minio/pkg/ioutil/ioutil.go
Andreas Auernhammer ca6b4773ed add SSE-C support for HEAD, GET, PUT (#4894)
This change adds server-side-encryption support for HEAD, GET and PUT
operations. This PR only addresses single-part PUTs and GETs without
HTTP ranges.

Further this change adds the concept of reserved object metadata which is required
to make encrypted objects tamper-proof and provide API compatibility to AWS S3.
This PR adds the following reserved metadata entries:
- X-Minio-Internal-Server-Side-Encryption-Iv          ('guarantees' tamper-proof property)
- X-Minio-Internal-Server-Side-Encryption-Kdf         (makes Key-MAC computation negotiable in future)
- X-Minio-Internal-Server-Side-Encryption-Key-Mac     (provides AWS S3 API compatibility)

The prefix `X-Minio_Internal` specifies an internal metadata entry which must not
send to clients. All client requests containing a metadata key starting with `X-Minio-Internal`
must also rejected. This is implemented by a generic-handler.

This PR implements SSE-C separated from client-side-encryption (CSE). This cannot decrypt
server-side-encrypted objects on the client-side. However, clients can encrypted the same object
with CSE and SSE-C.

This PR does not address:
 - SSE-C Copy and Copy part
 - SSE-C GET with HTTP ranges
 - SSE-C multipart PUT
 - SSE-C Gateway

Each point must be addressed in a separate PR.

Added to vendor dir:
 - x/crypto/chacha20poly1305
 - x/crypto/poly1305
 - github.com/minio/sio
2017-11-07 15:18:59 -08:00

62 lines
1.7 KiB
Go

/*
* Minio Cloud Storage, (C) 2017 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 ioutil implements some I/O utility functions which are not covered
// by the standard library.
package ioutil
import (
"io"
)
// WriteOnCloser implements io.WriteCloser and always
// exectues at least one write operation if it is closed.
//
// This can be useful within the context of HTTP. At least
// one write operation must happen to send the HTTP headers
// to the peer.
type WriteOnCloser struct {
io.Writer
hasWritten bool
}
func (w *WriteOnCloser) Write(p []byte) (int, error) {
w.hasWritten = true
return w.Writer.Write(p)
}
// Close closes the WriteOnCloser. It behaves like io.Closer.
func (w *WriteOnCloser) Close() error {
if !w.hasWritten {
_, err := w.Write(nil)
if err != nil {
return err
}
}
if closer, ok := w.Writer.(io.Closer); ok {
return closer.Close()
}
return nil
}
// HasWritten returns true if at least one write operation was performed.
func (w *WriteOnCloser) HasWritten() bool { return w.hasWritten }
// WriteOnClose takes an io.Writer and returns an ioutil.WriteOnCloser.
func WriteOnClose(w io.Writer) *WriteOnCloser {
return &WriteOnCloser{w, false}
}