, mechanismType);
    } catch (NoSuchAlgorithmException nsae) {
        throw new NoSuchMechanismException(nsae);
    }
    XMLSignatureFactory factory = (XMLSignatureFactory) instance.impl;
    factory.mechanismType = mechanismType;
    factory.provider = instance.provider;
    return factory;
}