diff options
Diffstat (limited to 'pg/src/main/java/org/spongycastle/openpgp/operator/jcajce/JcePublicKeyKeyEncryptionMethodGenerator.java')
| -rw-r--r-- | pg/src/main/java/org/spongycastle/openpgp/operator/jcajce/JcePublicKeyKeyEncryptionMethodGenerator.java | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/pg/src/main/java/org/spongycastle/openpgp/operator/jcajce/JcePublicKeyKeyEncryptionMethodGenerator.java b/pg/src/main/java/org/spongycastle/openpgp/operator/jcajce/JcePublicKeyKeyEncryptionMethodGenerator.java new file mode 100644 index 00000000..bd7f4999 --- /dev/null +++ b/pg/src/main/java/org/spongycastle/openpgp/operator/jcajce/JcePublicKeyKeyEncryptionMethodGenerator.java @@ -0,0 +1,166 @@ +package org.spongycastle.openpgp.operator.jcajce; + +import java.io.IOException; +import java.math.BigInteger; +import java.security.InvalidKeyException; +import java.security.Key; +import java.security.Provider; +import java.security.SecureRandom; + +import javax.crypto.BadPaddingException; +import javax.crypto.Cipher; +import javax.crypto.IllegalBlockSizeException; +import javax.crypto.spec.SecretKeySpec; + +import org.spongycastle.asn1.nist.NISTNamedCurves; +import org.spongycastle.asn1.x9.X9ECParameters; +import org.spongycastle.bcpg.ECDHPublicBCPGKey; +import org.spongycastle.bcpg.MPInteger; +import org.spongycastle.bcpg.PublicKeyAlgorithmTags; +import org.spongycastle.crypto.EphemeralKeyPair; +import org.spongycastle.crypto.KeyEncoder; +import org.spongycastle.crypto.generators.ECKeyPairGenerator; +import org.spongycastle.crypto.generators.EphemeralKeyPairGenerator; +import org.spongycastle.crypto.params.AsymmetricKeyParameter; +import org.spongycastle.crypto.params.ECDomainParameters; +import org.spongycastle.crypto.params.ECKeyGenerationParameters; +import org.spongycastle.crypto.params.ECPrivateKeyParameters; +import org.spongycastle.crypto.params.ECPublicKeyParameters; +import org.spongycastle.jcajce.util.DefaultJcaJceHelper; +import org.spongycastle.jcajce.util.NamedJcaJceHelper; +import org.spongycastle.jcajce.util.ProviderJcaJceHelper; +import org.spongycastle.math.ec.ECPoint; +import org.spongycastle.openpgp.PGPException; +import org.spongycastle.openpgp.PGPPublicKey; +import org.spongycastle.openpgp.operator.PGPPad; +import org.spongycastle.openpgp.operator.PublicKeyKeyEncryptionMethodGenerator; +import org.spongycastle.openpgp.operator.RFC6637KDFCalculator; + +public class JcePublicKeyKeyEncryptionMethodGenerator + extends PublicKeyKeyEncryptionMethodGenerator +{ + private OperatorHelper helper = new OperatorHelper(new DefaultJcaJceHelper()); + private SecureRandom random; + private JcaPGPKeyConverter keyConverter = new JcaPGPKeyConverter(); + private JcaPGPDigestCalculatorProviderBuilder digestCalculatorProviderBuilder = new JcaPGPDigestCalculatorProviderBuilder(); + + /** + * Create a public key encryption method generator with the method to be based on the passed in key. + * + * @param key the public key to use for encryption. + */ + public JcePublicKeyKeyEncryptionMethodGenerator(PGPPublicKey key) + { + super(key); + } + + public JcePublicKeyKeyEncryptionMethodGenerator setProvider(Provider provider) + { + this.helper = new OperatorHelper(new ProviderJcaJceHelper(provider)); + + keyConverter.setProvider(provider); + + return this; + } + + public JcePublicKeyKeyEncryptionMethodGenerator setProvider(String providerName) + { + this.helper = new OperatorHelper(new NamedJcaJceHelper(providerName)); + + keyConverter.setProvider(providerName); + + return this; + } + + /** + * Provide a user defined source of randomness. + * + * @param random the secure random to be used. + * @return the current generator. + */ + public JcePublicKeyKeyEncryptionMethodGenerator setSecureRandom(SecureRandom random) + { + this.random = random; + + return this; + } + + protected byte[] encryptSessionInfo(PGPPublicKey pubKey, byte[] sessionInfo) + throws PGPException + { + try + { + if (pubKey.getAlgorithm() == PublicKeyAlgorithmTags.ECDH) + { + ECDHPublicBCPGKey ecKey = (ECDHPublicBCPGKey)pubKey.getPublicKeyPacket().getKey(); + X9ECParameters x9Params = NISTNamedCurves.getByOID(ecKey.getCurveOID()); + ECDomainParameters ecParams = new ECDomainParameters(x9Params.getCurve(), x9Params.getG(), x9Params.getN()); + + // Generate the ephemeral key pair + ECKeyPairGenerator gen = new ECKeyPairGenerator(); + gen.init(new ECKeyGenerationParameters(ecParams, random)); + + EphemeralKeyPairGenerator kGen = new EphemeralKeyPairGenerator(gen, new KeyEncoder() + { + public byte[] getEncoded(AsymmetricKeyParameter keyParameter) + { + return ((ECPublicKeyParameters)keyParameter).getQ().getEncoded(false); + } + }); + + EphemeralKeyPair ephKp = kGen.generate(); + + ECPrivateKeyParameters ephPriv = (ECPrivateKeyParameters)ephKp.getKeyPair().getPrivate(); + + ECPoint S = ecKey.getPoint().multiply(ephPriv.getD()).normalize(); + + RFC6637KDFCalculator rfc6637KDFCalculator = new RFC6637KDFCalculator(digestCalculatorProviderBuilder.build().get(ecKey.getHashAlgorithm()), ecKey.getSymmetricKeyAlgorithm()); + + Key key = new SecretKeySpec(rfc6637KDFCalculator.createKey(ecKey.getCurveOID(), S, pubKey.getFingerprint()), "AESWrap"); + + Cipher c = helper.createKeyWrapper(ecKey.getSymmetricKeyAlgorithm()); + + c.init(Cipher.WRAP_MODE, key, random); + + byte[] paddedSessionData = PGPPad.padSessionData(sessionInfo); + + byte[] C = c.wrap(new SecretKeySpec(paddedSessionData, PGPUtil.getSymmetricCipherName(sessionInfo[0]))); + byte[] VB = new MPInteger(new BigInteger(1, ephKp.getEncodedPublicKey())).getEncoded(); + + byte[] rv = new byte[VB.length + 1 + C.length]; + + System.arraycopy(VB, 0, rv, 0, VB.length); + rv[VB.length] = (byte)C.length; + System.arraycopy(C, 0, rv, VB.length + 1, C.length); + + return rv; + } + else + { + Cipher c = helper.createPublicKeyCipher(pubKey.getAlgorithm()); + + Key key = keyConverter.getPublicKey(pubKey); + + c.init(Cipher.ENCRYPT_MODE, key, random); + + return c.doFinal(sessionInfo); + } + } + catch (IllegalBlockSizeException e) + { + throw new PGPException("illegal block size: " + e.getMessage(), e); + } + catch (BadPaddingException e) + { + throw new PGPException("bad padding: " + e.getMessage(), e); + } + catch (InvalidKeyException e) + { + throw new PGPException("key invalid: " + e.getMessage(), e); + } + catch (IOException e) + { + throw new PGPException("unable to encode MPI: " + e.getMessage(), e); + } + } +} |