minio/cmd/crypto/header.go
Andreas Auernhammer 8cdf2106b0
refactor cmd/crypto code for SSE handling and parsing (#11045)
This commit refactors the code in `cmd/crypto`
and separates SSE-S3, SSE-C and SSE-KMS.

This commit should not cause any behavior change
except for:
  - `IsRequested(http.Header)`

which now returns the requested type {SSE-C, SSE-S3,
SSE-KMS} and does not consider SSE-C copy headers.

However, SSE-C copy headers alone are anyway not valid.
2020-12-22 09:19:32 -08:00

84 lines
2.8 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"
"crypto/md5"
"encoding/base64"
"net/http"
xhttp "github.com/minio/minio/cmd/http"
)
// RemoveSensitiveHeaders removes confidential encryption
// information - e.g. the SSE-C key - from the HTTP headers.
// It has the same semantics as RemoveSensitiveEntires.
func RemoveSensitiveHeaders(h http.Header) {
h.Del(xhttp.AmzServerSideEncryptionCustomerKey)
h.Del(xhttp.AmzServerSideEncryptionCopyCustomerKey)
h.Del(xhttp.AmzMetaUnencryptedContentLength)
h.Del(xhttp.AmzMetaUnencryptedContentMD5)
}
var (
// SSECopy represents AWS SSE-C for copy requests. It provides
// functionality to handle SSE-C copy requests.
SSECopy = ssecCopy{}
)
type ssecCopy struct{}
// IsRequested returns true if the HTTP headers contains
// at least one SSE-C copy header. Regular SSE-C headers
// are ignored.
func (ssecCopy) IsRequested(h http.Header) bool {
if _, ok := h[xhttp.AmzServerSideEncryptionCopyCustomerAlgorithm]; ok {
return true
}
if _, ok := h[xhttp.AmzServerSideEncryptionCopyCustomerKey]; ok {
return true
}
if _, ok := h[xhttp.AmzServerSideEncryptionCopyCustomerKeyMD5]; ok {
return true
}
return false
}
// ParseHTTP parses the SSE-C copy headers and returns the SSE-C client key
// on success. Regular SSE-C headers are ignored.
func (ssecCopy) ParseHTTP(h http.Header) (key [32]byte, err error) {
if h.Get(xhttp.AmzServerSideEncryptionCopyCustomerAlgorithm) != xhttp.AmzEncryptionAES {
return key, ErrInvalidCustomerAlgorithm
}
if h.Get(xhttp.AmzServerSideEncryptionCopyCustomerKey) == "" {
return key, ErrMissingCustomerKey
}
if h.Get(xhttp.AmzServerSideEncryptionCopyCustomerKeyMD5) == "" {
return key, ErrMissingCustomerKeyMD5
}
clientKey, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCopyCustomerKey))
if err != nil || len(clientKey) != 32 { // The client key must be 256 bits long
return key, ErrInvalidCustomerKey
}
keyMD5, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCopyCustomerKeyMD5))
if md5Sum := md5.Sum(clientKey); err != nil || !bytes.Equal(md5Sum[:], keyMD5) {
return key, ErrCustomerKeyMD5Mismatch
}
copy(key[:], clientKey)
return key, nil
}