Avoid infinite recursion in RSAEncryptionPadding equality check

src/libraries/System.Security.Cryptography.Algorithms/src/System/Security/Cryptography/RSAEncryptionPadding.cs

@@ -100,7 +100,7 @@ public override bool Equals(object obj)
 
         public bool Equals(RSAEncryptionPadding other)
         {
-            return other != null
+            return !object.ReferenceEquals(other, null)
                 && _mode == other._mode
                 && _oaepHashAlgorithm == other._oaepHashAlgorithm;
         }

src/libraries/System.Security.Cryptography.Algorithms/tests/RSATests.cs

@@ -192,6 +192,12 @@ public void VerifyDataStream_UsesHashDataAndVerifyHash()
             Assert.True(rsa.VerifyData(new MemoryStream(new byte[] { 42 }), new byte[1] { 24 }, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1));
         }
 
+        [Fact]
+        public void RSAEncryptionPadding_Equals()
+        {
+            Assert.Equal(RSAEncryptionPadding.Pkcs1, RSAEncryptionPadding.Pkcs1);
+        }
+
         private sealed class EmptyRSA : RSA
         {
             public override RSAParameters ExportParameters(bool includePrivateParameters) => throw new NotImplementedException();