Handle for null and 0 length

Author: MaddyMicrosoft

src/KeyVault/KeyVault.Test/UnitTests/JwkHelperKeySizeTests.cs

@@ -73,6 +73,17 @@ public void ComputeKeySize_RsaFamilyWithoutModulus_ReturnsNull(string kty)
             Assert.Null(JwkHelper.ComputeKeySize(jwk));
         }
 
+        [Theory]
+        [Trait(Category.AcceptanceType, Category.CheckIn)]
+        [InlineData(JsonWebKeyType.Rsa)]
+        [InlineData(JsonWebKeyType.RsaHsm)]
+        public void ComputeKeySize_RsaFamilyWithEmptyModulus_ReturnsNull(string kty)
+        {
+            // Empty material is "size unknown", not a 0-bit key.
+            var jwk = new JsonWebKey { Kty = kty, N = new byte[0] };
+            Assert.Null(JwkHelper.ComputeKeySize(jwk));
+        }
+
         // ---- ComputeKeySize: oct / oct-HSM ----
 
         [Theory]
@@ -99,6 +110,17 @@ public void ComputeKeySize_OctFamilyWithoutMaterial_ReturnsNull(string kty)
             Assert.Null(JwkHelper.ComputeKeySize(jwk));
         }
 
+        [Theory]
+        [Trait(Category.AcceptanceType, Category.CheckIn)]
+        [InlineData(JsonWebKeyType.Octet)]
+        [InlineData(OctHsm)]
+        public void ComputeKeySize_OctFamilyWithEmptyMaterial_ReturnsNull(string kty)
+        {
+            // Empty material is "size unknown", not a 0-bit key.
+            var jwk = new JsonWebKey { Kty = kty, K = new byte[0] };
+            Assert.Null(JwkHelper.ComputeKeySize(jwk));
+        }
+
         // ---- ComputeKeySize: EC / EC-HSM ----
 
         [Theory]

src/KeyVault/KeyVault/Helpers/JwkHelper.cs

@@ -74,7 +74,7 @@ internal static bool IsEC(string keyType)
 
         private static int? BitsFromByteArray(byte[] material)
         {
-            return material == null ? (int?)null : material.Length * 8;
+            return (material == null || material.Length == 0) ? (int?)null : material.Length * 8;
         }
 
         private static int? BitsFromCurveName(string curveName)

src/KeyVault/KeyVault/Models/Key/PSKeyVaultKeyIdentityItem.cs

@@ -103,7 +103,7 @@ internal PSKeyVaultKeyIdentityItem(Track2Sdk.KeyProperties keyProperties, VaultU
             Created = keyProperties.CreatedOn?.UtcDateTime;
             Updated = keyProperties.UpdatedOn?.UtcDateTime;
             RecoveryLevel = keyProperties.RecoveryLevel;
-            Tags = keyProperties.Tags.ConvertToHashtable();
+            Tags = keyProperties.Tags?.ConvertToHashtable();
             KeySize = keyProperties.KeySize;
 
             IsHsm = isHsm;