1 files changed, 28 insertions, 44 deletions

diff --git a/crypto/src/asn1/pkcs/IssuerAndSerialNumber.cs b/crypto/src/asn1/pkcs/IssuerAndSerialNumber.cs
index da863cb62..0a2c05d41 100644
--- a/crypto/src/asn1/pkcs/IssuerAndSerialNumber.cs
+++ b/crypto/src/asn1/pkcs/IssuerAndSerialNumber.cs
@@ -2,71 +2,55 @@ using System;
 
 using Org.BouncyCastle.Asn1.X509;
 using Org.BouncyCastle.Math;
-using Org.BouncyCastle.Utilities;
 
 namespace Org.BouncyCastle.Asn1.Pkcs
 {
     public class IssuerAndSerialNumber
         : Asn1Encodable
     {
-        private readonly X509Name name;
-        private readonly DerInteger certSerialNumber;
-
-		public static IssuerAndSerialNumber GetInstance(
-            object obj)
+		public static IssuerAndSerialNumber GetInstance(object obj)
         {
-            if (obj is IssuerAndSerialNumber)
-            {
-                return (IssuerAndSerialNumber) obj;
-            }
+            if (obj == null)
+                return null;
+            if (obj is IssuerAndSerialNumber issuerAndSerialNumber)
+                return issuerAndSerialNumber;
+            return new IssuerAndSerialNumber(Asn1Sequence.GetInstance(obj));
+		}
 
-			if (obj is Asn1Sequence)
-            {
-                return new IssuerAndSerialNumber((Asn1Sequence) obj);
-            }
+        public static IssuerAndSerialNumber GetInstance(Asn1TaggedObject taggedObject, bool declaredExplicit)
+        {
+            return new IssuerAndSerialNumber(Asn1Sequence.GetInstance(taggedObject, declaredExplicit));
+        }
 
-			throw new ArgumentException("Unknown object in factory: " + Platform.GetTypeName(obj), "obj");
-		}
+        private readonly X509Name m_name;
+        private readonly DerInteger m_certSerialNumber;
 
-		private IssuerAndSerialNumber(
-            Asn1Sequence seq)
+        private IssuerAndSerialNumber(Asn1Sequence seq)
         {
-			if (seq.Count != 2)
-				throw new ArgumentException("Wrong number of elements in sequence", "seq");
+            int count = seq.Count;
+			if (count != 2)
+                throw new ArgumentException("Bad sequence size: " + count, nameof(seq));
 
-			this.name = X509Name.GetInstance(seq[0]);
-            this.certSerialNumber = DerInteger.GetInstance(seq[1]);
+            m_name = X509Name.GetInstance(seq[0]);
+            m_certSerialNumber = DerInteger.GetInstance(seq[1]);
         }
 
-		public IssuerAndSerialNumber(
-            X509Name	name,
-            BigInteger	certSerialNumber)
+        public IssuerAndSerialNumber(X509Name name, BigInteger certSerialNumber)
         {
-            this.name = name;
-            this.certSerialNumber = new DerInteger(certSerialNumber);
+            m_name = name ?? throw new ArgumentNullException(nameof(name));
+            m_certSerialNumber = new DerInteger(certSerialNumber);
         }
 
-		public IssuerAndSerialNumber(
-            X509Name	name,
-            DerInteger	certSerialNumber)
+        public IssuerAndSerialNumber(X509Name name, DerInteger certSerialNumber)
         {
-            this.name = name;
-            this.certSerialNumber = certSerialNumber;
+            m_name = name ?? throw new ArgumentNullException(nameof(name));
+            m_certSerialNumber = certSerialNumber ?? throw new ArgumentNullException(nameof(certSerialNumber));
         }
 
-		public X509Name Name
-		{
-			get { return name; }
-		}
+        public X509Name Name => m_name;
 
-		public DerInteger CertificateSerialNumber
-		{
-			get { return certSerialNumber; }
-		}
+        public DerInteger CertificateSerialNumber => m_certSerialNumber;
 
-		public override Asn1Object ToAsn1Object()
-        {
-			return new DerSequence(name, certSerialNumber);
-        }
+		public override Asn1Object ToAsn1Object() => new DerSequence(m_name, m_certSerialNumber);
     }
 }