minio/pkg/kms/kes.go
Harshavardhana c6b7dc012a
fix: use key.Ciphertext for DecryptKey in KeyStatus (#12313)
enhance GlobalKMS.Stat() for kes to actually perform
a network call to check Version() of kes and also
implicitly that its reachable.
2021-05-18 07:22:31 -07:00

143 lines
4.1 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package kms
import (
"context"
"crypto/tls"
"crypto/x509"
"errors"
"time"
"github.com/minio/kes"
)
// Config contains various KMS-related configuration
// parameters - like KMS endpoints or authentication
// credentials.
type Config struct {
// Endpoints contains a list of KMS server
// HTTP endpoints.
Endpoints []string
// DefaultKeyID is the key ID used when
// no explicit key ID is specified for
// a cryptographic operation.
DefaultKeyID string
// Certificate is the client TLS certificate
// to authenticate to KMS via mTLS.
Certificate tls.Certificate
// RootCAs is a set of root CA certificates
// to verify the KMS server TLS certificate.
RootCAs *x509.CertPool
}
// NewWithConfig returns a new KMS using the given
// configuration.
func NewWithConfig(config Config) (KMS, error) {
if len(config.Endpoints) == 0 {
return nil, errors.New("kms: no server endpoints")
}
var endpoints = make([]string, len(config.Endpoints)) // Copy => avoid being affect by any changes to the original slice
copy(endpoints, config.Endpoints)
client := kes.NewClientWithConfig("", &tls.Config{
MinVersion: tls.VersionTLS12,
Certificates: []tls.Certificate{config.Certificate},
RootCAs: config.RootCAs,
})
client.Endpoints = endpoints
return &kesClient{
client: client,
defaultKeyID: config.DefaultKeyID,
}, nil
}
type kesClient struct {
defaultKeyID string
client *kes.Client
}
var _ KMS = (*kesClient)(nil) // compiler check
// Stat returns the current KES status containing a
// list of KES endpoints and the default key ID.
func (c *kesClient) Stat() (Status, error) {
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
if _, err := c.client.Version(ctx); err != nil {
return Status{}, err
}
var endpoints = make([]string, len(c.client.Endpoints))
copy(endpoints, c.client.Endpoints)
return Status{
Name: "KES",
Endpoints: endpoints,
DefaultKey: c.defaultKeyID,
}, nil
}
// CreateKey tries to create a new key at the KMS with the
// given key ID.
//
// If the a key with the same keyID already exists then
// CreateKey returns kes.ErrKeyExists.
func (c *kesClient) CreateKey(keyID string) error {
return c.client.CreateKey(context.Background(), keyID)
}
// GenerateKey generates a new data encryption key using
// the key at the KES server referenced by the key ID.
//
// The default key ID will be used if keyID is empty.
//
// The context is associated and tied to the generated DEK.
// The same context must be provided when the generated
// key should be decrypted.
func (c *kesClient) GenerateKey(keyID string, ctx Context) (DEK, error) {
if keyID == "" {
keyID = c.defaultKeyID
}
ctxBytes, err := ctx.MarshalText()
if err != nil {
return DEK{}, err
}
dek, err := c.client.GenerateKey(context.Background(), keyID, ctxBytes)
if err != nil {
return DEK{}, err
}
return DEK{
KeyID: keyID,
Plaintext: dek.Plaintext,
Ciphertext: dek.Ciphertext,
}, nil
}
// DecryptKey decrypts the ciphertext with the key at the KES
// server referenced by the key ID. The context must match the
// context value used to generate the ciphertext.
func (c *kesClient) DecryptKey(keyID string, ciphertext []byte, ctx Context) ([]byte, error) {
ctxBytes, err := ctx.MarshalText()
if err != nil {
return nil, err
}
return c.client.Decrypt(context.Background(), keyID, ciphertext, ctxBytes)
}