* crypto: add support for parsing SSE-C/SSE-S3 metadata This commit adds support for detecting and parsing SSE-C/SSE-S3 object metadata. With the `IsEncrypted` functions it is possible to determine whether an object seems to be encrypted. With the `ParseMetadata` functions it is possible to validate such metadata and extract the SSE-C/SSE-S3 related values. It also fixes some naming issues. * crypto: add functions for creating SSE object metadata This commit adds functions for creating SSE-S3 and SSE-C metadata. It also adds a `CreateMultipartMetadata` for creating multipart metadata. For all functions unit tests are included.
138 lines
4.2 KiB
Go
138 lines
4.2 KiB
Go
// Minio Cloud Storage, (C) 2015, 2016, 2017, 2018 Minio, Inc.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package crypto
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"crypto/hmac"
|
|
"crypto/rand"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"sort"
|
|
|
|
"github.com/minio/minio/cmd/logger"
|
|
sha256 "github.com/minio/sha256-simd"
|
|
"github.com/minio/sio"
|
|
)
|
|
|
|
// Context is a list of key-value pairs cryptographically
|
|
// associated with a certain object.
|
|
type Context map[string]string
|
|
|
|
// WriteTo writes the context in a canonical from to w.
|
|
// It returns the number of bytes and the first error
|
|
// encounter during writing to w, if any.
|
|
//
|
|
// WriteTo sorts the context keys and writes the sorted
|
|
// key-value pairs as canonical JSON object to w.
|
|
func (c Context) WriteTo(w io.Writer) (n int64, err error) {
|
|
sortedKeys := make(sort.StringSlice, 0, len(c))
|
|
for k := range c {
|
|
sortedKeys = append(sortedKeys, k)
|
|
}
|
|
sort.Sort(sortedKeys)
|
|
|
|
nn, err := io.WriteString(w, "{")
|
|
if err != nil {
|
|
return n + int64(nn), err
|
|
}
|
|
n += int64(nn)
|
|
for i, k := range sortedKeys {
|
|
s := fmt.Sprintf("\"%s\":\"%s\",", k, c[k])
|
|
if i == len(sortedKeys)-1 {
|
|
s = s[:len(s)-1] // remove last ','
|
|
}
|
|
|
|
nn, err = io.WriteString(w, s)
|
|
if err != nil {
|
|
return n + int64(nn), err
|
|
}
|
|
n += int64(nn)
|
|
}
|
|
nn, err = io.WriteString(w, "}")
|
|
return n + int64(nn), err
|
|
}
|
|
|
|
// KMS represents an active and authenticted connection
|
|
// to a Key-Management-Service. It supports generating
|
|
// data key generation and unsealing of KMS-generated
|
|
// data keys.
|
|
type KMS interface {
|
|
// GenerateKey generates a new random data key using
|
|
// the master key referenced by the keyID. It returns
|
|
// the plaintext key and the sealed plaintext key
|
|
// on success.
|
|
//
|
|
// The context is cryptographically bound to the
|
|
// generated key. The same context must be provided
|
|
// again to unseal the generated key.
|
|
GenerateKey(keyID string, context Context) (key [32]byte, sealedKey []byte, err error)
|
|
|
|
// UnsealKey unseals the sealedKey using the master key
|
|
// referenced by the keyID. The provided context must
|
|
// match the context used to generate the sealed key.
|
|
UnsealKey(keyID string, sealedKey []byte, context Context) (key [32]byte, err error)
|
|
}
|
|
|
|
type masterKeyKMS struct {
|
|
masterKey [32]byte
|
|
}
|
|
|
|
// NewKMS returns a basic KMS implementation from a single 256 bit master key.
|
|
//
|
|
// The KMS accepts any keyID but binds the keyID and context cryptographically
|
|
// to the generated keys.
|
|
func NewKMS(key [32]byte) KMS { return &masterKeyKMS{masterKey: key} }
|
|
|
|
func (kms *masterKeyKMS) GenerateKey(keyID string, ctx Context) (key [32]byte, sealedKey []byte, err error) {
|
|
if _, err = io.ReadFull(rand.Reader, key[:]); err != nil {
|
|
logger.CriticalIf(context.Background(), errOutOfEntropy)
|
|
}
|
|
|
|
var (
|
|
buffer bytes.Buffer
|
|
derivedKey = kms.deriveKey(keyID, ctx)
|
|
)
|
|
if n, err := sio.Encrypt(&buffer, bytes.NewReader(key[:]), sio.Config{Key: derivedKey[:]}); err != nil || n != 64 {
|
|
logger.CriticalIf(context.Background(), errors.New("KMS: unable to encrypt data key"))
|
|
}
|
|
sealedKey = buffer.Bytes()
|
|
return key, sealedKey, nil
|
|
}
|
|
|
|
func (kms *masterKeyKMS) UnsealKey(keyID string, sealedKey []byte, ctx Context) (key [32]byte, err error) {
|
|
var (
|
|
buffer bytes.Buffer
|
|
derivedKey = kms.deriveKey(keyID, ctx)
|
|
)
|
|
if n, err := sio.Decrypt(&buffer, bytes.NewReader(sealedKey), sio.Config{Key: derivedKey[:]}); err != nil || n != 32 {
|
|
return key, err // TODO(aead): upgrade sio to use sio.Error
|
|
}
|
|
copy(key[:], buffer.Bytes())
|
|
return key, nil
|
|
}
|
|
|
|
func (kms *masterKeyKMS) deriveKey(keyID string, context Context) (key [32]byte) {
|
|
if context == nil {
|
|
context = Context{}
|
|
}
|
|
mac := hmac.New(sha256.New, kms.masterKey[:])
|
|
mac.Write([]byte(keyID))
|
|
context.WriteTo(mac)
|
|
mac.Sum(key[:0])
|
|
return key
|
|
}
|