77 lines
2.2 KiB
Go
77 lines
2.2 KiB
Go
// Copyright 2016 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library 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 Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package api
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"errors"
|
|
|
|
"github.com/ethereum/go-ethereum/crypto/sha3"
|
|
"github.com/ethereum/go-ethereum/swarm/storage/encryption"
|
|
)
|
|
|
|
type RefEncryption struct {
|
|
spanEncryption encryption.Encryption
|
|
dataEncryption encryption.Encryption
|
|
span []byte
|
|
}
|
|
|
|
func NewRefEncryption(refSize int) *RefEncryption {
|
|
span := make([]byte, 8)
|
|
binary.LittleEndian.PutUint64(span, uint64(refSize))
|
|
return &RefEncryption{
|
|
spanEncryption: encryption.New(0, uint32(refSize/32), sha3.NewKeccak256),
|
|
dataEncryption: encryption.New(refSize, 0, sha3.NewKeccak256),
|
|
span: span,
|
|
}
|
|
}
|
|
|
|
func (re *RefEncryption) Encrypt(ref []byte, key []byte) ([]byte, error) {
|
|
encryptedSpan, err := re.spanEncryption.Encrypt(re.span, key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
encryptedData, err := re.dataEncryption.Encrypt(ref, key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
encryptedRef := make([]byte, len(ref)+8)
|
|
copy(encryptedRef[:8], encryptedSpan)
|
|
copy(encryptedRef[8:], encryptedData)
|
|
|
|
return encryptedRef, nil
|
|
}
|
|
|
|
func (re *RefEncryption) Decrypt(ref []byte, key []byte) ([]byte, error) {
|
|
decryptedSpan, err := re.spanEncryption.Decrypt(ref[:8], key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
size := binary.LittleEndian.Uint64(decryptedSpan)
|
|
if size != uint64(len(ref)-8) {
|
|
return nil, errors.New("invalid span in encrypted reference")
|
|
}
|
|
|
|
decryptedRef, err := re.dataEncryption.Decrypt(ref[8:], key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return decryptedRef, nil
|
|
}
|