// TestVarBytesOverflowErrors performs tests to ensure deserializing variable
// length byte arrays intentionally crafted to use large values for the array
// length are handled properly. This could otherwise potentially be used as an
// attack vector.
func TestVarBytesOverflowErrors(t *testing.T) {
pver := btcwire.ProtocolVersion
tests := []struct {
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
err error // Expected error
}{
{[]byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
pver, &btcwire.MessageError{}},
{[]byte{0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01},
pver, &btcwire.MessageError{}},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Decode from wire format.
rbuf := bytes.NewReader(test.buf)
_, err := btcwire.TstReadVarBytes(rbuf, test.pver,
btcwire.MaxMessagePayload, "test payload")
if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
t.Errorf("readVarBytes #%d wrong error got: %v, "+
"want: %v", i, err, reflect.TypeOf(test.err))
continue
}
}
}
// TestVarBytesWire tests wire encode and decode for variable length byte array.
func TestVarBytesWire(t *testing.T) {
pver := btcwire.ProtocolVersion
// bytes256 is a byte array that takes a 2-byte varint to encode.
bytes256 := bytes.Repeat([]byte{0x01}, 256)
tests := []struct {
in []byte // Byte Array to write
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
}{
// Latest protocol version.
// Empty byte array
{[]byte{}, []byte{0x00}, pver},
// Single byte varint + byte array
{[]byte{0x01}, []byte{0x01, 0x01}, pver},
// 2-byte varint + byte array
{bytes256, append([]byte{0xfd, 0x00, 0x01}, bytes256...), pver},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Encode to wire format.
var buf bytes.Buffer
err := btcwire.TstWriteVarBytes(&buf, test.pver, test.in)
if err != nil {
t.Errorf("writeVarBytes #%d error %v", i, err)
continue
}
if !bytes.Equal(buf.Bytes(), test.buf) {
t.Errorf("writeVarBytes #%d\n got: %s want: %s", i,
spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
continue
}
// Decode from wire format.
rbuf := bytes.NewReader(test.buf)
val, err := btcwire.TstReadVarBytes(rbuf, test.pver,
btcwire.MaxMessagePayload, "test payload")
if err != nil {
t.Errorf("readVarBytes #%d error %v", i, err)
continue
}
if !bytes.Equal(buf.Bytes(), test.buf) {
t.Errorf("readVarBytes #%d\n got: %s want: %s", i,
val, test.buf)
continue
}
}
}
// TestVarBytesWireErrors performs negative tests against wire encode and
// decode of variable length byte arrays to confirm error paths work correctly.
func TestVarBytesWireErrors(t *testing.T) {
pver := btcwire.ProtocolVersion
// bytes256 is a byte array that takes a 2-byte varint to encode.
bytes256 := bytes.Repeat([]byte{0x01}, 256)
tests := []struct {
in []byte // Byte Array to write
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 empty byte array.
{[]byte{}, []byte{0x00}, pver, 0, io.ErrShortWrite, io.EOF},
// Force error on single byte varint + byte array.
{[]byte{0x01, 0x02, 0x03}, []byte{0x04}, pver, 2, io.ErrShortWrite, io.ErrUnexpectedEOF},
// Force errors on 2-byte varint + byte array.
{bytes256, []byte{0xfd}, 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.TstWriteVarBytes(w, test.pver, test.in)
if err != test.writeErr {
t.Errorf("writeVarBytes #%d wrong error got: %v, want: %v",
i, err, test.writeErr)
continue
}
// Decode from wire format.
r := newFixedReader(test.max, test.buf)
_, err = btcwire.TstReadVarBytes(r, test.pver,
btcwire.MaxMessagePayload, "test payload")
if err != test.readErr {
t.Errorf("readVarBytes #%d wrong error got: %v, want: %v",
i, err, test.readErr)
continue
}
}
}