1 files changed, 14 insertions, 35 deletions
diff --git a/crypto/src/cms/SignerId.cs b/crypto/src/cms/SignerId.cs
index 3d38a58dc..ca84a6cf7 100644
--- a/crypto/src/cms/SignerId.cs
+++ b/crypto/src/cms/SignerId.cs
@@ -1,51 +1,30 @@
 using System;
 
-using Org.BouncyCastle.Asn1.X509;
-using Org.BouncyCastle.Math;
 using Org.BouncyCastle.Utilities;
 using Org.BouncyCastle.X509.Store;
 
 namespace Org.BouncyCastle.Cms
 {
-    /**
-    * a basic index for a signer.
-    */
+    // TODO[api] sealed
     public class SignerID
-        : X509CertStoreSelector
+        : X509CertStoreSelector, IEquatable<SignerID>
     {
-        public override int GetHashCode()
+        public virtual bool Equals(SignerID other)
         {
-            int code = Arrays.GetHashCode(this.SubjectKeyIdentifier);
-
-			BigInteger serialNumber = this.SerialNumber;
-			if (serialNumber != null)
-            {
-                code ^= serialNumber.GetHashCode();
-            }
-
-			X509Name issuer = this.Issuer;
-            if (issuer != null)
-            {
-                code ^= issuer.GetHashCode();
-            }
-
-			return code;
+            return other == null ? false
+                :  other == this ? true
+                :  MatchesSubjectKeyIdentifier(other)
+                && MatchesSerialNumber(other)
+                && MatchesIssuer(other);
         }
 
-        public override bool Equals(
-            object obj)
-        {
-			if (obj == this)
-				return true;
+        public override bool Equals(object obj) => Equals(obj as SignerID);
 
-			SignerID id = obj as SignerID;
-
-			if (id == null)
-				return false;
-
-			return Arrays.AreEqual(SubjectKeyIdentifier, id.SubjectKeyIdentifier)
-				&& Objects.Equals(SerialNumber, id.SerialNumber)
-				&& IssuersMatch(Issuer, id.Issuer);
+        public override int GetHashCode()
+        {
+            return GetHashCodeOfSubjectKeyIdentifier()
+                ^  Objects.GetHashCode(SerialNumber)
+                ^  Objects.GetHashCode(Issuer);
         }
     }
 }