/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
* add the following below this CDDL HEADER, with the fields enclosed
* by brackets "[]" replaced with your own identifying information:
* Portions Copyright [yyyy] [name of copyright owner]
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*
*
* Copyright 2006-2008 Sun Microsystems, Inc.
*/
package org.opends.server.extensions;
import java.security.MessageDigest;
import java.util.Arrays;
import java.util.Random;
import org.opends.messages.Message;
import org.opends.server.admin.std.server.SaltedMD5PasswordStorageSchemeCfg;
import org.opends.server.api.PasswordStorageScheme;
import org.opends.server.config.ConfigException;
import org.opends.server.core.DirectoryServer;
import org.opends.server.loggers.ErrorLogger;
import org.opends.server.loggers.debug.DebugTracer;
import org.opends.server.types.*;
import org.opends.server.util.Base64;
import static org.opends.messages.ExtensionMessages.*;
import static org.opends.server.extensions.ExtensionsConstants.*;
import static org.opends.server.loggers.debug.DebugLogger.*;
import static org.opends.server.util.StaticUtils.*;
/**
* This class defines a Directory Server password storage scheme based on the
* MD5 algorithm defined in RFC 1321. This is a one-way digest algorithm so
* there is no way to retrieve the original clear-text version of the
* password from the hashed value (although this means that it is not suitable
* for things that need the clear-text password like DIGEST-MD5). The values
* that it generates are also salted, which protects against dictionary attacks.
* It does this by generating a 64-bit random salt which is appended to the
* clear-text value. A MD5 hash is then generated based on this, the salt is
* appended to the hash, and then the entire value is base64-encoded.
*/
public class SaltedMD5PasswordStorageScheme
extends PasswordStorageScheme<SaltedMD5PasswordStorageSchemeCfg>
{
/**
* The tracer object for the debug logger.
*/
private static final DebugTracer TRACER = getTracer();
/**
* The fully-qualified name of this class.
*/
private static final String CLASS_NAME =
"org.opends.server.extensions.SaltedMD5PasswordStorageScheme";
/**
* The number of bytes of random data to use as the salt when generating the
* hashes.
*/
private static final int NUM_SALT_BYTES = 8;
// The message digest that will actually be used to generate the MD5 hashes.
private MessageDigest messageDigest;
// The lock used to provide threadsafe access to the message digest.
private Object digestLock;
// The secure random number generator to use to generate the salt values.
private Random random;
/**
* Creates a new instance of this password storage scheme. Note that no
* initialization should be performed here, as all initialization should be
* done in the <CODE>initializePasswordStorageScheme</CODE> method.
*/
public SaltedMD5PasswordStorageScheme()
{
super();
}
/**
* {@inheritDoc}
*/
@Override()
public void initializePasswordStorageScheme(
SaltedMD5PasswordStorageSchemeCfg configuration)
throws ConfigException, InitializationException
{
try
{
messageDigest = MessageDigest.getInstance(MESSAGE_DIGEST_ALGORITHM_MD5);
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
Message message = ERR_PWSCHEME_CANNOT_INITIALIZE_MESSAGE_DIGEST.get(
MESSAGE_DIGEST_ALGORITHM_MD5, String.valueOf(e));
throw new InitializationException(message, e);
}
digestLock = new Object();
random = new Random();
}
/**
* {@inheritDoc}
*/
@Override()
public String getStorageSchemeName()
{
return STORAGE_SCHEME_NAME_SALTED_MD5;
}
/**
* {@inheritDoc}
*/
@Override()
public ByteString encodePassword(ByteSequence plaintext)
throws DirectoryException
{
int plainBytesLength = plaintext.length();
byte[] saltBytes = new byte[NUM_SALT_BYTES];
byte[] plainPlusSalt = new byte[plainBytesLength + NUM_SALT_BYTES];
plaintext.copyTo(plainPlusSalt);
byte[] digestBytes;
synchronized (digestLock)
{
try
{
// Generate the salt and put in the plain+salt array.
random.nextBytes(saltBytes);
System.arraycopy(saltBytes,0, plainPlusSalt, plainBytesLength,
NUM_SALT_BYTES);
// Create the hash from the concatenated value.
digestBytes = messageDigest.digest(plainPlusSalt);
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
Message message = ERR_PWSCHEME_CANNOT_ENCODE_PASSWORD.get(
CLASS_NAME, getExceptionMessage(e));
throw new DirectoryException(DirectoryServer.getServerErrorResultCode(),
message, e);
}
}
// Append the salt to the hashed value and base64-the whole thing.
byte[] hashPlusSalt = new byte[digestBytes.length + NUM_SALT_BYTES];
System.arraycopy(digestBytes, 0, hashPlusSalt, 0, digestBytes.length);
System.arraycopy(saltBytes, 0, hashPlusSalt, digestBytes.length,
NUM_SALT_BYTES);
return ByteString.valueOf(Base64.encode(hashPlusSalt));
}
/**
* {@inheritDoc}
*/
@Override()
public ByteString encodePasswordWithScheme(ByteSequence plaintext)
throws DirectoryException
{
StringBuilder buffer = new StringBuilder();
buffer.append('{');
buffer.append(STORAGE_SCHEME_NAME_SALTED_MD5);
buffer.append('}');
int plainBytesLength = plaintext.length();
byte[] saltBytes = new byte[NUM_SALT_BYTES];
byte[] plainPlusSalt = new byte[plainBytesLength + NUM_SALT_BYTES];
plaintext.copyTo(plainPlusSalt);
byte[] digestBytes;
synchronized (digestLock)
{
try
{
// Generate the salt and put in the plain+salt array.
random.nextBytes(saltBytes);
System.arraycopy(saltBytes,0, plainPlusSalt, plainBytesLength,
NUM_SALT_BYTES);
// Create the hash from the concatenated value.
digestBytes = messageDigest.digest(plainPlusSalt);
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
Message message = ERR_PWSCHEME_CANNOT_ENCODE_PASSWORD.get(
CLASS_NAME, getExceptionMessage(e));
throw new DirectoryException(DirectoryServer.getServerErrorResultCode(),
message, e);
}
}
// Append the salt to the hashed value and base64-the whole thing.
byte[] hashPlusSalt = new byte[digestBytes.length + NUM_SALT_BYTES];
System.arraycopy(digestBytes, 0, hashPlusSalt, 0, digestBytes.length);
System.arraycopy(saltBytes, 0, hashPlusSalt, digestBytes.length,
NUM_SALT_BYTES);
buffer.append(Base64.encode(hashPlusSalt));
return ByteString.valueOf(buffer.toString());
}
/**
* {@inheritDoc}
*/
@Override()
public boolean passwordMatches(ByteSequence plaintextPassword,
ByteSequence storedPassword)
{
// Base64-decode the stored value and take the last 8 bytes as the salt.
byte[] saltBytes = new byte[NUM_SALT_BYTES];
byte[] digestBytes;
try
{
byte[] decodedBytes = Base64.decode(storedPassword.toString());
int digestLength = decodedBytes.length - NUM_SALT_BYTES;
digestBytes = new byte[digestLength];
System.arraycopy(decodedBytes, 0, digestBytes, 0, digestLength);
System.arraycopy(decodedBytes, digestLength, saltBytes, 0,
NUM_SALT_BYTES);
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
Message message = ERR_PWSCHEME_CANNOT_BASE64_DECODE_STORED_PASSWORD.get(
storedPassword.toString(), String.valueOf(e));
ErrorLogger.logError(message);
return false;
}
// Use the salt to generate a digest based on the provided plain-text value.
int plainBytesLength = plaintextPassword.length();
byte[] plainPlusSalt = new byte[plainBytesLength + NUM_SALT_BYTES];
plaintextPassword.copyTo(plainPlusSalt);
System.arraycopy(saltBytes, 0,plainPlusSalt, plainBytesLength,
NUM_SALT_BYTES);
byte[] userDigestBytes;
synchronized (digestLock)
{
try
{
userDigestBytes = messageDigest.digest(plainPlusSalt);
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
return false;
}
}
return Arrays.equals(digestBytes, userDigestBytes);
}
/**
* {@inheritDoc}
*/
@Override()
public boolean supportsAuthPasswordSyntax()
{
// This storage scheme does support the authentication password syntax.
return true;
}
/**
* {@inheritDoc}
*/
@Override()
public String getAuthPasswordSchemeName()
{
return AUTH_PASSWORD_SCHEME_NAME_SALTED_MD5;
}
/**
* {@inheritDoc}
*/
@Override()
public ByteString encodeAuthPassword(ByteSequence plaintext)
throws DirectoryException
{
int plaintextLength = plaintext.length();
byte[] saltBytes = new byte[NUM_SALT_BYTES];
byte[] plainPlusSalt = new byte[plaintextLength + NUM_SALT_BYTES];
plaintext.copyTo(plainPlusSalt);
byte[] digestBytes;
synchronized (digestLock)
{
try
{
// Generate the salt and put in the plain+salt array.
random.nextBytes(saltBytes);
System.arraycopy(saltBytes,0, plainPlusSalt, plaintextLength,
NUM_SALT_BYTES);
// Create the hash from the concatenated value.
digestBytes = messageDigest.digest(plainPlusSalt);
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
Message message = ERR_PWSCHEME_CANNOT_ENCODE_PASSWORD.get(
CLASS_NAME, getExceptionMessage(e));
throw new DirectoryException(DirectoryServer.getServerErrorResultCode(),
message, e);
}
}
// Encode and return the value.
StringBuilder authPWValue = new StringBuilder();
authPWValue.append(AUTH_PASSWORD_SCHEME_NAME_SALTED_MD5);
authPWValue.append('$');
authPWValue.append(Base64.encode(saltBytes));
authPWValue.append('$');
authPWValue.append(Base64.encode(digestBytes));
return ByteString.valueOf(authPWValue.toString());
}
/**
* {@inheritDoc}
*/
@Override()
public boolean authPasswordMatches(ByteSequence plaintextPassword,
String authInfo, String authValue)
{
byte[] saltBytes;
byte[] digestBytes;
try
{
saltBytes = Base64.decode(authInfo);
digestBytes = Base64.decode(authValue);
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
return false;
}
int plainBytesLength = plaintextPassword.length();
byte[] plainPlusSaltBytes = new byte[plainBytesLength + saltBytes.length];
plaintextPassword.copyTo(plainPlusSaltBytes);
System.arraycopy(saltBytes, 0, plainPlusSaltBytes, plainBytesLength,
saltBytes.length);
synchronized (digestLock)
{
return Arrays.equals(digestBytes,
messageDigest.digest(plainPlusSaltBytes));
}
}
/**
* {@inheritDoc}
*/
@Override()
public boolean isReversible()
{
return false;
}
/**
* {@inheritDoc}
*/
@Override()
public ByteString getPlaintextValue(ByteSequence storedPassword)
throws DirectoryException
{
Message message =
ERR_PWSCHEME_NOT_REVERSIBLE.get(STORAGE_SCHEME_NAME_SALTED_MD5);
throw new DirectoryException(ResultCode.CONSTRAINT_VIOLATION, message);
}
/**
* {@inheritDoc}
*/
@Override()
public ByteString getAuthPasswordPlaintextValue(String authInfo,
String authValue)
throws DirectoryException
{
Message message =
ERR_PWSCHEME_NOT_REVERSIBLE.get(AUTH_PASSWORD_SCHEME_NAME_SALTED_MD5);
throw new DirectoryException(ResultCode.CONSTRAINT_VIOLATION, message);
}
/**
* {@inheritDoc}
*/
@Override()
public boolean isStorageSchemeSecure()
{
// MD5 may be considered reasonably secure for this purpose.
return true;
}
}