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 * Copyright (c) 1996, 2018, Oracle and/or its affiliates. All rights reserved.

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

 *

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

 * under the terms of the GNU General Public License version 2 only, as

 * 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).

 *

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

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package java.security;

import java.util.*;

import java.util.concurrent.ConcurrentHashMap;

import java.io.*;

import java.net.URL;

import jdk.internal.event.EventHelper;

import jdk.internal.event.SecurityPropertyModificationEvent;

import jdk.internal.access.SharedSecrets;

import jdk.internal.util.StaticProperty;

import sun.security.util.Debug;

import sun.security.util.PropertyExpander;

import sun.security.jca.*;

/**

 * <p>This class centralizes all security properties and common security

 * methods. One of its primary uses is to manage providers.

 *

 * <p>The default values of security properties are read from an

 * implementation-specific location, which is typically the properties file

 * {@code conf/security/java.security} in the Java installation directory.

 *

 * @author Benjamin Renaud

 * @since 1.1

 */

public final class Security {

    /* Are we debugging? -- for developers */

    private static final Debug sdebug =

                        Debug.getInstance("properties");

    /* The java.security properties */

    private static Properties props;

    // An element in the cache

    private static class ProviderProperty {

        String className;

        Provider provider;

    }

    static {

        // doPrivileged here because there are multiple

        // things in initialize that might require privs.

        // (the FileInputStream call and the File.exists call,

        // the securityPropFile call, etc)

        AccessController.doPrivileged(new PrivilegedAction<>() {

            public Void run() {

                initialize();

                return null;

            }

        });

    }

    private static void initialize() {

        props = new Properties();

        boolean loadedProps = false;

        boolean overrideAll = false;

        // first load the system properties file

        // to determine the value of security.overridePropertiesFile

        File propFile = securityPropFile("java.security");

        if (propFile.exists()) {

            InputStream is = null;

            try {

                FileInputStream fis = new FileInputStream(propFile);

                is = new BufferedInputStream(fis);

                props.load(is);

                loadedProps = true;

                if (sdebug != null) {

                    sdebug.println("reading security properties file: " +

                                propFile);

                }

            } catch (IOException e) {

                if (sdebug != null) {

                    sdebug.println("unable to load security properties from " +

                                propFile);

                    e.printStackTrace();

                }

            } finally {

                if (is != null) {

                    try {

                        is.close();

                    } catch (IOException ioe) {

                        if (sdebug != null) {

                            sdebug.println("unable to close input stream");

                        }

                    }

                }

            }

        }

        if ("true".equalsIgnoreCase(props.getProperty

                ("security.overridePropertiesFile"))) {

            String extraPropFile = System.getProperty

                                        ("java.security.properties");

            if (extraPropFile != null && extraPropFile.startsWith("=")) {

                overrideAll = true;

                extraPropFile = extraPropFile.substring(1);

            }

            if (overrideAll) {

                props = new Properties();

                if (sdebug != null) {

                    sdebug.println

                        ("overriding other security properties files!");

                }

            }

            // now load the user-specified file so its values

            // will win if they conflict with the earlier values

            if (extraPropFile != null) {

                BufferedInputStream bis = null;

                try {

                    URL propURL;

                    extraPropFile = PropertyExpander.expand(extraPropFile);

                    propFile = new File(extraPropFile);

                    if (propFile.exists()) {

                        propURL = new URL

                                ("file:" + propFile.getCanonicalPath());

                    } else {

                        propURL = new URL(extraPropFile);

                    }

                    bis = new BufferedInputStream(propURL.openStream());

                    props.load(bis);

                    loadedProps = true;

                    if (sdebug != null) {

                        sdebug.println("reading security properties file: " +

                                        propURL);

                        if (overrideAll) {

                            sdebug.println

                                ("overriding other security properties files!");

                        }

                    }

                } catch (Exception e) {

                    if (sdebug != null) {

                        sdebug.println

                                ("unable to load security properties from " +

                                extraPropFile);

                        e.printStackTrace();

                    }

                } finally {

                    if (bis != null) {

                        try {

                            bis.close();

                        } catch (IOException ioe) {

                            if (sdebug != null) {

                                sdebug.println("unable to close input stream");

                            }

                        }

                    }

                }

            }

        }

        if (!loadedProps) {

            initializeStatic();

            if (sdebug != null) {

                sdebug.println("unable to load security properties " +

                        "-- using defaults");

            }

        }

    }

    /*

     * Initialize to default values, if <java.home>/lib/java.security

     * is not found.

     */

    private static void initializeStatic() {

        props.put("security.provider.1", "sun.security.provider.Sun");

        props.put("security.provider.2", "sun.security.rsa.SunRsaSign");

        props.put("security.provider.3", "com.sun.net.ssl.internal.ssl.Provider");

        props.put("security.provider.4", "com.sun.crypto.provider.SunJCE");

        props.put("security.provider.5", "sun.security.jgss.SunProvider");

        props.put("security.provider.6", "com.sun.security.sasl.Provider");

    }

    /**

     * Don't let anyone instantiate this.

     */

    private Security() {

    }

    private static File securityPropFile(String filename) {

        // maybe check for a system property which will specify where to

        // look. Someday.

        String sep = File.separator;

        return new File(StaticProperty.javaHome() + sep + "conf" + sep +

                        "security" + sep + filename);

    }

    /**

     * Looks up providers, and returns the property (and its associated

     * provider) mapping the key, if any.

     * The order in which the providers are looked up is the

     * provider-preference order, as specificed in the security

     * properties file.

     */

    private static ProviderProperty getProviderProperty(String key) {

        ProviderProperty entry = null;

        List<Provider> providers = Providers.getProviderList().providers();

        for (int i = 0; i < providers.size(); i++) {

            String matchKey = null;

            Provider prov = providers.get(i);

            String prop = prov.getProperty(key);

            if (prop == null) {

                // Is there a match if we do a case-insensitive property name

                // comparison? Let's try ...

                for (Enumeration<Object> e = prov.keys();

                                e.hasMoreElements() && prop == null; ) {

                    matchKey = (String)e.nextElement();

                    if (key.equalsIgnoreCase(matchKey)) {

                        prop = prov.getProperty(matchKey);

                        break;

                    }

                }

            }

            if (prop != null) {

                ProviderProperty newEntry = new ProviderProperty();

                newEntry.className = prop;

                newEntry.provider = prov;

                return newEntry;

            }

        }

        return entry;

    }

    /**

     * Returns the property (if any) mapping the key for the given provider.

     */

    private static String getProviderProperty(String key, Provider provider) {

        String prop = provider.getProperty(key);

        if (prop == null) {

            // Is there a match if we do a case-insensitive property name

            // comparison? Let's try ...

            for (Enumeration<Object> e = provider.keys();

                                e.hasMoreElements() && prop == null; ) {

                String matchKey = (String)e.nextElement();

                if (key.equalsIgnoreCase(matchKey)) {

                    prop = provider.getProperty(matchKey);

                    break;

                }

            }

        }

        return prop;

    }

    /**

     * Gets a specified property for an algorithm. The algorithm name

     * should be a standard name. See the <a href=

     * "{@docRoot}/../specs/security/standard-names.html">

     * Java Security Standard Algorithm Names Specification</a>

     * for information about standard algorithm names.

     *

     * One possible use is by specialized algorithm parsers, which may map

     * classes to algorithms which they understand (much like Key parsers

     * do).

     *

     * @param algName the algorithm name.

     *

     * @param propName the name of the property to get.

     *

     * @return the value of the specified property.

     *

     * @deprecated This method used to return the value of a proprietary

     * property in the master file of the "SUN" Cryptographic Service

     * Provider in order to determine how to parse algorithm-specific

     * parameters. Use the new provider-based and algorithm-independent

     * {@code AlgorithmParameters} and {@code KeyFactory} engine

     * classes (introduced in the J2SE version 1.2 platform) instead.

     */

    @Deprecated

    public static String getAlgorithmProperty(String algName,

                                              String propName) {

        ProviderProperty entry = getProviderProperty("Alg." + propName

                                                     + "." + algName);

        if (entry != null) {

            return entry.className;

        } else {

            return null;

        }

    }

    /**

     * Adds a new provider, at a specified position. The position is

     * the preference order in which providers are searched for

     * requested algorithms.  The position is 1-based, that is,

     * 1 is most preferred, followed by 2, and so on.

     *

     * <p>If the given provider is installed at the requested position,

     * the provider that used to be at that position, and all providers

     * with a position greater than {@code position}, are shifted up

     * one position (towards the end of the list of installed providers).

     *

     * <p>A provider cannot be added if it is already installed.

     *

     * <p>If there is a security manager, the

     * {@link java.lang.SecurityManager#checkSecurityAccess} method is called

     * with the {@code "insertProvider"} permission target name to see if

     * it's ok to add a new provider. If this permission check is denied,

     * {@code checkSecurityAccess} is called again with the

     * {@code "insertProvider."+provider.getName()} permission target name. If

     * both checks are denied, a {@code SecurityException} is thrown.

     *

     * @param provider the provider to be added.

     *

     * @param position the preference position that the caller would

     * like for this provider.

     *

     * @return the actual preference position in which the provider was

     * added, or -1 if the provider was not added because it is

     * already installed.

     *

     * @throws  NullPointerException if provider is null

     * @throws  SecurityException

     *          if a security manager exists and its {@link

     *          java.lang.SecurityManager#checkSecurityAccess} method

     *          denies access to add a new provider

     *

     * @see #getProvider

     * @see #removeProvider

     * @see java.security.SecurityPermission

     */

    public static synchronized int insertProviderAt(Provider provider,

            int position) {

        String providerName = provider.getName();

        checkInsertProvider(providerName);

        ProviderList list = Providers.getFullProviderList();

        ProviderList newList = ProviderList.insertAt(list, provider, position - 1);

        if (list == newList) {

            return -1;

        }

        Providers.setProviderList(newList);

        return newList.getIndex(providerName) + 1;

    }

    /**

     * Adds a provider to the next position available.

     *

     * <p>If there is a security manager, the

     * {@link java.lang.SecurityManager#checkSecurityAccess} method is called

     * with the {@code "insertProvider"} permission target name to see if

     * it's ok to add a new provider. If this permission check is denied,

     * {@code checkSecurityAccess} is called again with the

     * {@code "insertProvider."+provider.getName()} permission target name. If

     * both checks are denied, a {@code SecurityException} is thrown.

     *

     * @param provider the provider to be added.

     *

     * @return the preference position in which the provider was

     * added, or -1 if the provider was not added because it is

     * already installed.

     *

     * @throws  NullPointerException if provider is null

     * @throws  SecurityException

     *          if a security manager exists and its {@link

     *          java.lang.SecurityManager#checkSecurityAccess} method

     *          denies access to add a new provider

     *

     * @see #getProvider

     * @see #removeProvider

     * @see java.security.SecurityPermission

     */

    public static int addProvider(Provider provider) {

        /*

         * We can't assign a position here because the statically

         * registered providers may not have been installed yet.

         * insertProviderAt() will fix that value after it has

         * loaded the static providers.

         */

        return insertProviderAt(provider, 0);

    }

    /**

     * Removes the provider with the specified name.

     *

     * <p>When the specified provider is removed, all providers located

     * at a position greater than where the specified provider was are shifted

     * down one position (towards the head of the list of installed

     * providers).

     *

     * <p>This method returns silently if the provider is not installed or

     * if name is null.

     *

     * <p>First, if there is a security manager, its

     * {@code checkSecurityAccess}

     * method is called with the string {@code "removeProvider."+name}

     * to see if it's ok to remove the provider.

     * If the default implementation of {@code checkSecurityAccess}

     * is used (i.e., that method is not overridden), then this will result in

     * a call to the security manager's {@code checkPermission} method

     * with a {@code SecurityPermission("removeProvider."+name)}

     * permission.

     *

     * @param name the name of the provider to remove.

     *

     * @throws  SecurityException

     *          if a security manager exists and its {@link

     *          java.lang.SecurityManager#checkSecurityAccess} method

     *          denies

     *          access to remove the provider

     *

     * @see #getProvider

     * @see #addProvider

     */

    public static synchronized void removeProvider(String name) {

        check("removeProvider." + name);

        ProviderList list = Providers.getFullProviderList();

        ProviderList newList = ProviderList.remove(list, name);

        Providers.setProviderList(newList);

    }

    /**

     * Returns an array containing all the installed providers. The order of

     * the providers in the array is their preference order.

     *

     * @return an array of all the installed providers.

     */

    public static Provider[] getProviders() {

        return Providers.getFullProviderList().toArray();

    }

    /**

     * Returns the provider installed with the specified name, if

     * any. Returns null if no provider with the specified name is

     * installed or if name is null.

     *

     * @param name the name of the provider to get.

     *

     * @return the provider of the specified name.

     *

     * @see #removeProvider

     * @see #addProvider

     */

    public static Provider getProvider(String name) {

        return Providers.getProviderList().getProvider(name);

    }

    /**

     * Returns an array containing all installed providers that satisfy the

     * specified selection criterion, or null if no such providers have been

     * installed. The returned providers are ordered

     * according to their

     * {@linkplain #insertProviderAt(java.security.Provider, int) preference order}.

     *

     * <p> A cryptographic service is always associated with a particular

     * algorithm or type. For example, a digital signature service is

     * always associated with a particular algorithm (e.g., DSA),

     * and a CertificateFactory service is always associated with

     * a particular certificate type (e.g., X.509).

     *

     * <p>The selection criterion must be specified in one of the following two

     * formats:

     * <ul>

     * <li> <i>{@literal <crypto_service>.<algorithm_or_type>}</i>

     * <p> The cryptographic service name must not contain any dots.

     * <p> A

     * provider satisfies the specified selection criterion iff the provider

     * implements the

     * specified algorithm or type for the specified cryptographic service.

     * <p> For example, "CertificateFactory.X.509"

     * would be satisfied by any provider that supplied

     * a CertificateFactory implementation for X.509 certificates.

     * <li> <i>{@literal <crypto_service>.<algorithm_or_type>

     * <attribute_name>:<attribute_value>}</i>

     * <p> The cryptographic service name must not contain any dots. There

     * must be one or more space characters between the

     * <i>{@literal <algorithm_or_type>}</i> and the

     * <i>{@literal <attribute_name>}</i>.

     *  <p> A provider satisfies this selection criterion iff the

     * provider implements the specified algorithm or type for the specified

     * cryptographic service and its implementation meets the

     * constraint expressed by the specified attribute name/value pair.

     * <p> For example, "Signature.SHA1withDSA KeySize:1024" would be

     * satisfied by any provider that implemented

     * the SHA1withDSA signature algorithm with a keysize of 1024 (or larger).

     *

     * </ul>

     *

     * <p> See the <a href=

     * "{@docRoot}/../specs/security/standard-names.html">

     * Java Security Standard Algorithm Names Specification</a>

     * for information about standard cryptographic service names, standard