brontide: migrate fuzz tests

brontide/fuzz_test.go

@@ -0,0 +1,701 @@
+package brontide
+
+import (
+	"bytes"
+	"encoding/hex"
+	"math"
+	"testing"
+
+	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/davecgh/go-spew/spew"
+	"github.com/lightningnetwork/lnd/keychain"
+)
+
+var (
+	initBytes = []byte{
+		0x81, 0xb6, 0x37, 0xd8, 0xfc, 0xd2, 0xc6, 0xda,
+		0x63, 0x59, 0xe6, 0x96, 0x31, 0x13, 0xa1, 0x17,
+		0xd, 0xe7, 0x95, 0xe4, 0xb7, 0x25, 0xb8, 0x4d,
+		0x1e, 0xb, 0x4c, 0xfd, 0x9e, 0xc5, 0x8c, 0xe9,
+	}
+
+	respBytes = []byte{
+		0xaa, 0xb6, 0x37, 0xd9, 0xfc, 0xd2, 0xc6, 0xda,
+		0x63, 0x59, 0xe6, 0x99, 0x31, 0x13, 0xa1, 0x17,
+		0xd, 0xe7, 0x95, 0xe9, 0xb7, 0x25, 0xb8, 0x4d,
+		0x1e, 0xb, 0x4c, 0xf9, 0x9e, 0xc5, 0x8c, 0xe9,
+	}
+
+	// Returns the initiator's ephemeral private key.
+	initEphemeral = EphemeralGenerator(func() (*btcec.PrivateKey, error) {
+		e := "121212121212121212121212121212121212121212121212121212" +
+			"1212121212"
+		eBytes, err := hex.DecodeString(e)
+		if err != nil {
+			return nil, err
+		}
+
+		priv, _ := btcec.PrivKeyFromBytes(eBytes)
+		return priv, nil
+	})
+
+	// Returns the responder's ephemeral private key.
+	respEphemeral = EphemeralGenerator(func() (*btcec.PrivateKey, error) {
+		e := "222222222222222222222222222222222222222222222222222" +
+			"2222222222222"
+		eBytes, err := hex.DecodeString(e)
+		if err != nil {
+			return nil, err
+		}
+
+		priv, _ := btcec.PrivKeyFromBytes(eBytes)
+		return priv, nil
+	})
+)
+
+// completeHandshake takes two brontide machines (initiator, responder)
+// and completes the brontide handshake between them. If any part of the
+// handshake fails, this function will panic.
+func completeHandshake(initiator, responder *Machine, t *testing.T) {
+	if err := handshake(initiator, responder); err != nil {
+		nilAndPanic(initiator, responder, err, t)
+	}
+}
+
+// handshake actually completes the brontide handshake and bubbles up
+// an error to the calling function.
+func handshake(initiator, responder *Machine) error {
+	// Generate ActOne and send to the responder.
+	actOne, err := initiator.GenActOne()
+	if err != nil {
+		return err
+	}
+
+	if err := responder.RecvActOne(actOne); err != nil {
+		return err
+	}
+
+	// Generate ActTwo and send to initiator.
+	actTwo, err := responder.GenActTwo()
+	if err != nil {
+		return err
+	}
+
+	if err := initiator.RecvActTwo(actTwo); err != nil {
+		return err
+	}
+
+	// Generate ActThree and send to responder.
+	actThree, err := initiator.GenActThree()
+	if err != nil {
+		return err
+	}
+
+	return responder.RecvActThree(actThree)
+}
+
+// nilAndPanic first nils the initiator and responder's Curve fields and then
+// panics.
+func nilAndPanic(initiator, responder *Machine, err error, t *testing.T) {
+	t.Fatalf("error: %v, initiator: %v, responder: %v", err,
+		spew.Sdump(initiator), spew.Sdump(responder))
+}
+
+// getBrontideMachines returns two brontide machines that use random keys
+// everywhere.
+func getBrontideMachines() (*Machine, *Machine) {
+	initPriv, _ := btcec.NewPrivateKey()
+	respPriv, _ := btcec.NewPrivateKey()
+	respPub := (respPriv.PubKey())
+
+	initPrivECDH := &keychain.PrivKeyECDH{PrivKey: initPriv}
+	respPrivECDH := &keychain.PrivKeyECDH{PrivKey: respPriv}
+
+	initiator := NewBrontideMachine(true, initPrivECDH, respPub)
+	responder := NewBrontideMachine(false, respPrivECDH, nil)
+
+	return initiator, responder
+}
+
+// getStaticBrontideMachines returns two brontide machines that use static keys
+// everywhere.
+func getStaticBrontideMachines() (*Machine, *Machine) {
+	initPriv, _ := btcec.PrivKeyFromBytes(initBytes)
+	respPriv, respPub := btcec.PrivKeyFromBytes(respBytes)
+
+	initPrivECDH := &keychain.PrivKeyECDH{PrivKey: initPriv}
+	respPrivECDH := &keychain.PrivKeyECDH{PrivKey: respPriv}
+
+	initiator := NewBrontideMachine(
+		true, initPrivECDH, respPub, initEphemeral,
+	)
+	responder := NewBrontideMachine(
+		false, respPrivECDH, nil, respEphemeral,
+	)
+
+	return initiator, responder
+}
+
+// Fuzz_random_actone fuzz tests ActOne in the brontide handshake.
+func Fuzz_random_actone(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Check if data is large enough.
+		if len(data) < ActOneSize {
+			return
+		}
+
+		// This will return brontide machines with random keys.
+		_, responder := getBrontideMachines()
+
+		// Copy data into [ActOneSize]byte.
+		var actOne [ActOneSize]byte
+		copy(actOne[:], data)
+
+		// Responder receives ActOne, should fail on the MAC check.
+		if err := responder.RecvActOne(actOne); err == nil {
+			nilAndPanic(nil, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_random_actthree fuzz tests ActThree in the brontide handshake.
+func Fuzz_random_actthree(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Check if data is large enough.
+		if len(data) < ActThreeSize {
+			return
+		}
+
+		// This will return brontide machines with random keys.
+		initiator, responder := getBrontideMachines()
+
+		// Generate ActOne and send to the responder.
+		actOne, err := initiator.GenActOne()
+		if err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Receiving ActOne should succeed, so we panic on error.
+		if err := responder.RecvActOne(actOne); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Generate ActTwo - this is not sent to the initiator because
+		// nothing is done with the initiator after this point and it
+		// would slow down fuzzing.  GenActTwo needs to be called to set
+		// the appropriate state in the responder machine.
+		_, err = responder.GenActTwo()
+		if err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Copy data into [ActThreeSize]byte.
+		var actThree [ActThreeSize]byte
+		copy(actThree[:], data)
+
+		// Responder receives ActThree, should fail on the MAC check.
+		if err := responder.RecvActThree(actThree); err == nil {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_random_acttwo fuzz tests ActTwo in the brontide handshake.
+func Fuzz_random_acttwo(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Check if data is large enough.
+		if len(data) < ActTwoSize {
+			return
+		}
+
+		// This will return brontide machines with random keys.
+		initiator, _ := getBrontideMachines()
+
+		// Generate ActOne - this isn't sent to the responder because
+		// nothing is done with the responder machine and this would
+		// slow down fuzzing.  GenActOne needs to be called to set the
+		// appropriate state in the initiator machine.
+		_, err := initiator.GenActOne()
+		if err != nil {
+			nilAndPanic(initiator, nil, err, t)
+		}
+
+		// Copy data into [ActTwoSize]byte.
+		var actTwo [ActTwoSize]byte
+		copy(actTwo[:], data)
+
+		// Initiator receives ActTwo, should fail.
+		if err := initiator.RecvActTwo(actTwo); err == nil {
+			nilAndPanic(initiator, nil, nil, t)
+		}
+	})
+}
+
+// Fuzz_random_init_decrypt fuzz tests decrypting arbitrary data with the
+// initiator.
+func Fuzz_random_init_decrypt(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// This will return brontide machines with random keys.
+		initiator, responder := getBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		// Create a reader with the byte array.
+		r := bytes.NewReader(data)
+
+		// Decrypt the encrypted message using ReadMessage w/ initiator
+		// machine.
+		if _, err := initiator.ReadMessage(r); err == nil {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_random_init_enc_dec fuzz tests round-trip encryption and decryption
+// between the initiator and the responder.
+func Fuzz_random_init_enc_dec(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Ensure that length of message is not greater than max allowed
+		// size.
+		if len(data) > math.MaxUint16 {
+			return
+		}
+
+		// This will return brontide machines with random keys.
+		initiator, responder := getBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		var b bytes.Buffer
+
+		// Encrypt the message using WriteMessage w/ initiator machine.
+		if err := initiator.WriteMessage(data); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Flush the encrypted message w/ initiator machine.
+		if _, err := initiator.Flush(&b); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Decrypt the ciphertext using ReadMessage w/ responder machine.
+		plaintext, err := responder.ReadMessage(&b)
+		if err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Check that the decrypted message and the original message are
+		// equal.
+		if !bytes.Equal(data, plaintext) {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_random_init_encrypt fuzz tests the encryption of arbitrary data with
+// the initiator.
+func Fuzz_random_init_encrypt(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Ensure that length of message is not greater than max allowed
+		// size.
+		if len(data) > math.MaxUint16 {
+			return
+		}
+
+		// This will return brontide machines with random keys.
+		initiator, responder := getBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		var b bytes.Buffer
+
+		// Encrypt the message using WriteMessage w/ initiator machine.
+		if err := initiator.WriteMessage(data); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Flush the encrypted message w/ initiator machine.
+		if _, err := initiator.Flush(&b); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+	})
+}
+
+// Fuzz_random_resp_decrypt fuzz tests the decryption of arbitrary data with
+// the responder.
+func Fuzz_random_resp_decrypt(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// This will return brontide machines with random keys.
+		initiator, responder := getBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		// Create a reader with the byte array.
+		r := bytes.NewReader(data)
+
+		// Decrypt the encrypted message using ReadMessage w/ responder
+		// machine.
+		if _, err := responder.ReadMessage(r); err == nil {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_random_resp_enc_dec fuzz tests round-trip encryption and decryption
+// between the responder and the initiator.
+func Fuzz_random_resp_enc_dec(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Ensure that length of message is not greater than max allowed
+		// size.
+		if len(data) > math.MaxUint16 {
+			return
+		}
+
+		// This will return brontide machines with random keys.
+		initiator, responder := getBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		var b bytes.Buffer
+
+		// Encrypt the message using WriteMessage w/ responder machine.
+		if err := responder.WriteMessage(data); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Flush the encrypted message w/ responder machine.
+		if _, err := responder.Flush(&b); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Decrypt the ciphertext using ReadMessage w/ initiator machine.
+		plaintext, err := initiator.ReadMessage(&b)
+		if err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Check that the decrypted message and the original message are
+		// equal.
+		if !bytes.Equal(data, plaintext) {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_random_resp_encrypt fuzz tests encryption of arbitrary data with the
+// responder.
+func Fuzz_random_resp_encrypt(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Ensure that length of message is not greater than max allowed
+		// size.
+		if len(data) > math.MaxUint16 {
+			return
+		}
+
+		// This will return brontide machines with random keys.
+		initiator, responder := getBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		var b bytes.Buffer
+
+		// Encrypt the message using WriteMessage w/ responder machine.
+		if err := responder.WriteMessage(data); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Flush the encrypted message w/ responder machine.
+		if _, err := responder.Flush(&b); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+	})
+}
+
+// Fuzz_static_actone fuzz tests ActOne in the brontide handshake.
+func Fuzz_static_actone(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Check if data is large enough.
+		if len(data) < ActOneSize {
+			return
+		}
+
+		// This will return brontide machines with static keys.
+		_, responder := getStaticBrontideMachines()
+
+		// Copy data into [ActOneSize]byte.
+		var actOne [ActOneSize]byte
+		copy(actOne[:], data)
+
+		// Responder receives ActOne, should fail.
+		if err := responder.RecvActOne(actOne); err == nil {
+			nilAndPanic(nil, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_static_actthree fuzz tests ActThree in the brontide handshake.
+func Fuzz_static_actthree(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Check if data is large enough.
+		if len(data) < ActThreeSize {
+			return
+		}
+
+		// This will return brontide machines with static keys.
+		initiator, responder := getStaticBrontideMachines()
+
+		// Generate ActOne and send to the responder.
+		actOne, err := initiator.GenActOne()
+		if err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Receiving ActOne should succeed, so we panic on error.
+		if err := responder.RecvActOne(actOne); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Generate ActTwo - this is not sent to the initiator because
+		// nothing is done with the initiator after this point and it
+		// would slow down fuzzing.  GenActTwo needs to be called to set
+		// the appropriate state in the responder machine.
+		_, err = responder.GenActTwo()
+		if err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Copy data into [ActThreeSize]byte.
+		var actThree [ActThreeSize]byte
+		copy(actThree[:], data)
+
+		// Responder receives ActThree, should fail.
+		if err := responder.RecvActThree(actThree); err == nil {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_static_acttwo fuzz tests ActTwo in the brontide handshake.
+func Fuzz_static_acttwo(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Check if data is large enough.
+		if len(data) < ActTwoSize {
+			return
+		}
+
+		// This will return brontide machines with static keys.
+		initiator, _ := getStaticBrontideMachines()
+
+		// Generate ActOne - this isn't sent to the responder because
+		// nothing is done with the responder machine and this would
+		// slow down fuzzing.  GenActOne needs to be called to set the
+		// appropriate state in the initiator machine.
+		_, err := initiator.GenActOne()
+		if err != nil {
+			nilAndPanic(initiator, nil, err, t)
+		}
+
+		// Copy data into [ActTwoSize]byte.
+		var actTwo [ActTwoSize]byte
+		copy(actTwo[:], data)
+
+		// Initiator receives ActTwo, should fail.
+		if err := initiator.RecvActTwo(actTwo); err == nil {
+			nilAndPanic(initiator, nil, nil, t)
+		}
+	})
+}
+
+// Fuzz_static_init_decrypt fuzz tests the decryption of arbitrary data with
+// the initiator.
+func Fuzz_static_init_decrypt(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// This will return brontide machines with static keys.
+		initiator, responder := getStaticBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		// Create a reader with the byte array.
+		r := bytes.NewReader(data)
+
+		// Decrypt the encrypted message using ReadMessage w/ initiator
+		// machine.
+		if _, err := initiator.ReadMessage(r); err == nil {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_static_init_enc_dec fuzz tests round-trip encryption and decryption
+// between the initiator and the responder.
+func Fuzz_static_init_enc_dec(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Ensure that length of message is not greater than max allowed
+		// size.
+		if len(data) > math.MaxUint16 {
+			return
+		}
+
+		// This will return brontide machines with static keys.
+		initiator, responder := getStaticBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		var b bytes.Buffer
+
+		// Encrypt the message using WriteMessage w/ initiator machine.
+		if err := initiator.WriteMessage(data); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Flush the encrypted message w/ initiator machine.
+		if _, err := initiator.Flush(&b); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Decrypt the ciphertext using ReadMessage w/ responder
+		// machine.
+		plaintext, err := responder.ReadMessage(&b)
+		if err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Check that the decrypted message and the original message are
+		// equal.
+		if !bytes.Equal(data, plaintext) {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_static_init_encrypt fuzz tests the encryption of arbitrary data with
+// the initiator.
+func Fuzz_static_init_encrypt(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Ensure that length of message is not greater than max allowed
+		// size.
+		if len(data) > math.MaxUint16 {
+			return
+		}
+
+		// This will return brontide machines with static keys.
+		initiator, responder := getStaticBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		var b bytes.Buffer
+
+		// Encrypt the message using WriteMessage w/ initiator machine.
+		if err := initiator.WriteMessage(data); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Flush the encrypted message w/ initiator machine.
+		if _, err := initiator.Flush(&b); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+	})
+}
+
+// Fuzz_static_resp_decrypt fuzz tests the decryption of arbitrary data with
+// the responder.
+func Fuzz_static_resp_decrypt(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// This will return brontide machines with static keys.
+		initiator, responder := getStaticBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		// Create a reader with the byte array.
+		r := bytes.NewReader(data)
+
+		// Decrypt the encrypted message using ReadMessage w/ responder
+		// machine.
+		if _, err := responder.ReadMessage(r); err == nil {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_static_resp_enc_dec fuzz tests the round-trip encryption and decryption
+// between the responder and the initiator.
+func Fuzz_static_resp_enc_dec(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Ensure that length of message is not greater than max allowed
+		// size.
+		if len(data) > math.MaxUint16 {
+			return
+		}
+
+		// This will return brontide machines with static keys.
+		initiator, responder := getStaticBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		var b bytes.Buffer
+
+		// Encrypt the message using WriteMessage w/ responder machine.
+		if err := responder.WriteMessage(data); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Flush the encrypted message w/ responder machine.
+		if _, err := responder.Flush(&b); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Decrypt the ciphertext using ReadMessage w/ initiator
+		// machine.
+		plaintext, err := initiator.ReadMessage(&b)
+		if err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Check that the decrypted message and the original message are
+		// equal.
+		if !bytes.Equal(data, plaintext) {
+			nilAndPanic(initiator, responder, nil, t)
+		}
+	})
+}
+
+// Fuzz_static_resp_encrypt fuzz tests the encryption of arbitrary data with
+// the responder.
+func Fuzz_static_resp_encrypt(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Ensure that length of message is not greater than max allowed
+		// size.
+		if len(data) > math.MaxUint16 {
+			return
+		}
+
+		// This will return brontide machines with static keys.
+		initiator, responder := getStaticBrontideMachines()
+
+		// Complete the brontide handshake.
+		completeHandshake(initiator, responder, t)
+
+		var b bytes.Buffer
+
+		// Encrypt the message using WriteMessage w/ responder machine.
+		if err := responder.WriteMessage(data); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+
+		// Flush the encrypted message w/ responder machine.
+		if _, err := responder.Flush(&b); err != nil {
+			nilAndPanic(initiator, responder, err, t)
+		}
+	})
+}