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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package java.security;

import java.io.*;
import java.util.*;
import static java.util.Locale.ENGLISH;
import java.lang.ref.*;
import java.lang.reflect.*;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.concurrent.ConcurrentHashMap;

This class represents a "provider" for the
Java Security API, where a provider implements some or all parts of
Java Security. Services that a provider may implement include:

Algorithms (such as DSA, RSA, or SHA-256).
Key generation, conversion, and management facilities (such as for
algorithm-specific keys).

Some provider implementations may encounter unrecoverable internal errors during their operation, for example a failure to communicate with a security token. A ProviderException should be used to indicate such errors. 
Please note that a provider can be used to implement any security
service in Java that uses a pluggable architecture with a choice
of implementations that fit underneath.
The service type Provider is reserved for use by the security framework. Services of this type cannot be added, removed, or modified by applications. The following attributes are automatically placed in each Provider object: 

Attributes Automatically Placed in a Provider Object

Name
Value


Provider.id name
    
String.valueOf(provider.getName())
Provider.id version
    
String.valueOf(provider.getVersionStr())
Provider.id info
    
String.valueOf(provider.getInfo())
Provider.id className
    
provider.getClass().getName()


Each provider has a name and a version string. A provider normally identifies itself with a file named java.security.Provider in the resource directory META-INF/services. Security providers are looked up via the ServiceLoader mechanism using the application class loader. 
Providers may be configured such that they are automatically installed and made available at runtime via the Security.getProviders() method. The mechanism for configuring and installing security providers is implementation-specific. 
Author:
Benjamin Renaud, Andreas Sterbenz
Implementation Note:
 The JDK implementation supports static registration of the security providers via the conf/security/java.security file in the Java installation directory. These providers are automatically installed by the JDK runtime, see {@extLink security_guide_jca_provider The Provider Class} in the Java Cryptography Architecture (JCA) Reference Guide for information about how a particular type of provider, the cryptographic service provider, works and is installed.
Since:
1.1/**
 * This class represents a "provider" for the
 * Java Security API, where a provider implements some or all parts of
 * Java Security. Services that a provider may implement include:
 *
 * <ul>
 *
 * <li>Algorithms (such as DSA, RSA, or SHA-256).
 *
 * <li>Key generation, conversion, and management facilities (such as for
 * algorithm-specific keys).
 *
 * </ul>
 *
 * <p>Some provider implementations may encounter unrecoverable internal
 * errors during their operation, for example a failure to communicate with a
 * security token. A {@link ProviderException} should be used to indicate
 * such errors.
 *
 * <p>Please note that a provider can be used to implement any security
 * service in Java that uses a pluggable architecture with a choice
 * of implementations that fit underneath.
 *
 * <p>The service type {@code Provider} is reserved for use by the
 * security framework. Services of this type cannot be added, removed,
 * or modified by applications.
 * The following attributes are automatically placed in each Provider object:
 * <table class="striped">
 * <caption><b>Attributes Automatically Placed in a Provider Object</b></caption>
 * <thead>
 * <tr><th scope="col">Name</th><th scope="col">Value</th>
 * </thead>
 * <tbody style="text-align:left">
 * <tr><th scope="row">{@code Provider.id name}</th>
 *     <td>{@code String.valueOf(provider.getName())}</td>
 * <tr><th scope="row">{@code Provider.id version}</th>
 *     <td>{@code String.valueOf(provider.getVersionStr())}</td>
 * <tr><th scope="row">{@code Provider.id info}</th>
 *     <td>{@code String.valueOf(provider.getInfo())}</td>
 * <tr><th scope="row">{@code Provider.id className}</th>
 *     <td>{@code provider.getClass().getName()}</td>
 * </tbody>
 * </table>
 *
 * <p>Each provider has a name and a version string. A provider normally
 * identifies itself with a file named {@code java.security.Provider}
 * in the resource directory {@code META-INF/services}.
 * Security providers are looked up via the {@link ServiceLoader} mechanism
 * using the {@link ClassLoader#getSystemClassLoader application class loader}.
 *
 * <p>Providers may be configured such that they are automatically
 * installed and made available at runtime via the
 * {@link Security#getProviders() Security.getProviders()} method.
 * The mechanism for configuring and installing security providers is
 * implementation-specific.
 *
 * @implNote
 * The JDK implementation supports static registration of the security
 * providers via the {@code conf/security/java.security} file in the Java
 * installation directory. These providers are automatically installed by
 * the JDK runtime, see {@extLink security_guide_jca_provider
 * The Provider Class}
 * in the Java Cryptography Architecture (JCA) Reference Guide
 * for information about how a particular type of provider, the cryptographic
 * service provider, works and is installed.
 *
 * @author Benjamin Renaud
 * @author Andreas Sterbenz
 * @since 1.1
 */
public abstract class Provider extends Properties {

    // Declare serialVersionUID to be compatible with JDK1.1
    @java.io.Serial
    private static final long serialVersionUID = -4298000515446427739L;

    private static final sun.security.util.Debug debug =
        sun.security.util.Debug.getInstance("provider", "Provider");

    
The provider name.
@serial
/**
     * The provider name.
     *
     * @serial
     */
    private String name;

    
A description of the provider and its services.
@serial
/**
     * A description of the provider and its services.
     *
     * @serial
     */
    private String info;

    
The provider version number.
@serial
/**
     * The provider version number.
     *
     * @serial
     */
    private double version;

    
The provider version string.
@serial
/**
     * The provider version string.
     *
     * @serial
     */
    private String versionStr;

    private transient Set<Map.Entry<Object,Object>> entrySet = null;
    private transient int entrySetCallCount = 0;

    private transient boolean initialized;

    private static final Object[] EMPTY = new Object[0];

    private static double parseVersionStr(String s) {
        try {
            int firstDotIdx = s.indexOf('.');
            int nextDotIdx = s.indexOf('.', firstDotIdx + 1);
            if (nextDotIdx != -1) {
                s = s.substring(0, nextDotIdx);
            }
            int endIdx = s.indexOf('-');
            if (endIdx > 0) {
                s = s.substring(0, endIdx);
            }
            endIdx = s.indexOf('+');
            if (endIdx > 0) {
                s = s.substring(0, endIdx);
            }
            return Double.parseDouble(s);
        } catch (NullPointerException | NumberFormatException e) {
            return 0d;
        }
    }

    
Constructs a provider with the specified name, version number, and information. Calling this constructor is equivalent to call the Provider(String, String, String) with name name, Double.toString(version), and info. 
Params:
name – the provider name.
version – the provider version number.
info – a description of the provider and its services.
Deprecated:
use Provider(String, String, String) instead./**
     * Constructs a provider with the specified name, version number,
     * and information. Calling this constructor is equivalent to call the
     * {@link #Provider(String, String, String)} with {@code name}
     * name, {@code Double.toString(version)}, and {@code info}.
     *
     * @param name the provider name.
     *
     * @param version the provider version number.
     *
     * @param info a description of the provider and its services.
     *
     * @deprecated use {@link #Provider(String, String, String)} instead.
     */
    @Deprecated(since="9")
    protected Provider(String name, double version, String info) {
        this.name = name;
        this.version = version;
        this.versionStr = Double.toString(version);
        this.info = info;
        this.serviceMap = new ConcurrentHashMap<>();
        putId();
        initialized = true;
    }

    
Constructs a provider with the specified name, version string,
and information.
The version string contains a version number optionally followed
by other information separated by one of the characters of '+', '-'.
The format for the version number is:
    ^[0-9]+(\.[0-9]+)*

In order to return the version number in a double, when there are more than two components (separated by '.' as defined above), only the first two components are retained. The resulting string is then passed to Double.valueOf(String) to generate version number, i.e. getVersion. 
If the conversion failed, value 0 will be used.
Params:
name – the provider name.
versionStr – the provider version string.
info – a description of the provider and its services.
Since:
9/**
     * Constructs a provider with the specified name, version string,
     * and information.
     *
     * <p>The version string contains a version number optionally followed
     * by other information separated by one of the characters of '+', '-'.
     *
     * The format for the version number is:
     *
     * <blockquote><pre>
     *     ^[0-9]+(\.[0-9]+)*
     * </pre></blockquote>
     *
     * <p>In order to return the version number in a double, when there are
     * more than two components (separated by '.' as defined above), only
     * the first two components are retained. The resulting string is then
     * passed to {@link Double#valueOf(String)} to generate version number,
     * i.e. {@link #getVersion}.
     * <p>If the conversion failed, value 0 will be used.
     *
     * @param name the provider name.
     *
     * @param versionStr the provider version string.
     *
     * @param info a description of the provider and its services.
     *
     * @since 9
     */
    protected Provider(String name, String versionStr, String info) {
        this.name = name;
        this.versionStr = versionStr;
        this.version = parseVersionStr(versionStr);
        this.info = info;
        this.serviceMap = new ConcurrentHashMap<>();
        putId();
        initialized = true;
    }

    
Apply the supplied configuration argument to this provider instance
and return the configured provider. Note that if this provider cannot
be configured in-place, a new provider will be created and returned.
Therefore, callers should always use the returned provider.
Params:
configArg – the configuration information for configuring this
        provider.
Throws:
UnsupportedOperationException – if a configuration argument is
        not supported.
NullPointerException – if the supplied configuration argument is
        null.
InvalidParameterException – if the supplied configuration argument
        is invalid.
Implementation Requirements:
 The default implementation throws UnsupportedOperationException. Subclasses should override this method only if a configuration argument is supported.
Returns:
a provider configured with the supplied configuration argument.
Since:
9/**
     * Apply the supplied configuration argument to this provider instance
     * and return the configured provider. Note that if this provider cannot
     * be configured in-place, a new provider will be created and returned.
     * Therefore, callers should always use the returned provider.
     *
     * @implSpec
     * The default implementation throws {@code UnsupportedOperationException}.
     * Subclasses should override this method only if a configuration argument
     * is supported.
     *
     * @param configArg the configuration information for configuring this
     *         provider.
     *
     * @throws UnsupportedOperationException if a configuration argument is
     *         not supported.
     * @throws NullPointerException if the supplied configuration argument is
     *         null.
     * @throws InvalidParameterException if the supplied configuration argument
     *         is invalid.
     * @return a provider configured with the supplied configuration argument.
     *
     * @since 9
     */
    public Provider configure(String configArg) {
        throw new UnsupportedOperationException("configure is not supported");
    }

    
Check if this provider instance has been configured.
Implementation Requirements:
 The default implementation returns true. Subclasses should override this method if the provider instance requires an explicit configure call after being constructed.
Returns:
true if no further configuration is needed, false otherwise.
Since:
9/**
     * Check if this provider instance has been configured.
     *
     * @implSpec
     * The default implementation returns true.
     * Subclasses should override this method if the provider instance requires
     * an explicit {@code configure} call after being constructed.
     *
     * @return true if no further configuration is needed, false otherwise.
     *
     * @since 9
     */
    public boolean isConfigured() {
        return true;
    }


    
Returns the name of this provider.
Returns:
the name of this provider./**
     * Returns the name of this provider.
     *
     * @return the name of this provider.
     */
    public String getName() {
        return name;
    }

    
Returns the version number for this provider.
Returns:
the version number for this provider.
Deprecated:
use getVersionStr instead./**
     * Returns the version number for this provider.
     *
     * @return the version number for this provider.
     *
     * @deprecated use {@link #getVersionStr} instead.
     */
    @Deprecated(since="9")
    public double getVersion() {
        return version;
    }

    
Returns the version string for this provider.
Returns:
the version string for this provider.
Since:
9/**
     * Returns the version string for this provider.
     *
     * @return the version string for this provider.
     *
     * @since 9
     */
    public String getVersionStr() {
        return versionStr;
    }

    
Returns a human-readable description of the provider and its
services.  This may return an HTML page, with relevant links.
Returns:
a description of the provider and its services./**
     * Returns a human-readable description of the provider and its
     * services.  This may return an HTML page, with relevant links.
     *
     * @return a description of the provider and its services.
     */
    public String getInfo() {
        return info;
    }

    
Returns a string with the name and the version string
of this provider.
Returns:
the string with the name and the version string
for this provider./**
     * Returns a string with the name and the version string
     * of this provider.
     *
     * @return the string with the name and the version string
     * for this provider.
     */
    public String toString() {
        return name + " version " + versionStr;
    }

    /*
     * override the following methods to ensure that provider
     * information can only be changed if the caller has the appropriate
     * permissions.
     */

    
Clears this provider so that it no longer contains the properties
used to look up facilities implemented by the provider.
If a security manager is enabled, its checkSecurityAccess method is called with the string "clearProviderProperties."+name (where name is the provider name) to see if it's ok to clear this provider. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to clear this provider
Since:
1.2/**
     * Clears this provider so that it no longer contains the properties
     * used to look up facilities implemented by the provider.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the string {@code "clearProviderProperties."+name}
     * (where {@code name} is the provider name) to see if it's ok to clear
     * this provider.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to clear this provider
     *
     * @since 1.2
     */
    @Override
    public synchronized void clear() {
        check("clearProviderProperties."+name);
        if (debug != null) {
            debug.println("Remove " + name + " provider properties");
        }
        implClear();
    }

    
Reads a property list (key and element pairs) from the input stream.
Params:
inStream – the input stream.
Throws:
IOException – if an error occurred when reading from the
              input stream.
See Also:
Properties.load/**
     * Reads a property list (key and element pairs) from the input stream.
     *
     * @param inStream the input stream.
     * @throws    IOException if an error occurred when reading from the
     *               input stream.
     * @see java.util.Properties#load
     */
    @Override
    public synchronized void load(InputStream inStream) throws IOException {
        check("putProviderProperty."+name);
        if (debug != null) {
            debug.println("Load " + name + " provider properties");
        }
        Properties tempProperties = new Properties();
        tempProperties.load(inStream);
        implPutAll(tempProperties);
    }

    
Copies all of the mappings from the specified Map to this provider.
These mappings will replace any properties that this provider had
for any of the keys currently in the specified Map.
Since:
1.2/**
     * Copies all of the mappings from the specified Map to this provider.
     * These mappings will replace any properties that this provider had
     * for any of the keys currently in the specified Map.
     *
     * @since 1.2
     */
    @Override
    public synchronized void putAll(Map<?,?> t) {
        check("putProviderProperty."+name);
        if (debug != null) {
            debug.println("Put all " + name + " provider properties");
        }
        implPutAll(t);
    }

    
Returns an unmodifiable Set view of the property entries contained
in this Provider.
See Also:
Entry
Since:
1.2/**
     * Returns an unmodifiable Set view of the property entries contained
     * in this Provider.
     *
     * @see   java.util.Map.Entry
     * @since 1.2
     */
    @Override
    public synchronized Set<Map.Entry<Object,Object>> entrySet() {
        checkInitialized();
        if (entrySet == null) {
            if (entrySetCallCount++ == 0)  // Initial call
                entrySet = Collections.unmodifiableMap(this).entrySet();
            else
                return super.entrySet();   // Recursive call
        }

        // This exception will be thrown if the implementation of
        // Collections.unmodifiableMap.entrySet() is changed such that it
        // no longer calls entrySet() on the backing Map.  (Provider's
        // entrySet implementation depends on this "implementation detail",
        // which is unlikely to change.
        if (entrySetCallCount != 2)
            throw new RuntimeException("Internal error.");

        return entrySet;
    }

    
Returns an unmodifiable Set view of the property keys contained in
this provider.
Since:
1.2/**
     * Returns an unmodifiable Set view of the property keys contained in
     * this provider.
     *
     * @since 1.2
     */
    @Override
    public Set<Object> keySet() {
        checkInitialized();
        return Collections.unmodifiableSet(super.keySet());
    }

    
Returns an unmodifiable Collection view of the property values
contained in this provider.
Since:
1.2/**
     * Returns an unmodifiable Collection view of the property values
     * contained in this provider.
     *
     * @since 1.2
     */
    @Override
    public Collection<Object> values() {
        checkInitialized();
        return Collections.unmodifiableCollection(super.values());
    }

    
Sets the key property to have the specified value. 
If a security manager is enabled, its checkSecurityAccess method is called with the string "putProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values.
Since:
1.2/**
     * Sets the {@code key} property to have the specified
     * {@code value}.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the string {@code "putProviderProperty."+name},
     * where {@code name} is the provider name, to see if it's ok to set this
     * provider's property values.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values.
     *
     * @since 1.2
     */
    @Override
    public synchronized Object put(Object key, Object value) {
        check("putProviderProperty."+name);
        if (debug != null) {
            debug.println("Set " + name + " provider property [" +
                          key + "/" + value +"]");
        }
        return implPut(key, value);
    }

    
If the specified key is not already associated with a value (or is mapped to null) associates it with the given value and returns null, else returns the current value. 
If a security manager is enabled, its checkSecurityAccess method is called with the string "putProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values.
Since:
1.8/**
     * If the specified key is not already associated with a value (or is mapped
     * to {@code null}) associates it with the given value and returns
     * {@code null}, else returns the current value.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the string {@code "putProviderProperty."+name},
     * where {@code name} is the provider name, to see if it's ok to set this
     * provider's property values.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values.
     *
     * @since 1.8
     */
    @Override
    public synchronized Object putIfAbsent(Object key, Object value) {
        check("putProviderProperty."+name);
        if (debug != null) {
            debug.println("Set " + name + " provider property [" +
                          key + "/" + value +"]");
        }
        return implPutIfAbsent(key, value);
    }

    
Removes the key property (and its corresponding value). 
If a security manager is enabled, its checkSecurityAccess method is called with the string "removeProviderProperty."+name, where name is the provider name, to see if it's ok to remove this provider's properties. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to remove this provider's properties.
Since:
1.2/**
     * Removes the {@code key} property (and its corresponding
     * {@code value}).
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the string {@code "removeProviderProperty."+name},
     * where {@code name} is the provider name, to see if it's ok to remove this
     * provider's properties.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to remove this provider's properties.
     *
     * @since 1.2
     */
    @Override
    public synchronized Object remove(Object key) {
        check("removeProviderProperty."+name);
        if (debug != null) {
            debug.println("Remove " + name + " provider property " + key);
        }
        return implRemove(key);
    }

    
Removes the entry for the specified key only if it is currently
mapped to the specified value.
If a security manager is enabled, its checkSecurityAccess method is called with the string "removeProviderProperty."+name, where name is the provider name, to see if it's ok to remove this provider's properties. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to remove this provider's properties.
Since:
1.8/**
     * Removes the entry for the specified key only if it is currently
     * mapped to the specified value.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the string {@code "removeProviderProperty."+name},
     * where {@code name} is the provider name, to see if it's ok to remove this
     * provider's properties.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to remove this provider's properties.
     *
     * @since 1.8
     */
    @Override
    public synchronized boolean remove(Object key, Object value) {
        check("removeProviderProperty."+name);
        if (debug != null) {
            debug.println("Remove " + name + " provider property " + key);
        }
        return implRemove(key, value);
    }

    
Replaces the entry for the specified key only if currently
mapped to the specified value.
If a security manager is enabled, its checkSecurityAccess method is called with the string "putProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values.
Since:
1.8/**
     * Replaces the entry for the specified key only if currently
     * mapped to the specified value.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the string {@code "putProviderProperty."+name},
     * where {@code name} is the provider name, to see if it's ok to set this
     * provider's property values.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values.
     *
     * @since 1.8
     */
    @Override
    public synchronized boolean replace(Object key, Object oldValue,
            Object newValue) {
        check("putProviderProperty." + name);

        if (debug != null) {
            debug.println("Replace " + name + " provider property " + key);
        }
        return implReplace(key, oldValue, newValue);
    }

    
Replaces the entry for the specified key only if it is
currently mapped to some value.
If a security manager is enabled, its checkSecurityAccess method is called with the string "putProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values.
Since:
1.8/**
     * Replaces the entry for the specified key only if it is
     * currently mapped to some value.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the string {@code "putProviderProperty."+name},
     * where {@code name} is the provider name, to see if it's ok to set this
     * provider's property values.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values.
     *
     * @since 1.8
     */
    @Override
    public synchronized Object replace(Object key, Object value) {
        check("putProviderProperty." + name);

        if (debug != null) {
            debug.println("Replace " + name + " provider property " + key);
        }
        return implReplace(key, value);
    }

    
Replaces each entry's value with the result of invoking the given
function on that entry, in the order entries are returned by an entry
set iterator, until all entries have been processed or the function
throws an exception.
If a security manager is enabled, its checkSecurityAccess method is called with the string "putProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values.
Since:
1.8/**
     * Replaces each entry's value with the result of invoking the given
     * function on that entry, in the order entries are returned by an entry
     * set iterator, until all entries have been processed or the function
     * throws an exception.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the string {@code "putProviderProperty."+name},
     * where {@code name} is the provider name, to see if it's ok to set this
     * provider's property values.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values.
     *
     * @since 1.8
     */
    @Override
    public synchronized void replaceAll(BiFunction<? super Object,
            ? super Object, ? extends Object> function) {
        check("putProviderProperty." + name);

        if (debug != null) {
            debug.println("ReplaceAll " + name + " provider property ");
        }
        implReplaceAll(function);
    }

    
Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping). 
If a security manager is enabled, its checkSecurityAccess method is called with the strings "putProviderProperty."+name and "removeProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values and remove this provider's properties. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values or remove properties.
Since:
1.8/**
     * Attempts to compute a mapping for the specified key and its
     * current mapped value (or {@code null} if there is no current
     * mapping).
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the strings {@code "putProviderProperty."+name}
     * and {@code "removeProviderProperty."+name}, where {@code name} is the
     * provider name, to see if it's ok to set this provider's property values
     * and remove this provider's properties.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values or remove properties.
     *
     * @since 1.8
     */
    @Override
    public synchronized Object compute(Object key, BiFunction<? super Object,
            ? super Object, ? extends Object> remappingFunction) {
        check("putProviderProperty." + name);
        check("removeProviderProperty." + name);

        if (debug != null) {
            debug.println("Compute " + name + " provider property " + key);
        }
        return implCompute(key, remappingFunction);
    }

    
If the specified key is not already associated with a value (or is mapped to null), attempts to compute its value using the given mapping function and enters it into this map unless null. 
If a security manager is enabled, its checkSecurityAccess method is called with the strings "putProviderProperty."+name and "removeProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values and remove this provider's properties. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values and remove properties.
Since:
1.8/**
     * If the specified key is not already associated with a value (or
     * is mapped to {@code null}), attempts to compute its value using
     * the given mapping function and enters it into this map unless
     * {@code null}.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the strings {@code "putProviderProperty."+name}
     * and {@code "removeProviderProperty."+name}, where {@code name} is the
     * provider name, to see if it's ok to set this provider's property values
     * and remove this provider's properties.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values and remove properties.
     *
     * @since 1.8
     */
    @Override
    public synchronized Object computeIfAbsent(Object key, Function<? super Object,
            ? extends Object> mappingFunction) {
        check("putProviderProperty." + name);
        check("removeProviderProperty." + name);

        if (debug != null) {
            debug.println("ComputeIfAbsent " + name + " provider property " +
                    key);
        }
        return implComputeIfAbsent(key, mappingFunction);
    }

    
If the value for the specified key is present and non-null, attempts to
compute a new mapping given the key and its current mapped value.
If a security manager is enabled, its checkSecurityAccess method is called with the strings "putProviderProperty."+name and "removeProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values and remove this provider's properties. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values or remove properties.
Since:
1.8/**
     * If the value for the specified key is present and non-null, attempts to
     * compute a new mapping given the key and its current mapped value.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the strings {@code "putProviderProperty."+name}
     * and {@code "removeProviderProperty."+name}, where {@code name} is the
     * provider name, to see if it's ok to set this provider's property values
     * and remove this provider's properties.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values or remove properties.
     *
     * @since 1.8
     */
    @Override
    public synchronized Object computeIfPresent(Object key, BiFunction<? super Object,
            ? super Object, ? extends Object> remappingFunction) {
        check("putProviderProperty." + name);
        check("removeProviderProperty." + name);

        if (debug != null) {
            debug.println("ComputeIfPresent " + name + " provider property " +
                    key);
        }
        return implComputeIfPresent(key, remappingFunction);
    }

    
If the specified key is not already associated with a value or is
associated with null, associates it with the given value. Otherwise,
replaces the value with the results of the given remapping function,
or removes if the result is null. This method may be of use when
combining multiple mapped values for a key.
If a security manager is enabled, its checkSecurityAccess method is called with the strings "putProviderProperty."+name and "removeProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values and remove this provider's properties. 
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values or remove properties.
Since:
1.8/**
     * If the specified key is not already associated with a value or is
     * associated with null, associates it with the given value. Otherwise,
     * replaces the value with the results of the given remapping function,
     * or removes if the result is null. This method may be of use when
     * combining multiple mapped values for a key.
     *
     * <p>If a security manager is enabled, its {@code checkSecurityAccess}
     * method is called with the strings {@code "putProviderProperty."+name}
     * and {@code "removeProviderProperty."+name}, where {@code name} is the
     * provider name, to see if it's ok to set this provider's property values
     * and remove this provider's properties.
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method
     *          denies access to set property values or remove properties.
     *
     * @since 1.8
     */
    @Override
    public synchronized Object merge(Object key, Object value,  BiFunction<? super Object,
            ? super Object, ? extends Object>  remappingFunction) {
        check("putProviderProperty." + name);
        check("removeProviderProperty." + name);

        if (debug != null) {
            debug.println("Merge " + name + " provider property " + key);
        }
        return implMerge(key, value, remappingFunction);
    }

    // let javadoc show doc from superclass
    @Override
    public Object get(Object key) {
        checkInitialized();
        return super.get(key);
    }
    
Since:
1.8/**
     * @since 1.8
     */
    @Override
    public synchronized Object getOrDefault(Object key, Object defaultValue) {
        checkInitialized();
        return super.getOrDefault(key, defaultValue);
    }

    
Since:
1.8/**
     * @since 1.8
     */
    @Override
    public synchronized void forEach(BiConsumer<? super Object, ? super Object> action) {
        checkInitialized();
        super.forEach(action);
    }

    // let javadoc show doc from superclass
    @Override
    public Enumeration<Object> keys() {
        checkInitialized();
        return super.keys();
    }

    // let javadoc show doc from superclass
    @Override
    public Enumeration<Object> elements() {
        checkInitialized();
        return super.elements();
    }

    // let javadoc show doc from superclass
    public String getProperty(String key) {
        checkInitialized();
        return super.getProperty(key);
    }

    private void checkInitialized() {
        if (!initialized) {
            throw new IllegalStateException();
        }
    }

    private void check(String directive) {
        checkInitialized();
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkSecurityAccess(directive);
        }
    }

    // legacy properties changed since last call to any services method?
    private transient boolean legacyChanged;
    // serviceMap changed since last call to getServices()
    private volatile transient boolean servicesChanged;

    // Map<String,String> used to keep track of legacy registration
    private transient Map<String,String> legacyStrings;

    // Map<ServiceKey,Service>
    // used for services added via putService(), initialized on demand
    private transient Map<ServiceKey,Service> serviceMap;

    // For backward compatibility, the registration ordering of
    // SecureRandom (RNG) algorithms needs to be preserved for
    // "new SecureRandom()" calls when this provider is used
    private transient Set<String> prngAlgos;

    // Map<ServiceKey,Service>
    // used for services added via legacy methods, init on demand
    private transient Map<ServiceKey,Service> legacyMap;

    // Set<Service>
    // Unmodifiable set of all services. Initialized on demand.
    private transient Set<Service> serviceSet;

    // register the id attributes for this provider
    // this is to ensure that equals() and hashCode() do not incorrectly
    // report to different provider objects as the same
    private void putId() {
        // note: name and info may be null
        super.put("Provider.id name", String.valueOf(name));
        super.put("Provider.id version", String.valueOf(versionStr));
        super.put("Provider.id info", String.valueOf(info));
        super.put("Provider.id className", this.getClass().getName());
    }

   
Reads the ObjectInputStream for the default serializable fields. If the serialized field versionStr is found in the STREAM FIELDS, its String value will be used to populate both the version string and version number. If versionStr is not found, but version is, then its double value will be used to populate both fields. 
Params:
in – the ObjectInputStream to read
@serial
/**
    * Reads the {@code ObjectInputStream} for the default serializable fields.
    * If the serialized field {@code versionStr} is found in the STREAM FIELDS,
    * its String value will be used to populate both the version string and
    * version number. If {@code versionStr} is not found, but {@code version}
    * is, then its double value will be used to populate both fields.
    *
    * @param in the {@code ObjectInputStream} to read
    * @serial
    */
    @java.io.Serial
    private void readObject(ObjectInputStream in)
                throws IOException, ClassNotFoundException {
        Map<Object,Object> copy = new HashMap<>();
        for (Map.Entry<Object,Object> entry : super.entrySet()) {
            copy.put(entry.getKey(), entry.getValue());
        }
        defaults = null;
        in.defaultReadObject();
        if (this.versionStr == null) {
            // set versionStr based on version when not found in serialized bytes
            this.versionStr = Double.toString(this.version);
        } else {
            // otherwise, set version based on versionStr
            this.version = parseVersionStr(this.versionStr);
        }
        this.serviceMap = new ConcurrentHashMap<>();
        implClear();
        initialized = true;
        putAll(copy);
    }

    // check whether to update 'legacyString' with the specified key
    private boolean checkLegacy(Object key) {
        String keyString = (String)key;
        if (keyString.startsWith("Provider.")) {
            return false;
        }

        legacyChanged = true;
        if (legacyStrings == null) {
            legacyStrings = new LinkedHashMap<>();
        }
        return true;
    }

    
Copies all of the mappings from the specified Map to this provider.
Internal method to be called AFTER the security check has been
performed.
/**
     * Copies all of the mappings from the specified Map to this provider.
     * Internal method to be called AFTER the security check has been
     * performed.
     */
    private void implPutAll(Map<?,?> t) {
        for (Map.Entry<?,?> e : t.entrySet()) {
            implPut(e.getKey(), e.getValue());
        }
    }

    private Object implRemove(Object key) {
        if (key instanceof String) {
            if (!checkLegacy(key)) {
                return null;
            }
            legacyStrings.remove((String)key);
        }
        return super.remove(key);
    }

    private boolean implRemove(Object key, Object value) {
        if (key instanceof String && value instanceof String) {
            if (!checkLegacy(key)) {
                return false;
            }
            legacyStrings.remove((String)key, (String)value);
        }
        return super.remove(key, value);
    }

    private boolean implReplace(Object key, Object oldValue, Object newValue) {
        if ((key instanceof String) && (oldValue instanceof String) &&
                (newValue instanceof String)) {
            if (!checkLegacy(key)) {
                return false;
            }
            legacyStrings.replace((String)key, (String)oldValue,
                    (String)newValue);
        }
        return super.replace(key, oldValue, newValue);
    }

    private Object implReplace(Object key, Object value) {
        if ((key instanceof String) && (value instanceof String)) {
            if (!checkLegacy(key)) {
                return null;
            }
            legacyStrings.replace((String)key, (String)value);
        }
        return super.replace(key, value);
    }

    @SuppressWarnings("unchecked") // Function must actually operate over strings
    private void implReplaceAll(BiFunction<? super Object, ? super Object,
            ? extends Object> function) {
        legacyChanged = true;
        if (legacyStrings == null) {
            legacyStrings = new LinkedHashMap<>();
        } else {
            legacyStrings.replaceAll((BiFunction<? super String, ? super String,
                    ? extends String>) function);
        }
        super.replaceAll(function);
    }

    @SuppressWarnings("unchecked") // Function must actually operate over strings
    private Object implMerge(Object key, Object value,
            BiFunction<? super Object, ? super Object, ? extends Object>
            remappingFunction) {
        if ((key instanceof String) && (value instanceof String)) {
            if (!checkLegacy(key)) {
                return null;
            }
            legacyStrings.merge((String)key, (String)value,
                    (BiFunction<? super String, ? super String,
                    ? extends String>) remappingFunction);
        }
        return super.merge(key, value, remappingFunction);
    }

    @SuppressWarnings("unchecked") // Function must actually operate over strings
    private Object implCompute(Object key, BiFunction<? super Object,
            ? super Object, ? extends Object> remappingFunction) {
        if (key instanceof String) {
            if (!checkLegacy(key)) {
                return null;
            }
            legacyStrings.compute((String) key,
                    (BiFunction<? super String,? super String,
                    ? extends String>) remappingFunction);
        }
        return super.compute(key, remappingFunction);
    }

    @SuppressWarnings("unchecked") // Function must actually operate over strings
    private Object implComputeIfAbsent(Object key, Function<? super Object,
            ? extends Object> mappingFunction) {
        if (key instanceof String) {
            if (!checkLegacy(key)) {
                return null;
            }
            legacyStrings.computeIfAbsent((String) key,
                    (Function<? super String, ? extends String>)
                    mappingFunction);
        }
        return super.computeIfAbsent(key, mappingFunction);
    }

    @SuppressWarnings("unchecked") // Function must actually operate over strings
    private Object implComputeIfPresent(Object key, BiFunction<? super Object,
            ? super Object, ? extends Object> remappingFunction) {
        if (key instanceof String) {
            if (!checkLegacy(key)) {
                return null;
            }
            legacyStrings.computeIfPresent((String) key,
                    (BiFunction<? super String, ? super String,
                    ? extends String>) remappingFunction);
        }
        return super.computeIfPresent(key, remappingFunction);
    }

    private Object implPut(Object key, Object value) {
        if ((key instanceof String) && (value instanceof String)) {
            if (!checkLegacy(key)) {
                return null;
            }
            legacyStrings.put((String)key, (String)value);
        }
        return super.put(key, value);
    }

    private Object implPutIfAbsent(Object key, Object value) {
        if ((key instanceof String) && (value instanceof String)) {
            if (!checkLegacy(key)) {
                return null;
            }
            legacyStrings.putIfAbsent((String)key, (String)value);
        }
        return super.putIfAbsent(key, value);
    }

    private void implClear() {
        if (legacyStrings != null) {
            legacyStrings.clear();
        }
        if (legacyMap != null) {
            legacyMap.clear();
        }
        serviceMap.clear();
        legacyChanged = false;
        servicesChanged = false;
        serviceSet = null;
        prngAlgos = null;
        super.clear();
        putId();
    }

    // used as key in the serviceMap and legacyMap HashMaps
    private static class ServiceKey {
        private final String type;
        private final String algorithm;
        private final String originalAlgorithm;
        private ServiceKey(String type, String algorithm, boolean intern) {
            this.type = type;
            this.originalAlgorithm = algorithm;
            algorithm = algorithm.toUpperCase(ENGLISH);
            this.algorithm = intern ? algorithm.intern() : algorithm;
        }
        public int hashCode() {
            return type.hashCode() * 31 + algorithm.hashCode();
        }
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (!(obj instanceof ServiceKey other)) {
                return false;
            }
            return this.type.equals(other.type)
                && this.algorithm.equals(other.algorithm);
        }
        boolean matches(String type, String algorithm) {
            return (this.type == type) && (this.originalAlgorithm == algorithm);
        }
    }

    
Ensure all the legacy String properties are fully parsed into
service objects.
/**
     * Ensure all the legacy String properties are fully parsed into
     * service objects.
     */
    private void ensureLegacyParsed() {
        if (legacyChanged == false || (legacyStrings == null)) {
            return;
        }
        serviceSet = null;
        if (legacyMap == null) {
            legacyMap = new ConcurrentHashMap<>();
        } else {
            legacyMap.clear();
        }
        for (Map.Entry<String,String> entry : legacyStrings.entrySet()) {
            parseLegacyPut(entry.getKey(), entry.getValue());
        }
        removeInvalidServices(legacyMap);
        legacyChanged = false;
    }

    
Remove all invalid services from the Map. Invalid services can only
occur if the legacy properties are inconsistent or incomplete.
/**
     * Remove all invalid services from the Map. Invalid services can only
     * occur if the legacy properties are inconsistent or incomplete.
     */
    private void removeInvalidServices(Map<ServiceKey,Service> map) {
        for (Iterator<Map.Entry<ServiceKey, Service>> t =
                map.entrySet().iterator(); t.hasNext(); ) {
            Service s = t.next().getValue();
            if (s.isValid() == false) {
                t.remove();
            }
        }
    }

    private static String[] getTypeAndAlgorithm(String key) {
        int i = key.indexOf('.');
        if (i < 1) {
            if (debug != null) {
                debug.println("Ignoring invalid entry in provider: "
                        + key);
            }
            return null;
        }
        String type = key.substring(0, i);
        String alg = key.substring(i + 1);
        return new String[] {type, alg};
    }

    private static final String ALIAS_PREFIX = "Alg.Alias.";
    private static final String ALIAS_PREFIX_LOWER = "alg.alias.";
    private static final int ALIAS_LENGTH = ALIAS_PREFIX.length();

    private void parseLegacyPut(String name, String value) {
        if (name.toLowerCase(ENGLISH).startsWith(ALIAS_PREFIX_LOWER)) {
            // e.g. put("Alg.Alias.MessageDigest.SHA", "SHA-1");
            // aliasKey ~ MessageDigest.SHA
            String stdAlg = value;
            String aliasKey = name.substring(ALIAS_LENGTH);
            String[] typeAndAlg = getTypeAndAlgorithm(aliasKey);
            if (typeAndAlg == null) {
                return;
            }
            String type = getEngineName(typeAndAlg[0]);
            String aliasAlg = typeAndAlg[1].intern();
            ServiceKey key = new ServiceKey(type, stdAlg, true);
            Service s = legacyMap.get(key);
            if (s == null) {
                s = new Service(this, type, stdAlg);
                legacyMap.put(key, s);
            }
            legacyMap.put(new ServiceKey(type, aliasAlg, true), s);
            s.addAlias(aliasAlg);
        } else {
            String[] typeAndAlg = getTypeAndAlgorithm(name);
            if (typeAndAlg == null) {
                return;
            }
            int i = typeAndAlg[1].indexOf(' ');
            if (i == -1) {
                // e.g. put("MessageDigest.SHA-1", "sun.security.provider.SHA");
                String type = getEngineName(typeAndAlg[0]);
                String stdAlg = typeAndAlg[1].intern();
                String className = value;
                ServiceKey key = new ServiceKey(type, stdAlg, true);
                Service s = legacyMap.get(key);
                if (s == null) {
                    s = new Service(this, type, stdAlg);
                    legacyMap.put(key, s);
                }
                s.className = className;

                if (type.equals("SecureRandom")) {
                    updateSecureRandomEntries(true, s.algorithm);
                }
            } else { // attribute
                // e.g. put("MessageDigest.SHA-1 ImplementedIn", "Software");
                String attributeValue = value;
                String type = getEngineName(typeAndAlg[0]);
                String attributeString = typeAndAlg[1];
                String stdAlg = attributeString.substring(0, i).intern();
                String attributeName = attributeString.substring(i + 1);
                // kill additional spaces
                while (attributeName.startsWith(" ")) {
                    attributeName = attributeName.substring(1);
                }
                attributeName = attributeName.intern();
                ServiceKey key = new ServiceKey(type, stdAlg, true);
                Service s = legacyMap.get(key);
                if (s == null) {
                    s = new Service(this, type, stdAlg);
                    legacyMap.put(key, s);
                }
                s.addAttribute(attributeName, attributeValue);
            }
        }
    }

    
Get the service describing this Provider's implementation of the specified type of this algorithm or alias. If no such implementation exists, this method returns null. If there are two matching services, one added to this provider using putService() and one added via put(), the service added via putService() is returned. 
Params:
type – the type of service requested (for example, MessageDigest)
algorithm – the case insensitive algorithm name (or alternate alias) of the service requested (for example, SHA-1)
Throws:
NullPointerException – if type or algorithm is null
Returns:
the service describing this Provider's matching service
or null if no such service exists
Since:
1.5/**
     * Get the service describing this Provider's implementation of the
     * specified type of this algorithm or alias. If no such
     * implementation exists, this method returns null. If there are two
     * matching services, one added to this provider using
     * {@link #putService putService()} and one added via {@link #put put()},
     * the service added via {@link #putService putService()} is returned.
     *
     * @param type the type of {@link Service service} requested
     * (for example, {@code MessageDigest})
     * @param algorithm the case insensitive algorithm name (or alternate
     * alias) of the service requested (for example, {@code SHA-1})
     *
     * @return the service describing this Provider's matching service
     * or null if no such service exists
     *
     * @throws NullPointerException if type or algorithm is null
     *
     * @since 1.5
     */
    public Service getService(String type, String algorithm) {
        checkInitialized();

        // avoid allocating a new ServiceKey object if possible
        ServiceKey key = previousKey;
        if (key.matches(type, algorithm) == false) {
            key = new ServiceKey(type, algorithm, false);
            previousKey = key;
        }
        if (!serviceMap.isEmpty()) {
            Service s = serviceMap.get(key);
            if (s != null) {
                return s;
            }
        }
        synchronized (this) {
            ensureLegacyParsed();
            if (legacyMap != null && !legacyMap.isEmpty()) {
                return legacyMap.get(key);
            }
        }
        return null;
    }

    // ServiceKey from previous getService() call
    // by re-using it if possible we avoid allocating a new object
    // and the toUpperCase() call.
    // re-use will occur e.g. as the framework traverses the provider
    // list and queries each provider with the same values until it finds
    // a matching service
    private static volatile ServiceKey previousKey =
                                            new ServiceKey("", "", false);

    
Get an unmodifiable Set of all services supported by
this Provider.
Returns:
an unmodifiable Set of all services supported by
this Provider
Since:
1.5/**
     * Get an unmodifiable Set of all services supported by
     * this Provider.
     *
     * @return an unmodifiable Set of all services supported by
     * this Provider
     *
     * @since 1.5
     */
    public synchronized Set<Service> getServices() {
        checkInitialized();
        if (legacyChanged || servicesChanged) {
            serviceSet = null;
        }
        if (serviceSet == null) {
            ensureLegacyParsed();
            Set<Service> set = new LinkedHashSet<>();
            if (!serviceMap.isEmpty()) {
                set.addAll(serviceMap.values());
            }
            if (legacyMap != null && !legacyMap.isEmpty()) {
                set.addAll(legacyMap.values());
            }
            serviceSet = Collections.unmodifiableSet(set);
            servicesChanged = false;
        }
        return serviceSet;
    }

    
Add a service. If a service of the same type with the same algorithm name exists and it was added using putService(), it is replaced by the new service. This method also places information about this service in the provider's Hashtable values in the format described in the {@extLink security_guide_jca Java Cryptography Architecture (JCA) Reference Guide}. 
Also, if there is a security manager, its checkSecurityAccess method is called with the string "putProviderProperty."+name, where name is the provider name, to see if it's ok to set this provider's property values. If the default implementation of checkSecurityAccess is used (that is, that method is not overridden), then this results in a call to the security manager's checkPermission method with a SecurityPermission("putProviderProperty."+name) permission. 
Params:
s – the Service to add
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to set property values.
NullPointerException – if s is null
Since:
1.5/**
     * Add a service. If a service of the same type with the same algorithm
     * name exists and it was added using {@link #putService putService()},
     * it is replaced by the new service.
     * This method also places information about this service
     * in the provider's Hashtable values in the format described in the
     * {@extLink security_guide_jca
     * Java Cryptography Architecture (JCA) Reference Guide}.
     *
     * <p>Also, if there is a security manager, its
     * {@code checkSecurityAccess} method is called with the string
     * {@code "putProviderProperty."+name}, where {@code name} is
     * the provider name, to see if it's ok to set this provider's property
     * values. If the default implementation of {@code checkSecurityAccess}
     * is used (that is, that method is not overridden), then this results in
     * a call to the security manager's {@code checkPermission} method with
     * a {@code SecurityPermission("putProviderProperty."+name)}
     * permission.
     *
     * @param s the Service to add
     *
     * @throws SecurityException
     *      if a security manager exists and its {@link
     *      java.lang.SecurityManager#checkSecurityAccess} method denies
     *      access to set property values.
     * @throws NullPointerException if s is null
     *
     * @since 1.5
     */
    protected void putService(Service s) {
        check("putProviderProperty." + name);
        if (debug != null) {
            debug.println(name + ".putService(): " + s);
        }
        if (s == null) {
            throw new NullPointerException();
        }
        if (s.getProvider() != this) {
            throw new IllegalArgumentException
                    ("service.getProvider() must match this Provider object");
        }
        String type = s.getType();
        String algorithm = s.getAlgorithm();
        ServiceKey key = new ServiceKey(type, algorithm, true);
        implRemoveService(serviceMap.get(key));
        serviceMap.put(key, s);
        for (String alias : s.getAliases()) {
            serviceMap.put(new ServiceKey(type, alias, true), s);
        }
        servicesChanged = true;
        synchronized (this) {
            putPropertyStrings(s);
            if (type.equals("SecureRandom")) {
                updateSecureRandomEntries(true, s.algorithm);
            }
        }
    }

    // keep tracks of the registered secure random algos and store them in order
    private void updateSecureRandomEntries(boolean doAdd, String s) {
        Objects.requireNonNull(s);
        if (doAdd) {
            if (prngAlgos == null) {
                prngAlgos = new LinkedHashSet<String>();
            }
            prngAlgos.add(s);
        } else {
            prngAlgos.remove(s);
        }

        if (debug != null) {
            debug.println((doAdd? "Add":"Remove") + " SecureRandom algo " + s);
        }
    }

    // used by new SecureRandom() to find out the default SecureRandom
    // service for this provider
    synchronized Service getDefaultSecureRandomService() {
        checkInitialized();

        if (legacyChanged) {
            prngAlgos = null;
            ensureLegacyParsed();
        }

        if (prngAlgos != null && !prngAlgos.isEmpty()) {
            // IMPORTANT: use the Service obj returned by getService(...) call
            // as providers may override putService(...)/getService(...) and
            // return their own Service objects
            return getService("SecureRandom", prngAlgos.iterator().next());
        }

        return null;
    }

    
Put the string properties for this Service in this Provider's
Hashtable.
/**
     * Put the string properties for this Service in this Provider's
     * Hashtable.
     */
    private void putPropertyStrings(Service s) {
        String type = s.getType();
        String algorithm = s.getAlgorithm();
        // use super() to avoid permission check and other processing
        super.put(type + "." + algorithm, s.getClassName());
        for (String alias : s.getAliases()) {
            super.put(ALIAS_PREFIX + type + "." + alias, algorithm);
        }
        for (Map.Entry<UString,String> entry : s.attributes.entrySet()) {
            String key = type + "." + algorithm + " " + entry.getKey();
            super.put(key, entry.getValue());
        }
    }

    
Remove the string properties for this Service from this Provider's
Hashtable.
/**
     * Remove the string properties for this Service from this Provider's
     * Hashtable.
     */
    private void removePropertyStrings(Service s) {
        String type = s.getType();
        String algorithm = s.getAlgorithm();
        // use super() to avoid permission check and other processing
        super.remove(type + "." + algorithm);
        for (String alias : s.getAliases()) {
            super.remove(ALIAS_PREFIX + type + "." + alias);
        }
        for (Map.Entry<UString,String> entry : s.attributes.entrySet()) {
            String key = type + "." + algorithm + " " + entry.getKey();
            super.remove(key);
        }
    }

    
Remove a service previously added using putService(). The specified service is removed from this provider. It will no longer be returned by getService() and its information will be removed from this provider's Hashtable. 
Also, if there is a security manager, its checkSecurityAccess method is called with the string "removeProviderProperty."+name, where name is the provider name, to see if it's ok to remove this provider's properties. If the default implementation of checkSecurityAccess is used (that is, that method is not overridden), then this results in a call to the security manager's checkPermission method with a SecurityPermission("removeProviderProperty."+name) permission. 
Params:
s – the Service to be removed
Throws:
SecurityException –  if a security manager exists and its SecurityManager.checkSecurityAccess method denies access to remove this provider's properties.
NullPointerException – if s is null
Since:
1.5/**
     * Remove a service previously added using
     * {@link #putService putService()}. The specified service is removed from
     * this provider. It will no longer be returned by
     * {@link #getService getService()} and its information will be removed
     * from this provider's Hashtable.
     *
     * <p>Also, if there is a security manager, its
     * {@code checkSecurityAccess} method is called with the string
     * {@code "removeProviderProperty."+name}, where {@code name} is
     * the provider name, to see if it's ok to remove this provider's
     * properties. If the default implementation of
     * {@code checkSecurityAccess} is used (that is, that method is not
     * overridden), then this results in a call to the security manager's
     * {@code checkPermission} method with a
     * {@code SecurityPermission("removeProviderProperty."+name)}
     * permission.
     *
     * @param s the Service to be removed
     *
     * @throws  SecurityException
     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkSecurityAccess} method denies
     *          access to remove this provider's properties.
     * @throws NullPointerException if s is null
     *
     * @since 1.5
     */
    protected void removeService(Service s) {
        check("removeProviderProperty." + name);
        if (debug != null) {
            debug.println(name + ".removeService(): " + s);
        }
        if (s == null) {
            throw new NullPointerException();
        }
        implRemoveService(s);
    }

    private void implRemoveService(Service s) {
        if ((s == null) || serviceMap.isEmpty()) {
            return;
        }
        String type = s.getType();
        String algorithm = s.getAlgorithm();
        ServiceKey key = new ServiceKey(type, algorithm, false);
        Service oldService = serviceMap.get(key);
        if (s != oldService) {
            return;
        }
        servicesChanged = true;
        serviceMap.remove(key);
        for (String alias : s.getAliases()) {
            serviceMap.remove(new ServiceKey(type, alias, false));
        }
        synchronized (this) {
            removePropertyStrings(s);
            if (type.equals("SecureRandom")) {
                updateSecureRandomEntries(false, s.algorithm);
            }
        }
    }

    // Wrapped String that behaves in a case insensitive way for equals/hashCode
    private static class UString {
        final String string;
        final String lowerString;

        UString(String s) {
            this.string = s;
            this.lowerString = s.toLowerCase(ENGLISH);
        }

        public int hashCode() {
            return lowerString.hashCode();
        }

        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj instanceof UString == false) {
                return false;
            }
            UString other = (UString)obj;
            return lowerString.equals(other.lowerString);
        }

        public String toString() {
            return string;
        }
    }

    // describe relevant properties of a type of engine
    private static class EngineDescription {
        final String name;
        final boolean supportsParameter;
        final String constructorParameterClassName;
        private volatile Class<?> constructorParameterClass;

        EngineDescription(String name, boolean sp, String paramName) {
            this.name = name;
            this.supportsParameter = sp;
            this.constructorParameterClassName = paramName;
        }
        Class<?> getConstructorParameterClass() throws ClassNotFoundException {
            Class<?> clazz = constructorParameterClass;
            if (clazz == null) {
                clazz = Class.forName(constructorParameterClassName);
                constructorParameterClass = clazz;
            }
            return clazz;
        }
    }

    // built in knowledge of the engine types shipped as part of the JDK
    private static final Map<String,EngineDescription> knownEngines;

    private static void addEngine(String name, boolean sp, String paramName) {
        EngineDescription ed = new EngineDescription(name, sp, paramName);
        // also index by canonical name to avoid toLowerCase() for some lookups
        knownEngines.put(name.toLowerCase(ENGLISH), ed);
        knownEngines.put(name, ed);
    }

    static {
        knownEngines = new HashMap<>();
        // JCA
        addEngine("AlgorithmParameterGenerator",        false, null);
        addEngine("AlgorithmParameters",                false, null);
        addEngine("KeyFactory",                         false, null);
        addEngine("KeyPairGenerator",                   false, null);
        addEngine("KeyStore",                           false, null);
        addEngine("MessageDigest",                      false, null);
        addEngine("SecureRandom",                       false,
                "java.security.SecureRandomParameters");
        addEngine("Signature",                          true,  null);
        addEngine("CertificateFactory",                 false, null);
        addEngine("CertPathBuilder",                    false, null);
        addEngine("CertPathValidator",                  false, null);
        addEngine("CertStore",                          false,
                            "java.security.cert.CertStoreParameters");
        // JCE
        addEngine("Cipher",                             true,  null);
        addEngine("ExemptionMechanism",                 false, null);
        addEngine("Mac",                                true,  null);
        addEngine("KeyAgreement",                       true,  null);
        addEngine("KeyGenerator",                       false, null);
        addEngine("SecretKeyFactory",                   false, null);
        // JSSE
        addEngine("KeyManagerFactory",                  false, null);
        addEngine("SSLContext",                         false, null);
        addEngine("TrustManagerFactory",                false, null);
        // JGSS
        addEngine("GssApiMechanism",                    false, null);
        // SASL
        addEngine("SaslClientFactory",                  false, null);
        addEngine("SaslServerFactory",                  false, null);
        // POLICY
        addEngine("Policy",                             false,
                            "java.security.Policy$Parameters");
        // CONFIGURATION
        addEngine("Configuration",                      false,
                            "javax.security.auth.login.Configuration$Parameters");
        // XML DSig
        addEngine("XMLSignatureFactory",                false, null);
        addEngine("KeyInfoFactory",                     false, null);
        addEngine("TransformService",                   false, null);
        // Smart Card I/O
        addEngine("TerminalFactory",                    false,
                            "java.lang.Object");
    }

    // get the "standard" (mixed-case) engine name for arbitary case engine name
    // if there is no known engine by that name, return s
    private static String getEngineName(String s) {
        // try original case first, usually correct
        EngineDescription e = knownEngines.get(s);
        if (e == null) {
            e = knownEngines.get(s.toLowerCase(ENGLISH));
        }
        return (e == null) ? s : e.name;
    }

    
The description of a security service. It encapsulates the properties
of a service and contains a factory method to obtain new implementation
instances of this service.
Each service has a provider that offers the service, a type,
an algorithm name, and the name of the class that implements the
service. Optionally, it also includes a list of alternate algorithm
names for this service (aliases) and attributes, which are a map of
(name, value) String pairs.
This class defines the methods 
supportsParameter() and newInstance() which are used by the Java security framework when it searches for suitable services and instantiates them. The valid arguments to those methods depend on the type of service. For the service types defined within Java SE, see the {@extLink security_guide_jca Java Cryptography Architecture (JCA) Reference Guide} for the valid values. Note that components outside of Java SE can define additional types of services and their behavior. 
Instances of this class are immutable.
Since:
1.5/**
     * The description of a security service. It encapsulates the properties
     * of a service and contains a factory method to obtain new implementation
     * instances of this service.
     *
     * <p>Each service has a provider that offers the service, a type,
     * an algorithm name, and the name of the class that implements the
     * service. Optionally, it also includes a list of alternate algorithm
     * names for this service (aliases) and attributes, which are a map of
     * (name, value) String pairs.
     *
     * <p>This class defines the methods {@link #supportsParameter
     * supportsParameter()} and {@link #newInstance newInstance()}
     * which are used by the Java security framework when it searches for
     * suitable services and instantiates them. The valid arguments to those
     * methods depend on the type of service. For the service types defined
     * within Java SE, see the
     * {@extLink security_guide_jca
     * Java Cryptography Architecture (JCA) Reference Guide}
     * for the valid values.
     * Note that components outside of Java SE can define additional types of
     * services and their behavior.
     *
     * <p>Instances of this class are immutable.
     *
     * @since 1.5
     */
    public static class Service {
        private final String type;
        private final String algorithm;
        private String className;
        private final Provider provider;
        private List<String> aliases;
        private Map<UString,String> attributes;
        private final EngineDescription engineDescription;

        // Reference to the cached implementation Class object.
        // Will be a Class if this service is loaded from the built-in
        // classloader (unloading not possible), otherwise a WeakReference to a
        // Class
        private Object classCache;

        // Will be a Constructor if this service is loaded from the built-in
        // classloader (unloading not possible), otherwise a WeakReference to
        // a Constructor
        private Object constructorCache;

        // flag indicating whether this service has its attributes for
        // supportedKeyFormats or supportedKeyClasses set
        // if null, the values have not been initialized
        // if TRUE, at least one of supportedFormats/Classes is non null
        private volatile Boolean hasKeyAttributes;

        // supported encoding formats
        private String[] supportedFormats;

        // names of the supported key (super) classes
        private Class<?>[] supportedClasses;

        // whether this service has been registered with the Provider
        private boolean registered;

        private static final Class<?>[] CLASS0 = new Class<?>[0];

        // this constructor and these methods are used for parsing
        // the legacy string properties.

        private Service(Provider provider, String type, String algorithm) {
            this.provider = provider;
            this.type = type;
            this.algorithm = algorithm;
            engineDescription = knownEngines.get(type);
            aliases = Collections.<String>emptyList();
            attributes = Collections.<UString,String>emptyMap();
        }

        private boolean isValid() {
            return (type != null) && (algorithm != null) && (className != null);
        }

        private void addAlias(String alias) {
            if (aliases.isEmpty()) {
                aliases = new ArrayList<>(2);
            }
            aliases.add(alias);
        }

        void addAttribute(String type, String value) {
            if (attributes.isEmpty()) {
                attributes = new HashMap<>(8);
            }
            attributes.put(new UString(type), value);
        }

        
Construct a new service.
Params:
provider – the provider that offers this service
type – the type of this service
algorithm – the algorithm name
className – the name of the class implementing this service
aliases – List of aliases or null if algorithm has no aliases
attributes – Map of attributes or null if this implementation
                  has no attributes
Throws:
NullPointerException – if provider, type, algorithm, or
className is null/**
         * Construct a new service.
         *
         * @param provider the provider that offers this service
         * @param type the type of this service
         * @param algorithm the algorithm name
         * @param className the name of the class implementing this service
         * @param aliases List of aliases or null if algorithm has no aliases
         * @param attributes Map of attributes or null if this implementation
         *                   has no attributes
         *
         * @throws NullPointerException if provider, type, algorithm, or
         * className is null
         */
        public Service(Provider provider, String type, String algorithm,
                String className, List<String> aliases,
                Map<String,String> attributes) {
            if ((provider == null) || (type == null) ||
                    (algorithm == null) || (className == null)) {
                throw new NullPointerException();
            }
            this.provider = provider;
            this.type = getEngineName(type);
            engineDescription = knownEngines.get(type);
            this.algorithm = algorithm;
            this.className = className;
            if (aliases == null) {
                this.aliases = Collections.<String>emptyList();
            } else {
                this.aliases = new ArrayList<>(aliases);
            }
            if (attributes == null) {
                this.attributes = Collections.<UString,String>emptyMap();
            } else {
                this.attributes = new HashMap<>();
                for (Map.Entry<String,String> entry : attributes.entrySet()) {
                    this.attributes.put(new UString(entry.getKey()), entry.getValue());
                }
            }
        }

        
Get the type of this service. For example, MessageDigest. 
Returns:
the type of this service/**
         * Get the type of this service. For example, {@code MessageDigest}.
         *
         * @return the type of this service
         */
        public final String getType() {
            return type;
        }

        
Return the name of the algorithm of this service. For example, SHA-1. 
Returns:
the algorithm of this service/**
         * Return the name of the algorithm of this service. For example,
         * {@code SHA-1}.
         *
         * @return the algorithm of this service
         */
        public final String getAlgorithm() {
            return algorithm;
        }

        
Return the Provider of this service.
Returns:
the Provider of this service/**
         * Return the Provider of this service.
         *
         * @return the Provider of this service
         */
        public final Provider getProvider() {
            return provider;
        }

        
Return the name of the class implementing this service.
Returns:
the name of the class implementing this service/**
         * Return the name of the class implementing this service.
         *
         * @return the name of the class implementing this service
         */
        public final String getClassName() {
            return className;
        }

        // internal only
        private final List<String> getAliases() {
            return aliases;
        }

        
Return the value of the specified attribute or null if this
attribute is not set for this Service.
Params:
name – the name of the requested attribute
Throws:
NullPointerException – if name is null
Returns:
the value of the specified attribute or null if the
        attribute is not present/**
         * Return the value of the specified attribute or null if this
         * attribute is not set for this Service.
         *
         * @param name the name of the requested attribute
         *
         * @return the value of the specified attribute or null if the
         *         attribute is not present
         *
         * @throws NullPointerException if name is null
         */
        public final String getAttribute(String name) {
            if (name == null) {
                throw new NullPointerException();
            }
            return attributes.get(new UString(name));
        }

        
Return a new instance of the implementation described by this
service. The security provider framework uses this method to
construct implementations. Applications will typically not need
to call it.
The default implementation uses reflection to invoke the
standard constructor for this type of service.
Security providers can override this method to implement
instantiation in a different way.
For details and the values of constructorParameter that are
valid for the various types of services see the
{@extLink security_guide_jca
Java Cryptography Architecture (JCA) Reference Guide}.
Params:
constructorParameter – the value to pass to the constructor,
or null if this type of service does not use a constructorParameter.
Throws:
InvalidParameterException – if the value of
constructorParameter is invalid for this type of service.
NoSuchAlgorithmException – if instantiation failed for
any other reason.
Returns:
a new implementation of this service/**
         * Return a new instance of the implementation described by this
         * service. The security provider framework uses this method to
         * construct implementations. Applications will typically not need
         * to call it.
         *
         * <p>The default implementation uses reflection to invoke the
         * standard constructor for this type of service.
         * Security providers can override this method to implement
         * instantiation in a different way.
         * For details and the values of constructorParameter that are
         * valid for the various types of services see the
         * {@extLink security_guide_jca
         * Java Cryptography Architecture (JCA) Reference Guide}.
         *
         * @param constructorParameter the value to pass to the constructor,
         * or null if this type of service does not use a constructorParameter.
         *
         * @return a new implementation of this service
         *
         * @throws InvalidParameterException if the value of
         * constructorParameter is invalid for this type of service.
         * @throws NoSuchAlgorithmException if instantiation failed for
         * any other reason.
         */
        public Object newInstance(Object constructorParameter)
                throws NoSuchAlgorithmException {
            if (registered == false) {
                if (provider.getService(type, algorithm) != this) {
                    throw new NoSuchAlgorithmException
                        ("Service not registered with Provider "
                        + provider.getName() + ": " + this);
                }
                registered = true;
            }
            Class<?> ctrParamClz;
            try {
                EngineDescription cap = engineDescription;
                if (cap == null) {
                    // unknown engine type, use generic code
                    // this is the code path future for non-core
                    // optional packages
                    ctrParamClz = constructorParameter == null?
                        null : constructorParameter.getClass();
                } else {
                    ctrParamClz = cap.constructorParameterClassName == null?
                        null : Class.forName(cap.constructorParameterClassName);
                    if (constructorParameter != null) {
                        if (ctrParamClz == null) {
                            throw new InvalidParameterException
                                ("constructorParameter not used with " + type
                                + " engines");
                        } else {
                            Class<?> argClass = constructorParameter.getClass();
                            if (ctrParamClz.isAssignableFrom(argClass) == false) {
                                throw new InvalidParameterException
                                    ("constructorParameter must be instanceof "
                                    + cap.constructorParameterClassName.replace('$', '.')
                                    + " for engine type " + type);
                            }
                        }
                    }
                }
                // constructorParameter can be null if not provided
                return newInstanceUtil(ctrParamClz, constructorParameter);
            } catch (NoSuchAlgorithmException e) {
                throw e;
            } catch (InvocationTargetException e) {
                throw new NoSuchAlgorithmException
                    ("Error constructing implementation (algorithm: "
                    + algorithm + ", provider: " + provider.getName()
                    + ", class: " + className + ")", e.getCause());
            } catch (Exception e) {
                throw new NoSuchAlgorithmException
                    ("Error constructing implementation (algorithm: "
                    + algorithm + ", provider: " + provider.getName()
                    + ", class: " + className + ")", e);
            }
        }

        private Object newInstanceOf() throws Exception {
            Constructor<?> con = getDefaultConstructor();
            return con.newInstance(EMPTY);
        }

        private Object newInstanceUtil(Class<?> ctrParamClz, Object ctorParamObj)
                throws Exception
        {
            if (ctrParamClz == null) {
                return newInstanceOf();
            } else {
                // Looking for the constructor with a params first and fallback
                // to one without if not found. This is to support the enhanced
                // SecureRandom where both styles of constructors are supported.
                // Before jdk9, there was no params support (only getInstance(alg))
                // and an impl only had the params-less constructor. Since jdk9,
                // there is getInstance(alg,params) and an impl can contain
                // an Impl(params) constructor.
                try {
                    Constructor<?> con = getImplClass().getConstructor(ctrParamClz);
                    return con.newInstance(ctorParamObj);
                } catch (NoSuchMethodException nsme) {
                    // For pre-jdk9 SecureRandom implementations, they only
                    // have params-less constructors which still works when
                    // the input ctorParamObj is null.
                    //
                    // For other primitives using params, ctorParamObj should not
                    // be null and nsme is thrown, just like before.
                    if (ctorParamObj == null) {
                        try {
                            return newInstanceOf();
                        } catch (NoSuchMethodException nsme2) {
                            nsme.addSuppressed(nsme2);
                            throw nsme;
                        }
                    } else {
                        throw nsme;
                    }
                }
            }
        }

        // return the implementation Class object for this service
        private Class<?> getImplClass() throws NoSuchAlgorithmException {
            try {
                Object cache = classCache;
                if (cache instanceof Class<?> clazz) {
                    return clazz;
                }
                Class<?> clazz = null;
                if (cache instanceof WeakReference<?> ref){
                    clazz = (Class<?>)ref.get();
                }
                if (clazz == null) {
                    ClassLoader cl = provider.getClass().getClassLoader();
                    if (cl == null) {
                        clazz = Class.forName(className);
                    } else {
                        clazz = cl.loadClass(className);
                    }
                    if (!Modifier.isPublic(clazz.getModifiers())) {
                        throw new NoSuchAlgorithmException
                            ("class configured for " + type + " (provider: " +
                            provider.getName() + ") is not public.");
                    }
                    classCache = (cl == null) ? clazz : new WeakReference<Class<?>>(clazz);
                }
                return clazz;
            } catch (ClassNotFoundException e) {
                throw new NoSuchAlgorithmException
                    ("class configured for " + type + " (provider: " +
                    provider.getName() + ") cannot be found.", e);
            }
        }

        private Constructor<?> getDefaultConstructor()
            throws NoSuchAlgorithmException, NoSuchMethodException
        {
            Object cache = constructorCache;
            if (cache instanceof Constructor<?> con) {
                return con;
            }
            Constructor<?> con = null;
            if (cache instanceof WeakReference<?> ref){
                con = (Constructor<?>)ref.get();
            }
            if (con == null) {
                Class<?> clazz = getImplClass();
                con = clazz.getConstructor();
                constructorCache = (clazz.getClassLoader() == null)
                        ? con : new WeakReference<Constructor<?>>(con);
            }
            return con;
        }

        
Test whether this Service can use the specified parameter.
Returns false if this service cannot use the parameter. Returns
true if this service can use the parameter, if a fast test is
infeasible, or if the status is unknown.
The security provider framework uses this method with
some types of services to quickly exclude non-matching
implementations for consideration.
Applications will typically not need to call it.
For details and the values of parameter that are valid for the
various types of services see the top of this class and the
{@extLink security_guide_jca
Java Cryptography Architecture (JCA) Reference Guide}.
Security providers can override it to implement their own test.
Params:
parameter – the parameter to test
Throws:
InvalidParameterException – if the value of parameter is
invalid for this type of service or if this method cannot be
used with this type of service
Returns:
false if this service cannot use the specified
parameter; true if it can possibly use the parameter/**
         * Test whether this Service can use the specified parameter.
         * Returns false if this service cannot use the parameter. Returns
         * true if this service can use the parameter, if a fast test is
         * infeasible, or if the status is unknown.
         *
         * <p>The security provider framework uses this method with
         * some types of services to quickly exclude non-matching
         * implementations for consideration.
         * Applications will typically not need to call it.
         *
         * <p>For details and the values of parameter that are valid for the
         * various types of services see the top of this class and the
         * {@extLink security_guide_jca
         * Java Cryptography Architecture (JCA) Reference Guide}.
         * Security providers can override it to implement their own test.
         *
         * @param parameter the parameter to test
         *
         * @return false if this service cannot use the specified
         * parameter; true if it can possibly use the parameter
         *
         * @throws InvalidParameterException if the value of parameter is
         * invalid for this type of service or if this method cannot be
         * used with this type of service
         */
        public boolean supportsParameter(Object parameter) {
            EngineDescription cap = engineDescription;
            if (cap == null) {
                // unknown engine type, return true by default
                return true;
            }
            if (cap.supportsParameter == false) {
                throw new InvalidParameterException("supportsParameter() not "
                    + "used with " + type + " engines");
            }
            // allow null for keys without attributes for compatibility
            if ((parameter != null) && (parameter instanceof Key == false)) {
                throw new InvalidParameterException
                    ("Parameter must be instanceof Key for engine " + type);
            }
            if (hasKeyAttributes() == false) {
                return true;
            }
            if (parameter == null) {
                return false;
            }
            Key key = (Key)parameter;
            if (supportsKeyFormat(key)) {
                return true;
            }
            if (supportsKeyClass(key)) {
                return true;
            }
            return false;
        }

        
Return whether this service has its supported properties for
keys defined. Parses the attributes if not yet initialized.
/**
         * Return whether this service has its supported properties for
         * keys defined. Parses the attributes if not yet initialized.
         */
        private boolean hasKeyAttributes() {
            Boolean b = hasKeyAttributes;
            if (b == null) {
                synchronized (this) {
                    b = hasKeyAttributes;
                    if (b == null) {
                        String s;
                        s = getAttribute("SupportedKeyFormats");
                        if (s != null) {
                            supportedFormats = s.split("\\|");
                        }
                        s = getAttribute("SupportedKeyClasses");
                        if (s != null) {
                            String[] classNames = s.split("\\|");
                            List<Class<?>> classList =
                                new ArrayList<>(classNames.length);
                            for (String className : classNames) {
                                Class<?> clazz = getKeyClass(className);
                                if (clazz != null) {
                                    classList.add(clazz);
                                }
                            }
                            supportedClasses = classList.toArray(CLASS0);
                        }
                        boolean bool = (supportedFormats != null)
                            || (supportedClasses != null);
                        b = Boolean.valueOf(bool);
                        hasKeyAttributes = b;
                    }
                }
            }
            return b.booleanValue();
        }

        // get the key class object of the specified name
        private Class<?> getKeyClass(String name) {
            try {
                return Class.forName(name);
            } catch (ClassNotFoundException e) {
                // ignore
            }
            try {
                ClassLoader cl = provider.getClass().getClassLoader();
                if (cl != null) {
                    return cl.loadClass(name);
                }
            } catch (ClassNotFoundException e) {
                // ignore
            }
            return null;
        }

        private boolean supportsKeyFormat(Key key) {
            if (supportedFormats == null) {
                return false;
            }
            String format = key.getFormat();
            if (format == null) {
                return false;
            }
            for (String supportedFormat : supportedFormats) {
                if (supportedFormat.equals(format)) {
                    return true;
                }
            }
            return false;
        }

        private boolean supportsKeyClass(Key key) {
            if (supportedClasses == null) {
                return false;
            }
            Class<?> keyClass = key.getClass();
            for (Class<?> clazz : supportedClasses) {
                if (clazz.isAssignableFrom(keyClass)) {
                    return true;
                }
            }
            return false;
        }

        
Return a String representation of this service.
Returns:
a String representation of this service./**
         * Return a String representation of this service.
         *
         * @return a String representation of this service.
         */
        public String toString() {
            String aString = aliases.isEmpty()
                ? "" : "\r\n  aliases: " + aliases.toString();
            String attrs = attributes.isEmpty()
                ? "" : "\r\n  attributes: " + attributes.toString();
            return provider.getName() + ": " + type + "." + algorithm
                + " -> " + className + aString + attrs + "\r\n";
        }
    }
}