author | weijun |
Wed, 06 Jul 2016 21:52:12 +0800 | |
changeset 39481 | 63ceb7ef04d4 |
parent 38853 | 971a7101da5b |
permissions | -rw-r--r-- |
37796 | 1 |
/* |
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* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package sun.security.provider; |
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import sun.security.util.Debug; |
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import java.security.*; |
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import java.util.Arrays; |
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import java.util.Objects; |
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import static java.security.DrbgParameters.Capability.*; |
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/** |
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* The abstract base class for all DRBGs. It is used as {@link DRBG#impl}. |
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* <p> |
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* This class has 5 abstract methods. 3 are defined by SP800-90A: |
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* <ol> |
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* <li>{@link #generateAlgorithm(byte[], byte[])} |
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* <li>{@link #reseedAlgorithm(byte[], byte[])} (In fact this is not an |
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* abstract method, but any DRBG supporting reseeding must override it.) |
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* <li>{@link #instantiateAlgorithm(byte[])} |
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* </ol> |
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* and 2 for implementation purpose: |
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* <ol> |
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* <li>{@link #initEngine()} |
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* <li>{@link #chooseAlgorithmAndStrength} |
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* </ol> |
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* Although this class is not a child class of {@link SecureRandomSpi}, it |
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* implements all abstract methods there as final. |
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* <p> |
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* The initialization process of a DRBG is divided into 2 phases: |
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* {@link #configure configuration} is eagerly called to set up parameters, |
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* and {@link #instantiateIfNecessary instantiation} is lazily called only |
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* when nextBytes or reseed is called. |
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* <p> |
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* SecureRandom methods like reseed and nextBytes are not thread-safe. |
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* An implementation is required to protect shared access to instantiate states |
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* (instantiated, nonce) and DRBG states (v, c, key, reseedCounter, etc). |
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*/ |
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public abstract class AbstractDrbg { |
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/** |
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* This field is not null if {@code -Djava.security.debug=securerandom} is |
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* specified on the command line. An implementation can print useful |
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* debug info. |
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*/ |
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protected static final Debug debug = Debug.getInstance( |
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"securerandom", "drbg"); |
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// Common working status |
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private boolean instantiated = false; |
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/** |
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* Reseed counter of a DRBG instance. A mechanism should increment it |
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* after each random bits generation and reset it in reseed. A mechanism |
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* does <em>not</em> need to compare it to {@link #reseedInterval}. |
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* |
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* Volatile, will be used in a double checked locking. |
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*/ |
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protected volatile int reseedCounter = 0; |
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// Mech features. If not same as below, must be redefined in constructor. |
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/** |
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* Default strength of a DRBG instance if it is not configured. |
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* 128 is considered secure enough now. A mechanism |
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* can change it in a constructor. |
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* |
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* Remember to sync with "securerandom.drbg.config" in java.security. |
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*/ |
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protected static final int DEFAULT_STRENGTH = 128; |
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/** |
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* Mechanism name, say, {@code HashDRBG}. Must be set in constructor. |
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* This value will be used in {@code toString}. |
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*/ |
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protected String mechName = "DRBG"; |
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/** |
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* highest_supported_security_strength of this mechanism for all algorithms |
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* it supports. A mechanism should update the value in its constructor |
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* if the value is not 256. |
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*/ |
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protected int highestSupportedSecurityStrength = 256; |
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/** |
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* Whether prediction resistance is supported. A mechanism should update |
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* the value in its constructor if it is <em>not</em> supported. |
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*/ |
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protected boolean supportPredictionResistance = true; |
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/** |
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* Whether reseed is supported. A mechanism should update |
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* the value in its constructor if it is <em>not</em> supported. |
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*/ |
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protected boolean supportReseeding = true; |
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// Strength features. If not same as below, must be redefined in |
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// chooseAlgorithmAndStrength. Among these, minLength and seedLen have no |
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// default value and must be redefined. If personalization string or |
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// additional input is not supported, set maxPersonalizationStringLength |
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// or maxAdditionalInputLength to -1. |
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/** |
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* Minimum entropy input length in bytes for this DRBG instance. |
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* Must be assigned in {@link #chooseAlgorithmAndStrength}. |
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*/ |
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protected int minLength; |
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/** |
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* Maximum entropy input length in bytes for this DRBG instance. |
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* Should be assigned in {@link #chooseAlgorithmAndStrength} if it is not |
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* {@link Integer#MAX_VALUE}. |
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* <p> |
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* In theory this value (and the values below) can be bigger than |
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* {@code Integer.MAX_VALUE} but a Java array can only have an int32 index. |
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*/ |
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protected int maxLength = Integer.MAX_VALUE; |
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/** |
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* Maximum personalization string length in bytes for this DRBG instance. |
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* Should be assigned in {@link #chooseAlgorithmAndStrength} if it is not |
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* {@link Integer#MAX_VALUE}. |
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*/ |
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protected int maxPersonalizationStringLength = Integer.MAX_VALUE; |
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/** |
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* Maximum additional input length in bytes for this DRBG instance. |
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* Should be assigned in {@link #chooseAlgorithmAndStrength} if it is not |
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* {@link Integer#MAX_VALUE}. |
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*/ |
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protected int maxAdditionalInputLength = Integer.MAX_VALUE; |
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/** |
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* max_number_of_bits_per_request in bytes for this DRBG instance. |
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* Should be assigned in {@link #chooseAlgorithmAndStrength} if it is not |
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* {@link Integer#MAX_VALUE}. |
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*/ |
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protected int maxNumberOfBytesPerRequest = Integer.MAX_VALUE; |
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/** |
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* Maximum number of requests between reseeds for this DRBG instance. |
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* Should be assigned in {@link #chooseAlgorithmAndStrength} if it is not |
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* {@link Integer#MAX_VALUE}. |
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*/ |
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protected int reseedInterval = Integer.MAX_VALUE; |
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/** |
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* Algorithm used by this instance (SHA-512 or AES-256). Must be assigned |
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* in {@link #chooseAlgorithmAndStrength}. This field is used in |
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* {@link #toString()}. |
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*/ |
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protected String algorithm; |
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// Configurable parameters |
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/** |
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* Security strength for this instance. Must be assigned in |
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* {@link #chooseAlgorithmAndStrength}. Should be at least the requested |
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* strength. Might be smaller than the highest strength |
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* {@link #algorithm} supports. Must not be -1. |
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*/ |
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protected int securityStrength; // in bits |
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/** |
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* Strength requested in {@link DrbgParameters.Instantiation}. |
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* The real strength is based on it. Do not modify it in a mechanism. |
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*/ |
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protected int requestedInstantiationSecurityStrength = -1; |
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/** |
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* The personalization string used by this instance. Set inside |
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* {@link #configure(SecureRandomParameters)} and |
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* can be used in a mechanism. Do not modify it in a mechanism. |
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*/ |
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protected byte[] personalizationString; |
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/** |
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* The prediction resistance flag used by this instance. Set inside |
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* {@link #configure(SecureRandomParameters)}. |
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*/ |
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private boolean predictionResistanceFlag; |
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// Non-standard configurable parameters |
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/** |
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* Whether a derivation function is used. Requested in |
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* {@link MoreDrbgParameters}. Only CtrDRBG uses it. |
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* Do not modify it in a mechanism. |
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*/ |
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protected boolean usedf; |
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/** |
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* The nonce for this instance. Set in {@link #instantiateIfNecessary}. |
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* After instantiation, this field is not null. Do not modify it |
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* in a mechanism. |
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*/ |
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protected byte[] nonce; |
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/** |
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* Requested nonce in {@link MoreDrbgParameters}. If set to null, |
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* nonce will be chosen by system, and a reinstantiated DRBG will get a |
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* new system-provided nonce. |
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*/ |
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private byte[] requestedNonce; |
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/** |
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* Requested algorithm in {@link MoreDrbgParameters}. |
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* Do not modify it in a mechanism. |
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*/ |
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protected String requestedAlgorithm; |
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/** |
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* The entropy source used by this instance. Set inside |
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* {@link #configure(SecureRandomParameters)}. This field |
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* can be null. {@link #getEntropyInput} will take care of null check. |
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*/ |
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private EntropySource es; |
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// Five abstract methods for SP 800-90A DRBG |
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/** |
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* Decides what algorithm and strength to use (SHA-256 or AES-256, |
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* 128 or 256). Strength related fields must also be defined or redefined |
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* here. Called in {@link #configure}. A mechanism uses |
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* {@link #requestedAlgorithm}, |
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* {@link #requestedInstantiationSecurityStrength}, and |
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* {@link #DEFAULT_STRENGTH} to decide which algorithm and strength to use. |
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* <p> |
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* If {@code requestedAlgorithm} is provided, it will always be used. |
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* If {@code requestedInstantiationSecurityStrength} is also provided, |
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* the algorithm will use the strength (an exception will be thrown if |
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* the strength is not supported), otherwise, the smaller one of |
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* the highest supported strength of the algorithm and the default strength |
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* will be used. |
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* <p> |
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* If {@code requestedAlgorithm} is not provided, an algorithm will be |
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* chosen that supports {@code requestedInstantiationSecurityStrength} |
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* (or {@code DEFAULT_STRENGTH} if there is no request). |
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* <p> |
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* Since every call to {@link #configure} will call this method, |
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* make sure to the calls do not contradict with each other. |
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* <p> |
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* Here are some examples of the algorithm and strength chosen (suppose |
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* {@code DEFAULT_STRENGTH} is 128) for HashDRBG: |
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* <pre> |
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* requested effective |
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cd841af7dcd0
8156213: Remove SHA-1 and 3KeyTDEA algorithms from DRBG
weijun
parents:
37895
diff
changeset
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* (SHA-224, 256) IAE |
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* (SHA-256, -1) (SHA-256,128) |
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parents:
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diff
changeset
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* (SHA-256, 112) (SHA-256,112) |
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* (SHA-256, 128) (SHA-256,128) |
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* (SHA-3, -1) IAE |
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* (null, -1) (SHA-256,128) |
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* (null, 112) (SHA-256,112) |
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* (null, 192) (SHA-256,192) |
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* (null, 256) (SHA-256,256) |
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* (null, 384) IAE |
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* </pre> |
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* |
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* @throws IllegalArgumentException if the requested parameters |
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* can not be supported or contradict with each other. |
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*/ |
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protected abstract void chooseAlgorithmAndStrength(); |
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/** |
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* Initiates security engines ({@code MessageDigest}, {@code Mac}, |
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* or {@code Cipher}). This method is called during instantiation. |
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*/ |
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protected abstract void initEngine(); |
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/** |
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* Instantiates a DRBG. Called automatically before the first |
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* {@code nextBytes} call. |
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* <p> |
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* Note that the other parameters (nonce, strength, ps) are already |
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* stored inside at configuration. |
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* |
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* @param ei the entropy input, its length is already conditioned to be |
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* between {@link #minLength} and {@link #maxLength}. |
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*/ |
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protected abstract void instantiateAlgorithm(byte[] ei); |
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/** |
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* The generate function. |
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* |
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* @param result fill result here, not null |
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* @param additionalInput additional input, can be null. If not null, |
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* its length is smaller than {@link #maxAdditionalInputLength} |
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*/ |
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protected abstract void generateAlgorithm( |
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byte[] result, byte[] additionalInput); |
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/** |
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* The reseed function. |
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* |
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* @param ei the entropy input, its length is already conditioned to be |
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* between {@link #minLength} and {@link #maxLength}. |
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* @param additionalInput additional input, can be null. If not null, |
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* its length is smaller than {@link #maxAdditionalInputLength} |
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* @throws UnsupportedOperationException if reseed is not supported |
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*/ |
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protected void reseedAlgorithm( |
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byte[] ei, byte[] additionalInput) { |
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throw new UnsupportedOperationException("No reseed function"); |
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} |
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// SecureRandomSpi methods taken care of here. All final. |
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protected final void engineNextBytes(byte[] result) { |
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engineNextBytes(result, DrbgParameters.nextBytes( |
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-1, predictionResistanceFlag, null)); |
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} |
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protected final void engineNextBytes( |
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byte[] result, SecureRandomParameters params) { |
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Objects.requireNonNull(result); |
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if (debug != null) { |
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debug.println(this, "nextBytes"); |
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} |
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if (params instanceof DrbgParameters.NextBytes) { |
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// 800-90Ar1 9.3: Generate Process. |
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DrbgParameters.NextBytes dp = (DrbgParameters.NextBytes) params; |
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// Step 2: max_number_of_bits_per_request |
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if (result.length > maxNumberOfBytesPerRequest) { |
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// generateAlgorithm should be called multiple times to fill |
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// up result. Unimplemented since maxNumberOfBytesPerRequest |
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// is now Integer.MAX_VALUE. |
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} |
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// Step 3: check requested_security_strength |
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if (dp.getStrength() > securityStrength) { |
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throw new IllegalArgumentException("strength too high: " |
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+ dp.getStrength()); |
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} |
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364 |
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// Step 4: check max_additional_input_length |
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byte[] ai = dp.getAdditionalInput(); |
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367 |
if (ai != null && ai.length > maxAdditionalInputLength) { |
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throw new IllegalArgumentException("ai too long: " |
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+ ai.length); |
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370 |
} |
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371 |
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372 |
// Step 5: check prediction_resistance_flag |
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boolean pr = dp.getPredictionResistance(); |
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374 |
if (!predictionResistanceFlag && pr) { |
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375 |
throw new IllegalArgumentException("pr not available"); |
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376 |
} |
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377 |
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378 |
instantiateIfNecessary(null); |
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379 |
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39481
63ceb7ef04d4
8158589: Possible integer overflow issues for DRBG
weijun
parents:
38853
diff
changeset
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380 |
// Step 7: Auto reseed (reseedCounter might overflow) |
37895 | 381 |
// Double checked locking, safe because reseedCounter is volatile |
39481
63ceb7ef04d4
8158589: Possible integer overflow issues for DRBG
weijun
parents:
38853
diff
changeset
|
382 |
if (reseedCounter < 0 || reseedCounter > reseedInterval || pr) { |
37895 | 383 |
synchronized (this) { |
39481
63ceb7ef04d4
8158589: Possible integer overflow issues for DRBG
weijun
parents:
38853
diff
changeset
|
384 |
if (reseedCounter < 0 || reseedCounter > reseedInterval |
63ceb7ef04d4
8158589: Possible integer overflow issues for DRBG
weijun
parents:
38853
diff
changeset
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385 |
|| pr) { |
37895 | 386 |
reseedAlgorithm(getEntropyInput(pr), ai); |
387 |
ai = null; |
|
388 |
} |
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389 |
} |
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37796 | 390 |
} |
391 |
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392 |
// Step 8, 10: Generate_algorithm |
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393 |
// Step 9: Unnecessary. reseedCounter only updated after generation |
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394 |
generateAlgorithm(result, ai); |
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395 |
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396 |
// Step 11: Return |
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397 |
} else { |
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398 |
throw new IllegalArgumentException("unknown params type:" |
|
399 |
+ params.getClass()); |
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400 |
} |
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401 |
} |
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402 |
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403 |
public final void engineReseed(SecureRandomParameters params) { |
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404 |
if (debug != null) { |
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405 |
debug.println(this, "reseed with params"); |
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406 |
} |
|
407 |
if (!supportReseeding) { |
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408 |
throw new UnsupportedOperationException("Reseed not supported"); |
|
409 |
} |
|
410 |
if (params == null) { |
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411 |
params = DrbgParameters.reseed(predictionResistanceFlag, null); |
|
412 |
} |
|
413 |
if (params instanceof DrbgParameters.Reseed) { |
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414 |
DrbgParameters.Reseed dp = (DrbgParameters.Reseed) params; |
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415 |
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416 |
// 800-90Ar1 9.2: Reseed Process. |
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417 |
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418 |
// Step 2: Check prediction_resistance_request |
|
419 |
boolean pr = dp.getPredictionResistance(); |
|
420 |
if (!predictionResistanceFlag && pr) { |
|
421 |
throw new IllegalArgumentException("pr not available"); |
|
422 |
} |
|
423 |
||
424 |
// Step 3: Check additional_input length |
|
425 |
byte[] ai = dp.getAdditionalInput(); |
|
426 |
if (ai != null && ai.length > maxAdditionalInputLength) { |
|
427 |
throw new IllegalArgumentException("ai too long: " |
|
428 |
+ ai.length); |
|
429 |
} |
|
430 |
instantiateIfNecessary(null); |
|
431 |
||
432 |
// Step 4: Get_entropy_input |
|
433 |
// Step 5: Check step 4 |
|
434 |
// Step 6-7: Reseed_algorithm |
|
435 |
reseedAlgorithm(getEntropyInput(pr), ai); |
|
436 |
||
437 |
// Step 8: Return |
|
438 |
} else { |
|
439 |
throw new IllegalArgumentException("unknown params type: " |
|
440 |
+ params.getClass()); |
|
441 |
} |
|
442 |
} |
|
443 |
||
444 |
/** |
|
445 |
* Returns the given number of seed bytes. A DRBG always uses |
|
446 |
* {@link SeedGenerator} to get an array with full-entropy. |
|
447 |
* <p> |
|
448 |
* The implementation is identical to SHA1PRNG's |
|
449 |
* {@link SecureRandom#engineGenerateSeed}. |
|
450 |
* |
|
451 |
* @param numBytes the number of seed bytes to generate. |
|
452 |
* @return the seed bytes. |
|
453 |
*/ |
|
454 |
public final byte[] engineGenerateSeed(int numBytes) { |
|
455 |
byte[] b = new byte[numBytes]; |
|
456 |
SeedGenerator.generateSeed(b); |
|
457 |
return b; |
|
458 |
} |
|
459 |
||
460 |
/** |
|
461 |
* Reseeds this random object with the given seed. A DRBG always expands |
|
462 |
* or truncates the input to be between {@link #minLength} and |
|
463 |
* {@link #maxLength} and uses it to instantiate or reseed itself |
|
464 |
* (depending on whether the DRBG is instantiated). |
|
465 |
* |
|
466 |
* @param input the seed |
|
467 |
*/ |
|
468 |
public final synchronized void engineSetSeed(byte[] input) { |
|
469 |
if (debug != null) { |
|
470 |
debug.println(this, "setSeed"); |
|
471 |
} |
|
472 |
if (input.length < minLength) { |
|
473 |
input = Arrays.copyOf(input, minLength); |
|
474 |
} else if (input.length > maxLength) { |
|
475 |
input = Arrays.copyOf(input, maxLength); |
|
476 |
} |
|
477 |
if (!instantiated) { |
|
478 |
instantiateIfNecessary(input); |
|
479 |
} else { |
|
480 |
reseedAlgorithm(input, null); |
|
481 |
} |
|
482 |
} |
|
483 |
||
484 |
// get_entropy_input |
|
485 |
||
486 |
private byte[] getEntropyInput(boolean isPr) { |
|
487 |
// Should the 1st arg be minEntropy or minLength? |
|
488 |
// |
|
489 |
// Technically it should be minEntropy, but CtrDRBG |
|
490 |
// (not using derivation function) is so confusing |
|
491 |
// (does it need only strength or seedlen of entropy?) |
|
492 |
// that it's safer to assume minLength. In all other |
|
493 |
// cases minLength equals to minEntropy. |
|
494 |
return getEntropyInput(minLength, minLength, maxLength, isPr); |
|
495 |
} |
|
496 |
||
497 |
private byte[] getEntropyInput(int minEntropy, int minLength, |
|
498 |
int maxLength, boolean pr) { |
|
499 |
if (debug != null) { |
|
500 |
debug.println(this, "getEntropy(" + minEntropy + "," + minLength + |
|
501 |
"," + maxLength + "," + pr + ")"); |
|
502 |
} |
|
503 |
EntropySource esNow = es; |
|
504 |
if (esNow == null) { |
|
505 |
esNow = pr ? SeederHolder.prseeder : SeederHolder.seeder; |
|
506 |
} |
|
507 |
return esNow.getEntropy(minEntropy, minLength, maxLength, pr); |
|
508 |
} |
|
509 |
||
510 |
// Defaults |
|
511 |
||
512 |
/** |
|
513 |
* The default {@code EntropySource} determined by system property |
|
514 |
* "java.security.egd" or security property "securerandom.source". |
|
515 |
* <p> |
|
516 |
* This object uses {@link SeedGenerator#generateSeed(byte[])} to |
|
517 |
* return a byte array containing {@code minLength} bytes. It is |
|
518 |
* assumed to support prediction resistance and always contains |
|
519 |
* full-entropy. A trusted application can update this field. |
|
520 |
*/ |
|
521 |
private final static EntropySource defaultES = |
|
522 |
(minE, minLen, maxLen, pr) -> { |
|
523 |
byte[] result = new byte[minLen]; |
|
524 |
SeedGenerator.generateSeed(result); |
|
525 |
return result; |
|
526 |
}; |
|
527 |
||
528 |
private static class SeederHolder { |
|
529 |
||
530 |
/** |
|
531 |
* Default EntropySource for SecureRandom with prediction resistance, |
|
532 |
*/ |
|
533 |
static final EntropySource prseeder; |
|
534 |
||
535 |
/** |
|
536 |
* Default EntropySource for SecureRandom without prediction resistance, |
|
537 |
* which is backed by a DRBG whose EntropySource is {@link #prseeder}. |
|
538 |
*/ |
|
539 |
static final EntropySource seeder; |
|
540 |
||
541 |
static { |
|
542 |
prseeder = defaultES; |
|
543 |
// According to SP800-90C section 7, a DRBG without live |
|
544 |
// entropy (drbg here, with pr being false) can instantiate |
|
545 |
// another DRBG with weaker strength. So we choose highest |
|
546 |
// strength we support. |
|
547 |
HashDrbg first = new HashDrbg(new MoreDrbgParameters( |
|
548 |
prseeder, null, "SHA-256", null, false, |
|
549 |
DrbgParameters.instantiation( |
|
550 |
256, NONE, |
|
551 |
SeedGenerator.getSystemEntropy()))); |
|
552 |
seeder = (entropy, minLen, maxLen, pr) -> { |
|
553 |
if (pr) { |
|
554 |
// This SEI does not support pr |
|
555 |
throw new IllegalArgumentException("pr not supported"); |
|
556 |
} |
|
557 |
byte[] result = new byte[minLen]; |
|
558 |
first.engineNextBytes(result); |
|
559 |
return result; |
|
560 |
}; |
|
561 |
} |
|
562 |
} |
|
563 |
||
564 |
// Constructor called by overridden methods, initializer... |
|
565 |
||
566 |
/** |
|
567 |
* A constructor without argument so that an implementation does not |
|
568 |
* need to always write {@code super(params)}. |
|
569 |
*/ |
|
570 |
protected AbstractDrbg() { |
|
571 |
// Nothing |
|
572 |
} |
|
573 |
||
574 |
/** |
|
575 |
* A mechanism shall override this constructor to setup {@link #mechName}, |
|
576 |
* {@link #highestSupportedSecurityStrength}, |
|
577 |
* {@link #supportPredictionResistance}, {@link #supportReseeding} |
|
578 |
* or other features like {@link #DEFAULT_STRENGTH}. Finally it shall |
|
579 |
* call {@link #configure} on {@code params}. |
|
580 |
* |
|
581 |
* @param params the {@link SecureRandomParameters} object. |
|
582 |
* This argument can be {@code null}. |
|
583 |
* @throws IllegalArgumentException if {@code params} is |
|
584 |
* inappropriate for this SecureRandom. |
|
585 |
*/ |
|
586 |
protected AbstractDrbg(SecureRandomParameters params) { |
|
587 |
// Nothing |
|
588 |
} |
|
589 |
||
590 |
/** |
|
591 |
* Returns the current configuration as a {@link DrbgParameters.Instantiation} |
|
592 |
* object. |
|
593 |
* |
|
594 |
* @return the curent configuration |
|
595 |
*/ |
|
596 |
protected SecureRandomParameters engineGetParameters() { |
|
597 |
// Or read from variable. |
|
598 |
return DrbgParameters.instantiation( |
|
599 |
securityStrength, |
|
600 |
predictionResistanceFlag ? PR_AND_RESEED : |
|
601 |
(supportReseeding ? RESEED_ONLY : NONE), |
|
602 |
personalizationString); |
|
603 |
} |
|
604 |
||
605 |
/** |
|
606 |
* Configure this DRBG. This method calls |
|
607 |
* {@link #chooseAlgorithmAndStrength()} and {@link #initEngine()} |
|
608 |
* but does not do the actual instantiation. |
|
609 |
* |
|
610 |
* @param params configuration, if null, default configuration (default |
|
611 |
* strength, pr_false, no personalization string) is used. |
|
612 |
* @throws IllegalArgumentException if {@code params} is |
|
613 |
* inappropriate for this SecureRandom. |
|
614 |
*/ |
|
37895 | 615 |
protected final void configure(SecureRandomParameters params) { |
37796 | 616 |
if (debug != null) { |
617 |
debug.println(this, "configure " + this + " with " + params); |
|
618 |
} |
|
619 |
if (params == null) { |
|
620 |
params = DrbgParameters.instantiation(-1, RESEED_ONLY, null); |
|
621 |
} |
|
622 |
if (params instanceof MoreDrbgParameters) { |
|
623 |
MoreDrbgParameters m = (MoreDrbgParameters)params; |
|
624 |
this.requestedNonce = m.nonce; |
|
625 |
this.es = m.es; |
|
626 |
this.requestedAlgorithm = m.algorithm; |
|
627 |
this.usedf = m.usedf; |
|
38853 | 628 |
params = DrbgParameters.instantiation(m.strength, |
629 |
m.capability, m.personalizationString); |
|
37796 | 630 |
} |
631 |
if (params != null) { |
|
632 |
if (params instanceof DrbgParameters.Instantiation) { |
|
633 |
DrbgParameters.Instantiation inst = |
|
634 |
(DrbgParameters.Instantiation) params; |
|
635 |
||
636 |
// 800-90Ar1 9.1: Instantiate Process. Steps 1-5. |
|
637 |
||
638 |
// Step 1: Check requested_instantiation_security_strength |
|
639 |
if (inst.getStrength() > highestSupportedSecurityStrength) { |
|
640 |
throw new IllegalArgumentException("strength too big: " |
|
641 |
+ inst.getStrength()); |
|
642 |
} |
|
643 |
||
644 |
// Step 2: Check prediction_resistance_flag |
|
645 |
if (inst.getCapability().supportsPredictionResistance() |
|
646 |
&& !supportPredictionResistance) { |
|
647 |
throw new IllegalArgumentException("pr not supported"); |
|
648 |
} |
|
649 |
||
650 |
// Step 3: Check personalization_string |
|
651 |
byte[] ps = inst.getPersonalizationString(); |
|
652 |
if (ps != null && ps.length > maxPersonalizationStringLength) { |
|
653 |
throw new IllegalArgumentException("ps too long: " |
|
654 |
+ ps.length); |
|
655 |
} |
|
656 |
||
657 |
if (inst.getCapability().supportsReseeding() |
|
658 |
&& !supportReseeding) { |
|
659 |
throw new IllegalArgumentException("reseed not supported"); |
|
660 |
} |
|
661 |
this.personalizationString = ps; |
|
662 |
this.predictionResistanceFlag = |
|
663 |
inst.getCapability().supportsPredictionResistance(); |
|
664 |
this.requestedInstantiationSecurityStrength = inst.getStrength(); |
|
665 |
} else { |
|
666 |
throw new IllegalArgumentException("unknown params: " |
|
667 |
+ params.getClass()); |
|
668 |
} |
|
669 |
} |
|
670 |
||
671 |
// Step 4: Set security_strength |
|
672 |
chooseAlgorithmAndStrength(); |
|
673 |
instantiated = false; |
|
674 |
||
675 |
// Step 5: no-op. |
|
676 |
||
677 |
if (debug != null) { |
|
678 |
debug.println(this, "configured " + this); |
|
679 |
} |
|
680 |
} |
|
681 |
||
682 |
/** |
|
683 |
* Instantiate if necessary, |
|
684 |
* |
|
685 |
* @param entropy a user-provided entropy, the length is already good. |
|
686 |
* If null, will fetch entropy input automatically. |
|
687 |
*/ |
|
688 |
private synchronized void instantiateIfNecessary(byte[] entropy) { |
|
689 |
if (!instantiated) { |
|
690 |
||
691 |
// 800-90Ar1 9.1: Instantiate Process. Steps 6-12. |
|
692 |
||
693 |
// Step 6: Get_entropy_input |
|
694 |
// Step 7: check error (getEntropyInput throw no exception now) |
|
695 |
if (entropy == null) { |
|
696 |
entropy = getEntropyInput(predictionResistanceFlag); |
|
697 |
} |
|
698 |
||
699 |
// Step 8. nonce |
|
700 |
if (requestedNonce != null) { |
|
701 |
nonce = requestedNonce; |
|
702 |
} else { |
|
703 |
nonce = NonceProvider.next(); |
|
704 |
} |
|
705 |
initEngine(); |
|
706 |
||
707 |
// Step 9-11: Instantiate_algorithm |
|
708 |
instantiateAlgorithm(entropy); |
|
709 |
instantiated = true; |
|
710 |
||
711 |
// Step 12: Return |
|
712 |
} |
|
713 |
} |
|
714 |
||
715 |
// Nonce provider |
|
716 |
||
717 |
private static class NonceProvider { |
|
718 |
||
719 |
// 128 bits of nonce can be used by 256-bit strength DRBG |
|
720 |
private static final byte[] block = new byte[16]; |
|
721 |
||
722 |
private static synchronized byte[] next() { |
|
723 |
int k = 15; |
|
724 |
while ((k >= 0) && (++block[k] == 0)) { |
|
725 |
k--; |
|
726 |
} |
|
727 |
return block.clone(); |
|
728 |
} |
|
729 |
} |
|
730 |
||
731 |
// Misc |
|
732 |
||
733 |
/** A handy method returning hexdump string with no colon or new line. |
|
734 |
* |
|
735 |
* @param in input byte array |
|
736 |
* @return the hexdump string |
|
737 |
*/ |
|
738 |
protected static String hex(byte[] in) { |
|
739 |
StringBuilder sb = new StringBuilder(); |
|
740 |
for (byte b : in) { |
|
741 |
sb.append(String.format("%02x", b&0xff)); |
|
742 |
} |
|
743 |
return sb.toString(); |
|
744 |
} |
|
745 |
||
746 |
/** |
|
747 |
* Returns the smallest standard strength (112, 128, 192, 256) that is |
|
748 |
* greater or equal to the input. |
|
749 |
* |
|
750 |
* @param input the input strength |
|
751 |
* @return the standard strength |
|
752 |
*/ |
|
753 |
protected static int getStandardStrength(int input) { |
|
754 |
if (input <= 112) return 112; |
|
755 |
if (input <= 128) return 128; |
|
756 |
if (input <= 192) return 192; |
|
757 |
if (input <= 256) return 256; |
|
758 |
throw new IllegalArgumentException("input too big: " + input); |
|
759 |
} |
|
760 |
||
761 |
@Override |
|
762 |
public String toString() { |
|
763 |
return mechName + "," + algorithm |
|
764 |
+ "," + securityStrength + "," |
|
765 |
+ (predictionResistanceFlag ? "pr_and_reseed" |
|
766 |
: (supportReseeding ? "reseed_only" : "none")); |
|
767 |
} |
|
768 |
} |