minio/internal/crypto/sse.go

127 lines
4.2 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 crypto
import (
"context"
"errors"
"fmt"
"io"
"net/http"
"github.com/minio/minio/internal/fips"
"github.com/minio/minio/internal/ioutil"
"github.com/minio/minio/internal/logger"
"github.com/minio/sio"
)
const (
// SealAlgorithm is the encryption/sealing algorithm used to derive & seal
// the key-encryption-key and to en/decrypt the object data.
SealAlgorithm = "DAREv2-HMAC-SHA256"
// InsecureSealAlgorithm is the legacy encryption/sealing algorithm used
// to derive & seal the key-encryption-key and to en/decrypt the object data.
// This algorithm should not be used for new objects because its key derivation
// is not optimal. See: https://github.com/minio/minio/pull/6121
InsecureSealAlgorithm = "DARE-SHA256"
)
// Type represents an AWS SSE type:
// • SSE-C
// • SSE-S3
// • SSE-KMS
type Type interface {
fmt.Stringer
IsRequested(http.Header) bool
IsEncrypted(map[string]string) bool
}
// IsRequested returns true and the SSE Type if the HTTP headers
// indicate that some form server-side encryption is requested.
//
// If no SSE headers are present then IsRequested returns false
// and no Type.
func IsRequested(h http.Header) (Type, bool) {
switch {
case S3.IsRequested(h):
return S3, true
case S3KMS.IsRequested(h):
return S3KMS, true
case SSEC.IsRequested(h):
return SSEC, true
default:
return nil, false
}
}
// UnsealObjectKey extracts and decrypts the sealed object key
// from the metadata using the SSE-Copy client key of the HTTP headers
// and returns the decrypted object key.
func (sse ssecCopy) UnsealObjectKey(h http.Header, metadata map[string]string, bucket, object string) (key ObjectKey, err error) {
clientKey, err := sse.ParseHTTP(h)
if err != nil {
return
}
return unsealObjectKey(clientKey[:], metadata, bucket, object)
}
// unsealObjectKey decrypts and returns the sealed object key
// from the metadata using the SSE-C client key.
func unsealObjectKey(clientKey []byte, metadata map[string]string, bucket, object string) (key ObjectKey, err error) {
sealedKey, err := SSEC.ParseMetadata(metadata)
if err != nil {
return
}
err = key.Unseal(clientKey, sealedKey, SSEC.String(), bucket, object)
return
}
// EncryptSinglePart encrypts an io.Reader which must be the
// the body of a single-part PUT request.
func EncryptSinglePart(r io.Reader, key ObjectKey) io.Reader {
r, err := sio.EncryptReader(r, sio.Config{MinVersion: sio.Version20, Key: key[:], CipherSuites: fips.CipherSuitesDARE()})
if err != nil {
logger.CriticalIf(context.Background(), errors.New("Unable to encrypt io.Reader using object key"))
}
return r
}
// EncryptMultiPart encrypts an io.Reader which must be the body of
// multi-part PUT request. It derives an unique encryption key from
// the partID and the object key.
func EncryptMultiPart(r io.Reader, partID int, key ObjectKey) io.Reader {
partKey := key.DerivePartKey(uint32(partID))
return EncryptSinglePart(r, ObjectKey(partKey))
}
// DecryptSinglePart decrypts an io.Writer which must an object
// uploaded with the single-part PUT API. The offset and length
// specify the requested range.
func DecryptSinglePart(w io.Writer, offset, length int64, key ObjectKey) io.WriteCloser {
const PayloadSize = 1 << 16 // DARE 2.0
w = ioutil.LimitedWriter(w, offset%PayloadSize, length)
decWriter, err := sio.DecryptWriter(w, sio.Config{Key: key[:], CipherSuites: fips.CipherSuitesDARE()})
if err != nil {
logger.CriticalIf(context.Background(), errors.New("Unable to decrypt io.Writer using object key"))
}
return decWriter
}