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Diffstat (limited to 'bcprov/src/main/java/org/bouncycastle/crypto/agreement/jpake/JPAKEParticipant.java')
| -rw-r--r-- | bcprov/src/main/java/org/bouncycastle/crypto/agreement/jpake/JPAKEParticipant.java | 547 |
1 files changed, 0 insertions, 547 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/crypto/agreement/jpake/JPAKEParticipant.java b/bcprov/src/main/java/org/bouncycastle/crypto/agreement/jpake/JPAKEParticipant.java deleted file mode 100644 index 3fcb2df..0000000 --- a/bcprov/src/main/java/org/bouncycastle/crypto/agreement/jpake/JPAKEParticipant.java +++ /dev/null @@ -1,547 +0,0 @@ -package org.bouncycastle.crypto.agreement.jpake; - -import java.math.BigInteger; -import java.security.SecureRandom; - -import org.bouncycastle.crypto.CryptoException; -import org.bouncycastle.crypto.Digest; -import org.bouncycastle.crypto.digests.SHA256Digest; -import org.bouncycastle.util.Arrays; - -/** - * A participant in a Password Authenticated Key Exchange by Juggling (J-PAKE) exchange. - * <p> - * The J-PAKE exchange is defined by Feng Hao and Peter Ryan in the paper - * <a href="http://grouper.ieee.org/groups/1363/Research/contributions/hao-ryan-2008.pdf"> - * "Password Authenticated Key Exchange by Juggling, 2008."</a> - * <p> - * The J-PAKE protocol is symmetric. - * There is no notion of a <i>client</i> or <i>server</i>, but rather just two <i>participants</i>. - * An instance of {@link JPAKEParticipant} represents one participant, and - * is the primary interface for executing the exchange. - * <p> - * To execute an exchange, construct a {@link JPAKEParticipant} on each end, - * and call the following 7 methods - * (once and only once, in the given order, for each participant, sending messages between them as described): - * <ol> - * <li>{@link #createRound1PayloadToSend()} - and send the payload to the other participant</li> - * <li>{@link #validateRound1PayloadReceived(JPAKERound1Payload)} - use the payload received from the other participant</li> - * <li>{@link #createRound2PayloadToSend()} - and send the payload to the other participant</li> - * <li>{@link #validateRound2PayloadReceived(JPAKERound2Payload)} - use the payload received from the other participant</li> - * <li>{@link #calculateKeyingMaterial()}</li> - * <li>{@link #createRound3PayloadToSend(BigInteger)} - and send the payload to the other participant</li> - * <li>{@link #validateRound3PayloadReceived(JPAKERound3Payload, BigInteger)} - use the payload received from the other participant</li> - * </ol> - * <p> - * Each side should derive a session key from the keying material returned by {@link #calculateKeyingMaterial()}. - * The caller is responsible for deriving the session key using a secure key derivation function (KDF). - * <p> - * Round 3 is an optional key confirmation process. - * If you do not execute round 3, then there is no assurance that both participants are using the same key. - * (i.e. if the participants used different passwords, then their session keys will differ.) - * <p> - * If the round 3 validation succeeds, then the keys are guaranteed to be the same on both sides. - * <p> - * The symmetric design can easily support the asymmetric cases when one party initiates the communication. - * e.g. Sometimes the round1 payload and round2 payload may be sent in one pass. - * Also, in some cases, the key confirmation payload can be sent together with the round2 payload. - * These are the trivial techniques to optimize the communication. - * <p> - * The key confirmation process is implemented as specified in - * <a href="http://csrc.nist.gov/publications/nistpubs/800-56A/SP800-56A_Revision1_Mar08-2007.pdf">NIST SP 800-56A Revision 1</a>, - * Section 8.2 Unilateral Key Confirmation for Key Agreement Schemes. - * <p> - * This class is stateful and NOT threadsafe. - * Each instance should only be used for ONE complete J-PAKE exchange - * (i.e. a new {@link JPAKEParticipant} should be constructed for each new J-PAKE exchange). - * <p> - * See {@link JPAKEExample} for example usage. - */ -public class JPAKEParticipant -{ - /* - * Possible internal states. Used for state checking. - */ - - public static final int STATE_INITIALIZED = 0; - public static final int STATE_ROUND_1_CREATED = 10; - public static final int STATE_ROUND_1_VALIDATED = 20; - public static final int STATE_ROUND_2_CREATED = 30; - public static final int STATE_ROUND_2_VALIDATED = 40; - public static final int STATE_KEY_CALCULATED = 50; - public static final int STATE_ROUND_3_CREATED = 60; - public static final int STATE_ROUND_3_VALIDATED = 70; - - /** - * Unique identifier of this participant. - * The two participants in the exchange must NOT share the same id. - */ - private final String participantId; - - /** - * Shared secret. This only contains the secret between construction - * and the call to {@link #calculateKeyingMaterial()}. - * <p> - * i.e. When {@link #calculateKeyingMaterial()} is called, this buffer overwritten with 0's, - * and the field is set to null. - * </p> - */ - private char[] password; - - /** - * Digest to use during calculations. - */ - private final Digest digest; - - /** - * Source of secure random data. - */ - private final SecureRandom random; - - private final BigInteger p; - private final BigInteger q; - private final BigInteger g; - - /** - * The participantId of the other participant in this exchange. - */ - private String partnerParticipantId; - - /** - * Alice's x1 or Bob's x3. - */ - private BigInteger x1; - /** - * Alice's x2 or Bob's x4. - */ - private BigInteger x2; - /** - * Alice's g^x1 or Bob's g^x3. - */ - private BigInteger gx1; - /** - * Alice's g^x2 or Bob's g^x4. - */ - private BigInteger gx2; - /** - * Alice's g^x3 or Bob's g^x1. - */ - private BigInteger gx3; - /** - * Alice's g^x4 or Bob's g^x2. - */ - private BigInteger gx4; - /** - * Alice's B or Bob's A. - */ - private BigInteger b; - - /** - * The current state. - * See the <tt>STATE_*</tt> constants for possible values. - */ - private int state; - - /** - * Convenience constructor for a new {@link JPAKEParticipant} that uses - * the {@link JPAKEPrimeOrderGroups#NIST_3072} prime order group, - * a SHA-256 digest, and a default {@link SecureRandom} implementation. - * <p> - * After construction, the {@link #getState() state} will be {@link #STATE_INITIALIZED}. - * - * @param participantId unique identifier of this participant. - * The two participants in the exchange must NOT share the same id. - * @param password shared secret. - * A defensive copy of this array is made (and cleared once {@link #calculateKeyingMaterial()} is called). - * Caller should clear the input password as soon as possible. - * @throws NullPointerException if any argument is null - * @throws IllegalArgumentException if password is empty - */ - public JPAKEParticipant( - String participantId, - char[] password) - { - this( - participantId, - password, - JPAKEPrimeOrderGroups.NIST_3072); - } - - - /** - * Convenience constructor for a new {@link JPAKEParticipant} that uses - * a SHA-256 digest and a default {@link SecureRandom} implementation. - * <p> - * After construction, the {@link #getState() state} will be {@link #STATE_INITIALIZED}. - * - * @param participantId unique identifier of this participant. - * The two participants in the exchange must NOT share the same id. - * @param password shared secret. - * A defensive copy of this array is made (and cleared once {@link #calculateKeyingMaterial()} is called). - * Caller should clear the input password as soon as possible. - * @param group prime order group. - * See {@link JPAKEPrimeOrderGroups} for standard groups - * @throws NullPointerException if any argument is null - * @throws IllegalArgumentException if password is empty - */ - public JPAKEParticipant( - String participantId, - char[] password, - JPAKEPrimeOrderGroup group) - { - this( - participantId, - password, - group, - new SHA256Digest(), - new SecureRandom()); - } - - - /** - * Construct a new {@link JPAKEParticipant}. - * <p> - * After construction, the {@link #getState() state} will be {@link #STATE_INITIALIZED}. - * - * @param participantId unique identifier of this participant. - * The two participants in the exchange must NOT share the same id. - * @param password shared secret. - * A defensive copy of this array is made (and cleared once {@link #calculateKeyingMaterial()} is called). - * Caller should clear the input password as soon as possible. - * @param group prime order group. - * See {@link JPAKEPrimeOrderGroups} for standard groups - * @param digest digest to use during zero knowledge proofs and key confirmation (SHA-256 or stronger preferred) - * @param random source of secure random data for x1 and x2, and for the zero knowledge proofs - * @throws NullPointerException if any argument is null - * @throws IllegalArgumentException if password is empty - */ - public JPAKEParticipant( - String participantId, - char[] password, - JPAKEPrimeOrderGroup group, - Digest digest, - SecureRandom random) - { - JPAKEUtil.validateNotNull(participantId, "participantId"); - JPAKEUtil.validateNotNull(password, "password"); - JPAKEUtil.validateNotNull(group, "p"); - JPAKEUtil.validateNotNull(digest, "digest"); - JPAKEUtil.validateNotNull(random, "random"); - if (password.length == 0) - { - throw new IllegalArgumentException("Password must not be empty."); - } - - this.participantId = participantId; - - /* - * Create a defensive copy so as to fully encapsulate the password. - * - * This array will contain the password for the lifetime of this - * participant BEFORE {@link #calculateKeyingMaterial()} is called. - * - * i.e. When {@link #calculateKeyingMaterial()} is called, the array will be cleared - * in order to remove the password from memory. - * - * The caller is responsible for clearing the original password array - * given as input to this constructor. - */ - this.password = Arrays.copyOf(password, password.length); - - this.p = group.getP(); - this.q = group.getQ(); - this.g = group.getG(); - - this.digest = digest; - this.random = random; - - this.state = STATE_INITIALIZED; - } - - /** - * Gets the current state of this participant. - * See the <tt>STATE_*</tt> constants for possible values. - */ - public int getState() - { - return this.state; - } - - /** - * Creates and returns the payload to send to the other participant during round 1. - * <p> - * After execution, the {@link #getState() state} will be {@link #STATE_ROUND_1_CREATED}. - */ - public JPAKERound1Payload createRound1PayloadToSend() - { - if (this.state >= STATE_ROUND_1_CREATED) - { - throw new IllegalStateException("Round1 payload already created for " + participantId); - } - - this.x1 = JPAKEUtil.generateX1(q, random); - this.x2 = JPAKEUtil.generateX2(q, random); - - this.gx1 = JPAKEUtil.calculateGx(p, g, x1); - this.gx2 = JPAKEUtil.calculateGx(p, g, x2); - BigInteger[] knowledgeProofForX1 = JPAKEUtil.calculateZeroKnowledgeProof(p, q, g, gx1, x1, participantId, digest, random); - BigInteger[] knowledgeProofForX2 = JPAKEUtil.calculateZeroKnowledgeProof(p, q, g, gx2, x2, participantId, digest, random); - - this.state = STATE_ROUND_1_CREATED; - - return new JPAKERound1Payload(participantId, gx1, gx2, knowledgeProofForX1, knowledgeProofForX2); - } - - /** - * Validates the payload received from the other participant during round 1. - * <p> - * Must be called prior to {@link #createRound2PayloadToSend()}. - * <p> - * After execution, the {@link #getState() state} will be {@link #STATE_ROUND_1_VALIDATED}. - * - * @throws CryptoException if validation fails. - * @throws IllegalStateException if called multiple times. - */ - public void validateRound1PayloadReceived(JPAKERound1Payload round1PayloadReceived) - throws CryptoException - { - if (this.state >= STATE_ROUND_1_VALIDATED) - { - throw new IllegalStateException("Validation already attempted for round1 payload for" + participantId); - } - this.partnerParticipantId = round1PayloadReceived.getParticipantId(); - this.gx3 = round1PayloadReceived.getGx1(); - this.gx4 = round1PayloadReceived.getGx2(); - - BigInteger[] knowledgeProofForX3 = round1PayloadReceived.getKnowledgeProofForX1(); - BigInteger[] knowledgeProofForX4 = round1PayloadReceived.getKnowledgeProofForX2(); - - JPAKEUtil.validateParticipantIdsDiffer(participantId, round1PayloadReceived.getParticipantId()); - JPAKEUtil.validateGx4(gx4); - JPAKEUtil.validateZeroKnowledgeProof(p, q, g, gx3, knowledgeProofForX3, round1PayloadReceived.getParticipantId(), digest); - JPAKEUtil.validateZeroKnowledgeProof(p, q, g, gx4, knowledgeProofForX4, round1PayloadReceived.getParticipantId(), digest); - - this.state = STATE_ROUND_1_VALIDATED; - } - - /** - * Creates and returns the payload to send to the other participant during round 2. - * <p> - * {@link #validateRound1PayloadReceived(JPAKERound1Payload)} must be called prior to this method. - * <p> - * After execution, the {@link #getState() state} will be {@link #STATE_ROUND_2_CREATED}. - * - * @throws IllegalStateException if called prior to {@link #validateRound1PayloadReceived(JPAKERound1Payload)}, or multiple times - */ - public JPAKERound2Payload createRound2PayloadToSend() - { - if (this.state >= STATE_ROUND_2_CREATED) - { - throw new IllegalStateException("Round2 payload already created for " + this.participantId); - } - if (this.state < STATE_ROUND_1_VALIDATED) - { - throw new IllegalStateException("Round1 payload must be validated prior to creating Round2 payload for " + this.participantId); - } - BigInteger gA = JPAKEUtil.calculateGA(p, gx1, gx3, gx4); - BigInteger s = JPAKEUtil.calculateS(password); - BigInteger x2s = JPAKEUtil.calculateX2s(q, x2, s); - BigInteger A = JPAKEUtil.calculateA(p, q, gA, x2s); - BigInteger[] knowledgeProofForX2s = JPAKEUtil.calculateZeroKnowledgeProof(p, q, gA, A, x2s, participantId, digest, random); - - this.state = STATE_ROUND_2_CREATED; - - return new JPAKERound2Payload(participantId, A, knowledgeProofForX2s); - } - - /** - * Validates the payload received from the other participant during round 2. - * <p> - * Note that this DOES NOT detect a non-common password. - * The only indication of a non-common password is through derivation - * of different keys (which can be detected explicitly by executing round 3 and round 4) - * <p> - * Must be called prior to {@link #calculateKeyingMaterial()}. - * <p> - * After execution, the {@link #getState() state} will be {@link #STATE_ROUND_2_VALIDATED}. - * - * @throws CryptoException if validation fails. - * @throws IllegalStateException if called prior to {@link #validateRound1PayloadReceived(JPAKERound1Payload)}, or multiple times - */ - public void validateRound2PayloadReceived(JPAKERound2Payload round2PayloadReceived) - throws CryptoException - { - if (this.state >= STATE_ROUND_2_VALIDATED) - { - throw new IllegalStateException("Validation already attempted for round2 payload for" + participantId); - } - if (this.state < STATE_ROUND_1_VALIDATED) - { - throw new IllegalStateException("Round1 payload must be validated prior to validating Round2 payload for " + this.participantId); - } - BigInteger gB = JPAKEUtil.calculateGA(p, gx3, gx1, gx2); - this.b = round2PayloadReceived.getA(); - BigInteger[] knowledgeProofForX4s = round2PayloadReceived.getKnowledgeProofForX2s(); - - JPAKEUtil.validateParticipantIdsDiffer(participantId, round2PayloadReceived.getParticipantId()); - JPAKEUtil.validateParticipantIdsEqual(this.partnerParticipantId, round2PayloadReceived.getParticipantId()); - JPAKEUtil.validateGa(gB); - JPAKEUtil.validateZeroKnowledgeProof(p, q, gB, b, knowledgeProofForX4s, round2PayloadReceived.getParticipantId(), digest); - - this.state = STATE_ROUND_2_VALIDATED; - } - - /** - * Calculates and returns the key material. - * A session key must be derived from this key material using a secure key derivation function (KDF). - * The KDF used to derive the key is handled externally (i.e. not by {@link JPAKEParticipant}). - * <p> - * The keying material will be identical for each participant if and only if - * each participant's password is the same. i.e. If the participants do not - * share the same password, then each participant will derive a different key. - * Therefore, if you immediately start using a key derived from - * the keying material, then you must handle detection of incorrect keys. - * If you want to handle this detection explicitly, you can optionally perform - * rounds 3 and 4. See {@link JPAKEParticipant} for details on how to execute - * rounds 3 and 4. - * <p> - * The keying material will be in the range <tt>[0, p-1]</tt>. - * <p> - * {@link #validateRound2PayloadReceived(JPAKERound2Payload)} must be called prior to this method. - * <p> - * As a side effect, the internal {@link #password} array is cleared, since it is no longer needed. - * <p> - * After execution, the {@link #getState() state} will be {@link #STATE_KEY_CALCULATED}. - * - * @throws IllegalStateException if called prior to {@link #validateRound2PayloadReceived(JPAKERound2Payload)}, - * or if called multiple times. - */ - public BigInteger calculateKeyingMaterial() - { - if (this.state >= STATE_KEY_CALCULATED) - { - throw new IllegalStateException("Key already calculated for " + participantId); - } - if (this.state < STATE_ROUND_2_VALIDATED) - { - throw new IllegalStateException("Round2 payload must be validated prior to creating key for " + participantId); - } - BigInteger s = JPAKEUtil.calculateS(password); - - /* - * Clear the password array from memory, since we don't need it anymore. - * - * Also set the field to null as a flag to indicate that the key has already been calculated. - */ - Arrays.fill(password, (char)0); - this.password = null; - - BigInteger keyingMaterial = JPAKEUtil.calculateKeyingMaterial(p, q, gx4, x2, s, b); - - /* - * Clear the ephemeral private key fields as well. - * Note that we're relying on the garbage collector to do its job to clean these up. - * The old objects will hang around in memory until the garbage collector destroys them. - * - * If the ephemeral private keys x1 and x2 are leaked, - * the attacker might be able to brute-force the password. - */ - this.x1 = null; - this.x2 = null; - this.b = null; - - /* - * Do not clear gx* yet, since those are needed by round 3. - */ - - this.state = STATE_KEY_CALCULATED; - - return keyingMaterial; - } - - - /** - * Creates and returns the payload to send to the other participant during round 3. - * <p> - * See {@link JPAKEParticipant} for more details on round 3. - * <p> - * After execution, the {@link #getState() state} will be {@link #STATE_ROUND_3_CREATED}. - * - * @param keyingMaterial The keying material as returned from {@link #calculateKeyingMaterial()}. - * @throws IllegalStateException if called prior to {@link #calculateKeyingMaterial()}, or multiple times - */ - public JPAKERound3Payload createRound3PayloadToSend(BigInteger keyingMaterial) - { - if (this.state >= STATE_ROUND_3_CREATED) - { - throw new IllegalStateException("Round3 payload already created for " + this.participantId); - } - if (this.state < STATE_KEY_CALCULATED) - { - throw new IllegalStateException("Keying material must be calculated prior to creating Round3 payload for " + this.participantId); - } - - BigInteger macTag = JPAKEUtil.calculateMacTag( - this.participantId, - this.partnerParticipantId, - this.gx1, - this.gx2, - this.gx3, - this.gx4, - keyingMaterial, - this.digest); - - this.state = STATE_ROUND_3_CREATED; - - return new JPAKERound3Payload(participantId, macTag); - } - - /** - * Validates the payload received from the other participant during round 3. - * <p> - * See {@link JPAKEParticipant} for more details on round 3. - * <p> - * After execution, the {@link #getState() state} will be {@link #STATE_ROUND_3_VALIDATED}. - * - * @param keyingMaterial The keying material as returned from {@link #calculateKeyingMaterial()}. - * @throws CryptoException if validation fails. - * @throws IllegalStateException if called prior to {@link #calculateKeyingMaterial()}, or multiple times - */ - public void validateRound3PayloadReceived(JPAKERound3Payload round3PayloadReceived, BigInteger keyingMaterial) - throws CryptoException - { - if (this.state >= STATE_ROUND_3_VALIDATED) - { - throw new IllegalStateException("Validation already attempted for round3 payload for" + participantId); - } - if (this.state < STATE_KEY_CALCULATED) - { - throw new IllegalStateException("Keying material must be calculated validated prior to validating Round3 payload for " + this.participantId); - } - JPAKEUtil.validateParticipantIdsDiffer(participantId, round3PayloadReceived.getParticipantId()); - JPAKEUtil.validateParticipantIdsEqual(this.partnerParticipantId, round3PayloadReceived.getParticipantId()); - - JPAKEUtil.validateMacTag( - this.participantId, - this.partnerParticipantId, - this.gx1, - this.gx2, - this.gx3, - this.gx4, - keyingMaterial, - this.digest, - round3PayloadReceived.getMacTag()); - - - /* - * Clear the rest of the fields. - */ - this.gx1 = null; - this.gx2 = null; - this.gx3 = null; - this.gx4 = null; - - this.state = STATE_ROUND_3_VALIDATED; - } - -} |