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Diffstat (limited to 'core/src/main/java/org/spongycastle/crypto/util/PublicKeyFactory.java')
| -rw-r--r-- | core/src/main/java/org/spongycastle/crypto/util/PublicKeyFactory.java | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/crypto/util/PublicKeyFactory.java b/core/src/main/java/org/spongycastle/crypto/util/PublicKeyFactory.java new file mode 100644 index 00000000..ec588f46 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/util/PublicKeyFactory.java @@ -0,0 +1,195 @@ +package org.spongycastle.crypto.util; + +import java.io.IOException; +import java.io.InputStream; +import java.math.BigInteger; + +import org.spongycastle.asn1.ASN1Encodable; +import org.spongycastle.asn1.ASN1InputStream; +import org.spongycastle.asn1.ASN1Integer; +import org.spongycastle.asn1.ASN1ObjectIdentifier; +import org.spongycastle.asn1.ASN1OctetString; +import org.spongycastle.asn1.ASN1Primitive; +import org.spongycastle.asn1.DEROctetString; +import org.spongycastle.asn1.oiw.ElGamalParameter; +import org.spongycastle.asn1.oiw.OIWObjectIdentifiers; +import org.spongycastle.asn1.pkcs.DHParameter; +import org.spongycastle.asn1.pkcs.PKCSObjectIdentifiers; +import org.spongycastle.asn1.pkcs.RSAPublicKey; +import org.spongycastle.asn1.x509.AlgorithmIdentifier; +import org.spongycastle.asn1.x509.DSAParameter; +import org.spongycastle.asn1.x509.SubjectPublicKeyInfo; +import org.spongycastle.asn1.x509.X509ObjectIdentifiers; +import org.spongycastle.asn1.x9.DHDomainParameters; +import org.spongycastle.asn1.x9.DHPublicKey; +import org.spongycastle.asn1.x9.DHValidationParms; +import org.spongycastle.asn1.x9.ECNamedCurveTable; +import org.spongycastle.asn1.x9.X962Parameters; +import org.spongycastle.asn1.x9.X9ECParameters; +import org.spongycastle.asn1.x9.X9ECPoint; +import org.spongycastle.asn1.x9.X9ObjectIdentifiers; +import org.spongycastle.crypto.ec.CustomNamedCurves; +import org.spongycastle.crypto.params.AsymmetricKeyParameter; +import org.spongycastle.crypto.params.DHParameters; +import org.spongycastle.crypto.params.DHPublicKeyParameters; +import org.spongycastle.crypto.params.DHValidationParameters; +import org.spongycastle.crypto.params.DSAParameters; +import org.spongycastle.crypto.params.DSAPublicKeyParameters; +import org.spongycastle.crypto.params.ECDomainParameters; +import org.spongycastle.crypto.params.ECNamedDomainParameters; +import org.spongycastle.crypto.params.ECPublicKeyParameters; +import org.spongycastle.crypto.params.ElGamalParameters; +import org.spongycastle.crypto.params.ElGamalPublicKeyParameters; +import org.spongycastle.crypto.params.RSAKeyParameters; + +/** + * Factory to create asymmetric public key parameters for asymmetric ciphers from range of + * ASN.1 encoded SubjectPublicKeyInfo objects. + */ +public class PublicKeyFactory +{ + /** + * Create a public key from a SubjectPublicKeyInfo encoding + * + * @param keyInfoData the SubjectPublicKeyInfo encoding + * @return the appropriate key parameter + * @throws IOException on an error decoding the key + */ + public static AsymmetricKeyParameter createKey(byte[] keyInfoData) throws IOException + { + return createKey(SubjectPublicKeyInfo.getInstance(ASN1Primitive.fromByteArray(keyInfoData))); + } + + /** + * Create a public key from a SubjectPublicKeyInfo encoding read from a stream + * + * @param inStr the stream to read the SubjectPublicKeyInfo encoding from + * @return the appropriate key parameter + * @throws IOException on an error decoding the key + */ + public static AsymmetricKeyParameter createKey(InputStream inStr) throws IOException + { + return createKey(SubjectPublicKeyInfo.getInstance(new ASN1InputStream(inStr).readObject())); + } + + /** + * Create a public key from the passed in SubjectPublicKeyInfo + * + * @param keyInfo the SubjectPublicKeyInfo containing the key data + * @return the appropriate key parameter + * @throws IOException on an error decoding the key + */ + public static AsymmetricKeyParameter createKey(SubjectPublicKeyInfo keyInfo) throws IOException + { + AlgorithmIdentifier algId = keyInfo.getAlgorithm(); + + if (algId.getAlgorithm().equals(PKCSObjectIdentifiers.rsaEncryption) + || algId.getAlgorithm().equals(X509ObjectIdentifiers.id_ea_rsa)) + { + RSAPublicKey pubKey = RSAPublicKey.getInstance(keyInfo.parsePublicKey()); + + return new RSAKeyParameters(false, pubKey.getModulus(), pubKey.getPublicExponent()); + } + else if (algId.getAlgorithm().equals(X9ObjectIdentifiers.dhpublicnumber)) + { + DHPublicKey dhPublicKey = DHPublicKey.getInstance(keyInfo.parsePublicKey()); + + BigInteger y = dhPublicKey.getY().getValue(); + + DHDomainParameters dhParams = DHDomainParameters.getInstance(algId.getParameters()); + + BigInteger p = dhParams.getP().getValue(); + BigInteger g = dhParams.getG().getValue(); + BigInteger q = dhParams.getQ().getValue(); + + BigInteger j = null; + if (dhParams.getJ() != null) + { + j = dhParams.getJ().getValue(); + } + + DHValidationParameters validation = null; + DHValidationParms dhValidationParms = dhParams.getValidationParms(); + if (dhValidationParms != null) + { + byte[] seed = dhValidationParms.getSeed().getBytes(); + BigInteger pgenCounter = dhValidationParms.getPgenCounter().getValue(); + + // TODO Check pgenCounter size? + + validation = new DHValidationParameters(seed, pgenCounter.intValue()); + } + + return new DHPublicKeyParameters(y, new DHParameters(p, g, q, j, validation)); + } + else if (algId.getAlgorithm().equals(PKCSObjectIdentifiers.dhKeyAgreement)) + { + DHParameter params = DHParameter.getInstance(algId.getParameters()); + ASN1Integer derY = (ASN1Integer)keyInfo.parsePublicKey(); + + BigInteger lVal = params.getL(); + int l = lVal == null ? 0 : lVal.intValue(); + DHParameters dhParams = new DHParameters(params.getP(), params.getG(), null, l); + + return new DHPublicKeyParameters(derY.getValue(), dhParams); + } + else if (algId.getAlgorithm().equals(OIWObjectIdentifiers.elGamalAlgorithm)) + { + ElGamalParameter params = ElGamalParameter.getInstance(algId.getParameters()); + ASN1Integer derY = (ASN1Integer)keyInfo.parsePublicKey(); + + return new ElGamalPublicKeyParameters(derY.getValue(), new ElGamalParameters( + params.getP(), params.getG())); + } + else if (algId.getAlgorithm().equals(X9ObjectIdentifiers.id_dsa) + || algId.getAlgorithm().equals(OIWObjectIdentifiers.dsaWithSHA1)) + { + ASN1Integer derY = (ASN1Integer)keyInfo.parsePublicKey(); + ASN1Encodable de = algId.getParameters(); + + DSAParameters parameters = null; + if (de != null) + { + DSAParameter params = DSAParameter.getInstance(de.toASN1Primitive()); + parameters = new DSAParameters(params.getP(), params.getQ(), params.getG()); + } + + return new DSAPublicKeyParameters(derY.getValue(), parameters); + } + else if (algId.getAlgorithm().equals(X9ObjectIdentifiers.id_ecPublicKey)) + { + X962Parameters params = X962Parameters.getInstance(algId.getParameters()); + + X9ECParameters x9; + ECDomainParameters dParams; + + if (params.isNamedCurve()) + { + ASN1ObjectIdentifier oid = (ASN1ObjectIdentifier)params.getParameters(); + + x9 = CustomNamedCurves.getByOID(oid); + if (x9 == null) + { + x9 = ECNamedCurveTable.getByOID(oid); + } + dParams = new ECNamedDomainParameters( + oid, x9.getCurve(), x9.getG(), x9.getN(), x9.getH(), x9.getSeed()); + } + else + { + x9 = X9ECParameters.getInstance(params.getParameters()); + dParams = new ECDomainParameters( + x9.getCurve(), x9.getG(), x9.getN(), x9.getH(), x9.getSeed()); + } + + ASN1OctetString key = new DEROctetString(keyInfo.getPublicKeyData().getBytes()); + X9ECPoint derQ = new X9ECPoint(x9.getCurve(), key); + + return new ECPublicKeyParameters(derQ.getPoint(), dParams); + } + else + { + throw new RuntimeException("algorithm identifier in key not recognised"); + } + } +} |