constellation/s3proxy/internal/kms/kms.go
2024-02-08 14:20:01 +00:00

77 lines
2.0 KiB
Go

/*
Copyright (c) Edgeless Systems GmbH
SPDX-License-Identifier: AGPL-3.0-only
*/
/*
Package kms is used to interact with the Constellation keyservice.
So far it is a copy of the joinservice's kms package.
*/
package kms
import (
"context"
"fmt"
"log/slog"
"github.com/edgelesssys/constellation/v2/keyservice/keyserviceproto"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials/insecure"
)
// Client interacts with Constellation's keyservice.
type Client struct {
log *slog.Logger
endpoint string
grpc grpcClient
}
// New creates a new KMS.
func New(log *slog.Logger, endpoint string) Client {
return Client{
log: log,
endpoint: endpoint,
grpc: client{},
}
}
// GetDataKey returns a data encryption key for the given UUID.
func (c Client) GetDataKey(ctx context.Context, keyID string, length int) ([]byte, error) {
log := c.log.With("keyID", keyID, "endpoint", c.endpoint)
// the KMS does not use aTLS since traffic is only routed through the Constellation cluster
// cluster internal connections are considered trustworthy
log.Info("Connecting to KMS")
conn, err := grpc.DialContext(ctx, c.endpoint, grpc.WithTransportCredentials(insecure.NewCredentials()))
if err != nil {
return nil, err
}
defer conn.Close()
log.Info("Requesting data key")
res, err := c.grpc.GetDataKey(
ctx,
&keyserviceproto.GetDataKeyRequest{
DataKeyId: keyID,
Length: uint32(length),
},
conn,
)
if err != nil {
return nil, fmt.Errorf("fetching data encryption key from Constellation KMS: %w", err)
}
log.Info("Data key request successful")
return res.DataKey, nil
}
type grpcClient interface {
GetDataKey(context.Context, *keyserviceproto.GetDataKeyRequest, *grpc.ClientConn) (*keyserviceproto.GetDataKeyResponse, error)
}
type client struct{}
func (c client) GetDataKey(ctx context.Context, req *keyserviceproto.GetDataKeyRequest, conn *grpc.ClientConn) (*keyserviceproto.GetDataKeyResponse, error) {
return keyserviceproto.NewAPIClient(conn).GetDataKey(ctx, req)
}