ECDH1PUX25519Decrypter.java
/*
* nimbus-jose-jwt
*
* Copyright 2012-2021, Connect2id Ltd and contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use
* this file except in compliance with the License. You may obtain a copy of the
* License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed
* under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
* CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
*/
package com.nimbusds.jose.crypto;
import com.nimbusds.jose.*;
import com.nimbusds.jose.crypto.impl.*;
import com.nimbusds.jose.jwk.Curve;
import com.nimbusds.jose.jwk.OctetKeyPair;
import com.nimbusds.jose.util.Base64URL;
import net.jcip.annotations.ThreadSafe;
import javax.crypto.SecretKey;
import java.util.Collections;
import java.util.Set;
/**
* Elliptic Curve Diffie-Hellman decrypter of
* {@link com.nimbusds.jose.JWEObject JWE objects} for curves using an OKP JWK.
* Expects a private {@link OctetKeyPair} key with {@code "crv"} X25519.
*
* <p>See <a href="https://tools.ietf.org/html/rfc8037">RFC 8037</a>
* for more information.
*
* <p>See also {@link ECDH1PUDecrypter} for ECDH on other curves.
*
* <p>Public Key Authenticated Encryption for JOSE
* <a href="https://datatracker.ietf.org/doc/html/draft-madden-jose-ecdh-1pu-04">ECDH-1PU</a>
* for more information.
*
* <p>This class is thread-safe.
*
* <p>Supports the following key management algorithms:
*
* <ul>
* <li>{@link com.nimbusds.jose.JWEAlgorithm#ECDH_1PU}
* <li>{@link com.nimbusds.jose.JWEAlgorithm#ECDH_1PU_A128KW}
* <li>{@link com.nimbusds.jose.JWEAlgorithm#ECDH_1PU_A192KW}
* <li>{@link com.nimbusds.jose.JWEAlgorithm#ECDH_1PU_A256KW}
* </ul>
*
* <p>Supports the following elliptic curves:
*
* <ul>
* <li>{@link Curve#X25519}
* </ul>
*
* <p>Supports the following content encryption algorithms for Direct key
* agreement mode:
*
* <ul>
* <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A192CBC_HS384}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A128GCM}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A192GCM}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A256GCM}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256_DEPRECATED}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512_DEPRECATED}
* <li>{@link com.nimbusds.jose.EncryptionMethod#XC20P}
* </ul>
*
* <p>Supports the following content encryption algorithms for Key wrapping
* mode:
*
* <ul>
* <li>{@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A192CBC_HS384}
* <li>{@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512}
* </ul>
*
* @author Alexander Martynov
* @author Egor Puzanov
* @version 2023-05-17
*/
@ThreadSafe
public class ECDH1PUX25519Decrypter extends ECDH1PUCryptoProvider implements JWEDecrypter, CriticalHeaderParamsAware {
/**
* The private key.
*/
private final OctetKeyPair privateKey;
/**
* The public key.
*/
private final OctetKeyPair publicKey;
/**
* The critical header policy.
*/
private final CriticalHeaderParamsDeferral critPolicy = new CriticalHeaderParamsDeferral();
/**
* Creates a new Curve25519 Elliptic Curve Diffie-Hellman decrypter.
*
* @param privateKey The private key. Must not be {@code null}.
* @param publicKey The private key. Must not be {@code null}.
*
* @throws JOSEException If the key subtype is not supported.
*/
public ECDH1PUX25519Decrypter(final OctetKeyPair privateKey, final OctetKeyPair publicKey)
throws JOSEException {
this(privateKey, publicKey, null);
}
/**
* Creates a new Curve25519 Elliptic Curve Diffie-Hellman decrypter.
*
* @param privateKey The private key. Must not be {@code null}.
* @param publicKey The private key. Must not be {@code null}.
* @param defCritHeaders The names of the critical header parameters
* that are deferred to the application for
* processing, empty set or {@code null} if none.
*
* @throws JOSEException If the key subtype is not supported.
*/
public ECDH1PUX25519Decrypter(final OctetKeyPair privateKey,
final OctetKeyPair publicKey,
final Set<String> defCritHeaders)
throws JOSEException {
super(privateKey.getCurve(), null);
this.privateKey = privateKey;
this.publicKey = publicKey;
critPolicy.setDeferredCriticalHeaderParams(defCritHeaders);
}
@Override
public Set<Curve> supportedEllipticCurves() {
return Collections.singleton(Curve.X25519);
}
/**
* Returns the private key.
*
* @return The private key.
*/
public OctetKeyPair getPrivateKey() {
return privateKey;
}
/**
* Returns the public key.
*
* @return The public key.
*/
public OctetKeyPair getPublicKey() {
return publicKey;
}
@Override
public Set<String> getProcessedCriticalHeaderParams() {
return critPolicy.getProcessedCriticalHeaderParams();
}
@Override
public Set<String> getDeferredCriticalHeaderParams() {
return critPolicy.getProcessedCriticalHeaderParams();
}
/**
* Decrypts the specified cipher text of a {@link JWEObject JWE Object}.
*
* @param header The JSON Web Encryption (JWE) header. Must
* specify a supported JWE algorithm and method.
* Must not be {@code null}.
* @param encryptedKey The encrypted key, {@code null} if not required
* by the JWE algorithm.
* @param iv The initialisation vector, {@code null} if not
* required by the JWE algorithm.
* @param cipherText The cipher text to decrypt. Must not be
* {@code null}.
* @param authTag The authentication tag, {@code null} if not
* required.
*
* @return The clear text.
*
* @throws JOSEException If the JWE algorithm or method is not
* supported, if a critical header parameter is
* not supported or marked for deferral to the
* application, or if decryption failed for some
* other reason.
*/
@Deprecated
public byte[] decrypt(final JWEHeader header,
final Base64URL encryptedKey,
final Base64URL iv,
final Base64URL cipherText,
final Base64URL authTag)
throws JOSEException {
return decrypt(header, encryptedKey, iv, cipherText, authTag, AAD.compute(header));
}
@Override
public byte[] decrypt(final JWEHeader header,
final Base64URL encryptedKey,
final Base64URL iv,
final Base64URL cipherText,
final Base64URL authTag,
final byte[] aad)
throws JOSEException {
// Check for unrecognizable "crit" properties
critPolicy.ensureHeaderPasses(header);
// Get ephemeral key from header
OctetKeyPair ephemeralPublicKey = (OctetKeyPair) header.getEphemeralPublicKey();
if (ephemeralPublicKey == null) {
throw new JOSEException("Missing ephemeral public key \"epk\" JWE header parameter");
}
SecretKey Z = ECDH1PU.deriveRecipientZ(
privateKey,
publicKey,
ephemeralPublicKey
);
return decryptWithZ(header, aad, Z, encryptedKey, iv, cipherText, authTag);
}
}