internal async Task <(byte[], EncryptionKeyWrapMetadata, InMemoryRawDek)> WrapAsync(
string id,
byte[] key,
string encryptionAlgorithm,
EncryptionKeyWrapMetadata metadata,
CosmosDiagnosticsContext diagnosticsContext,
CancellationToken cancellationToken)
{
EncryptionKeyWrapResult keyWrapResponse = null;
using (diagnosticsContext.CreateScope("WrapDataEncryptionKey"))
{
keyWrapResponse = string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized) && this.DekProvider.EncryptionKeyWrapProvider != null
? await this.DekProvider.EncryptionKeyWrapProvider.WrapKeyAsync(key, metadata, cancellationToken)
: string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.MdeAeadAes256CbcHmac256Randomized) && this.DekProvider.MdeKeyWrapProvider != null
? await this.DekProvider.MdeKeyWrapProvider.WrapKeyAsync(key, metadata, cancellationToken)
: throw new ArgumentException(string.Format(
"Unsupported encryption algorithm {0}." +
" Please initialize the Encryptor or CosmosDataEncryptionKeyProvider with an implementation of the EncryptionKeyStoreProvider / EncryptionKeyWrapProvider.",
encryptionAlgorithm));
}
// Verify
DataEncryptionKeyProperties tempDekProperties = new DataEncryptionKeyProperties(
id,
encryptionAlgorithm,
keyWrapResponse.WrappedDataEncryptionKey,
keyWrapResponse.EncryptionKeyWrapMetadata,
DateTime.UtcNow);
byte[] rawKey = null;
InMemoryRawDek roundTripResponse = null;
if (string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized))
{
roundTripResponse = await this.UnwrapAsync(tempDekProperties, diagnosticsContext, cancellationToken);
rawKey = roundTripResponse.DataEncryptionKey.RawKey;
}
else if (string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.MdeAeadAes256CbcHmac256Randomized))
{
EncryptionKeyUnwrapResult unwrapResult = await this.UnWrapDekMdeEncAlgoAsync(
tempDekProperties,
diagnosticsContext,
cancellationToken);
rawKey = unwrapResult.DataEncryptionKey;
}
if (!rawKey.SequenceEqual(key))
{
throw new InvalidOperationException("The key wrapping provider configured was unable to unwrap the wrapped key correctly.");
}
return(keyWrapResponse.WrappedDataEncryptionKey, keyWrapResponse.EncryptionKeyWrapMetadata, roundTripResponse);
}
/// <inheritdoc/>
public override async Task <DataEncryptionKey> FetchDataEncryptionKeyAsync(
string id,
string encryptionAlgorithm,
CancellationToken cancellationToken)
{
DataEncryptionKeyProperties dataEncryptionKeyProperties = await this.dataEncryptionKeyContainerCore.FetchDataEncryptionKeyPropertiesAsync(
id,
diagnosticsContext : CosmosDiagnosticsContext.Create(null),
cancellationToken : cancellationToken);
// supports Encryption with MDE based algorithm using Legacy Encryption Algorithm Configured DEK.
if (string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.MdeAeadAes256CbcHmac256Randomized) &&
string.Equals(dataEncryptionKeyProperties.EncryptionAlgorithm, CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized))
{
return(await this.dataEncryptionKeyContainerCore.FetchUnWrappedMdeSupportedLegacyDekAsync(
dataEncryptionKeyProperties,
cancellationToken));
}
// supports Encryption with Legacy based algorithm using Mde Encryption Algorithm Configured DEK.
if (string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized) &&
string.Equals(dataEncryptionKeyProperties.EncryptionAlgorithm, CosmosEncryptionAlgorithm.MdeAeadAes256CbcHmac256Randomized))
{
return(await this.dataEncryptionKeyContainerCore.FetchUnWrappedLegacySupportedMdeDekAsync(
dataEncryptionKeyProperties,
encryptionAlgorithm,
diagnosticsContext : CosmosDiagnosticsContext.Create(null),
cancellationToken));
}
InMemoryRawDek inMemoryRawDek = await this.dataEncryptionKeyContainerCore.FetchUnwrappedAsync(
dataEncryptionKeyProperties,
diagnosticsContext : CosmosDiagnosticsContext.Create(null),
cancellationToken : cancellationToken);
return(inMemoryRawDek.DataEncryptionKey);
}
public async Task <InMemoryRawDek> GetOrAddRawDekAsync(
DataEncryptionKeyProperties dekProperties,
Func <DataEncryptionKeyProperties, CosmosDiagnosticsContext, CancellationToken, Task <InMemoryRawDek> > unwrapper,
CosmosDiagnosticsContext diagnosticsContext,
CancellationToken cancellationToken)
{
InMemoryRawDek inMemoryRawDek = await this.RawDekCache.GetAsync(
dekProperties.SelfLink,
null,
() => unwrapper(dekProperties, diagnosticsContext, cancellationToken),
cancellationToken);
if (inMemoryRawDek.RawDekExpiry <= DateTime.UtcNow)
{
inMemoryRawDek = await this.RawDekCache.GetAsync(
dekProperties.SelfLink,
null,
() => unwrapper(dekProperties, diagnosticsContext, cancellationToken),
cancellationToken,
forceRefresh : true);
}
return(inMemoryRawDek);
}
public override async Task <ItemResponse <DataEncryptionKeyProperties> > CreateDataEncryptionKeyAsync(
string id,
string encryptionAlgorithm,
EncryptionKeyWrapMetadata encryptionKeyWrapMetadata,
ItemRequestOptions requestOptions = null,
CancellationToken cancellationToken = default)
{
if (string.IsNullOrEmpty(id))
{
throw new ArgumentNullException(nameof(id));
}
if (!CosmosEncryptionAlgorithm.VerifyIfSupportedAlgorithm(encryptionAlgorithm))
{
throw new ArgumentException(string.Format("Unsupported Encryption Algorithm {0}", encryptionAlgorithm), nameof(encryptionAlgorithm));
}
if (encryptionKeyWrapMetadata == null)
{
throw new ArgumentNullException(nameof(encryptionKeyWrapMetadata));
}
CosmosDiagnosticsContext diagnosticsContext = CosmosDiagnosticsContext.Create(requestOptions);
byte[] wrappedDek = null;
EncryptionKeyWrapMetadata updatedMetadata = null;
InMemoryRawDek inMemoryRawDek = null;
if (string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized))
{
(wrappedDek, updatedMetadata, inMemoryRawDek) = await this.GenerateAndWrapRawDekForLegacyEncAlgoAsync(
id,
encryptionAlgorithm,
encryptionKeyWrapMetadata,
diagnosticsContext,
cancellationToken);
}
else if (string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.MdeAeadAes256CbcHmac256Randomized))
{
(wrappedDek, updatedMetadata) = this.GenerateAndWrapPdekForMdeEncAlgo(encryptionKeyWrapMetadata);
}
DataEncryptionKeyProperties dekProperties = new DataEncryptionKeyProperties(
id,
encryptionAlgorithm,
wrappedDek,
updatedMetadata,
DateTime.UtcNow);
ItemResponse <DataEncryptionKeyProperties> dekResponse = await this.DekProvider.Container.CreateItemAsync(
dekProperties,
new PartitionKey(dekProperties.Id),
cancellationToken : cancellationToken);
this.DekProvider.DekCache.SetDekProperties(id, dekResponse.Resource);
if (string.Equals(encryptionAlgorithm, CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized))
{
this.DekProvider.DekCache.SetRawDek(id, inMemoryRawDek);
}
return(dekResponse);
}
/// <inheritdoc/>
public override async Task <ItemResponse <DataEncryptionKeyProperties> > RewrapDataEncryptionKeyAsync(
string id,
EncryptionKeyWrapMetadata newWrapMetadata,
ItemRequestOptions requestOptions = null,
CancellationToken cancellationToken = default)
{
if (newWrapMetadata == null)
{
throw new ArgumentNullException(nameof(newWrapMetadata));
}
CosmosDiagnosticsContext diagnosticsContext = CosmosDiagnosticsContext.Create(requestOptions);
DataEncryptionKeyProperties dekProperties = await this.FetchDataEncryptionKeyPropertiesAsync(
id,
diagnosticsContext,
cancellationToken);
byte[] rawkey = null;
if (string.Equals(dekProperties.EncryptionAlgorithm, CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized))
{
InMemoryRawDek inMemoryRawDek = await this.FetchUnwrappedAsync(
dekProperties,
diagnosticsContext,
cancellationToken);
rawkey = inMemoryRawDek.DataEncryptionKey.RawKey;
}
else if (string.Equals(dekProperties.EncryptionAlgorithm, CosmosEncryptionAlgorithm.MdeAeadAes256CbcHmac256Randomized))
{
EncryptionKeyUnwrapResult encryptionKeyUnwrapResult = await this.DekProvider.MdeKeyWrapProvider.UnwrapKeyAsync(
dekProperties.WrappedDataEncryptionKey,
dekProperties.EncryptionKeyWrapMetadata,
cancellationToken);
rawkey = encryptionKeyUnwrapResult.DataEncryptionKey;
}
(byte[] wrappedDek, EncryptionKeyWrapMetadata updatedMetadata, InMemoryRawDek updatedRawDek) = await this.WrapAsync(
id,
rawkey,
dekProperties.EncryptionAlgorithm,
newWrapMetadata,
diagnosticsContext,
cancellationToken);
if (requestOptions == null)
{
requestOptions = new ItemRequestOptions();
}
requestOptions.IfMatchEtag = dekProperties.ETag;
DataEncryptionKeyProperties newDekProperties = new DataEncryptionKeyProperties(dekProperties)
{
WrappedDataEncryptionKey = wrappedDek,
EncryptionKeyWrapMetadata = updatedMetadata,
};
ItemResponse <DataEncryptionKeyProperties> response;
try
{
response = await this.DekProvider.Container.ReplaceItemAsync(
newDekProperties,
newDekProperties.Id,
new PartitionKey(newDekProperties.Id),
requestOptions,
cancellationToken);
Debug.Assert(response.Resource != null);
}
catch (CosmosException ex)
{
if (!ex.StatusCode.Equals(HttpStatusCode.PreconditionFailed))
{
throw;
}
// Handle if exception is due to etag mismatch. The scenario is as follows - say there are 2 clients A and B that both have the DEK properties cached.
// From A, rewrap worked and the DEK is updated. Now from B, rewrap was attempted later based on the cached properties which will fail due to etag mismatch.
// To address this, we do an explicit read, which reads the key from storage and updates the cached properties; and then attempt rewrap again.
await this.ReadDataEncryptionKeyAsync(
newDekProperties.Id,
requestOptions,
cancellationToken);
return(await this.RewrapDataEncryptionKeyAsync(
id,
newWrapMetadata,
requestOptions,
cancellationToken));
}
this.DekProvider.DekCache.SetDekProperties(id, response.Resource);
if (string.Equals(dekProperties.EncryptionAlgorithm, CosmosEncryptionAlgorithm.AEAes256CbcHmacSha256Randomized))
{
this.DekProvider.DekCache.SetRawDek(id, updatedRawDek);
}
return(response);
}
public void SetRawDek(string dekId, InMemoryRawDek inMemoryRawDek)
{
this.RawDekCache.Set(dekId, inMemoryRawDek);
}