/
message.go
360 lines (322 loc) · 7.26 KB
/
message.go
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//此源码被清华学神尹成大魔王专业翻译分析并修改
//尹成QQ77025077
//尹成微信18510341407
//尹成所在QQ群721929980
//尹成邮箱 yinc13@mails.tsinghua.edu.cn
//尹成毕业于清华大学,微软区块链领域全球最有价值专家
//https://mvp.microsoft.com/zh-cn/PublicProfile/4033620
//
//
//
//
//
//
//
//
//
//
//
//
//
//
//
//
package whisperv5
import (
"crypto/aes"
"crypto/cipher"
"crypto/ecdsa"
crand "crypto/rand"
"encoding/binary"
"errors"
"strconv"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/crypto/ecies"
"github.com/ethereum/go-ethereum/log"
)
//
type MessageParams struct {
TTL uint32
Src *ecdsa.PrivateKey
Dst *ecdsa.PublicKey
KeySym []byte
Topic TopicType
WorkTime uint32
PoW float64
Payload []byte
Padding []byte
}
//
//
//
type sentMessage struct {
Raw []byte
}
//
//
type ReceivedMessage struct {
Raw []byte
Payload []byte
Padding []byte
Signature []byte
PoW float64 //
Sent uint32 //
TTL uint32 //
Src *ecdsa.PublicKey //
Dst *ecdsa.PublicKey //
Topic TopicType
SymKeyHash common.Hash //
EnvelopeHash common.Hash //
EnvelopeVersion uint64
}
func isMessageSigned(flags byte) bool {
return (flags & signatureFlag) != 0
}
func (msg *ReceivedMessage) isSymmetricEncryption() bool {
return msg.SymKeyHash != common.Hash{}
}
func (msg *ReceivedMessage) isAsymmetricEncryption() bool {
return msg.Dst != nil
}
//
func NewSentMessage(params *MessageParams) (*sentMessage, error) {
msg := sentMessage{}
msg.Raw = make([]byte, 1, len(params.Payload)+len(params.Padding)+signatureLength+padSizeLimit)
msg.Raw[0] = 0 //
err := msg.appendPadding(params)
if err != nil {
return nil, err
}
msg.Raw = append(msg.Raw, params.Payload...)
return &msg, nil
}
//
func getSizeOfLength(b []byte) (sz int, err error) {
sz = intSize(len(b)) //
sz = intSize(len(b) + sz) //
if sz > 3 {
err = errors.New("oversized padding parameter")
}
return sz, err
}
//
func intSize(i int) (s int) {
for s = 1; i >= 256; s++ {
i /= 256
}
return s
}
//
//
func (msg *sentMessage) appendPadding(params *MessageParams) error {
rawSize := len(params.Payload) + 1
if params.Src != nil {
rawSize += signatureLength
}
odd := rawSize % padSizeLimit
if len(params.Padding) != 0 {
padSize := len(params.Padding)
padLengthSize, err := getSizeOfLength(params.Padding)
if err != nil {
return err
}
totalPadSize := padSize + padLengthSize
buf := make([]byte, 8)
binary.LittleEndian.PutUint32(buf, uint32(totalPadSize))
buf = buf[:padLengthSize]
msg.Raw = append(msg.Raw, buf...)
msg.Raw = append(msg.Raw, params.Padding...)
msg.Raw[0] |= byte(padLengthSize) //
} else if odd != 0 {
totalPadSize := padSizeLimit - odd
if totalPadSize > 255 {
//
//
//
panic("please fix the padding algorithm before releasing new version")
}
buf := make([]byte, totalPadSize)
_, err := crand.Read(buf[1:])
if err != nil {
return err
}
if totalPadSize > 6 && !validateSymmetricKey(buf) {
return errors.New("failed to generate random padding of size " + strconv.Itoa(totalPadSize))
}
buf[0] = byte(totalPadSize)
msg.Raw = append(msg.Raw, buf...)
msg.Raw[0] |= byte(0x1) //
}
return nil
}
//
//
func (msg *sentMessage) sign(key *ecdsa.PrivateKey) error {
if isMessageSigned(msg.Raw[0]) {
//
log.Error("failed to sign the message: already signed")
return nil
}
msg.Raw[0] |= signatureFlag
hash := crypto.Keccak256(msg.Raw)
signature, err := crypto.Sign(hash, key)
if err != nil {
msg.Raw[0] &= ^signatureFlag //
return err
}
msg.Raw = append(msg.Raw, signature...)
return nil
}
//
func (msg *sentMessage) encryptAsymmetric(key *ecdsa.PublicKey) error {
if !ValidatePublicKey(key) {
return errors.New("invalid public key provided for asymmetric encryption")
}
encrypted, err := ecies.Encrypt(crand.Reader, ecies.ImportECDSAPublic(key), msg.Raw, nil, nil)
if err == nil {
msg.Raw = encrypted
}
return err
}
//
//
func (msg *sentMessage) encryptSymmetric(key []byte) (nonce []byte, err error) {
if !validateSymmetricKey(key) {
return nil, errors.New("invalid key provided for symmetric encryption")
}
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
aesgcm, err := cipher.NewGCM(block)
if err != nil {
return nil, err
}
//
nonce = make([]byte, aesgcm.NonceSize())
_, err = crand.Read(nonce)
if err != nil {
return nil, err
} else if !validateSymmetricKey(nonce) {
return nil, errors.New("crypto/rand failed to generate nonce")
}
msg.Raw = aesgcm.Seal(nil, nonce, msg.Raw, nil)
return nonce, nil
}
//
func (msg *sentMessage) Wrap(options *MessageParams) (envelope *Envelope, err error) {
if options.TTL == 0 {
options.TTL = DefaultTTL
}
if options.Src != nil {
if err = msg.sign(options.Src); err != nil {
return nil, err
}
}
var nonce []byte
if options.Dst != nil {
err = msg.encryptAsymmetric(options.Dst)
} else if options.KeySym != nil {
nonce, err = msg.encryptSymmetric(options.KeySym)
} else {
err = errors.New("unable to encrypt the message: neither symmetric nor assymmetric key provided")
}
if err != nil {
return nil, err
}
envelope = NewEnvelope(options.TTL, options.Topic, nonce, msg)
if err = envelope.Seal(options); err != nil {
return nil, err
}
return envelope, nil
}
//
//
func (msg *ReceivedMessage) decryptSymmetric(key []byte, nonce []byte) error {
block, err := aes.NewCipher(key)
if err != nil {
return err
}
aesgcm, err := cipher.NewGCM(block)
if err != nil {
return err
}
if len(nonce) != aesgcm.NonceSize() {
log.Error("decrypting the message", "AES nonce size", len(nonce))
return errors.New("wrong AES nonce size")
}
decrypted, err := aesgcm.Open(nil, nonce, msg.Raw, nil)
if err != nil {
return err
}
msg.Raw = decrypted
return nil
}
//
func (msg *ReceivedMessage) decryptAsymmetric(key *ecdsa.PrivateKey) error {
decrypted, err := ecies.ImportECDSA(key).Decrypt(msg.Raw, nil, nil)
if err == nil {
msg.Raw = decrypted
}
return err
}
//
func (msg *ReceivedMessage) Validate() bool {
end := len(msg.Raw)
if end < 1 {
return false
}
if isMessageSigned(msg.Raw[0]) {
end -= signatureLength
if end <= 1 {
return false
}
msg.Signature = msg.Raw[end:]
msg.Src = msg.SigToPubKey()
if msg.Src == nil {
return false
}
}
padSize, ok := msg.extractPadding(end)
if !ok {
return false
}
msg.Payload = msg.Raw[1+padSize : end]
return true
}
//
//
//
//
func (msg *ReceivedMessage) extractPadding(end int) (int, bool) {
paddingSize := 0
sz := int(msg.Raw[0] & paddingMask) //
//
if sz != 0 {
paddingSize = int(bytesToUintLittleEndian(msg.Raw[1 : 1+sz]))
if paddingSize < sz || paddingSize+1 > end {
return 0, false
}
msg.Padding = msg.Raw[1+sz : 1+paddingSize]
}
return paddingSize, true
}
//
func (msg *ReceivedMessage) SigToPubKey() *ecdsa.PublicKey {
defer func() { recover() }() //
pub, err := crypto.SigToPub(msg.hash(), msg.Signature)
if err != nil {
log.Error("failed to recover public key from signature", "err", err)
return nil
}
return pub
}
//
func (msg *ReceivedMessage) hash() []byte {
if isMessageSigned(msg.Raw[0]) {
sz := len(msg.Raw) - signatureLength
return crypto.Keccak256(msg.Raw[:sz])
}
return crypto.Keccak256(msg.Raw)
}