xjava.security

Class IJCE


public class IJCE
extends java.lang.Object

The IJCE class provides an interface to features that were not present in JavaSoft's initial version of JCE. Hopefully the getAlgorithms and/or the enable/disableTracing methods will be incorporated into a later version of the standard.

If you bundle this classfile, and the other classfiles in java.security.* that have names starting "IJCE_" with your application, these methods should work as documented even if linked against JavaSoft's implementation, so using them does not result in any loss of compatibility.

This class also defines the version number of the IJCE library:

Version numbers should be written as a triple of integers, not as a decimal. If the last number is omitted it is assumed to be 0, so for example, version 1.10 is after version 1.2.

The IJCE version number corresponding to this documentation is 1.1. (This is independent of the version numbers of any libraries that IJCE may be distributed with, such as Cryptix.)

Copyright © 1997 Systemics Ltd on behalf of the Cryptix Development Team.
All rights reserved.

$Revision: 1.5 $

Authors:
David Hopwood
Raif S. Naffah
Since:
IJCE 1.0.1

Method Summary

(package private) static void
debug(String s)
Prints a debugging message that may be significant to a developer.
static void
disableTracing(Object obj)
Disables tracing of SPI methods for obj.
static boolean
enableTracing(Object obj)
Enables tracing of calls to SPI methods for the algorithm object obj, with Output sent to the default location, given by getDebugOutput().
static boolean
enableTracing(Object obj, PrintWriter out)
Enables tracing of calls to SPI methods for the algorithm object obj.
(package private) static void
error(String s)
Prints an error message that may be significant to a user.
static Target
findTarget(String name)
Returns a Target that can be passed to PrivilegeManager.enablePrivilege(...), in order to request permission for an action that requires the user's trust.
static Target
findTarget(String name, Object arg)
Reserved for future use, in case parameterized targets are needed.
static String[]
getAlgorithms(Provider provider, String type)
Gets the standard names of all algorithms of the given type implemented by a provider.
static String[]
getAlgorithms(String type)
Gets the standard names of all algorithms of the given type implemented by any installed provider.
(package private) static int
getDebugLevel(String label)
Returns the debug level for label.
(package private) static PrintWriter
getDebugOutput()
Returns the PrintWriter that debugging Output is to be sent to.
static Object
getImplementation(String algorithm, String type)
Returns an object configured to the specified type.
static Object
getImplementation(String algorithm, String provider, String type)
Returns an object configured to the specified type.
static Class
getImplementationClass(String algorithm, String type)
Given an algorithm name (which may be an alias) and type, returns the corresponding algorithm class from any provider.
static Class
getImplementationClass(String algorithm, String provider, String type)
Given an algorithm name (which may be an alias), a provider name, and a type, returns the corresponding algorithm class.
static int
getIntermediateVersion()
Returns the intermediate version of this release of IJCE.
static int
getMajorVersion()
Returns the major version of this release of IJCE.
static int
getMinorVersion()
Returns the minor version of this release of IJCE.
static String
getReleaseDate()
Returns the release date of this version of IJCE, as a string in the form "yyyy/mm/dd".
static String
getStandardName(String algorithm, String type)
Expands the possible alias algorithm to a standard name.
static String
getVersionString()
Returns a string describing this version of IJCE.
static boolean
isProvidingJCA()
Returns true if IJCE is providing the implementations of the JCA classes (MessageDigest, Signature, etc).
static boolean
isProvidingJCE()
Returns true if IJCE is providing the implementations of the JCE classes (Cipher, KeyGenerator, etc).
static boolean
isVersionAtLeast(int major, int minor, int intermediate)
Returns true iff this version of IJCE is at least the given version.
(package private) static void
listProviders()
Debugging method to list all providers.
static void
main(String[] args)
Prints the IJCE version string, a list of statically configured providers, and the location of the library directory.
(package private) static void
reportBug(String s)
Prints a "can't happen" error, with a request to report this as a bug.

Method Details

debug

(package private) static void debug(String s)
Prints a debugging message that may be significant to a developer.

disableTracing

public static void disableTracing(Object obj)
Disables tracing of SPI methods for obj. Returns silently if tracing was not enabled or is not supported for this object.

enableTracing

public static boolean enableTracing(Object obj)
Enables tracing of calls to SPI methods for the algorithm object obj, with Output sent to the default location, given by getDebugOutput().

enableTracing

public static boolean enableTracing(Object obj,
                                    PrintWriter out)
Enables tracing of calls to SPI methods for the algorithm object obj. Output is sent to the PrintWriter out. This method will return true if tracing was enabled successfully, or false if it is not supported for this class.

Some trivial methods (such as those that get the block size) are not traced.

This can produce a lot of Output, and it should only be used for debugging, when the data being processed by the algorithm object is not secret.

Tracing only works for classes whose implementations are being provided by IJCE. If there is a non-IJCE implementation of the base class for obj (Cipher, MessageDigest, etc.) earlier in the CLASSPATH, it will probably not support tracing, and false will be returned.

Note that the IJCE library includes an implementation of java.io.PrintWriter that will be used automatically when running on Java 1.0.2.


error

(package private) static void error(String s)
Prints an error message that may be significant to a user.

findTarget

public static Target findTarget(String name)
            throws ForbiddenTargetException
Returns a Target that can be passed to PrivilegeManager.enablePrivilege(...), in order to request permission for an action that requires the user's trust.

Currently the following target names are recognized:

  • AddSecurityProvider - add a new security provider to the system.
  • RemoveSecurityProvider - remove a security provider from the system.
  • SecurityPropertyRead - read the security properties.
  • SecurityPropertyWrite - change the value of any security property.
  • GetSecurityProviders - get a reference to any security Provider object.
Parameters:
name - the name of the target to be returned
Returns:
the Target object
Throws:
ForbiddenTargetException - if name is not recognized.

findTarget

public static Target findTarget(String name,
                                Object arg)
            throws ForbiddenTargetException
Reserved for future use, in case parameterized targets are needed. Currently this always throws a ForbiddenTargetException.
Parameters:
name - the name of the target to be returned
arg - a parameter object
Returns:
the Target object
Throws:
ForbiddenTargetException - if name is not recognized.

getAlgorithms

public static String[] getAlgorithms(Provider provider,
                                     String type)
Gets the standard names of all algorithms of the given type implemented by a provider.

Possible values for type include "Cipher", "Mode", "PaddingScheme", "MessageDigest", "Signature", "KeyGenerator", and "KeyPairGenerator". Other types can be configured in the IJCE.properties file.


getAlgorithms

public static String[] getAlgorithms(String type)
Gets the standard names of all algorithms of the given type implemented by any installed provider. Algorithm names are not duplicated if they are supported by more than one provider (but specialized cipher/mode implementations are treated as distinct, for example "DES/CBC" is different from "DES").

Possible values for type include "Cipher", "Mode", "PaddingScheme", "MessageDigest", "Signature", "KeyGenerator", and "KeyPairGenerator". Other types can be configured in the IJCE.properties file.

The built-in padding scheme "NONE", or the built-in mode "ECB" are included if applicable.


getDebugLevel

(package private) static int getDebugLevel(String label)
Returns the debug level for label. Its value is normally given by the numeric provider property "Debug.Level.label".

If this property is not set, "Debug.Level.*" is searched next. If neither property is set, or if the first property found is not a valid decimal integer, then this method returns 0.


getDebugOutput

(package private) static PrintWriter getDebugOutput()
Returns the PrintWriter that debugging Output is to be sent to.

getImplementation

public static Object getImplementation(String algorithm,
                                       String type)
            throws NoSuchAlgorithmException
Returns an object configured to the specified type. All providers will be searched in order of preference.

Possible values for type include "Cipher", "Mode", "PaddingScheme", "MessageDigest", "Signature", "KeyGenerator", and "KeyPairGenerator". Other types can be configured in the IJCE.properties file.

Parameters:
algorithm - the standard name or an alias for the algorithm.
type - the type of algorithm.
Returns:
the implementation object.

getImplementation

public static Object getImplementation(String algorithm,
                                       String provider,
                                       String type)
            throws NoSuchAlgorithmException,
                   NoSuchProviderException
Returns an object configured to the specified type. Provider can be null, in which case all providers will be searched in order of preference.

Possible values for type include "Cipher", "Mode", "PaddingScheme", "MessageDigest", "Signature", "KeyGenerator", and "KeyPairGenerator". Other types can be configured in the IJCE.properties file.

Parameters:
algorithm - the standard name or an alias for the algorithm.
provider - the string name of the provider.
type - the type of algorithm.
Returns:
the implementation object.

getImplementationClass

public static Class getImplementationClass(String algorithm,
                                           String type)
            throws NoSuchAlgorithmException
Given an algorithm name (which may be an alias) and type, returns the corresponding algorithm class from any provider.

getImplementationClass

public static Class getImplementationClass(String algorithm,
                                           String provider,
                                           String type)
            throws NoSuchAlgorithmException,
                   NoSuchProviderException
Given an algorithm name (which may be an alias), a provider name, and a type, returns the corresponding algorithm class.

getIntermediateVersion

public static int getIntermediateVersion()
Returns the intermediate version of this release of IJCE.

getMajorVersion

public static int getMajorVersion()
Returns the major version of this release of IJCE.

getMinorVersion

public static int getMinorVersion()
Returns the minor version of this release of IJCE.

getReleaseDate

public static String getReleaseDate()
Returns the release date of this version of IJCE, as a string in the form "yyyy/mm/dd".

getStandardName

public static String getStandardName(String algorithm,
                                     String type)
Expands the possible alias algorithm to a standard name. If algorithm is not an alias, it is returned as-is. This method does not check whether a corresponding algorithm implementation exists.

Possible values for type include "Cipher", "Mode", "PaddingScheme", "MessageDigest", "Signature", "KeyGenerator", and "KeyPairGenerator". Other types can be configured in the IJCE.properties file.

Parameters:
algorithm - the possible alias
type - the type of algorithm
Returns:
the standard name

getVersionString

public static String getVersionString()
Returns a string describing this version of IJCE.

isProvidingJCA

public static boolean isProvidingJCA()
Returns true if IJCE is providing the implementations of the JCA classes (MessageDigest, Signature, etc). This will be false if another version of JCA (for example JavaSoft's) is installed earlier in the CLASSPATH.

isProvidingJCE

public static boolean isProvidingJCE()
Returns true if IJCE is providing the implementations of the JCE classes (Cipher, KeyGenerator, etc). This will be false if another version of JCE (for example JavaSoft's) is installed earlier in the CLASSPATH.

isVersionAtLeast

public static boolean isVersionAtLeast(int major,
                                       int minor,
                                       int intermediate)
Returns true iff this version of IJCE is at least the given version.

listProviders

(package private) static void listProviders()
Debugging method to list all providers.

main

public static void main(String[] args)
Prints the IJCE version string, a list of statically configured providers, and the location of the library directory.

reportBug

(package private) static void reportBug(String s)
Prints a "can't happen" error, with a request to report this as a bug. Always throws an InternalError.