p2p/conn: add a test for MakeSecretConnection (#4829)

Refs #4154
2026-01-07 13:55:17 +00:00 · 2020-06-03 16:28:23 +04:00
parent c8483531d8
commit 994912211c
4 changed files with 353 additions and 88 deletions
--- a/p2p/conn/evil_secret_connection_test.go
+++ b/p2p/conn/evil_secret_connection_test.go
@@ -0,0 +1,258 @@
+package conn
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"testing"
+
+	"github.com/gtank/merlin"
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/crypto/chacha20poly1305"
+
+	"github.com/tendermint/tendermint/crypto"
+	"github.com/tendermint/tendermint/crypto/ed25519"
+)
+
+type buffer struct {
+	next bytes.Buffer
+}
+
+func (b *buffer) Read(data []byte) (n int, err error) {
+	return b.next.Read(data)
+}
+
+func (b *buffer) Write(data []byte) (n int, err error) {
+	return b.next.Write(data)
+}
+
+func (b *buffer) Bytes() []byte {
+	return b.next.Bytes()
+}
+
+func (b *buffer) Close() error {
+	return nil
+}
+
+type evilConn struct {
+	secretConn *SecretConnection
+	buffer     *buffer
+
+	locEphPub  *[32]byte
+	locEphPriv *[32]byte
+	remEphPub  *[32]byte
+	privKey    crypto.PrivKey
+
+	readStep   int
+	writeStep  int
+	readOffset int
+
+	shareEphKey        bool
+	badEphKey          bool
+	shareAuthSignature bool
+	badAuthSignature   bool
+}
+
+func newEvilConn(shareEphKey, badEphKey, shareAuthSignature, badAuthSignature bool) *evilConn {
+	privKey := ed25519.GenPrivKey()
+	locEphPub, locEphPriv := genEphKeys()
+	var rep [32]byte
+	c := &evilConn{
+		locEphPub:  locEphPub,
+		locEphPriv: locEphPriv,
+		remEphPub:  &rep,
+		privKey:    privKey,
+
+		shareEphKey:        shareEphKey,
+		badEphKey:          badEphKey,
+		shareAuthSignature: shareAuthSignature,
+		badAuthSignature:   badAuthSignature,
+	}
+
+	return c
+}
+
+func (c *evilConn) Read(data []byte) (n int, err error) {
+	if !c.shareEphKey {
+		return 0, io.EOF
+	}
+
+	switch c.readStep {
+	case 0:
+		if !c.badEphKey {
+			bz, err := cdc.MarshalBinaryLengthPrefixed(c.locEphPub)
+			if err != nil {
+				panic(err)
+			}
+			copy(data, bz[c.readOffset:])
+			n = len(data)
+		} else {
+			bz, err := cdc.MarshalBinaryLengthPrefixed([]byte("drop users;"))
+			if err != nil {
+				panic(err)
+			}
+			copy(data, bz)
+			n = len(data)
+		}
+		c.readOffset += n
+
+		if n >= 32 {
+			c.readOffset = 0
+			c.readStep = 1
+			if !c.shareAuthSignature {
+				c.readStep = 2
+			}
+		}
+
+		return n, nil
+	case 1:
+		signature := c.signChallenge()
+		if !c.badAuthSignature {
+			bz, err := cdc.MarshalBinaryLengthPrefixed(authSigMessage{c.privKey.PubKey(), signature})
+			if err != nil {
+				panic(err)
+			}
+			n, err = c.secretConn.Write(bz)
+			if err != nil {
+				panic(err)
+			}
+			if c.readOffset > len(c.buffer.Bytes()) {
+				return len(data), nil
+			}
+			copy(data, c.buffer.Bytes()[c.readOffset:])
+		} else {
+			bz, err := cdc.MarshalBinaryLengthPrefixed([]byte("select * from users;"))
+			if err != nil {
+				panic(err)
+			}
+			n, err = c.secretConn.Write(bz)
+			if err != nil {
+				panic(err)
+			}
+			if c.readOffset > len(c.buffer.Bytes()) {
+				return len(data), nil
+			}
+			copy(data, c.buffer.Bytes())
+		}
+		c.readOffset += len(data)
+		return n, nil
+	default:
+		return 0, io.EOF
+	}
+}
+
+func (c *evilConn) Write(data []byte) (n int, err error) {
+	switch c.writeStep {
+	case 0:
+		err := cdc.UnmarshalBinaryLengthPrefixed(data, c.remEphPub)
+		if err != nil {
+			panic(err)
+		}
+		c.writeStep = 1
+		if !c.shareAuthSignature {
+			c.writeStep = 2
+		}
+		return len(data), nil
+	case 1:
+		// Signature is not needed, therefore skipped.
+		return len(data), nil
+	default:
+		return 0, io.EOF
+	}
+}
+
+func (c *evilConn) Close() error {
+	return nil
+}
+
+func (c *evilConn) signChallenge() []byte {
+	// Sort by lexical order.
+	loEphPub, hiEphPub := sort32(c.locEphPub, c.remEphPub)
+
+	transcript := merlin.NewTranscript("TENDERMINT_SECRET_CONNECTION_TRANSCRIPT_HASH")
+
+	transcript.AppendMessage(labelEphemeralLowerPublicKey, loEphPub[:])
+	transcript.AppendMessage(labelEphemeralUpperPublicKey, hiEphPub[:])
+
+	// Check if the local ephemeral public key was the least, lexicographically
+	// sorted.
+	locIsLeast := bytes.Equal(c.locEphPub[:], loEphPub[:])
+
+	// Compute common diffie hellman secret using X25519.
+	dhSecret, err := computeDHSecret(c.remEphPub, c.locEphPriv)
+	if err != nil {
+		panic(err)
+	}
+
+	transcript.AppendMessage(labelDHSecret, dhSecret[:])
+
+	// Generate the secret used for receiving, sending, challenge via HKDF-SHA2
+	// on the transcript state (which itself also uses HKDF-SHA2 to derive a key
+	// from the dhSecret).
+	recvSecret, sendSecret := deriveSecrets(dhSecret, locIsLeast)
+
+	const challengeSize = 32
+	var challenge [challengeSize]byte
+	challengeSlice := transcript.ExtractBytes(labelSecretConnectionMac, challengeSize)
+
+	copy(challenge[:], challengeSlice[0:challengeSize])
+
+	sendAead, err := chacha20poly1305.New(sendSecret[:])
+	if err != nil {
+		panic(errors.New("invalid send SecretConnection Key"))
+	}
+	recvAead, err := chacha20poly1305.New(recvSecret[:])
+	if err != nil {
+		panic(errors.New("invalid receive SecretConnection Key"))
+	}
+
+	b := &buffer{}
+	c.secretConn = &SecretConnection{
+		conn:       b,
+		recvBuffer: nil,
+		recvNonce:  new([aeadNonceSize]byte),
+		sendNonce:  new([aeadNonceSize]byte),
+		recvAead:   recvAead,
+		sendAead:   sendAead,
+	}
+	c.buffer = b
+
+	// Sign the challenge bytes for authentication.
+	locSignature, err := signChallenge(&challenge, c.privKey)
+	if err != nil {
+		panic(err)
+	}
+
+	return locSignature
+}
+
+// TestMakeSecretConnection creates an evil connection and tests that
+// MakeSecretConnection errors at different stages.
+func TestMakeSecretConnection(t *testing.T) {
+	testCases := []struct {
+		name   string
+		conn   *evilConn
+		errMsg string
+	}{
+		{"refuse to share ethimeral key", newEvilConn(false, false, false, false), "EOF"},
+		{"share bad ethimeral key", newEvilConn(true, true, false, false), "Insufficient bytes to decode"},
+		{"refuse to share auth signature", newEvilConn(true, false, false, false), "EOF"},
+		{"share bad auth signature", newEvilConn(true, false, true, true), "failed to decrypt SecretConnection"},
+		{"all good", newEvilConn(true, false, true, false), ""},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			privKey := ed25519.GenPrivKey()
+			_, err := MakeSecretConnection(tc.conn, privKey)
+			if tc.errMsg != "" {
+				if assert.Error(t, err) {
+					assert.Contains(t, err.Error(), tc.errMsg)
+				}
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}
--- a/p2p/conn/secret_connection_test.go
+++ b/p2p/conn/secret_connection_test.go
@@ -25,6 +25,10 @@ import (
 	tmrand "github.com/tendermint/tendermint/libs/rand"
 )

+// Run go test -update from within this module
+// to update the golden test vector file
+var update = flag.Bool("update", false, "update .golden files")
+
 type kvstoreConn struct {
 	*io.PipeReader
 	*io.PipeWriter
@@ -39,60 +43,14 @@ func (drw kvstoreConn) Close() (err error) {
 	return err1
 }

-// Each returned ReadWriteCloser is akin to a net.Connection
-func makeKVStoreConnPair() (fooConn, barConn kvstoreConn) {
-	barReader, fooWriter := io.Pipe()
-	fooReader, barWriter := io.Pipe()
-	return kvstoreConn{fooReader, fooWriter}, kvstoreConn{barReader, barWriter}
+type privKeyWithNilPubKey struct {
+	orig crypto.PrivKey
 }

-func makeSecretConnPair(tb testing.TB) (fooSecConn, barSecConn *SecretConnection) {
-
-	var fooConn, barConn = makeKVStoreConnPair()
-	var fooPrvKey = ed25519.GenPrivKey()
-	var fooPubKey = fooPrvKey.PubKey()
-	var barPrvKey = ed25519.GenPrivKey()
-	var barPubKey = barPrvKey.PubKey()
-
-	// Make connections from both sides in parallel.
-	var trs, ok = async.Parallel(
-		func(_ int) (val interface{}, abort bool, err error) {
-			fooSecConn, err = MakeSecretConnection(fooConn, fooPrvKey)
-			if err != nil {
-				tb.Errorf("failed to establish SecretConnection for foo: %v", err)
-				return nil, true, err
-			}
-			remotePubBytes := fooSecConn.RemotePubKey()
-			if !remotePubBytes.Equals(barPubKey) {
-				err = fmt.Errorf("unexpected fooSecConn.RemotePubKey.  Expected %v, got %v",
-					barPubKey, fooSecConn.RemotePubKey())
-				tb.Error(err)
-				return nil, false, err
-			}
-			return nil, false, nil
-		},
-		func(_ int) (val interface{}, abort bool, err error) {
-			barSecConn, err = MakeSecretConnection(barConn, barPrvKey)
-			if barSecConn == nil {
-				tb.Errorf("failed to establish SecretConnection for bar: %v", err)
-				return nil, true, err
-			}
-			remotePubBytes := barSecConn.RemotePubKey()
-			if !remotePubBytes.Equals(fooPubKey) {
-				err = fmt.Errorf("unexpected barSecConn.RemotePubKey.  Expected %v, got %v",
-					fooPubKey, barSecConn.RemotePubKey())
-				tb.Error(err)
-				return nil, false, nil
-			}
-			return nil, false, nil
-		},
-	)
-
-	require.Nil(tb, trs.FirstError())
-	require.True(tb, ok, "Unexpected task abortion")
-
-	return fooSecConn, barSecConn
-}
+func (pk privKeyWithNilPubKey) Bytes() []byte                   { return pk.orig.Bytes() }
+func (pk privKeyWithNilPubKey) Sign(msg []byte) ([]byte, error) { return pk.orig.Sign(msg) }
+func (pk privKeyWithNilPubKey) PubKey() crypto.PubKey           { return nil }
+func (pk privKeyWithNilPubKey) Equals(pk2 crypto.PrivKey) bool  { return pk.orig.Equals(pk2) }

 func TestSecretConnectionHandshake(t *testing.T) {
 	fooSecConn, barSecConn := makeSecretConnPair(t)
@@ -148,26 +106,6 @@ func TestConcurrentRead(t *testing.T) {
 	}
 }

-func writeLots(t *testing.T, wg *sync.WaitGroup, conn io.Writer, txt string, n int) {
-	defer wg.Done()
-	for i := 0; i < n; i++ {
-		_, err := conn.Write([]byte(txt))
-		if err != nil {
-			t.Errorf("failed to write to fooSecConn: %v", err)
-			return
-		}
-	}
-}
-
-func readLots(t *testing.T, wg *sync.WaitGroup, conn io.Reader, n int) {
-	readBuffer := make([]byte, dataMaxSize)
-	for i := 0; i < n; i++ {
-		_, err := conn.Read(readBuffer)
-		assert.NoError(t, err)
-	}
-	wg.Done()
-}
-
 func TestSecretConnectionReadWrite(t *testing.T) {
 	fooConn, barConn := makeKVStoreConnPair()
 	fooWrites, barWrites := []string{}, []string{}
@@ -282,13 +220,8 @@ func TestSecretConnectionReadWrite(t *testing.T) {

 	compareWritesReads(fooWrites, barReads)
 	compareWritesReads(barWrites, fooReads)
-
 }

-// Run go test -update from within this module
-// to update the golden test vector file
-var update = flag.Bool("update", false, "update .golden files")
-
 func TestDeriveSecretsAndChallengeGolden(t *testing.T) {
 	goldenFilepath := filepath.Join("testdata", t.Name()+".golden")
 	if *update {
@@ -322,15 +255,6 @@ func TestDeriveSecretsAndChallengeGolden(t *testing.T) {
 	}
 }

-type privKeyWithNilPubKey struct {
-	orig crypto.PrivKey
-}
-
-func (pk privKeyWithNilPubKey) Bytes() []byte                   { return pk.orig.Bytes() }
-func (pk privKeyWithNilPubKey) Sign(msg []byte) ([]byte, error) { return pk.orig.Sign(msg) }
-func (pk privKeyWithNilPubKey) PubKey() crypto.PubKey           { return nil }
-func (pk privKeyWithNilPubKey) Equals(pk2 crypto.PrivKey) bool  { return pk.orig.Equals(pk2) }
-
 func TestNilPubkey(t *testing.T) {
 	var fooConn, barConn = makeKVStoreConnPair()
 	var fooPrvKey = ed25519.GenPrivKey()
@@ -367,6 +291,26 @@ func TestNonEd25519Pubkey(t *testing.T) {
 	})
 }

+func writeLots(t *testing.T, wg *sync.WaitGroup, conn io.Writer, txt string, n int) {
+	defer wg.Done()
+	for i := 0; i < n; i++ {
+		_, err := conn.Write([]byte(txt))
+		if err != nil {
+			t.Errorf("failed to write to fooSecConn: %v", err)
+			return
+		}
+	}
+}
+
+func readLots(t *testing.T, wg *sync.WaitGroup, conn io.Reader, n int) {
+	readBuffer := make([]byte, dataMaxSize)
+	for i := 0; i < n; i++ {
+		_, err := conn.Read(readBuffer)
+		assert.NoError(t, err)
+	}
+	wg.Done()
+}
+
 // Creates the data for a test vector file.
 // The file format is:
 // Hex(diffie_hellman_secret), loc_is_least, Hex(recvSecret), Hex(sendSecret), Hex(challenge)
@@ -386,6 +330,65 @@ func createGoldenTestVectors(t *testing.T) string {
 	return data
 }

+// Each returned ReadWriteCloser is akin to a net.Connection
+func makeKVStoreConnPair() (fooConn, barConn kvstoreConn) {
+	barReader, fooWriter := io.Pipe()
+	fooReader, barWriter := io.Pipe()
+	return kvstoreConn{fooReader, fooWriter}, kvstoreConn{barReader, barWriter}
+}
+
+func makeSecretConnPair(tb testing.TB) (fooSecConn, barSecConn *SecretConnection) {
+	var (
+		fooConn, barConn = makeKVStoreConnPair()
+		fooPrvKey        = ed25519.GenPrivKey()
+		fooPubKey        = fooPrvKey.PubKey()
+		barPrvKey        = ed25519.GenPrivKey()
+		barPubKey        = barPrvKey.PubKey()
+	)
+
+	// Make connections from both sides in parallel.
+	var trs, ok = async.Parallel(
+		func(_ int) (val interface{}, abort bool, err error) {
+			fooSecConn, err = MakeSecretConnection(fooConn, fooPrvKey)
+			if err != nil {
+				tb.Errorf("failed to establish SecretConnection for foo: %v", err)
+				return nil, true, err
+			}
+			remotePubBytes := fooSecConn.RemotePubKey()
+			if !remotePubBytes.Equals(barPubKey) {
+				err = fmt.Errorf("unexpected fooSecConn.RemotePubKey.  Expected %v, got %v",
+					barPubKey, fooSecConn.RemotePubKey())
+				tb.Error(err)
+				return nil, true, err
+			}
+			return nil, false, nil
+		},
+		func(_ int) (val interface{}, abort bool, err error) {
+			barSecConn, err = MakeSecretConnection(barConn, barPrvKey)
+			if barSecConn == nil {
+				tb.Errorf("failed to establish SecretConnection for bar: %v", err)
+				return nil, true, err
+			}
+			remotePubBytes := barSecConn.RemotePubKey()
+			if !remotePubBytes.Equals(fooPubKey) {
+				err = fmt.Errorf("unexpected barSecConn.RemotePubKey.  Expected %v, got %v",
+					fooPubKey, barSecConn.RemotePubKey())
+				tb.Error(err)
+				return nil, true, err
+			}
+			return nil, false, nil
+		},
+	)
+
+	require.Nil(tb, trs.FirstError())
+	require.True(tb, ok, "Unexpected task abortion")
+
+	return fooSecConn, barSecConn
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Benchmarks
+
 func BenchmarkWriteSecretConnection(b *testing.B) {
 	b.StopTimer()
 	b.ReportAllocs()