diff options
Diffstat (limited to 'libjava/classpath/gnu/javax/crypto/key/dh/ElGamalKeyAgreement.java')
| -rw-r--r-- | libjava/classpath/gnu/javax/crypto/key/dh/ElGamalKeyAgreement.java | 91 |
1 files changed, 38 insertions, 53 deletions
diff --git a/libjava/classpath/gnu/javax/crypto/key/dh/ElGamalKeyAgreement.java b/libjava/classpath/gnu/javax/crypto/key/dh/ElGamalKeyAgreement.java index 1c4e11ce26b..967eda3f508 100644 --- a/libjava/classpath/gnu/javax/crypto/key/dh/ElGamalKeyAgreement.java +++ b/libjava/classpath/gnu/javax/crypto/key/dh/ElGamalKeyAgreement.java @@ -47,77 +47,62 @@ import gnu.javax.crypto.key.KeyAgreementException; import java.math.BigInteger; /** - * <p>The ElGamal key agreement, also known as the half-certified Diffie-Hellman + * The ElGamal key agreement, also known as the half-certified Diffie-Hellman * key agreement, is described in the Handbook of Applied Cryptography [HAC] as - * follows:</p> + * follows: * <ul> - * <li>A sends to B a single message allowing one-pass key agreement.</li> - * <li>A obtains an authentic copy of B's public key (p, g, yb), where - * yb = g**xb.</li> - * <li>A chooses a random integer x, 1 <= x <= p-2, and sends B the - * message g**x. A computes the shared secret key K as yb**x.</li> - * <li>B computes the same key K on receipt of the previous message as - * (g**x)**xb.</li> + * <li>A sends to B a single message allowing one-pass key agreement.</li> + * <li>A obtains an authentic copy of B's public key (p, g, yb), where yb = + * g**xb.</li> + * <li>A chooses a random integer x, 1 <= x <= p-2, and sends B the + * message g**x. A computes the shared secret key K as yb**x.</li> + * <li>B computes the same key K on receipt of the previous message as + * (g**x)**xb.</li> * </ul> - * - * <p>RFC-2631 describes an <i>Ephemeral-Static Mode</i> of operations with - * Diffie-Hellman keypairs as follows:</p> + * <p> + * RFC-2631 describes an <i>Ephemeral-Static Mode</i> of operations with + * Diffie-Hellman keypairs as follows: * <pre> - * "In Ephemeral-Static mode, the recipient has a static (and certified) - * key pair, but the sender generates a new key pair for each message - * and sends it using the originatorKey production. If the sender's key - * is freshly generated for each message, the shared secret ZZ will be - * similarly different for each message and partyAInfo MAY be omitted, - * since it serves merely to decouple multiple KEKs generated by the - * same set of pairwise keys. If, however, the same ephemeral sender key - * is used for multiple messages (e.g. it is cached as a performance - * optimization) then a separate partyAInfo MUST be used for each - * message. All implementations of this standard MUST implement - * Ephemeral-Static mode." + * "In Ephemeral-Static mode, the recipient has a static (and certified) + * key pair, but the sender generates a new key pair for each message + * and sends it using the originatorKey production. If the sender's key + * is freshly generated for each message, the shared secret ZZ will be + * similarly different for each message and partyAInfo MAY be omitted, + * since it serves merely to decouple multiple KEKs generated by the + * same set of pairwise keys. If, however, the same ephemeral sender key + * is used for multiple messages (e.g. it is cached as a performance + * optimization) then a separate partyAInfo MUST be used for each + * message. All implementations of this standard MUST implement + * Ephemeral-Static mode." * </pre> - * - * <p>Reference:</p> + * <p> + * Reference: * <ol> - * <li><a href="http://www.ietf.org/rfc/rfc2631.txt">Diffie-Hellman Key - * Agreement Method</a><br> - * Eric Rescorla.</li> - * <li><a href="http://www.cacr.math.uwaterloo.ca/hac">[HAC]</a>: Handbook of - * Applied Cryptography.<br> - * CRC Press, Inc. ISBN 0-8493-8523-7, 1997<br> - * Menezes, A., van Oorschot, P. and S. Vanstone.</li> + * <li><a href="http://www.ietf.org/rfc/rfc2631.txt">Diffie-Hellman Key + * Agreement Method</a><br> + * Eric Rescorla.</li> + * <li><a href="http://www.cacr.math.uwaterloo.ca/hac">[HAC]</a>: Handbook of + * Applied Cryptography.<br> + * CRC Press, Inc. ISBN 0-8493-8523-7, 1997<br> + * Menezes, A., van Oorschot, P. and S. Vanstone.</li> * </ol> */ -public abstract class ElGamalKeyAgreement extends BaseKeyAgreementParty +public abstract class ElGamalKeyAgreement + extends BaseKeyAgreementParty { - - // Constants and variables - // ------------------------------------------------------------------------- - public static final String SOURCE_OF_RANDOMNESS = "gnu.crypto.elgamal.ka.prng"; - - public static final String KA_ELGAMAL_RECIPIENT_PRIVATE_KEY = "gnu.crypto.elgamal.ka.recipient.private.key"; - - public static final String KA_ELGAMAL_RECIPIENT_PUBLIC_KEY = "gnu.crypto.elgamal.ka.recipient.public.key"; - + public static final String KA_ELGAMAL_RECIPIENT_PRIVATE_KEY = + "gnu.crypto.elgamal.ka.recipient.private.key"; + public static final String KA_ELGAMAL_RECIPIENT_PUBLIC_KEY = + "gnu.crypto.elgamal.ka.recipient.public.key"; /** The shared secret key. */ protected BigInteger ZZ; - // Constructor(s) - // ------------------------------------------------------------------------- - protected ElGamalKeyAgreement() { super(Registry.ELGAMAL_KA); } - // Class methods - // ------------------------------------------------------------------------- - - // Instance methods - // ------------------------------------------------------------------------- - - // implementation of common abstract methods in BaseKeyAGreementParty ------ - protected byte[] engineSharedSecret() throws KeyAgreementException { return Util.trim(ZZ); |
