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using System;
using System.Collections;
using System.IO;
using System.Text;
using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.CryptoPro;
using Org.BouncyCastle.Asn1.Oiw;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.Sec;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Asn1.X9;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Math.EC;
namespace Org.BouncyCastle.Security
{
public sealed class PublicKeyFactory
{
private PublicKeyFactory()
{
}
public static AsymmetricKeyParameter CreateKey(
byte[] keyInfoData)
{
return CreateKey(
SubjectPublicKeyInfo.GetInstance(
Asn1Object.FromByteArray(keyInfoData)));
}
public static AsymmetricKeyParameter CreateKey(
Stream inStr)
{
return CreateKey(
SubjectPublicKeyInfo.GetInstance(
Asn1Object.FromStream(inStr)));
}
public static AsymmetricKeyParameter CreateKey(
SubjectPublicKeyInfo keyInfo)
{
AlgorithmIdentifier algID = keyInfo.AlgorithmID;
DerObjectIdentifier algOid = algID.Algorithm;
// TODO See RSAUtil.isRsaOid in Java build
if (algOid.Equals(PkcsObjectIdentifiers.RsaEncryption)
|| algOid.Equals(X509ObjectIdentifiers.IdEARsa)
|| algOid.Equals(PkcsObjectIdentifiers.IdRsassaPss)
|| algOid.Equals(PkcsObjectIdentifiers.IdRsaesOaep))
{
RsaPublicKeyStructure pubKey = RsaPublicKeyStructure.GetInstance(
keyInfo.GetPublicKey());
return new RsaKeyParameters(false, pubKey.Modulus, pubKey.PublicExponent);
}
else if (algOid.Equals(X9ObjectIdentifiers.DHPublicNumber))
{
Asn1Sequence seq = Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object());
DHPublicKey dhPublicKey = DHPublicKey.GetInstance(keyInfo.GetPublicKey());
BigInteger y = dhPublicKey.Y.Value;
if (IsPkcsDHParam(seq))
return ReadPkcsDHParam(algOid, y, seq);
DHDomainParameters dhParams = DHDomainParameters.GetInstance(seq);
BigInteger p = dhParams.P.Value;
BigInteger g = dhParams.G.Value;
BigInteger q = dhParams.Q.Value;
BigInteger j = null;
if (dhParams.J != null)
{
j = dhParams.J.Value;
}
DHValidationParameters validation = null;
DHValidationParms dhValidationParms = dhParams.ValidationParms;
if (dhValidationParms != null)
{
byte[] seed = dhValidationParms.Seed.GetBytes();
BigInteger pgenCounter = dhValidationParms.PgenCounter.Value;
// TODO Check pgenCounter size?
validation = new DHValidationParameters(seed, pgenCounter.IntValue);
}
return new DHPublicKeyParameters(y, new DHParameters(p, g, q, j, validation));
}
else if (algOid.Equals(PkcsObjectIdentifiers.DhKeyAgreement))
{
Asn1Sequence seq = Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object());
DerInteger derY = (DerInteger) keyInfo.GetPublicKey();
return ReadPkcsDHParam(algOid, derY.Value, seq);
}
else if (algOid.Equals(OiwObjectIdentifiers.ElGamalAlgorithm))
{
ElGamalParameter para = new ElGamalParameter(
Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object()));
DerInteger derY = (DerInteger) keyInfo.GetPublicKey();
return new ElGamalPublicKeyParameters(
derY.Value,
new ElGamalParameters(para.P, para.G));
}
else if (algOid.Equals(X9ObjectIdentifiers.IdDsa)
|| algOid.Equals(OiwObjectIdentifiers.DsaWithSha1))
{
DerInteger derY = (DerInteger) keyInfo.GetPublicKey();
Asn1Encodable ae = algID.Parameters;
DsaParameters parameters = null;
if (ae != null)
{
DsaParameter para = DsaParameter.GetInstance(ae.ToAsn1Object());
parameters = new DsaParameters(para.P, para.Q, para.G);
}
return new DsaPublicKeyParameters(derY.Value, parameters);
}
else if (algOid.Equals(X9ObjectIdentifiers.IdECPublicKey))
{
X962Parameters para = new X962Parameters(algID.Parameters.ToAsn1Object());
X9ECParameters x9;
if (para.IsNamedCurve)
{
x9 = ECKeyPairGenerator.FindECCurveByOid((DerObjectIdentifier)para.Parameters);
}
else
{
x9 = new X9ECParameters((Asn1Sequence)para.Parameters);
}
Asn1OctetString key = new DerOctetString(keyInfo.PublicKeyData.GetBytes());
X9ECPoint derQ = new X9ECPoint(x9.Curve, key);
ECPoint q = derQ.Point;
if (para.IsNamedCurve)
{
return new ECPublicKeyParameters("EC", q, (DerObjectIdentifier)para.Parameters);
}
ECDomainParameters dParams = new ECDomainParameters(x9.Curve, x9.G, x9.N, x9.H, x9.GetSeed());
return new ECPublicKeyParameters(q, dParams);
}
else if (algOid.Equals(CryptoProObjectIdentifiers.GostR3410x2001))
{
Gost3410PublicKeyAlgParameters gostParams = new Gost3410PublicKeyAlgParameters(
(Asn1Sequence) algID.Parameters);
Asn1OctetString key;
try
{
key = (Asn1OctetString) keyInfo.GetPublicKey();
}
catch (IOException)
{
throw new ArgumentException("invalid info structure in GOST3410 public key");
}
byte[] keyEnc = key.GetOctets();
byte[] x = new byte[32];
byte[] y = new byte[32];
for (int i = 0; i != y.Length; i++)
{
x[i] = keyEnc[32 - 1 - i];
}
for (int i = 0; i != x.Length; i++)
{
y[i] = keyEnc[64 - 1 - i];
}
ECDomainParameters ecP = ECGost3410NamedCurves.GetByOid(gostParams.PublicKeyParamSet);
if (ecP == null)
return null;
ECPoint q = ecP.Curve.CreatePoint(new BigInteger(1, x), new BigInteger(1, y));
return new ECPublicKeyParameters("ECGOST3410", q, gostParams.PublicKeyParamSet);
}
else if (algOid.Equals(CryptoProObjectIdentifiers.GostR3410x94))
{
Gost3410PublicKeyAlgParameters algParams = new Gost3410PublicKeyAlgParameters(
(Asn1Sequence) algID.Parameters);
DerOctetString derY;
try
{
derY = (DerOctetString) keyInfo.GetPublicKey();
}
catch (IOException)
{
throw new ArgumentException("invalid info structure in GOST3410 public key");
}
byte[] keyEnc = derY.GetOctets();
byte[] keyBytes = new byte[keyEnc.Length];
for (int i = 0; i != keyEnc.Length; i++)
{
keyBytes[i] = keyEnc[keyEnc.Length - 1 - i]; // was little endian
}
BigInteger y = new BigInteger(1, keyBytes);
return new Gost3410PublicKeyParameters(y, algParams.PublicKeyParamSet);
}
else
{
throw new SecurityUtilityException("algorithm identifier in key not recognised: " + algOid);
}
}
private static bool IsPkcsDHParam(Asn1Sequence seq)
{
if (seq.Count == 2)
return true;
if (seq.Count > 3)
return false;
DerInteger l = DerInteger.GetInstance(seq[2]);
DerInteger p = DerInteger.GetInstance(seq[0]);
return l.Value.CompareTo(BigInteger.ValueOf(p.Value.BitLength)) <= 0;
}
private static DHPublicKeyParameters ReadPkcsDHParam(DerObjectIdentifier algOid,
BigInteger y, Asn1Sequence seq)
{
DHParameter para = new DHParameter(seq);
BigInteger lVal = para.L;
int l = lVal == null ? 0 : lVal.IntValue;
DHParameters dhParams = new DHParameters(para.P, para.G, null, l);
return new DHPublicKeyParameters(y, dhParams, algOid);
}
}
}
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