using Org.BouncyCastle.Asn1; using Org.BouncyCastle.Math; using System; using System.Collections; namespace Org.BouncyCastle.Asn1.X509 { public class RsaPublicKeyStructure : Asn1Encodable { private BigInteger modulus; private BigInteger publicExponent; public static RsaPublicKeyStructure GetInstance( Asn1TaggedObject obj, bool explicitly) { return GetInstance(Asn1Sequence.GetInstance(obj, explicitly)); } public static RsaPublicKeyStructure GetInstance( object obj) { if (obj == null || obj is RsaPublicKeyStructure) { return (RsaPublicKeyStructure) obj; } if (obj is Asn1Sequence) { return new RsaPublicKeyStructure((Asn1Sequence) obj); } throw new ArgumentException("Invalid RsaPublicKeyStructure: " + obj.GetType().Name); } public RsaPublicKeyStructure( BigInteger modulus, BigInteger publicExponent) { if (modulus == null) throw new ArgumentNullException("modulus"); if (publicExponent == null) throw new ArgumentNullException("publicExponent"); if (modulus.SignValue <= 0) throw new ArgumentException("Not a valid RSA modulus", "modulus"); if (publicExponent.SignValue <= 0) throw new ArgumentException("Not a valid RSA public exponent", "publicExponent"); this.modulus = modulus; this.publicExponent = publicExponent; } private RsaPublicKeyStructure( Asn1Sequence seq) { if (seq.Count != 2) throw new ArgumentException("Bad sequence size: " + seq.Count); // Note: we are accepting technically incorrect (i.e. negative) values here modulus = DerInteger.GetInstance(seq[0]).PositiveValue; publicExponent = DerInteger.GetInstance(seq[1]).PositiveValue; } public BigInteger Modulus { get { return modulus; } } public BigInteger PublicExponent { get { return publicExponent; } } /** * This outputs the key in Pkcs1v2 format. *
         *      RSAPublicKey ::= Sequence {
         *                          modulus Integer, -- n
         *                          publicExponent Integer, -- e
         *                      }
         * 
*/ public override Asn1Object ToAsn1Object() { return new DerSequence( new DerInteger(Modulus), new DerInteger(PublicExponent)); } } }