mirror of
https://github.com/edgelesssys/constellation.git
synced 2024-12-29 01:16:12 -05:00
5eb73706f5
* Move storage clients to separate packages * Allow setting of client credentials for AWS S3 * Use managed identity client secret or default credentials for Azure Blob Storage * Use credentials file to authorize GCS client --------- Signed-off-by: Daniel Weiße <dw@edgeless.systems>
105 lines
3.5 KiB
Go
105 lines
3.5 KiB
Go
/*
|
|
Copyright (c) Edgeless Systems GmbH
|
|
|
|
SPDX-License-Identifier: AGPL-3.0-only
|
|
*/
|
|
|
|
// Package azureblob implements a storage backend for the KMS using Azure Blob Storage.
|
|
package azureblob
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"fmt"
|
|
"io"
|
|
|
|
"github.com/Azure/azure-sdk-for-go/sdk/azcore"
|
|
"github.com/Azure/azure-sdk-for-go/sdk/azidentity"
|
|
"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob"
|
|
"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob/blob"
|
|
"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob/bloberror"
|
|
"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob/container"
|
|
"github.com/edgelesssys/constellation/v2/internal/kms/config"
|
|
"github.com/edgelesssys/constellation/v2/internal/kms/storage"
|
|
"github.com/edgelesssys/constellation/v2/internal/kms/uri"
|
|
)
|
|
|
|
type azureBlobAPI interface {
|
|
CreateContainer(context.Context, string, *container.CreateOptions) (azblob.CreateContainerResponse, error)
|
|
DownloadStream(context.Context, string, string, *blob.DownloadStreamOptions) (azblob.DownloadStreamResponse, error)
|
|
UploadStream(context.Context, string, string, io.Reader, *azblob.UploadStreamOptions) (azblob.UploadStreamResponse, error)
|
|
}
|
|
|
|
// Storage is an implementation of the Storage interface, storing keys in the Azure Blob Store.
|
|
type Storage struct {
|
|
client azureBlobAPI
|
|
container string
|
|
}
|
|
|
|
// New initializes a storage client using Azure's Blob Storage using the provided config.
|
|
//
|
|
// See the Azure docs for more information: https://azure.microsoft.com/en-us/services/storage/blobs/
|
|
func New(ctx context.Context, cfg uri.AzureBlobConfig) (*Storage, error) {
|
|
var creds azcore.TokenCredential
|
|
|
|
creds, err := azidentity.NewClientSecretCredential(cfg.TenantID, cfg.ClientID, cfg.ClientSecret, nil)
|
|
if err != nil {
|
|
// Fallback: try to load default credentials
|
|
creds, err = azidentity.NewDefaultAzureCredential(nil)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("invalid client-secret credentials. Trying to load default credentials: %w", err)
|
|
}
|
|
}
|
|
|
|
client, err := azblob.NewClient(fmt.Sprintf("https://%s.blob.core.windows.net/", cfg.StorageAccount), creds, nil)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("creating storage client: %w", err)
|
|
}
|
|
|
|
s := &Storage{
|
|
client: client,
|
|
container: cfg.Container,
|
|
}
|
|
|
|
// Try to create a new storage container, continue if it already exists
|
|
if err := s.createContainerOrContinue(ctx); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return s, nil
|
|
}
|
|
|
|
// Get returns a DEK from from Azure Blob Storage by key ID.
|
|
func (s *Storage) Get(ctx context.Context, keyID string) ([]byte, error) {
|
|
res, err := s.client.DownloadStream(ctx, s.container, keyID, nil)
|
|
if err != nil {
|
|
if bloberror.HasCode(err, bloberror.BlobNotFound) {
|
|
return nil, storage.ErrDEKUnset
|
|
}
|
|
return nil, fmt.Errorf("downloading DEK from storage: %w", err)
|
|
}
|
|
defer res.Body.Close()
|
|
return io.ReadAll(res.Body)
|
|
}
|
|
|
|
// Put saves a DEK to Azure Blob Storage by key ID.
|
|
func (s *Storage) Put(ctx context.Context, keyID string, encDEK []byte) error {
|
|
if _, err := s.client.UploadStream(ctx, s.container, keyID, bytes.NewReader(encDEK), nil); err != nil {
|
|
return fmt.Errorf("uploading DEK to storage: %w", err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// createContainerOrContinue creates a new storage container if necessary, or continues if it already exists.
|
|
func (s *Storage) createContainerOrContinue(ctx context.Context) error {
|
|
_, err := s.client.CreateContainer(ctx, s.container, &azblob.CreateContainerOptions{
|
|
Metadata: config.StorageTags,
|
|
})
|
|
if (err == nil) || bloberror.HasCode(err, bloberror.ContainerAlreadyExists) {
|
|
return nil
|
|
}
|
|
|
|
return fmt.Errorf("creating storage container: %w", err)
|
|
}
|