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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * This code is free software; you can redistribute it and/or modify it

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 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

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 * You should have received a copy of the GNU General Public License version

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package java.security;

import java.io.*;

import java.util.*;

import java.security.KeyStore.*;

import java.security.cert.Certificate;

import java.security.cert.CertificateException;

import javax.crypto.SecretKey;

import javax.security.auth.callback.*;

/**

 * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)

 * for the {@code KeyStore} class.

 * All the abstract methods in this class must be implemented by each

 * cryptographic service provider who wishes to supply the implementation

 * of a keystore for a particular keystore type.

 *

 * @author Jan Luehe

 *

 *

 * @see KeyStore

 *

 * @since 1.2

 */

public abstract class KeyStoreSpi {

    /**

     * Returns the key associated with the given alias, using the given

     * password to recover it.  The key must have been associated with

     * the alias by a call to {@code setKeyEntry},

     * or by a call to {@code setEntry} with a

     * {@code PrivateKeyEntry} or {@code SecretKeyEntry}.

     *

     * @param alias the alias name

     * @param password the password for recovering the key

     *

     * @return the requested key, or null if the given alias does not exist

     * or does not identify a key-related entry.

     *

     * @exception NoSuchAlgorithmException if the algorithm for recovering the

     * key cannot be found

     * @exception UnrecoverableKeyException if the key cannot be recovered

     * (e.g., the given password is wrong).

     */

    public abstract Key engineGetKey(String alias, char[] password)

        throws NoSuchAlgorithmException, UnrecoverableKeyException;

    /**

     * Returns the certificate chain associated with the given alias.

     * The certificate chain must have been associated with the alias

     * by a call to {@code setKeyEntry},

     * or by a call to {@code setEntry} with a

     * {@code PrivateKeyEntry}.

     *

     * @param alias the alias name

     *

     * @return the certificate chain (ordered with the user's certificate first

     * and the root certificate authority last), or null if the given alias

     * does not exist or does not contain a certificate chain

     */

    public abstract Certificate[] engineGetCertificateChain(String alias);

    /**

     * Returns the certificate associated with the given alias.

     *

     * <p> If the given alias name identifies an entry

     * created by a call to {@code setCertificateEntry},

     * or created by a call to {@code setEntry} with a

     * {@code TrustedCertificateEntry},

     * then the trusted certificate contained in that entry is returned.

     *

     * <p> If the given alias name identifies an entry

     * created by a call to {@code setKeyEntry},

     * or created by a call to {@code setEntry} with a

     * {@code PrivateKeyEntry},

     * then the first element of the certificate chain in that entry

     * (if a chain exists) is returned.

     *

     * @param alias the alias name

     *

     * @return the certificate, or null if the given alias does not exist or

     * does not contain a certificate.

     */

    public abstract Certificate engineGetCertificate(String alias);

    /**

     * Returns the creation date of the entry identified by the given alias.

     *

     * @param alias the alias name

     *

     * @return the creation date of this entry, or null if the given alias does

     * not exist

     */

    public abstract Date engineGetCreationDate(String alias);

    /**

     * Assigns the given key to the given alias, protecting it with the given

     * password.

     *

     * <p>If the given key is of type {@code java.security.PrivateKey},

     * it must be accompanied by a certificate chain certifying the

     * corresponding public key.

     *

     * <p>If the given alias already exists, the keystore information

     * associated with it is overridden by the given key (and possibly

     * certificate chain).

     *

     * @param alias the alias name

     * @param key the key to be associated with the alias

     * @param password the password to protect the key

     * @param chain the certificate chain for the corresponding public

     * key (only required if the given key is of type

     * {@code java.security.PrivateKey}).

     *

     * @exception KeyStoreException if the given key cannot be protected, or

     * this operation fails for some other reason

     */

    public abstract void engineSetKeyEntry(String alias, Key key,

                                           char[] password,

                                           Certificate[] chain)

        throws KeyStoreException;

    /**

     * Assigns the given key (that has already been protected) to the given

     * alias.

     *

     * <p>If the protected key is of type

     * {@code java.security.PrivateKey},

     * it must be accompanied by a certificate chain certifying the

     * corresponding public key.

     *

     * <p>If the given alias already exists, the keystore information

     * associated with it is overridden by the given key (and possibly

     * certificate chain).

     *

     * @param alias the alias name

     * @param key the key (in protected format) to be associated with the alias

     * @param chain the certificate chain for the corresponding public

     * key (only useful if the protected key is of type

     * {@code java.security.PrivateKey}).

     *

     * @exception KeyStoreException if this operation fails.

     */

    public abstract void engineSetKeyEntry(String alias, byte[] key,

                                           Certificate[] chain)

        throws KeyStoreException;

    /**

     * Assigns the given certificate to the given alias.

     *

     * <p> If the given alias identifies an existing entry

     * created by a call to {@code setCertificateEntry},

     * or created by a call to {@code setEntry} with a

     * {@code TrustedCertificateEntry},

     * the trusted certificate in the existing entry

     * is overridden by the given certificate.

     *

     * @param alias the alias name

     * @param cert the certificate

     *

     * @exception KeyStoreException if the given alias already exists and does

     * not identify an entry containing a trusted certificate,

     * or this operation fails for some other reason.

     */

    public abstract void engineSetCertificateEntry(String alias,

                                                   Certificate cert)

        throws KeyStoreException;

    /**

     * Deletes the entry identified by the given alias from this keystore.

     *

     * @param alias the alias name

     *

     * @exception KeyStoreException if the entry cannot be removed.

     */

    public abstract void engineDeleteEntry(String alias)

        throws KeyStoreException;

    /**

     * Lists all the alias names of this keystore.

     *

     * @return enumeration of the alias names

     */

    public abstract Enumeration<String> engineAliases();

    /**

     * Checks if the given alias exists in this keystore.

     *

     * @param alias the alias name

     *

     * @return true if the alias exists, false otherwise

     */

    public abstract boolean engineContainsAlias(String alias);

    /**

     * Retrieves the number of entries in this keystore.

     *

     * @return the number of entries in this keystore

     */

    public abstract int engineSize();

    /**

     * Returns true if the entry identified by the given alias

     * was created by a call to {@code setKeyEntry},

     * or created by a call to {@code setEntry} with a

     * {@code PrivateKeyEntry} or a {@code SecretKeyEntry}.

     *

     * @param alias the alias for the keystore entry to be checked

     *

     * @return true if the entry identified by the given alias is a

     * key-related, false otherwise.

     */

    public abstract boolean engineIsKeyEntry(String alias);

    /**

     * Returns true if the entry identified by the given alias

     * was created by a call to {@code setCertificateEntry},

     * or created by a call to {@code setEntry} with a

     * {@code TrustedCertificateEntry}.

     *

     * @param alias the alias for the keystore entry to be checked

     *

     * @return true if the entry identified by the given alias contains a

     * trusted certificate, false otherwise.

     */

    public abstract boolean engineIsCertificateEntry(String alias);

    /**

     * Returns the (alias) name of the first keystore entry whose certificate

     * matches the given certificate.

     *

     * <p>This method attempts to match the given certificate with each

     * keystore entry. If the entry being considered was

     * created by a call to {@code setCertificateEntry},

     * or created by a call to {@code setEntry} with a

     * {@code TrustedCertificateEntry},

     * then the given certificate is compared to that entry's certificate.

     *

     * <p> If the entry being considered was

     * created by a call to {@code setKeyEntry},

     * or created by a call to {@code setEntry} with a

     * {@code PrivateKeyEntry},

     * then the given certificate is compared to the first

     * element of that entry's certificate chain.

     *

     * @param cert the certificate to match with.

     *

     * @return the alias name of the first entry with matching certificate,

     * or null if no such entry exists in this keystore.

     */

    public abstract String engineGetCertificateAlias(Certificate cert);

    /**

     * Stores this keystore to the given output stream, and protects its

     * integrity with the given password.

     *

     * @param stream the output stream to which this keystore is written.

     * @param password the password to generate the keystore integrity check

     *

     * @exception IOException if there was an I/O problem with data

     * @exception NoSuchAlgorithmException if the appropriate data integrity

     * algorithm could not be found

     * @exception CertificateException if any of the certificates included in

     * the keystore data could not be stored

     */

    public abstract void engineStore(OutputStream stream, char[] password)

        throws IOException, NoSuchAlgorithmException, CertificateException;

    /**

     * Stores this keystore using the given

     * {@code KeyStore.LoadStoreParmeter}.

     *

     * @param param the {@code KeyStore.LoadStoreParmeter}

     *          that specifies how to store the keystore,

     *          which may be {@code null}

     *

     * @exception IllegalArgumentException if the given

     *          {@code KeyStore.LoadStoreParmeter}

     *          input is not recognized

     * @exception IOException if there was an I/O problem with data

     * @exception NoSuchAlgorithmException if the appropriate data integrity

     *          algorithm could not be found

     * @exception CertificateException if any of the certificates included in

     *          the keystore data could not be stored

     *

     * @since 1.5

     */

    public void engineStore(KeyStore.LoadStoreParameter param)

                throws IOException, NoSuchAlgorithmException,

                CertificateException {

        throw new UnsupportedOperationException();

    }

    /**

     * Loads the keystore from the given input stream.

     *

     * <p>A password may be given to unlock the keystore

     * (e.g. the keystore resides on a hardware token device),

     * or to check the integrity of the keystore data.

     * If a password is not given for integrity checking,

     * then integrity checking is not performed.

     *

     * @param stream the input stream from which the keystore is loaded,

     * or {@code null}

     * @param password the password used to check the integrity of

     * the keystore, the password used to unlock the keystore,

     * or {@code null}

     *

     * @exception IOException if there is an I/O or format problem with the

     * keystore data, if a password is required but not given,

     * or if the given password was incorrect. If the error is due to a

     * wrong password, the {@link Throwable#getCause cause} of the

     * {@code IOException} should be an

     * {@code UnrecoverableKeyException}

     * @exception NoSuchAlgorithmException if the algorithm used to check

     * the integrity of the keystore cannot be found

     * @exception CertificateException if any of the certificates in the

     * keystore could not be loaded

     */

    public abstract void engineLoad(InputStream stream, char[] password)

        throws IOException, NoSuchAlgorithmException, CertificateException;

    /**

     * Loads the keystore using the given

     * {@code KeyStore.LoadStoreParameter}.

     *

     * <p> Note that if this KeyStore has already been loaded, it is

     * reinitialized and loaded again from the given parameter.

     *

     * @param param the {@code KeyStore.LoadStoreParameter}

     *          that specifies how to load the keystore,

     *          which may be {@code null}

     *

     * @implSpec

     * The default implementation examines {@code KeyStore.LoadStoreParameter}

     * to extract its password and pass it to

     * {@link KeyStoreSpi#engineLoad(InputStream, char[])} along with a

     * {@code null} {@code InputStream}.

     * <p>

     * If {@code KeyStore.LoadStoreParameter} is {@code null} then

     * the password parameter will also be {@code null}.

     * Otherwise the {@code KeyStore.ProtectionParameter} of

     * {@code KeyStore.LoadStoreParameter} must be either a

     * {@code KeyStore.PasswordProtection} or a

     * {@code KeyStore.CallbackHandlerProtection} that supports

     * {@code PasswordCallback} so that the password parameter can be

     * extracted. If the {@code KeyStore.ProtectionParameter} is neither

     * of those classes then a {@code NoSuchAlgorithmException} is thrown.

     *

     * @exception IllegalArgumentException if the given

     *          {@code KeyStore.LoadStoreParameter}

     *          input is not recognized

     * @exception IOException if there is an I/O or format problem with the

     *          keystore data. If the error is due to an incorrect

     *         {@code ProtectionParameter} (e.g. wrong password)

     *         the {@link Throwable#getCause cause} of the

     *         {@code IOException} should be an

     *         {@code UnrecoverableKeyException}

     * @exception NoSuchAlgorithmException if the algorithm used to check

     *          the integrity of the keystore cannot be found

     * @exception CertificateException if any of the certificates in the

     *          keystore could not be loaded

     *

     * @since 1.5

     */

    public void engineLoad(KeyStore.LoadStoreParameter param)

                throws IOException, NoSuchAlgorithmException,

                CertificateException {

        if (param == null) {

            engineLoad((InputStream)null, (char[])null);

            return;

        }

        ProtectionParameter protection = param.getProtectionParameter();

        char[] password;

        if (protection instanceof PasswordProtection) {

            password = ((PasswordProtection)protection).getPassword();

        } else if (protection instanceof CallbackHandlerProtection) {

            CallbackHandler handler =

                ((CallbackHandlerProtection)protection).getCallbackHandler();

            PasswordCallback callback =

                new PasswordCallback("Password: ", false);

            try {

                handler.handle(new Callback[] {callback});

            } catch (UnsupportedCallbackException e) {

                throw new NoSuchAlgorithmException

                    ("Could not obtain password", e);

            }

            password = callback.getPassword();

            callback.clearPassword();

            if (password == null) {

                throw new NoSuchAlgorithmException("No password provided");

            }

        } else {

            throw new NoSuchAlgorithmException("ProtectionParameter must"

                + " be PasswordProtection or CallbackHandlerProtection");

        }

        engineLoad(null, password);

        return;

    }

    /**

     * Gets a {@code KeyStore.Entry} for the specified alias

     * with the specified protection parameter.

     *

     * @param alias get the {@code KeyStore.Entry} for this alias

     * @param protParam the {@code ProtectionParameter}

     *          used to protect the {@code Entry},

     *          which may be {@code null}

     *

     * @return the {@code KeyStore.Entry} for the specified alias,

     *          or {@code null} if there is no such entry

     *

     * @exception KeyStoreException if the operation failed

     * @exception NoSuchAlgorithmException if the algorithm for recovering the

     *          entry cannot be found

     * @exception UnrecoverableEntryException if the specified

     *          {@code protParam} were insufficient or invalid

     * @exception UnrecoverableKeyException if the entry is a

     *          {@code PrivateKeyEntry} or {@code SecretKeyEntry}

     *          and the specified {@code protParam} does not contain

     *          the information needed to recover the key (e.g. wrong password)

     *

     * @since 1.5

     */

    public KeyStore.Entry engineGetEntry(String alias,

                        KeyStore.ProtectionParameter protParam)

                throws KeyStoreException, NoSuchAlgorithmException,

                UnrecoverableEntryException {

        if (!engineContainsAlias(alias)) {

            return null;

        }

        if (protParam == null) {

            if (engineIsCertificateEntry(alias)) {

                return new KeyStore.TrustedCertificateEntry

                                (engineGetCertificate(alias));

            } else {

                throw new UnrecoverableKeyException

                        ("requested entry requires a password");

            }

        }

        if (protParam instanceof KeyStore.PasswordProtection) {

            if (engineIsCertificateEntry(alias)) {

                throw new UnsupportedOperationException

                    ("trusted certificate entries are not password-protected");

            } else if (engineIsKeyEntry(alias)) {

                KeyStore.PasswordProtection pp =

                        (KeyStore.PasswordProtection)protParam;

                if (pp.getProtectionAlgorithm() != null) {

                    throw new KeyStoreException(

                        "unsupported password protection algorithm");

                }

                char[] password = pp.getPassword();

                Key key = engineGetKey(alias, password);

                if (key instanceof PrivateKey) {

                    Certificate[] chain = engineGetCertificateChain(alias);

                    return new KeyStore.PrivateKeyEntry((PrivateKey)key, chain);

                } else if (key instanceof SecretKey) {

                    return new KeyStore.SecretKeyEntry((SecretKey)key);

                }

            }

        }

        throw new UnsupportedOperationException();

    }

    /**

     * Saves a {@code KeyStore.Entry} under the specified alias.

     * The specified protection parameter is used to protect the

     * {@code Entry}.

     *

     * <p> If an entry already exists for the specified alias,

     * it is overridden.

     *

     * @param alias save the {@code KeyStore.Entry} under this alias

     * @param entry the {@code Entry} to save

     * @param protParam the {@code ProtectionParameter}

     *          used to protect the {@code Entry},

     *          which may be {@code null}

     *

     * @exception KeyStoreException if this operation fails