Make sure IV for AES-CBC is initialized (Azure#16176)

Relates to Azure#14887

Author: heaths

sdk/keyvault/Azure.Security.KeyVault.Keys/src/Cryptography/AesCryptographyProvider.cs

@@ -81,6 +81,9 @@ public override EncryptResult Encrypt(EncryptOptions options, CancellationToken
             EncryptionAlgorithm algorithm = options.Algorithm;
             if (algorithm.GetAesCbcEncryptionAlgorithm() is AesCbc aesCbc)
             {
+                // Make sure the IV is initialized.
+                options.Initialize();
+
                 using ICryptoTransform encryptor = aesCbc.CreateEncryptor(KeyMaterial.K, options.Iv);
 
                 byte[] plaintext = options.Plaintext;

sdk/keyvault/Azure.Security.KeyVault.Keys/src/Cryptography/RemoteCryptographyClient.cs

@@ -49,6 +49,10 @@ public virtual async Task<Response<EncryptResult>> EncryptAsync(EncryptOptions o
 
             try
             {
+                // Make sure the IV is initialized.
+                // TODO: Remove this call once the service will initialized it: https://github.com/Azure/azure-sdk-for-net/issues/16175
+                options.Initialize();
+
                 return await Pipeline.SendRequestAsync(RequestMethod.Post, options, () => new EncryptResult { Algorithm = options.Algorithm }, cancellationToken, "/encrypt").ConfigureAwait(false);
             }
             catch (Exception e)
@@ -66,6 +70,10 @@ public virtual Response<EncryptResult> Encrypt(EncryptOptions options, Cancellat
 
             try
             {
+                // Make sure the IV is initialized.
+                // TODO: Remove this call once the service will initialized it: https://github.com/Azure/azure-sdk-for-net/issues/16175
+                options.Initialize();
+
                 return Pipeline.SendRequest(RequestMethod.Post, options, () => new EncryptResult { Algorithm = options.Algorithm }, cancellationToken, "/encrypt");
             }
             catch (Exception e)

sdk/keyvault/Azure.Security.KeyVault.Keys/tests/AesCryptographyProviderTests.cs

@@ -137,7 +137,7 @@ public void DecryptionAlgorithmNotSupported()
             Assert.AreEqual("invalid", e.GetProperty<string>("algorithm"));
         }
 
-        [TestCaseSource(nameof(EncryptDecryptRoundtripsData))]
+        [TestCaseSource(nameof(GetEncryptionAlgorithms), methodParams: new object[] { true })]
         public void EncryptDecryptRoundtrips(EncryptionAlgorithm algorithm)
         {
             // Use a 256-bit key which will be truncated based on the selected algorithm.
@@ -171,6 +171,73 @@ public void EncryptDecryptRoundtrips(EncryptionAlgorithm algorithm)
 #endif
             Assert.IsNotNull(encrypted);
 
+            switch (algorithm.ToString())
+            {
+                // TODO: Move to new test to make sure CryptoClient and LocalCryptoClient initialize a null ICM for AES-CBC(PAD).
+                case EncryptionAlgorithm.A128CbcValue:
+                    CollectionAssert.AreEqual(
+                        new byte[] { 0x63, 0x23, 0x21, 0xaf, 0x94, 0xf9, 0xe1, 0x21, 0xc2, 0xbd, 0xb1, 0x1b, 0x04, 0x89, 0x8c, 0x3a },
+                        encrypted.Ciphertext);
+                    CollectionAssert.AreEqual(iv, encrypted.Iv);
+                    Assert.IsNull(encrypted.AuthenticationTag);
+                    Assert.IsNull(encrypted.AdditionalAuthenticatedData);
+                    break;
+
+                case EncryptionAlgorithm.A192CbcValue:
+                    CollectionAssert.AreEqual(
+                        new byte[] { 0x95, 0x9d, 0x75, 0x91, 0x09, 0x8b, 0x70, 0x0b, 0x9c, 0xfe, 0xaf, 0xcd, 0x60, 0x1f, 0xaa, 0x79 },
+                        encrypted.Ciphertext);
+                    CollectionAssert.AreEqual(iv, encrypted.Iv);
+                    Assert.IsNull(encrypted.AuthenticationTag);
+                    Assert.IsNull(encrypted.AdditionalAuthenticatedData);
+                    break;
+
+                case EncryptionAlgorithm.A256CbcValue:
+                    CollectionAssert.AreEqual(
+                        new byte[] { 0xf4, 0xe8, 0x5a, 0xa4, 0xa8, 0xb3, 0xff, 0xc3, 0x85, 0x89, 0x17, 0x9a, 0x70, 0x09, 0x96, 0x7f },
+                        encrypted.Ciphertext);
+                    CollectionAssert.AreEqual(iv, encrypted.Iv);
+                    Assert.IsNull(encrypted.AuthenticationTag);
+                    Assert.IsNull(encrypted.AdditionalAuthenticatedData);
+                    break;
+
+                case EncryptionAlgorithm.A128CbcPadValue:
+                    CollectionAssert.AreEqual(
+                        new byte[] { 0xec, 0xb2, 0x63, 0x4c, 0xe0, 0x04, 0xe0, 0x31, 0x2d, 0x9a, 0x77, 0xb2, 0x11, 0xe5, 0x28, 0x7f },
+                        encrypted.Ciphertext);
+                    CollectionAssert.AreEqual(iv, encrypted.Iv);
+                    Assert.IsNull(encrypted.AuthenticationTag);
+                    Assert.IsNull(encrypted.AdditionalAuthenticatedData);
+                    break;
+
+                case EncryptionAlgorithm.A192CbcPadValue:
+                    CollectionAssert.AreEqual(
+                        new byte[] { 0xc3, 0x4e, 0x1b, 0xe7, 0x6e, 0xa1, 0xf1, 0xc3, 0x24, 0xae, 0x05, 0x1b, 0x0e, 0x32, 0xac, 0xb4 },
+                        encrypted.Ciphertext);
+                    CollectionAssert.AreEqual(iv, encrypted.Iv);
+                    Assert.IsNull(encrypted.AuthenticationTag);
+                    Assert.IsNull(encrypted.AdditionalAuthenticatedData);
+                    break;
+
+                case EncryptionAlgorithm.A256CbcPadValue:
+                    CollectionAssert.AreEqual(
+                        new byte[] { 0x4e, 0xbd, 0x78, 0xda, 0x90, 0x73, 0xc8, 0x97, 0x67, 0x2b, 0xa1, 0x0a, 0x41, 0x67, 0xf8, 0x99 },
+                        encrypted.Ciphertext);
+                    CollectionAssert.AreEqual(iv, encrypted.Iv);
+                    Assert.IsNull(encrypted.AuthenticationTag);
+                    Assert.IsNull(encrypted.AdditionalAuthenticatedData);
+                    break;
+
+                case EncryptionAlgorithm.A128GcmValue:
+                case EncryptionAlgorithm.A192GcmValue:
+                case EncryptionAlgorithm.A256GcmValue:
+                    Assert.IsNotNull(encrypted.Ciphertext);
+                    Assert.IsNotNull(encrypted.Iv);
+                    Assert.IsNotNull(encrypted.AuthenticationTag);
+                    CollectionAssert.AreEqual(aad, encrypted.AdditionalAuthenticatedData);
+                    break;
+            }
+
             DecryptOptions decryptOptions = algorithm.IsAesGcm() ?
                 new DecryptOptions(algorithm, encrypted.Ciphertext, encrypted.Iv, encrypted.AuthenticationTag, encrypted.AdditionalAuthenticatedData) :
                 new DecryptOptions(algorithm, encrypted.Ciphertext, encrypted.Iv);
@@ -182,19 +249,52 @@ public void EncryptDecryptRoundtrips(EncryptionAlgorithm algorithm)
             StringAssert.StartsWith("plaintext", Encoding.UTF8.GetString(decrypted.Plaintext));
         }
 
-        private static IEnumerable EncryptDecryptRoundtripsData => new[]
+        [TestCaseSource(nameof(GetEncryptionAlgorithms), methodParams: new object[] { false })]
+        public void InitializesIv(EncryptionAlgorithm algorithm)
+        {
+            // Use a 256-bit key which will be truncated based on the selected algorithm.
+            byte[] k = new byte[] { 0xe2, 0x7e, 0xd0, 0xc8, 0x45, 0x12, 0xbb, 0xd5, 0x5b, 0x6a, 0xf4, 0x34, 0xd2, 0x37, 0xc1, 0x1f, 0xeb, 0xa3, 0x11, 0x87, 0x0f, 0x80, 0xf2, 0xc2, 0xe3, 0x36, 0x42, 0x60, 0xf3, 0x1c, 0x82, 0xc8 };
+
+            JsonWebKey key = new JsonWebKey(new[] { KeyOperation.Encrypt, KeyOperation.Decrypt })
+            {
+                K = k,
+            };
+
+            AesCryptographyProvider provider = new AesCryptographyProvider(key, null);
+
+            byte[] plaintext = Encoding.UTF8.GetBytes("plaintext");
+
+            EncryptOptions encryptOptions = new EncryptOptions(algorithm, plaintext, null, null);
+            EncryptResult encrypted = provider.Encrypt(encryptOptions, default);
+
+            Assert.IsNotNull(encryptOptions.Iv);
+            CollectionAssert.AreEqual(encryptOptions.Iv, encrypted.Iv);
+
+            DecryptOptions decryptOptions = new DecryptOptions(algorithm, encrypted.Ciphertext, encrypted.Iv);
+            DecryptResult decrypted = provider.Decrypt(decryptOptions, default);
+
+            Assert.IsNotNull(decrypted);
+
+            // AES-CBC will be zero-padded.
+            StringAssert.StartsWith("plaintext", Encoding.UTF8.GetString(decrypted.Plaintext));
+        }
+
+        private static IEnumerable GetEncryptionAlgorithms(bool includeAesGcm)
         {
-            EncryptionAlgorithm.A128Cbc,
-            EncryptionAlgorithm.A192Cbc,
-            EncryptionAlgorithm.A256Cbc,
-
-            EncryptionAlgorithm.A128CbcPad,
-            EncryptionAlgorithm.A192CbcPad,
-            EncryptionAlgorithm.A256CbcPad,
-
-            EncryptionAlgorithm.A128Gcm,
-            EncryptionAlgorithm.A192Gcm,
-            EncryptionAlgorithm.A256Gcm,
-        };
+            yield return EncryptionAlgorithm.A128Cbc;
+            yield return EncryptionAlgorithm.A192Cbc;
+            yield return EncryptionAlgorithm.A256Cbc;
+
+            yield return EncryptionAlgorithm.A128CbcPad;
+            yield return EncryptionAlgorithm.A192CbcPad;
+            yield return EncryptionAlgorithm.A256CbcPad;
+
+            if (includeAesGcm)
+            {
+                yield return EncryptionAlgorithm.A128Gcm;
+                yield return EncryptionAlgorithm.A192Gcm;
+                yield return EncryptionAlgorithm.A256Gcm;
+            }
+        }
     }
 }