1// Copyright 2017 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package encoding
6
7import (
8	"bytes"
9	"io"
10	"testing"
11)
12
13var mpiTests = []struct {
14	encoded   []byte
15	bytes     []byte
16	reencoded []byte
17	bitLength uint16
18	err       error
19}{
20	{
21		encoded:   []byte{0x0, 0x0},
22		bytes:     []byte{},
23		bitLength: 0,
24	},
25	{
26		encoded:   []byte{0x0, 0x1, 0x1},
27		bytes:     []byte{0x1},
28		bitLength: 1,
29	},
30	{
31		encoded:   []byte{0x0, 0x9, 0x1, 0xff},
32		bytes:     []byte{0x1, 0xff},
33		bitLength: 9,
34	},
35	{
36		encoded:   append([]byte{0x1, 0x0, 0xff}, make([]byte, 0x1f)...),
37		bytes:     append([]byte{0xff}, make([]byte, 0x1f)...),
38		bitLength: 0x100,
39	},
40	// https://bugs.gnupg.org/gnupg/issue1853
41	{
42		encoded:   []byte{0x0, 0x10, 0x0, 0x1},
43		bytes:     []byte{0x0, 0x1},
44		reencoded: []byte{0x0, 0x1, 0x1},
45		bitLength: 0x10,
46	},
47	// EOF error,
48	{
49		encoded: []byte{},
50		err:     io.ErrUnexpectedEOF,
51	},
52	{
53		encoded: []byte{0x1, 0x0, 0x0},
54		err:     io.ErrUnexpectedEOF,
55	},
56}
57
58func TestMPI(t *testing.T) {
59	for i, test := range mpiTests {
60		mpi := new(MPI)
61		if _, err := mpi.ReadFrom(bytes.NewBuffer(test.encoded)); err != nil {
62			if !sameError(err, test.err) {
63				t.Errorf("#%d: ReadFrom error got:%q", i, err)
64			}
65			continue
66		}
67		if b := mpi.Bytes(); !bytes.Equal(b, test.bytes) {
68			t.Errorf("#%d: bad creation got:%x want:%x", i, b, test.bytes)
69		}
70		if bl := mpi.BitLength(); bl != test.bitLength {
71			t.Errorf("#%d: bad BitLength got:%d want:%d", i, bl, test.bitLength)
72		}
73
74		reencoded := test.encoded
75		if test.reencoded != nil {
76			reencoded = test.reencoded
77		}
78
79		if b := mpi.EncodedBytes(); !bytes.Equal(b, test.encoded) {
80			t.Errorf("#%d: bad encoding got:%x want:%x", i, b, test.encoded)
81		}
82		if b := NewMPI(mpi.Bytes()).EncodedBytes(); !bytes.Equal(b, reencoded) {
83			t.Errorf("#%d: bad encoding got:%x want:%x", i, b, reencoded)
84		}
85	}
86}
87