private static void ValidateInputForEncrypt(
Stream input,
Encryptor encryptor,
EncryptionOptions encryptionOptions)
{
if (input == null)
{
throw new ArgumentNullException(nameof(input));
}
if (encryptor == null)
{
throw new ArgumentNullException(nameof(encryptor));
}
if (encryptionOptions == null)
{
throw new ArgumentNullException(nameof(encryptionOptions));
}
if (string.IsNullOrWhiteSpace(encryptionOptions.DataEncryptionKeyId))
{
throw new ArgumentNullException(nameof(encryptionOptions.DataEncryptionKeyId));
}
if (string.IsNullOrWhiteSpace(encryptionOptions.EncryptionAlgorithm))
{
throw new ArgumentNullException(nameof(encryptionOptions.EncryptionAlgorithm));
}
if (encryptionOptions.PathsToEncrypt == null)
{
throw new ArgumentNullException(nameof(encryptionOptions.PathsToEncrypt));
}
}
/// <remarks>
/// If there isn't any PathsToEncrypt, input stream will be returned without any modification.
/// Else input stream will be disposed, and a new stream is returned.
/// In case of an exception, input stream won't be disposed, but position will be end of stream.
/// </remarks>
public static async Task <Stream> EncryptAsync(
Stream input,
Encryptor encryptor,
EncryptionOptions encryptionOptions,
CosmosDiagnosticsContext diagnosticsContext,
CancellationToken cancellationToken)
{
EncryptionProcessor.ValidateInputForEncrypt(
input,
encryptor,
encryptionOptions);
if (!encryptionOptions.PathsToEncrypt.Any())
{
return(input);
}
if (!encryptionOptions.PathsToEncrypt.Distinct().SequenceEqual(encryptionOptions.PathsToEncrypt))
{
throw new InvalidOperationException("Duplicate paths in PathsToEncrypt passed via EncryptionOptions.");
}
foreach (string path in encryptionOptions.PathsToEncrypt)
{
if (string.IsNullOrWhiteSpace(path) || path[0] != '/' || path.LastIndexOf('/') != 0)
{
throw new InvalidOperationException($"Invalid path {path ?? string.Empty}, {nameof(encryptionOptions.PathsToEncrypt)}");
}
if (string.Equals(path.Substring(1), "id"))
{
throw new InvalidOperationException($"{nameof(encryptionOptions.PathsToEncrypt)} includes a invalid path: '{path}'.");
}
}
JObject itemJObj = EncryptionProcessor.BaseSerializer.FromStream <JObject>(input);
List <string> pathsEncrypted = new List <string>();
EncryptionProperties encryptionProperties = null;
byte[] plainText = null;
byte[] cipherText = null;
TypeMarker typeMarker;
switch (encryptionOptions.EncryptionAlgorithm)
{
case CosmosEncryptionAlgorithm.MdeAeadAes256CbcHmac256Randomized:
foreach (string pathToEncrypt in encryptionOptions.PathsToEncrypt)
{
string propertyName = pathToEncrypt.Substring(1);
if (!itemJObj.TryGetValue(propertyName, out JToken propertyValue))
{
throw new ArgumentException($"{nameof(encryptionOptions.PathsToEncrypt)} includes a path: '{pathToEncrypt}' which was not found.");
}
if (propertyValue.Type == JTokenType.Null)
{
continue;
}
(typeMarker, plainText) = EncryptionProcessor.Serialize(propertyValue);
cipherText = await encryptor.EncryptAsync(
plainText,
encryptionOptions.DataEncryptionKeyId,
encryptionOptions.EncryptionAlgorithm);
if (cipherText == null)
{
throw new InvalidOperationException($"{nameof(Encryptor)} returned null cipherText from {nameof(EncryptAsync)}.");
}
byte[] cipherTextWithTypeMarker = new byte[cipherText.Length + 1];
cipherTextWithTypeMarker[0] = (byte)typeMarker;
Buffer.BlockCopy(cipherText, 0, cipherTextWithTypeMarker, 1, cipherText.Length);
itemJObj[propertyName] = cipherTextWithTypeMarker;
pathsEncrypted.Add(pathToEncrypt);
}
encryptionProperties = new EncryptionProperties(
encryptionFormatVersion: 3,
encryptionOptions.EncryptionAlgorithm,
encryptionOptions.DataEncryptionKeyId,
encryptedData: null,
pathsEncrypted);
break;
case CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized:
JObject toEncryptJObj = new JObject();
foreach (string pathToEncrypt in encryptionOptions.PathsToEncrypt)
{
string propertyName = pathToEncrypt.Substring(1);
if (!itemJObj.TryGetValue(propertyName, out JToken propertyValue))
{
throw new ArgumentException($"{nameof(encryptionOptions.PathsToEncrypt)} includes a path: '{pathToEncrypt}' which was not found.");
}
toEncryptJObj.Add(propertyName, propertyValue.Value <JToken>());
itemJObj.Remove(propertyName);
}
MemoryStream memoryStream = EncryptionProcessor.BaseSerializer.ToStream <JObject>(toEncryptJObj);
Debug.Assert(memoryStream != null);
Debug.Assert(memoryStream.TryGetBuffer(out _));
plainText = memoryStream.ToArray();
cipherText = await encryptor.EncryptAsync(
plainText,
encryptionOptions.DataEncryptionKeyId,
encryptionOptions.EncryptionAlgorithm,
cancellationToken);
if (cipherText == null)
{
throw new InvalidOperationException($"{nameof(Encryptor)} returned null cipherText from {nameof(EncryptAsync)}.");
}
encryptionProperties = new EncryptionProperties(
encryptionFormatVersion: 2,
encryptionOptions.EncryptionAlgorithm,
encryptionOptions.DataEncryptionKeyId,
encryptedData: cipherText,
encryptionOptions.PathsToEncrypt);
break;
default:
throw new NotSupportedException($"Encryption Algorithm : {encryptionOptions.EncryptionAlgorithm} is not supported.");
}
itemJObj.Add(Constants.EncryptedInfo, JObject.FromObject(encryptionProperties));
input.Dispose();
return(EncryptionProcessor.BaseSerializer.ToStream(itemJObj));
}