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      1 // Copyright 2009 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 
      5 package base64
      6 
      7 import (
      8 	"bytes"
      9 	"errors"
     10 	"io"
     11 	"io/ioutil"
     12 	"reflect"
     13 	"strings"
     14 	"testing"
     15 	"time"
     16 )
     17 
     18 type testpair struct {
     19 	decoded, encoded string
     20 }
     21 
     22 var pairs = []testpair{
     23 	// RFC 3548 examples
     24 	{"\x14\xfb\x9c\x03\xd9\x7e", "FPucA9l+"},
     25 	{"\x14\xfb\x9c\x03\xd9", "FPucA9k="},
     26 	{"\x14\xfb\x9c\x03", "FPucAw=="},
     27 
     28 	// RFC 4648 examples
     29 	{"", ""},
     30 	{"f", "Zg=="},
     31 	{"fo", "Zm8="},
     32 	{"foo", "Zm9v"},
     33 	{"foob", "Zm9vYg=="},
     34 	{"fooba", "Zm9vYmE="},
     35 	{"foobar", "Zm9vYmFy"},
     36 
     37 	// Wikipedia examples
     38 	{"sure.", "c3VyZS4="},
     39 	{"sure", "c3VyZQ=="},
     40 	{"sur", "c3Vy"},
     41 	{"su", "c3U="},
     42 	{"leasure.", "bGVhc3VyZS4="},
     43 	{"easure.", "ZWFzdXJlLg=="},
     44 	{"asure.", "YXN1cmUu"},
     45 	{"sure.", "c3VyZS4="},
     46 }
     47 
     48 // Do nothing to a reference base64 string (leave in standard format)
     49 func stdRef(ref string) string {
     50 	return ref
     51 }
     52 
     53 // Convert a reference string to URL-encoding
     54 func urlRef(ref string) string {
     55 	ref = strings.Replace(ref, "+", "-", -1)
     56 	ref = strings.Replace(ref, "/", "_", -1)
     57 	return ref
     58 }
     59 
     60 // Convert a reference string to raw, unpadded format
     61 func rawRef(ref string) string {
     62 	return strings.TrimRight(ref, "=")
     63 }
     64 
     65 // Both URL and unpadding conversions
     66 func rawUrlRef(ref string) string {
     67 	return rawRef(urlRef(ref))
     68 }
     69 
     70 // A nonstandard encoding with a funny padding character, for testing
     71 var funnyEncoding = NewEncoding(encodeStd).WithPadding(rune('@'))
     72 
     73 func funnyRef(ref string) string {
     74 	return strings.Replace(ref, "=", "@", -1)
     75 }
     76 
     77 type encodingTest struct {
     78 	enc  *Encoding           // Encoding to test
     79 	conv func(string) string // Reference string converter
     80 }
     81 
     82 var encodingTests = []encodingTest{
     83 	{StdEncoding, stdRef},
     84 	{URLEncoding, urlRef},
     85 	{RawStdEncoding, rawRef},
     86 	{RawURLEncoding, rawUrlRef},
     87 	{funnyEncoding, funnyRef},
     88 	{StdEncoding.Strict(), stdRef},
     89 	{URLEncoding.Strict(), urlRef},
     90 	{RawStdEncoding.Strict(), rawRef},
     91 	{RawURLEncoding.Strict(), rawUrlRef},
     92 	{funnyEncoding.Strict(), funnyRef},
     93 }
     94 
     95 var bigtest = testpair{
     96 	"Twas brillig, and the slithy toves",
     97 	"VHdhcyBicmlsbGlnLCBhbmQgdGhlIHNsaXRoeSB0b3Zlcw==",
     98 }
     99 
    100 func testEqual(t *testing.T, msg string, args ...interface{}) bool {
    101 	if args[len(args)-2] != args[len(args)-1] {
    102 		t.Errorf(msg, args...)
    103 		return false
    104 	}
    105 	return true
    106 }
    107 
    108 func TestEncode(t *testing.T) {
    109 	for _, p := range pairs {
    110 		for _, tt := range encodingTests {
    111 			got := tt.enc.EncodeToString([]byte(p.decoded))
    112 			testEqual(t, "Encode(%q) = %q, want %q", p.decoded,
    113 				got, tt.conv(p.encoded))
    114 		}
    115 	}
    116 }
    117 
    118 func TestEncoder(t *testing.T) {
    119 	for _, p := range pairs {
    120 		bb := &bytes.Buffer{}
    121 		encoder := NewEncoder(StdEncoding, bb)
    122 		encoder.Write([]byte(p.decoded))
    123 		encoder.Close()
    124 		testEqual(t, "Encode(%q) = %q, want %q", p.decoded, bb.String(), p.encoded)
    125 	}
    126 }
    127 
    128 func TestEncoderBuffering(t *testing.T) {
    129 	input := []byte(bigtest.decoded)
    130 	for bs := 1; bs <= 12; bs++ {
    131 		bb := &bytes.Buffer{}
    132 		encoder := NewEncoder(StdEncoding, bb)
    133 		for pos := 0; pos < len(input); pos += bs {
    134 			end := pos + bs
    135 			if end > len(input) {
    136 				end = len(input)
    137 			}
    138 			n, err := encoder.Write(input[pos:end])
    139 			testEqual(t, "Write(%q) gave error %v, want %v", input[pos:end], err, error(nil))
    140 			testEqual(t, "Write(%q) gave length %v, want %v", input[pos:end], n, end-pos)
    141 		}
    142 		err := encoder.Close()
    143 		testEqual(t, "Close gave error %v, want %v", err, error(nil))
    144 		testEqual(t, "Encoding/%d of %q = %q, want %q", bs, bigtest.decoded, bb.String(), bigtest.encoded)
    145 	}
    146 }
    147 
    148 func TestDecode(t *testing.T) {
    149 	for _, p := range pairs {
    150 		for _, tt := range encodingTests {
    151 			encoded := tt.conv(p.encoded)
    152 			dbuf := make([]byte, tt.enc.DecodedLen(len(encoded)))
    153 			count, end, err := tt.enc.decode(dbuf, []byte(encoded))
    154 			testEqual(t, "Decode(%q) = error %v, want %v", encoded, err, error(nil))
    155 			testEqual(t, "Decode(%q) = length %v, want %v", encoded, count, len(p.decoded))
    156 			if len(encoded) > 0 {
    157 				testEqual(t, "Decode(%q) = end %v, want %v", encoded, end, len(p.decoded)%3 != 0)
    158 			}
    159 			testEqual(t, "Decode(%q) = %q, want %q", encoded, string(dbuf[0:count]), p.decoded)
    160 
    161 			dbuf, err = tt.enc.DecodeString(encoded)
    162 			testEqual(t, "DecodeString(%q) = error %v, want %v", encoded, err, error(nil))
    163 			testEqual(t, "DecodeString(%q) = %q, want %q", string(dbuf), p.decoded)
    164 		}
    165 	}
    166 }
    167 
    168 func TestDecoder(t *testing.T) {
    169 	for _, p := range pairs {
    170 		decoder := NewDecoder(StdEncoding, strings.NewReader(p.encoded))
    171 		dbuf := make([]byte, StdEncoding.DecodedLen(len(p.encoded)))
    172 		count, err := decoder.Read(dbuf)
    173 		if err != nil && err != io.EOF {
    174 			t.Fatal("Read failed", err)
    175 		}
    176 		testEqual(t, "Read from %q = length %v, want %v", p.encoded, count, len(p.decoded))
    177 		testEqual(t, "Decoding of %q = %q, want %q", p.encoded, string(dbuf[0:count]), p.decoded)
    178 		if err != io.EOF {
    179 			count, err = decoder.Read(dbuf)
    180 		}
    181 		testEqual(t, "Read from %q = %v, want %v", p.encoded, err, io.EOF)
    182 	}
    183 }
    184 
    185 func TestDecoderBuffering(t *testing.T) {
    186 	for bs := 1; bs <= 12; bs++ {
    187 		decoder := NewDecoder(StdEncoding, strings.NewReader(bigtest.encoded))
    188 		buf := make([]byte, len(bigtest.decoded)+12)
    189 		var total int
    190 		for total = 0; total < len(bigtest.decoded); {
    191 			n, err := decoder.Read(buf[total : total+bs])
    192 			testEqual(t, "Read from %q at pos %d = %d, %v, want _, %v", bigtest.encoded, total, n, err, error(nil))
    193 			total += n
    194 		}
    195 		testEqual(t, "Decoding/%d of %q = %q, want %q", bs, bigtest.encoded, string(buf[0:total]), bigtest.decoded)
    196 	}
    197 }
    198 
    199 func TestDecodeCorrupt(t *testing.T) {
    200 	testCases := []struct {
    201 		input  string
    202 		offset int // -1 means no corruption.
    203 	}{
    204 		{"", -1},
    205 		{"!!!!", 0},
    206 		{"====", 0},
    207 		{"x===", 1},
    208 		{"=AAA", 0},
    209 		{"A=AA", 1},
    210 		{"AA=A", 2},
    211 		{"AA==A", 4},
    212 		{"AAA=AAAA", 4},
    213 		{"AAAAA", 4},
    214 		{"AAAAAA", 4},
    215 		{"A=", 1},
    216 		{"A==", 1},
    217 		{"AA=", 3},
    218 		{"AA==", -1},
    219 		{"AAA=", -1},
    220 		{"AAAA", -1},
    221 		{"AAAAAA=", 7},
    222 		{"YWJjZA=====", 8},
    223 	}
    224 	for _, tc := range testCases {
    225 		dbuf := make([]byte, StdEncoding.DecodedLen(len(tc.input)))
    226 		_, err := StdEncoding.Decode(dbuf, []byte(tc.input))
    227 		if tc.offset == -1 {
    228 			if err != nil {
    229 				t.Error("Decoder wrongly detected corruption in", tc.input)
    230 			}
    231 			continue
    232 		}
    233 		switch err := err.(type) {
    234 		case CorruptInputError:
    235 			testEqual(t, "Corruption in %q at offset %v, want %v", tc.input, int(err), tc.offset)
    236 		default:
    237 			t.Error("Decoder failed to detect corruption in", tc)
    238 		}
    239 	}
    240 }
    241 
    242 func TestEncodedLen(t *testing.T) {
    243 	for _, tt := range []struct {
    244 		enc  *Encoding
    245 		n    int
    246 		want int
    247 	}{
    248 		{RawStdEncoding, 0, 0},
    249 		{RawStdEncoding, 1, 2},
    250 		{RawStdEncoding, 2, 3},
    251 		{RawStdEncoding, 3, 4},
    252 		{RawStdEncoding, 7, 10},
    253 		{StdEncoding, 0, 0},
    254 		{StdEncoding, 1, 4},
    255 		{StdEncoding, 2, 4},
    256 		{StdEncoding, 3, 4},
    257 		{StdEncoding, 4, 8},
    258 		{StdEncoding, 7, 12},
    259 	} {
    260 		if got := tt.enc.EncodedLen(tt.n); got != tt.want {
    261 			t.Errorf("EncodedLen(%d): got %d, want %d", tt.n, got, tt.want)
    262 		}
    263 	}
    264 }
    265 
    266 func TestDecodedLen(t *testing.T) {
    267 	for _, tt := range []struct {
    268 		enc  *Encoding
    269 		n    int
    270 		want int
    271 	}{
    272 		{RawStdEncoding, 0, 0},
    273 		{RawStdEncoding, 2, 1},
    274 		{RawStdEncoding, 3, 2},
    275 		{RawStdEncoding, 4, 3},
    276 		{RawStdEncoding, 10, 7},
    277 		{StdEncoding, 0, 0},
    278 		{StdEncoding, 4, 3},
    279 		{StdEncoding, 8, 6},
    280 	} {
    281 		if got := tt.enc.DecodedLen(tt.n); got != tt.want {
    282 			t.Errorf("DecodedLen(%d): got %d, want %d", tt.n, got, tt.want)
    283 		}
    284 	}
    285 }
    286 
    287 func TestBig(t *testing.T) {
    288 	n := 3*1000 + 1
    289 	raw := make([]byte, n)
    290 	const alpha = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    291 	for i := 0; i < n; i++ {
    292 		raw[i] = alpha[i%len(alpha)]
    293 	}
    294 	encoded := new(bytes.Buffer)
    295 	w := NewEncoder(StdEncoding, encoded)
    296 	nn, err := w.Write(raw)
    297 	if nn != n || err != nil {
    298 		t.Fatalf("Encoder.Write(raw) = %d, %v want %d, nil", nn, err, n)
    299 	}
    300 	err = w.Close()
    301 	if err != nil {
    302 		t.Fatalf("Encoder.Close() = %v want nil", err)
    303 	}
    304 	decoded, err := ioutil.ReadAll(NewDecoder(StdEncoding, encoded))
    305 	if err != nil {
    306 		t.Fatalf("ioutil.ReadAll(NewDecoder(...)): %v", err)
    307 	}
    308 
    309 	if !bytes.Equal(raw, decoded) {
    310 		var i int
    311 		for i = 0; i < len(decoded) && i < len(raw); i++ {
    312 			if decoded[i] != raw[i] {
    313 				break
    314 			}
    315 		}
    316 		t.Errorf("Decode(Encode(%d-byte string)) failed at offset %d", n, i)
    317 	}
    318 }
    319 
    320 func TestNewLineCharacters(t *testing.T) {
    321 	// Each of these should decode to the string "sure", without errors.
    322 	const expected = "sure"
    323 	examples := []string{
    324 		"c3VyZQ==",
    325 		"c3VyZQ==\r",
    326 		"c3VyZQ==\n",
    327 		"c3VyZQ==\r\n",
    328 		"c3VyZ\r\nQ==",
    329 		"c3V\ryZ\nQ==",
    330 		"c3V\nyZ\rQ==",
    331 		"c3VyZ\nQ==",
    332 		"c3VyZQ\n==",
    333 		"c3VyZQ=\n=",
    334 		"c3VyZQ=\r\n\r\n=",
    335 	}
    336 	for _, e := range examples {
    337 		buf, err := StdEncoding.DecodeString(e)
    338 		if err != nil {
    339 			t.Errorf("Decode(%q) failed: %v", e, err)
    340 			continue
    341 		}
    342 		if s := string(buf); s != expected {
    343 			t.Errorf("Decode(%q) = %q, want %q", e, s, expected)
    344 		}
    345 	}
    346 }
    347 
    348 type nextRead struct {
    349 	n   int   // bytes to return
    350 	err error // error to return
    351 }
    352 
    353 // faultInjectReader returns data from source, rate-limited
    354 // and with the errors as written to nextc.
    355 type faultInjectReader struct {
    356 	source string
    357 	nextc  <-chan nextRead
    358 }
    359 
    360 func (r *faultInjectReader) Read(p []byte) (int, error) {
    361 	nr := <-r.nextc
    362 	if len(p) > nr.n {
    363 		p = p[:nr.n]
    364 	}
    365 	n := copy(p, r.source)
    366 	r.source = r.source[n:]
    367 	return n, nr.err
    368 }
    369 
    370 // tests that we don't ignore errors from our underlying reader
    371 func TestDecoderIssue3577(t *testing.T) {
    372 	next := make(chan nextRead, 10)
    373 	wantErr := errors.New("my error")
    374 	next <- nextRead{5, nil}
    375 	next <- nextRead{10, wantErr}
    376 	next <- nextRead{0, wantErr}
    377 	d := NewDecoder(StdEncoding, &faultInjectReader{
    378 		source: "VHdhcyBicmlsbGlnLCBhbmQgdGhlIHNsaXRoeSB0b3Zlcw==", // twas brillig...
    379 		nextc:  next,
    380 	})
    381 	errc := make(chan error)
    382 	go func() {
    383 		_, err := ioutil.ReadAll(d)
    384 		errc <- err
    385 	}()
    386 	select {
    387 	case err := <-errc:
    388 		if err != wantErr {
    389 			t.Errorf("got error %v; want %v", err, wantErr)
    390 		}
    391 	case <-time.After(5 * time.Second):
    392 		t.Errorf("timeout; Decoder blocked without returning an error")
    393 	}
    394 }
    395 
    396 func TestDecoderIssue4779(t *testing.T) {
    397 	encoded := `CP/EAT8AAAEF
    398 AQEBAQEBAAAAAAAAAAMAAQIEBQYHCAkKCwEAAQUBAQEBAQEAAAAAAAAAAQACAwQFBgcICQoLEAAB
    399 BAEDAgQCBQcGCAUDDDMBAAIRAwQhEjEFQVFhEyJxgTIGFJGhsUIjJBVSwWIzNHKC0UMHJZJT8OHx
    400 Y3M1FqKygyZEk1RkRcKjdDYX0lXiZfKzhMPTdePzRieUpIW0lcTU5PSltcXV5fVWZnaGlqa2xtbm
    401 9jdHV2d3h5ent8fX5/cRAAICAQIEBAMEBQYHBwYFNQEAAhEDITESBEFRYXEiEwUygZEUobFCI8FS
    402 0fAzJGLhcoKSQ1MVY3M08SUGFqKygwcmNcLSRJNUoxdkRVU2dGXi8rOEw9N14/NGlKSFtJXE1OT0
    403 pbXF1eX1VmZ2hpamtsbW5vYnN0dXZ3eHl6e3x//aAAwDAQACEQMRAD8A9VSSSSUpJJJJSkkkJ+Tj
    404 1kiy1jCJJDnAcCTykpKkuQ6p/jN6FgmxlNduXawwAzaGH+V6jn/R/wCt71zdn+N/qL3kVYFNYB4N
    405 ji6PDVjWpKp9TSXnvTf8bFNjg3qOEa2n6VlLpj/rT/pf567DpX1i6L1hs9Py67X8mqdtg/rUWbbf
    406 +gkp0kkkklKSSSSUpJJJJT//0PVUkkklKVLq3WMDpGI7KzrNjADtYNXvI/Mqr/Pd/q9W3vaxjnvM
    407 NaCXE9gNSvGPrf8AWS3qmba5jjsJhoB0DAf0NDf6sevf+/lf8Hj0JJATfWT6/dV6oXU1uOLQeKKn
    408 EQP+Hubtfe/+R7Mf/g7f5xcocp++Z11JMCJPgFBxOg7/AOuqDx8I/ikpkXkmSdU8mJIJA/O8EMAy
    409 j+mSARB/17pKVXYWHXjsj7yIex0PadzXMO1zT5KHoNA3HT8ietoGhgjsfA+CSnvvqh/jJtqsrwOv
    410 2b6NGNzXfTYexzJ+nU7/ALkf4P8Awv6P9KvTQQ4AgyDqCF85Pho3CTB7eHwXoH+LT65uZbX9X+o2
    411 bqbPb06551Y4
    412 `
    413 	encodedShort := strings.Replace(encoded, "\n", "", -1)
    414 
    415 	dec := NewDecoder(StdEncoding, strings.NewReader(encoded))
    416 	res1, err := ioutil.ReadAll(dec)
    417 	if err != nil {
    418 		t.Errorf("ReadAll failed: %v", err)
    419 	}
    420 
    421 	dec = NewDecoder(StdEncoding, strings.NewReader(encodedShort))
    422 	var res2 []byte
    423 	res2, err = ioutil.ReadAll(dec)
    424 	if err != nil {
    425 		t.Errorf("ReadAll failed: %v", err)
    426 	}
    427 
    428 	if !bytes.Equal(res1, res2) {
    429 		t.Error("Decoded results not equal")
    430 	}
    431 }
    432 
    433 func TestDecoderIssue7733(t *testing.T) {
    434 	s, err := StdEncoding.DecodeString("YWJjZA=====")
    435 	want := CorruptInputError(8)
    436 	if !reflect.DeepEqual(want, err) {
    437 		t.Errorf("Error = %v; want CorruptInputError(8)", err)
    438 	}
    439 	if string(s) != "abcd" {
    440 		t.Errorf("DecodeString = %q; want abcd", s)
    441 	}
    442 }
    443 
    444 func TestDecoderIssue15656(t *testing.T) {
    445 	_, err := StdEncoding.Strict().DecodeString("WvLTlMrX9NpYDQlEIFlnDB==")
    446 	want := CorruptInputError(22)
    447 	if !reflect.DeepEqual(want, err) {
    448 		t.Errorf("Error = %v; want CorruptInputError(22)", err)
    449 	}
    450 	_, err = StdEncoding.Strict().DecodeString("WvLTlMrX9NpYDQlEIFlnDA==")
    451 	if err != nil {
    452 		t.Errorf("Error = %v; want nil", err)
    453 	}
    454 	_, err = StdEncoding.DecodeString("WvLTlMrX9NpYDQlEIFlnDB==")
    455 	if err != nil {
    456 		t.Errorf("Error = %v; want nil", err)
    457 	}
    458 }
    459 
    460 func BenchmarkEncodeToString(b *testing.B) {
    461 	data := make([]byte, 8192)
    462 	b.SetBytes(int64(len(data)))
    463 	for i := 0; i < b.N; i++ {
    464 		StdEncoding.EncodeToString(data)
    465 	}
    466 }
    467 
    468 func BenchmarkDecodeString(b *testing.B) {
    469 	data := StdEncoding.EncodeToString(make([]byte, 8192))
    470 	b.SetBytes(int64(len(data)))
    471 	for i := 0; i < b.N; i++ {
    472 		StdEncoding.DecodeString(data)
    473 	}
    474 }
    475 
    476 func TestDecoderRaw(t *testing.T) {
    477 	source := "AAAAAA"
    478 	want := []byte{0, 0, 0, 0}
    479 
    480 	// Direct.
    481 	dec1, err := RawURLEncoding.DecodeString(source)
    482 	if err != nil || !bytes.Equal(dec1, want) {
    483 		t.Errorf("RawURLEncoding.DecodeString(%q) = %x, %v, want %x, nil", source, dec1, err, want)
    484 	}
    485 
    486 	// Through reader. Used to fail.
    487 	r := NewDecoder(RawURLEncoding, bytes.NewReader([]byte(source)))
    488 	dec2, err := ioutil.ReadAll(io.LimitReader(r, 100))
    489 	if err != nil || !bytes.Equal(dec2, want) {
    490 		t.Errorf("reading NewDecoder(RawURLEncoding, %q) = %x, %v, want %x, nil", source, dec2, err, want)
    491 	}
    492 
    493 	// Should work with padding.
    494 	r = NewDecoder(URLEncoding, bytes.NewReader([]byte(source+"==")))
    495 	dec3, err := ioutil.ReadAll(r)
    496 	if err != nil || !bytes.Equal(dec3, want) {
    497 		t.Errorf("reading NewDecoder(URLEncoding, %q) = %x, %v, want %x, nil", source+"==", dec3, err, want)
    498 	}
    499 }
    500