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whisper: message format changed

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This commit is contained in:
Vlad 2018-01-11 13:51:36 +02:00
parent 74eebe8fca
commit aa1a72fae4
7 changed files with 69 additions and 90 deletions
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6
whisper/whisperv6/api.go
View file

@ -277,7 +277,7 @@ func (api *PublicWhisperAPI) Post(ctx context.Context, req NewMessage) (bool, er
if params.KeySym, err = api.w.GetSymKey(req.SymKeyID); err != nil {
return false, err
}
if !validateSymmetricKey(params.KeySym) {
if !validateRandomData(params.KeySym, aesKeyLength) {
return false, ErrInvalidSymmetricKey
}
}
@ -383,7 +383,7 @@ func (api *PublicWhisperAPI) Messages(ctx context.Context, crit Criteria) (*rpc.
if err != nil {
return nil, err
}
if !validateSymmetricKey(key) {
if !validateRandomData(key, aesKeyLength) {
return nil, ErrInvalidSymmetricKey
}
filter.KeySym = key
@ -555,7 +555,7 @@ func (api *PublicWhisperAPI) NewMessageFilter(req Criteria) (string, error) {
if keySym, err = api.w.GetSymKey(req.SymKeyID); err != nil {
return "", err
}
if !validateSymmetricKey(keySym) {
if !validateRandomData(keySym, aesKeyLength) {
return "", ErrInvalidSymmetricKey
}
}

2
whisper/whisperv6/doc.go
View file

@ -54,7 +54,7 @@ const (
TopicLength = 4 // in bytes
signatureLength = 65 // in bytes
aesKeyLength = 32 // in bytes
AESNonceLength = 12 // in bytes; also returned by aesgcm.NonceSize()
aesNonceLength = 12 // in bytes; for more info please see cipher.gcmStandardNonceSize & aesgcm.NonceSize()
keyIdSize = 32 // in bytes
bloomFilterSize = 64 // in bytes

62
whisper/whisperv6/message.go
View file

@ -55,7 +55,7 @@ type sentMessage struct {
}
// ReceivedMessage represents a data packet to be received through the
// Whisper protocol.
// Whisper protocol and successfully decrypted.
type ReceivedMessage struct {
Raw []byte
@ -71,7 +71,7 @@ type ReceivedMessage struct {
Dst *ecdsa.PublicKey // Message recipient (identity used to decode the message)
Topic TopicType
SymKeyHash common.Hash // The Keccak256Hash of the key, associated with the Topic
SymKeyHash common.Hash // The Keccak256Hash of the key
EnvelopeHash common.Hash // Message envelope hash to act as a unique id
}
@ -131,9 +131,6 @@ func (msg *sentMessage) appendPadding(params *MessageParams) error {
if params.Src != nil {
rawSize += signatureLength
}
if params.KeySym != nil {
rawSize += AESNonceLength
}
odd := rawSize % padSizeLimit
paddingSize := padSizeLimit - odd
pad := make([]byte, paddingSize)
@ -141,7 +138,7 @@ func (msg *sentMessage) appendPadding(params *MessageParams) error {
if err != nil {
return err
}
if !validateSymmetricKey(pad) {
if !validateRandomData(pad, paddingSize) {
return errors.New("failed to generate random padding of size " + strconv.Itoa(paddingSize))
}
msg.Raw = append(msg.Raw, pad...)
@ -183,8 +180,8 @@ func (msg *sentMessage) encryptAsymmetric(key *ecdsa.PublicKey) error {
// encryptSymmetric encrypts a message with a topic key, using AES-GCM-256.
// nonce size should be 12 bytes (see cipher.gcmStandardNonceSize).
func (msg *sentMessage) encryptSymmetric(key []byte) (err error) {
if !validateSymmetricKey(key) {
return errors.New("invalid key provided for symmetric encryption")
if !validateRandomData(key, aesKeyLength) {
return errors.New("invalid key provided for symmetric encryption, size: " + strconv.Itoa(len(key)))
}
block, err := aes.NewCipher(key)
if err != nil {
@ -194,7 +191,7 @@ func (msg *sentMessage) encryptSymmetric(key []byte) (err error) {
if err != nil {
return err
}
salt, err := generateSalt(aesgcm)
salt, err := generateSecureRandomData(aesNonceLength) // never use more than 2^32 random nonces with a given key
if err != nil {
return err
}
@ -203,32 +200,35 @@ func (msg *sentMessage) encryptSymmetric(key []byte) (err error) {
return nil
}
func generateSalt(aesgcm cipher.AEAD) ([]byte, error) {
// never use more than 2^32 random nonces with a given key
sz := aesgcm.NonceSize()
x1 := make([]byte, sz)
x2 := make([]byte, sz)
salt := make([]byte, sz)
// generateSecureRandomData generates random data where extra security is required.
// The purpose of this function is to prevent some bugs in software or in hardware
// from delivering not-very-random data. This is especially useful for AES nonce,
// where true randomness does not really matter, but it is very important to have
// a unique nonce for every message.
func generateSecureRandomData(length int) ([]byte, error) {
x := make([]byte, length)
y := make([]byte, length)
res := make([]byte, length)
_, err := crand.Read(x1)
_, err := crand.Read(x)
if err != nil {
return nil, err
} else if !validateSymmetricKey(x1) {
return nil, errors.New("crypto/rand failed to generate salt")
} else if !validateRandomData(x, length) {
return nil, errors.New("crypto/rand failed to generate secure random data")
}
_, err = mrand.Read(x2)
_, err = mrand.Read(y)
if err != nil {
return nil, err
} else if !validateSymmetricKey(x2) {
return nil, errors.New("math/rand failed to generate salt")
} else if !validateRandomData(y, length) {
return nil, errors.New("math/rand failed to generate secure random data")
}
for i := 0; i < sz; i++ {
salt[i] = x1[i] ^ x2[i]
for i := 0; i < length; i++ {
res[i] = x[i] ^ y[i]
}
if !validateSymmetricKey(salt) {
return nil, errors.New("failed to generate salt")
if !validateRandomData(res, length) {
return nil, errors.New("failed to generate secure random data")
}
return salt, nil
return res, nil
}
// Wrap bundles the message into an Envelope to transmit over the network.
@ -263,10 +263,10 @@ func (msg *sentMessage) Wrap(options *MessageParams) (envelope *Envelope, err er
// nonce size should be 12 bytes (see cipher.gcmStandardNonceSize).
func (msg *ReceivedMessage) decryptSymmetric(key []byte) error {
// symmetric messages are expected to contain the 12-byte nonce at the end of the payload
if len(msg.Raw) < AESNonceLength {
if len(msg.Raw) < aesNonceLength {
return errors.New("missing salt or invalid payload in symmetric message")
}
salt := msg.Raw[len(msg.Raw)-AESNonceLength:]
salt := msg.Raw[len(msg.Raw)-aesNonceLength:]
block, err := aes.NewCipher(key)
if err != nil {
@ -276,11 +276,7 @@ func (msg *ReceivedMessage) decryptSymmetric(key []byte) error {
if err != nil {
return err
}
if len(salt) != aesgcm.NonceSize() {
log.Error("decrypting the message", "AES salt size", len(salt))
return errors.New("wrong AES salt size")
}
decrypted, err := aesgcm.Open(nil, salt, msg.Raw[:len(msg.Raw)-AESNonceLength], nil)
decrypted, err := aesgcm.Open(nil, salt, msg.Raw[:len(msg.Raw)-aesNonceLength], nil)
if err != nil {
return err
}

50
whisper/whisperv6/message_test.go
View file

@ -18,9 +18,12 @@ package whisperv6
import (
"bytes"
"crypto/aes"
"crypto/cipher"
mrand "math/rand"
"testing"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/rlp"
)
@ -206,7 +209,7 @@ func TestEnvelopeOpen(t *testing.T) {
InitSingleTest()
var symmetric bool
for i := 0; i < 256; i++ {
for i := 0; i < 32; i++ {
singleEnvelopeOpenTest(t, symmetric)
symmetric = !symmetric
}
@ -417,30 +420,6 @@ func TestPadding(t *testing.T) {
}
}
func TestPaddingAppendedToSymMessages(t *testing.T) {
params := &MessageParams{
Payload: make([]byte, 246),
KeySym: make([]byte, aesKeyLength),
}
// Simulate a message with a payload just under 256 so that
// payload + flag + aesnonce > 256. Check that the result
// is padded on the next 256 boundary.
msg := sentMessage{}
msg.Raw = make([]byte, 1+1+len(params.Payload))
err := msg.appendPadding(params)
if err != nil {
t.Fatalf("Error appending padding to message %v", err)
return
}
if len(msg.Raw) != 512-AESNonceLength {
t.Errorf("Invalid size %d != 512", len(msg.Raw))
}
}
func TestPaddingAppendedToSymMessagesWithSignature(t *testing.T) {
params := &MessageParams{
Payload: make([]byte, 246),
@ -456,7 +435,7 @@ func TestPaddingAppendedToSymMessagesWithSignature(t *testing.T) {
params.Src = pSrc
// Simulate a message with a payload just under 256 so that
// payload + flag + aesnonce > 256. Check that the result
// payload + flag + signature > 256. Check that the result
// is padded on the next 256 boundary.
msg := sentMessage{}
msg.Raw = make([]byte, 1+1+len(params.Payload))
@ -468,7 +447,24 @@ func TestPaddingAppendedToSymMessagesWithSignature(t *testing.T) {
return
}
if len(msg.Raw) != 512-AESNonceLength-signatureLength {
if len(msg.Raw) != 512-signatureLength {
t.Errorf("Invalid size %d != 512", len(msg.Raw))
}
}
func TestAesNonce(t *testing.T) {
key := hexutil.MustDecode("0x03ca634cae0d49acb401d8a4c6b6fe8c55b70d115bf400769cc1400f3258cd31")
block, err := aes.NewCipher(key)
if err != nil {
t.Fatalf("NewCipher failed: %s", err)
}
aesgcm, err := cipher.NewGCM(block)
if err != nil {
t.Fatalf("NewGCM failed: %s", err)
}
// This is the most important single test in this package.
// If it fails, whisper will not be working.
if aesgcm.NonceSize() != aesNonceLength {
t.Fatalf("Nonce size is wrong. This is a critical error. Apparently AES nonce size have changed in the new version of AES GCM package. Whisper will not be working untill this problem is resolved.")
}
}

3
whisper/whisperv6/peer_test.go
View file

@ -27,6 +27,7 @@ import (
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/discover"
@ -85,7 +86,7 @@ type TestNode struct {
var result TestData
var nodes [NumNodes]*TestNode
var sharedKey []byte = []byte("some arbitrary data here")
var sharedKey []byte = hexutil.MustDecode("0x03ca634cae0d49acb401d8a4c6b6fe8c55b70d115bf400769cc1400f3258cd31")
var sharedTopic TopicType = TopicType{0xF, 0x1, 0x2, 0}
var expectedMessage []byte = []byte("per rectum ad astra")
var masterBloomFilter []byte

18
whisper/whisperv6/whisper.go
View file

@ -19,7 +19,6 @@ package whisperv6
import (
"bytes"
"crypto/ecdsa"
crand "crypto/rand"
"crypto/sha256"
"fmt"
"math"
@ -442,11 +441,10 @@ func (w *Whisper) GetPrivateKey(id string) (*ecdsa.PrivateKey, error) {
// GenerateSymKey generates a random symmetric key and stores it under id,
// which is then returned. Will be used in the future for session key exchange.
func (w *Whisper) GenerateSymKey() (string, error) {
key := make([]byte, aesKeyLength)
_, err := crand.Read(key)
key, err := generateSecureRandomData(aesKeyLength)
if err != nil {
return "", err
} else if !validateSymmetricKey(key) {
} else if !validateRandomData(key, aesKeyLength) {
return "", fmt.Errorf("error in GenerateSymKey: crypto/rand failed to generate random data")
}
@ -983,9 +981,10 @@ func validatePrivateKey(k *ecdsa.PrivateKey) bool {
return ValidatePublicKey(&k.PublicKey)
}
// validateSymmetricKey returns false if the key contains all zeros
func validateSymmetricKey(k []byte) bool {
return len(k) > 0 && !containsOnlyZeros(k)
// validateSymmetricKey returns false if the key contains all zeros,
// which is a simplest and the most common bug.
func validateRandomData(k []byte, expectedSize int) bool {
return len(k) == expectedSize && !containsOnlyZeros(k)
}
// containsOnlyZeros checks if the data contain only zeros.
@ -1019,12 +1018,11 @@ func BytesToUintBigEndian(b []byte) (res uint64) {
// GenerateRandomID generates a random string, which is then returned to be used as a key id
func GenerateRandomID() (id string, err error) {
buf := make([]byte, keyIdSize)
_, err = crand.Read(buf)
buf, err := generateSecureRandomData(keyIdSize)
if err != nil {
return "", err
}
if !validateSymmetricKey(buf) {
if !validateRandomData(buf, keyIdSize) {
return "", fmt.Errorf("error in generateRandomID: crypto/rand failed to generate random data")
}
id = common.Bytes2Hex(buf)

18
whisper/whisperv6/whisper_test.go
View file

@ -81,7 +81,7 @@ func TestWhisperBasic(t *testing.T) {
}
derived := pbkdf2.Key([]byte(peerID), nil, 65356, aesKeyLength, sha256.New)
if !validateSymmetricKey(derived) {
if !validateRandomData(derived, aesKeyLength) {
t.Fatalf("failed validateSymmetricKey with param = %v.", derived)
}
if containsOnlyZeros(derived) {
@ -448,24 +448,12 @@ func TestWhisperSymKeyManagement(t *testing.T) {
if !w.HasSymKey(id2) {
t.Fatalf("HasSymKey(id2) failed.")
}
if k1 == nil {
t.Fatalf("k1 does not exist.")
}
if k2 == nil {
t.Fatalf("k2 does not exist.")
if !validateRandomData(k2, aesKeyLength) {
t.Fatalf("key validation failed.")
}
if !bytes.Equal(k1, k2) {
t.Fatalf("k1 != k2.")
}
if len(k1) != aesKeyLength {
t.Fatalf("wrong length of k1.")
}
if len(k2) != aesKeyLength {
t.Fatalf("wrong length of k2.")
}
if !validateSymmetricKey(k2) {
t.Fatalf("key validation failed.")
}
}
func TestExpiry(t *testing.T) {