Co-authored-by: Janos Guljas <janos@resenje.org> Co-authored-by: Anton Evangelatov <anton.evangelatov@gmail.com> Co-authored-by: Balint Gabor <balint.g@gmail.com>
		
			
				
	
	
		
			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
 | 
						|
}
 |