Initial Commit

iTechSharp/srcbc/security/PublicKeyFactory.cs

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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.Nist;
+using Org.BouncyCastle.Asn1.Oiw;
+using Org.BouncyCastle.Asn1.Pkcs;
+using Org.BouncyCastle.Asn1.Sec;
+using Org.BouncyCastle.Asn1.TeleTrust;
+using Org.BouncyCastle.Asn1.X509;
+using Org.BouncyCastle.Asn1.X9;
+using Org.BouncyCastle.Crypto;
+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.ObjectID;
+
+			if (algOid.Equals(PkcsObjectIdentifiers.RsaEncryption)
+				|| algOid.Equals(X509ObjectIdentifiers.IdEARsa))
+			{
+				RsaPublicKeyStructure pubKey = RsaPublicKeyStructure.GetInstance(
+					keyInfo.GetPublicKey());
+
+				return new RsaKeyParameters(false, pubKey.Modulus, pubKey.PublicExponent);
+			}
+			else if (algOid.Equals(PkcsObjectIdentifiers.DhKeyAgreement)
+				|| algOid.Equals(X9ObjectIdentifiers.DHPublicNumber))
+			{
+				DHParameter para = new DHParameter(
+					Asn1Sequence.GetInstance(algID.Parameters.ToAsn1Object()));
+				DerInteger derY = (DerInteger) keyInfo.GetPublicKey();
+
+				return new DHPublicKeyParameters(derY.Value, new DHParameters(para.P, para.G));
+			}
+			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;
+				Asn1Object ao = ae == null ? null : ae.ToAsn1Object();
+
+				DsaParameter para = DsaParameter.GetInstance(ao);
+
+				return new DsaPublicKeyParameters(
+					derY.Value,
+					new DsaParameters(para.P, para.Q, para.G));
+			}
+			else if (algOid.Equals(X9ObjectIdentifiers.IdECPublicKey))
+			{
+				X962Parameters para = new X962Parameters(
+					algID.Parameters.ToAsn1Object());
+				X9ECParameters ecP;
+
+				if (para.IsNamedCurve)
+				{
+					// TODO ECGost3410NamedCurves support (returns ECDomainParameters though)
+
+					DerObjectIdentifier oid = (DerObjectIdentifier)para.Parameters;
+					ecP = X962NamedCurves.GetByOid(oid);
+
+					if (ecP == null)
+					{
+						ecP = SecNamedCurves.GetByOid(oid);
+
+						if (ecP == null)
+						{
+							ecP = NistNamedCurves.GetByOid(oid);
+
+							if (ecP == null)
+							{
+								ecP = TeleTrusTNamedCurves.GetByOid(oid);
+							}
+						}
+					}
+				}
+				else
+				{
+					ecP = new X9ECParameters((Asn1Sequence)para.Parameters.ToAsn1Object());
+				}
+
+				ECDomainParameters dParams = new ECDomainParameters(
+					ecP.Curve,
+					ecP.G,
+					ecP.N,
+					ecP.H,
+					ecP.GetSeed());
+
+				DerBitString bits = keyInfo.PublicKeyData;
+				byte[] data = bits.GetBytes();
+				Asn1OctetString key = new DerOctetString(data);
+
+				X9ECPoint derQ = new X9ECPoint(dParams.Curve, key);
+
+				return new ECPublicKeyParameters(derQ.Point, 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), false);
+
+				return new ECPublicKeyParameters(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);
+            }
+        }
+    }
+}