// TestMerkleBlockOverflowErrors performs tests to ensure encoding and decoding
// merkle blocks that are intentionally crafted to use large values for the
// number of hashes and flags are handled properly.  This could otherwise
// potentially be used as an attack vector.
func TestMerkleBlockOverflowErrors(t *testing.T) {
	// Use protocol version 70001 specifically here instead of the latest
	// protocol version because the test data is using bytes encoded with
	// that version.
	pver := uint32(70001)

	// Create bytes for a merkle block that claims to have more than the max
	// allowed tx hashes.
	var buf bytes.Buffer
	btcwire.TstWriteVarInt(&buf, pver, btcwire.MaxTxPerBlock+1)
	numHashesOffset := 84
	exceedMaxHashes := make([]byte, numHashesOffset)
	copy(exceedMaxHashes, merkleBlockOneBytes[:numHashesOffset])
	exceedMaxHashes = append(exceedMaxHashes, buf.Bytes()...)

	// Create bytes for a merkle block that claims to have more than the max
	// allowed flag bytes.
	buf.Reset()
	btcwire.TstWriteVarInt(&buf, pver, btcwire.MaxFlagsPerMerkleBlock+1)
	numFlagBytesOffset := 117
	exceedMaxFlagBytes := make([]byte, numFlagBytesOffset)
	copy(exceedMaxFlagBytes, merkleBlockOneBytes[:numFlagBytesOffset])
	exceedMaxFlagBytes = append(exceedMaxFlagBytes, buf.Bytes()...)

	tests := []struct {
		buf  []byte // Wire encoding
		pver uint32 // Protocol version for wire encoding
		err  error  // Expected error
	}{
		// Block that claims to have more than max allowed hashes.
		{exceedMaxHashes, pver, &btcwire.MessageError{}},
		// Block that claims to have more than max allowed flag bytes.
		{exceedMaxFlagBytes, pver, &btcwire.MessageError{}},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Decode from wire format.
		var msg btcwire.MsgMerkleBlock
		r := bytes.NewReader(test.buf)
		err := msg.BtcDecode(r, test.pver)
		if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
			t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
				i, err, reflect.TypeOf(test.err))
			continue
		}
	}
}

// TestVarIntWireErrors performs negative tests against wire encode and decode
// of variable length integers to confirm error paths work correctly.
func TestVarIntWireErrors(t *testing.T) {
	pver := btcwire.ProtocolVersion

	tests := []struct {
		in       uint64 // Value to encode
		buf      []byte // Wire encoding
		pver     uint32 // Protocol version for wire encoding
		max      int    // Max size of fixed buffer to induce errors
		writeErr error  // Expected write error
		readErr  error  // Expected read error
	}{
		// Latest protocol version with intentional read/write errors.
		// Force errors on discriminant.
		{0, []byte{0x00}, pver, 0, io.ErrShortWrite, io.EOF},
		// Force errors on 2-byte read/write.
		{0xfd, []byte{0xfd}, pver, 2, io.ErrShortWrite, io.ErrUnexpectedEOF},
		// Force errors on 4-byte read/write.
		{0x10000, []byte{0xfe}, pver, 2, io.ErrShortWrite, io.ErrUnexpectedEOF},
		// Force errors on 8-byte read/write.
		{0x100000000, []byte{0xff}, pver, 2, io.ErrShortWrite, io.ErrUnexpectedEOF},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Encode to wire format.
		w := newFixedWriter(test.max)
		err := btcwire.TstWriteVarInt(w, test.pver, test.in)
		if err != test.writeErr {
			t.Errorf("writeVarInt #%d wrong error got: %v, want: %v",
				i, err, test.writeErr)
			continue
		}

		// Decode from wire format.
		r := newFixedReader(test.max, test.buf)
		_, err = btcwire.TstReadVarInt(r, test.pver)
		if err != test.readErr {
			t.Errorf("readVarInt #%d wrong error got: %v, want: %v",
				i, err, test.readErr)
			continue
		}
	}
}

// TestVersionWireErrors performs negative tests against wire encode and
// decode of MsgGetHeaders to confirm error paths work correctly.
func TestVersionWireErrors(t *testing.T) {
	// Use protocol version 60002 specifically here instead of the latest
	// because the test data is using bytes encoded with that protocol
	// version.
	pver := uint32(60002)
	btcwireErr := &btcwire.MessageError{}

	// Copy the base version and change the user agent to exceed max limits.
	bvc := *baseVersion
	exceedUAVer := &bvc
	newUA := "/" + strings.Repeat("t", btcwire.MaxUserAgentLen-8+1) + ":0.0.1/"
	exceedUAVer.UserAgent = newUA

	// Encode the new UA length as a varint.
	var newUAVarIntBuf bytes.Buffer
	err := btcwire.TstWriteVarInt(&newUAVarIntBuf, pver, uint64(len(newUA)))
	if err != nil {
		t.Errorf("writeVarInt: error %v", err)
	}

	// Make a new buffer big enough to hold the base version plus the new
	// bytes for the bigger varint to hold the new size of the user agent
	// and the new user agent string.  Then stich it all together.
	newLen := len(baseVersionEncoded) - len(baseVersion.UserAgent)
	newLen = newLen + len(newUAVarIntBuf.Bytes()) - 1 + len(newUA)
	exceedUAVerEncoded := make([]byte, newLen)
	copy(exceedUAVerEncoded, baseVersionEncoded[0:80])
	copy(exceedUAVerEncoded[80:], newUAVarIntBuf.Bytes())
	copy(exceedUAVerEncoded[83:], []byte(newUA))
	copy(exceedUAVerEncoded[83+len(newUA):], baseVersionEncoded[97:100])

	tests := []struct {
		in       *btcwire.MsgVersion // Value to encode
		buf      []byte              // Wire encoding
		pver     uint32              // Protocol version for wire encoding
		max      int                 // Max size of fixed buffer to induce errors
		writeErr error               // Expected write error
		readErr  error               // Expected read error
	}{
		// Force error in protocol version.
		{baseVersion, baseVersionEncoded, pver, 0, io.ErrShortWrite, io.EOF},
		// Force error in services.
		{baseVersion, baseVersionEncoded, pver, 4, io.ErrShortWrite, io.EOF},
		// Force error in timestamp.
		{baseVersion, baseVersionEncoded, pver, 12, io.ErrShortWrite, io.EOF},
		// Force error in remote address.
		{baseVersion, baseVersionEncoded, pver, 20, io.ErrShortWrite, io.EOF},
		// Force error in local address.
		{baseVersion, baseVersionEncoded, pver, 46, io.ErrShortWrite, io.EOF},
		// Force error in nonce.
		{baseVersion, baseVersionEncoded, pver, 72, io.ErrShortWrite, io.EOF},
		// Force error in user agent length.
		{baseVersion, baseVersionEncoded, pver, 80, io.ErrShortWrite, io.EOF},
		// Force error in user agent.
		{baseVersion, baseVersionEncoded, pver, 81, io.ErrShortWrite, io.EOF},
		// Force error in last block.
		{baseVersion, baseVersionEncoded, pver, 97, io.ErrShortWrite, io.EOF},
		// Force error due to user agent too big.
		{exceedUAVer, exceedUAVerEncoded, pver, newLen, btcwireErr, btcwireErr},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Encode to wire format.
		w := newFixedWriter(test.max)
		err := test.in.BtcEncode(w, test.pver)
		if reflect.TypeOf(err) != reflect.TypeOf(test.writeErr) {
			t.Errorf("BtcEncode #%d wrong error got: %v, want: %v",
				i, err, test.writeErr)
			continue
		}

		// For errors which are not of type btcwire.MessageError, check
		// them for equality.
		if _, ok := err.(*btcwire.MessageError); !ok {
			if err != test.writeErr {
				t.Errorf("BtcEncode #%d wrong error got: %v, "+
					"want: %v", i, err, test.writeErr)
				continue
			}
		}

		// Decode from wire format.
		var msg btcwire.MsgVersion
		r := newFixedReader(test.max, test.buf)
		err = msg.BtcDecode(r, test.pver)
		if reflect.TypeOf(err) != reflect.TypeOf(test.readErr) {
			t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
				i, err, test.readErr)
			continue
		}

		// For errors which are not of type btcwire.MessageError, check
		// them for equality.
		if _, ok := err.(*btcwire.MessageError); !ok {
			if err != test.readErr {
				t.Errorf("BtcDecode #%d wrong error got: %v, "+
					"want: %v", i, err, test.readErr)
//.........这里部分代码省略.........

// TestVarIntWire tests wire encode and decode for variable length integers.
func TestVarIntWire(t *testing.T) {
	pver := btcwire.ProtocolVersion

	tests := []struct {
		in   uint64 // Value to encode
		out  uint64 // Expected decoded value
		buf  []byte // Wire encoding
		pver uint32 // Protocol version for wire encoding
	}{
		// Latest protocol version.
		// Single byte
		{0, 0, []byte{0x00}, pver},
		// Max single byte
		{0xfc, 0xfc, []byte{0xfc}, pver},
		// Min 2-byte
		{0xfd, 0xfd, []byte{0xfd, 0x0fd, 0x00}, pver},
		// Max 2-byte
		{0xffff, 0xffff, []byte{0xfd, 0xff, 0xff}, pver},
		// Min 4-byte
		{0x10000, 0x10000, []byte{0xfe, 0x00, 0x00, 0x01, 0x00}, pver},
		// Max 4-byte
		{0xffffffff, 0xffffffff, []byte{0xfe, 0xff, 0xff, 0xff, 0xff}, pver},
		// Min 8-byte
		{
			0x100000000, 0x100000000,
			[]byte{0xff, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00},
			pver,
		},
		// Max 8-byte
		{
			0xffffffffffffffff, 0xffffffffffffffff,
			[]byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
			pver,
		},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Encode to wire format.
		var buf bytes.Buffer
		err := btcwire.TstWriteVarInt(&buf, test.pver, test.in)
		if err != nil {
			t.Errorf("writeVarInt #%d error %v", i, err)
			continue
		}
		if !bytes.Equal(buf.Bytes(), test.buf) {
			t.Errorf("writeVarInt #%d\n got: %s want: %s", i,
				spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
			continue
		}

		// Decode from wire format.
		rbuf := bytes.NewBuffer(test.buf)
		val, err := btcwire.TstReadVarInt(rbuf, test.pver)
		if err != nil {
			t.Errorf("readVarInt #%d error %v", i, err)
			continue
		}
		if val != test.out {
			t.Errorf("readVarInt #%d\n got: %d want: %d", i,
				val, test.out)
			continue
		}
	}
}

// BenchmarkWriteVarInt9 performs a benchmark on how long it takes to write
// a nine byte variable length integer.
func BenchmarkWriteVarInt9(b *testing.B) {
	for i := 0; i < b.N; i++ {
		btcwire.TstWriteVarInt(ioutil.Discard, 0, 18446744073709551615)
	}
}

// BenchmarkWriteVarInt5 performs a benchmark on how long it takes to write
// a five byte variable length integer.
func BenchmarkWriteVarInt5(b *testing.B) {
	for i := 0; i < b.N; i++ {
		btcwire.TstWriteVarInt(ioutil.Discard, 0, 4294967295)
	}
}

// BenchmarkWriteVarInt3 performs a benchmark on how long it takes to write
// a three byte variable length integer.
func BenchmarkWriteVarInt3(b *testing.B) {
	for i := 0; i < b.N; i++ {
		btcwire.TstWriteVarInt(ioutil.Discard, 0, 65535)
	}
}