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-rw-r--r--src/encoding/base64/base64.go612
-rw-r--r--src/encoding/base64/base64_test.go530
-rw-r--r--src/encoding/base64/example_test.go83
3 files changed, 1225 insertions, 0 deletions
diff --git a/src/encoding/base64/base64.go b/src/encoding/base64/base64.go
new file mode 100644
index 0000000..4a3e590
--- /dev/null
+++ b/src/encoding/base64/base64.go
@@ -0,0 +1,612 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package base64 implements base64 encoding as specified by RFC 4648.
+package base64
+
+import (
+ "encoding/binary"
+ "io"
+ "strconv"
+)
+
+/*
+ * Encodings
+ */
+
+// An Encoding is a radix 64 encoding/decoding scheme, defined by a
+// 64-character alphabet. The most common encoding is the "base64"
+// encoding defined in RFC 4648 and used in MIME (RFC 2045) and PEM
+// (RFC 1421). RFC 4648 also defines an alternate encoding, which is
+// the standard encoding with - and _ substituted for + and /.
+type Encoding struct {
+ encode [64]byte
+ decodeMap [256]byte
+ padChar rune
+ strict bool
+}
+
+const (
+ StdPadding rune = '=' // Standard padding character
+ NoPadding rune = -1 // No padding
+)
+
+const encodeStd = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+const encodeURL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
+
+// NewEncoding returns a new padded Encoding defined by the given alphabet,
+// which must be a 64-byte string that does not contain the padding character
+// or CR / LF ('\r', '\n').
+// The resulting Encoding uses the default padding character ('='),
+// which may be changed or disabled via WithPadding.
+func NewEncoding(encoder string) *Encoding {
+ if len(encoder) != 64 {
+ panic("encoding alphabet is not 64-bytes long")
+ }
+ for i := 0; i < len(encoder); i++ {
+ if encoder[i] == '\n' || encoder[i] == '\r' {
+ panic("encoding alphabet contains newline character")
+ }
+ }
+
+ e := new(Encoding)
+ e.padChar = StdPadding
+ copy(e.encode[:], encoder)
+
+ for i := 0; i < len(e.decodeMap); i++ {
+ e.decodeMap[i] = 0xFF
+ }
+ for i := 0; i < len(encoder); i++ {
+ e.decodeMap[encoder[i]] = byte(i)
+ }
+ return e
+}
+
+// WithPadding creates a new encoding identical to enc except
+// with a specified padding character, or NoPadding to disable padding.
+// The padding character must not be '\r' or '\n', must not
+// be contained in the encoding's alphabet and must be a rune equal or
+// below '\xff'.
+func (enc Encoding) WithPadding(padding rune) *Encoding {
+ if padding == '\r' || padding == '\n' || padding > 0xff {
+ panic("invalid padding")
+ }
+
+ for i := 0; i < len(enc.encode); i++ {
+ if rune(enc.encode[i]) == padding {
+ panic("padding contained in alphabet")
+ }
+ }
+
+ enc.padChar = padding
+ return &enc
+}
+
+// Strict creates a new encoding identical to enc except with
+// strict decoding enabled. In this mode, the decoder requires that
+// trailing padding bits are zero, as described in RFC 4648 section 3.5.
+//
+// Note that the input is still malleable, as new line characters
+// (CR and LF) are still ignored.
+func (enc Encoding) Strict() *Encoding {
+ enc.strict = true
+ return &enc
+}
+
+// StdEncoding is the standard base64 encoding, as defined in
+// RFC 4648.
+var StdEncoding = NewEncoding(encodeStd)
+
+// URLEncoding is the alternate base64 encoding defined in RFC 4648.
+// It is typically used in URLs and file names.
+var URLEncoding = NewEncoding(encodeURL)
+
+// RawStdEncoding is the standard raw, unpadded base64 encoding,
+// as defined in RFC 4648 section 3.2.
+// This is the same as StdEncoding but omits padding characters.
+var RawStdEncoding = StdEncoding.WithPadding(NoPadding)
+
+// RawURLEncoding is the unpadded alternate base64 encoding defined in RFC 4648.
+// It is typically used in URLs and file names.
+// This is the same as URLEncoding but omits padding characters.
+var RawURLEncoding = URLEncoding.WithPadding(NoPadding)
+
+/*
+ * Encoder
+ */
+
+// Encode encodes src using the encoding enc, writing
+// EncodedLen(len(src)) bytes to dst.
+//
+// The encoding pads the output to a multiple of 4 bytes,
+// so Encode is not appropriate for use on individual blocks
+// of a large data stream. Use NewEncoder() instead.
+func (enc *Encoding) Encode(dst, src []byte) {
+ if len(src) == 0 {
+ return
+ }
+ // enc is a pointer receiver, so the use of enc.encode within the hot
+ // loop below means a nil check at every operation. Lift that nil check
+ // outside of the loop to speed up the encoder.
+ _ = enc.encode
+
+ di, si := 0, 0
+ n := (len(src) / 3) * 3
+ for si < n {
+ // Convert 3x 8bit source bytes into 4 bytes
+ val := uint(src[si+0])<<16 | uint(src[si+1])<<8 | uint(src[si+2])
+
+ dst[di+0] = enc.encode[val>>18&0x3F]
+ dst[di+1] = enc.encode[val>>12&0x3F]
+ dst[di+2] = enc.encode[val>>6&0x3F]
+ dst[di+3] = enc.encode[val&0x3F]
+
+ si += 3
+ di += 4
+ }
+
+ remain := len(src) - si
+ if remain == 0 {
+ return
+ }
+ // Add the remaining small block
+ val := uint(src[si+0]) << 16
+ if remain == 2 {
+ val |= uint(src[si+1]) << 8
+ }
+
+ dst[di+0] = enc.encode[val>>18&0x3F]
+ dst[di+1] = enc.encode[val>>12&0x3F]
+
+ switch remain {
+ case 2:
+ dst[di+2] = enc.encode[val>>6&0x3F]
+ if enc.padChar != NoPadding {
+ dst[di+3] = byte(enc.padChar)
+ }
+ case 1:
+ if enc.padChar != NoPadding {
+ dst[di+2] = byte(enc.padChar)
+ dst[di+3] = byte(enc.padChar)
+ }
+ }
+}
+
+// EncodeToString returns the base64 encoding of src.
+func (enc *Encoding) EncodeToString(src []byte) string {
+ buf := make([]byte, enc.EncodedLen(len(src)))
+ enc.Encode(buf, src)
+ return string(buf)
+}
+
+type encoder struct {
+ err error
+ enc *Encoding
+ w io.Writer
+ buf [3]byte // buffered data waiting to be encoded
+ nbuf int // number of bytes in buf
+ out [1024]byte // output buffer
+}
+
+func (e *encoder) Write(p []byte) (n int, err error) {
+ if e.err != nil {
+ return 0, e.err
+ }
+
+ // Leading fringe.
+ if e.nbuf > 0 {
+ var i int
+ for i = 0; i < len(p) && e.nbuf < 3; i++ {
+ e.buf[e.nbuf] = p[i]
+ e.nbuf++
+ }
+ n += i
+ p = p[i:]
+ if e.nbuf < 3 {
+ return
+ }
+ e.enc.Encode(e.out[:], e.buf[:])
+ if _, e.err = e.w.Write(e.out[:4]); e.err != nil {
+ return n, e.err
+ }
+ e.nbuf = 0
+ }
+
+ // Large interior chunks.
+ for len(p) >= 3 {
+ nn := len(e.out) / 4 * 3
+ if nn > len(p) {
+ nn = len(p)
+ nn -= nn % 3
+ }
+ e.enc.Encode(e.out[:], p[:nn])
+ if _, e.err = e.w.Write(e.out[0 : nn/3*4]); e.err != nil {
+ return n, e.err
+ }
+ n += nn
+ p = p[nn:]
+ }
+
+ // Trailing fringe.
+ copy(e.buf[:], p)
+ e.nbuf = len(p)
+ n += len(p)
+ return
+}
+
+// Close flushes any pending output from the encoder.
+// It is an error to call Write after calling Close.
+func (e *encoder) Close() error {
+ // If there's anything left in the buffer, flush it out
+ if e.err == nil && e.nbuf > 0 {
+ e.enc.Encode(e.out[:], e.buf[:e.nbuf])
+ _, e.err = e.w.Write(e.out[:e.enc.EncodedLen(e.nbuf)])
+ e.nbuf = 0
+ }
+ return e.err
+}
+
+// NewEncoder returns a new base64 stream encoder. Data written to
+// the returned writer will be encoded using enc and then written to w.
+// Base64 encodings operate in 4-byte blocks; when finished
+// writing, the caller must Close the returned encoder to flush any
+// partially written blocks.
+func NewEncoder(enc *Encoding, w io.Writer) io.WriteCloser {
+ return &encoder{enc: enc, w: w}
+}
+
+// EncodedLen returns the length in bytes of the base64 encoding
+// of an input buffer of length n.
+func (enc *Encoding) EncodedLen(n int) int {
+ if enc.padChar == NoPadding {
+ return (n*8 + 5) / 6 // minimum # chars at 6 bits per char
+ }
+ return (n + 2) / 3 * 4 // minimum # 4-char quanta, 3 bytes each
+}
+
+/*
+ * Decoder
+ */
+
+type CorruptInputError int64
+
+func (e CorruptInputError) Error() string {
+ return "illegal base64 data at input byte " + strconv.FormatInt(int64(e), 10)
+}
+
+// decodeQuantum decodes up to 4 base64 bytes. The received parameters are
+// the destination buffer dst, the source buffer src and an index in the
+// source buffer si.
+// It returns the number of bytes read from src, the number of bytes written
+// to dst, and an error, if any.
+func (enc *Encoding) decodeQuantum(dst, src []byte, si int) (nsi, n int, err error) {
+ // Decode quantum using the base64 alphabet
+ var dbuf [4]byte
+ dlen := 4
+
+ // Lift the nil check outside of the loop.
+ _ = enc.decodeMap
+
+ for j := 0; j < len(dbuf); j++ {
+ if len(src) == si {
+ switch {
+ case j == 0:
+ return si, 0, nil
+ case j == 1, enc.padChar != NoPadding:
+ return si, 0, CorruptInputError(si - j)
+ }
+ dlen = j
+ break
+ }
+ in := src[si]
+ si++
+
+ out := enc.decodeMap[in]
+ if out != 0xff {
+ dbuf[j] = out
+ continue
+ }
+
+ if in == '\n' || in == '\r' {
+ j--
+ continue
+ }
+
+ if rune(in) != enc.padChar {
+ return si, 0, CorruptInputError(si - 1)
+ }
+
+ // We've reached the end and there's padding
+ switch j {
+ case 0, 1:
+ // incorrect padding
+ return si, 0, CorruptInputError(si - 1)
+ case 2:
+ // "==" is expected, the first "=" is already consumed.
+ // skip over newlines
+ for si < len(src) && (src[si] == '\n' || src[si] == '\r') {
+ si++
+ }
+ if si == len(src) {
+ // not enough padding
+ return si, 0, CorruptInputError(len(src))
+ }
+ if rune(src[si]) != enc.padChar {
+ // incorrect padding
+ return si, 0, CorruptInputError(si - 1)
+ }
+
+ si++
+ }
+
+ // skip over newlines
+ for si < len(src) && (src[si] == '\n' || src[si] == '\r') {
+ si++
+ }
+ if si < len(src) {
+ // trailing garbage
+ err = CorruptInputError(si)
+ }
+ dlen = j
+ break
+ }
+
+ // Convert 4x 6bit source bytes into 3 bytes
+ val := uint(dbuf[0])<<18 | uint(dbuf[1])<<12 | uint(dbuf[2])<<6 | uint(dbuf[3])
+ dbuf[2], dbuf[1], dbuf[0] = byte(val>>0), byte(val>>8), byte(val>>16)
+ switch dlen {
+ case 4:
+ dst[2] = dbuf[2]
+ dbuf[2] = 0
+ fallthrough
+ case 3:
+ dst[1] = dbuf[1]
+ if enc.strict && dbuf[2] != 0 {
+ return si, 0, CorruptInputError(si - 1)
+ }
+ dbuf[1] = 0
+ fallthrough
+ case 2:
+ dst[0] = dbuf[0]
+ if enc.strict && (dbuf[1] != 0 || dbuf[2] != 0) {
+ return si, 0, CorruptInputError(si - 2)
+ }
+ }
+
+ return si, dlen - 1, err
+}
+
+// DecodeString returns the bytes represented by the base64 string s.
+func (enc *Encoding) DecodeString(s string) ([]byte, error) {
+ dbuf := make([]byte, enc.DecodedLen(len(s)))
+ n, err := enc.Decode(dbuf, []byte(s))
+ return dbuf[:n], err
+}
+
+type decoder struct {
+ err error
+ readErr error // error from r.Read
+ enc *Encoding
+ r io.Reader
+ buf [1024]byte // leftover input
+ nbuf int
+ out []byte // leftover decoded output
+ outbuf [1024 / 4 * 3]byte
+}
+
+func (d *decoder) Read(p []byte) (n int, err error) {
+ // Use leftover decoded output from last read.
+ if len(d.out) > 0 {
+ n = copy(p, d.out)
+ d.out = d.out[n:]
+ return n, nil
+ }
+
+ if d.err != nil {
+ return 0, d.err
+ }
+
+ // This code assumes that d.r strips supported whitespace ('\r' and '\n').
+
+ // Refill buffer.
+ for d.nbuf < 4 && d.readErr == nil {
+ nn := len(p) / 3 * 4
+ if nn < 4 {
+ nn = 4
+ }
+ if nn > len(d.buf) {
+ nn = len(d.buf)
+ }
+ nn, d.readErr = d.r.Read(d.buf[d.nbuf:nn])
+ d.nbuf += nn
+ }
+
+ if d.nbuf < 4 {
+ if d.enc.padChar == NoPadding && d.nbuf > 0 {
+ // Decode final fragment, without padding.
+ var nw int
+ nw, d.err = d.enc.Decode(d.outbuf[:], d.buf[:d.nbuf])
+ d.nbuf = 0
+ d.out = d.outbuf[:nw]
+ n = copy(p, d.out)
+ d.out = d.out[n:]
+ if n > 0 || len(p) == 0 && len(d.out) > 0 {
+ return n, nil
+ }
+ if d.err != nil {
+ return 0, d.err
+ }
+ }
+ d.err = d.readErr
+ if d.err == io.EOF && d.nbuf > 0 {
+ d.err = io.ErrUnexpectedEOF
+ }
+ return 0, d.err
+ }
+
+ // Decode chunk into p, or d.out and then p if p is too small.
+ nr := d.nbuf / 4 * 4
+ nw := d.nbuf / 4 * 3
+ if nw > len(p) {
+ nw, d.err = d.enc.Decode(d.outbuf[:], d.buf[:nr])
+ d.out = d.outbuf[:nw]
+ n = copy(p, d.out)
+ d.out = d.out[n:]
+ } else {
+ n, d.err = d.enc.Decode(p, d.buf[:nr])
+ }
+ d.nbuf -= nr
+ copy(d.buf[:d.nbuf], d.buf[nr:])
+ return n, d.err
+}
+
+// Decode decodes src using the encoding enc. It writes at most
+// DecodedLen(len(src)) bytes to dst and returns the number of bytes
+// written. If src contains invalid base64 data, it will return the
+// number of bytes successfully written and CorruptInputError.
+// New line characters (\r and \n) are ignored.
+func (enc *Encoding) Decode(dst, src []byte) (n int, err error) {
+ if len(src) == 0 {
+ return 0, nil
+ }
+
+ // Lift the nil check outside of the loop. enc.decodeMap is directly
+ // used later in this function, to let the compiler know that the
+ // receiver can't be nil.
+ _ = enc.decodeMap
+
+ si := 0
+ for strconv.IntSize >= 64 && len(src)-si >= 8 && len(dst)-n >= 8 {
+ src2 := src[si : si+8]
+ if dn, ok := assemble64(
+ enc.decodeMap[src2[0]],
+ enc.decodeMap[src2[1]],
+ enc.decodeMap[src2[2]],
+ enc.decodeMap[src2[3]],
+ enc.decodeMap[src2[4]],
+ enc.decodeMap[src2[5]],
+ enc.decodeMap[src2[6]],
+ enc.decodeMap[src2[7]],
+ ); ok {
+ binary.BigEndian.PutUint64(dst[n:], dn)
+ n += 6
+ si += 8
+ } else {
+ var ninc int
+ si, ninc, err = enc.decodeQuantum(dst[n:], src, si)
+ n += ninc
+ if err != nil {
+ return n, err
+ }
+ }
+ }
+
+ for len(src)-si >= 4 && len(dst)-n >= 4 {
+ src2 := src[si : si+4]
+ if dn, ok := assemble32(
+ enc.decodeMap[src2[0]],
+ enc.decodeMap[src2[1]],
+ enc.decodeMap[src2[2]],
+ enc.decodeMap[src2[3]],
+ ); ok {
+ binary.BigEndian.PutUint32(dst[n:], dn)
+ n += 3
+ si += 4
+ } else {
+ var ninc int
+ si, ninc, err = enc.decodeQuantum(dst[n:], src, si)
+ n += ninc
+ if err != nil {
+ return n, err
+ }
+ }
+ }
+
+ for si < len(src) {
+ var ninc int
+ si, ninc, err = enc.decodeQuantum(dst[n:], src, si)
+ n += ninc
+ if err != nil {
+ return n, err
+ }
+ }
+ return n, err
+}
+
+// assemble32 assembles 4 base64 digits into 3 bytes.
+// Each digit comes from the decode map, and will be 0xff
+// if it came from an invalid character.
+func assemble32(n1, n2, n3, n4 byte) (dn uint32, ok bool) {
+ // Check that all the digits are valid. If any of them was 0xff, their
+ // bitwise OR will be 0xff.
+ if n1|n2|n3|n4 == 0xff {
+ return 0, false
+ }
+ return uint32(n1)<<26 |
+ uint32(n2)<<20 |
+ uint32(n3)<<14 |
+ uint32(n4)<<8,
+ true
+}
+
+// assemble64 assembles 8 base64 digits into 6 bytes.
+// Each digit comes from the decode map, and will be 0xff
+// if it came from an invalid character.
+func assemble64(n1, n2, n3, n4, n5, n6, n7, n8 byte) (dn uint64, ok bool) {
+ // Check that all the digits are valid. If any of them was 0xff, their
+ // bitwise OR will be 0xff.
+ if n1|n2|n3|n4|n5|n6|n7|n8 == 0xff {
+ return 0, false
+ }
+ return uint64(n1)<<58 |
+ uint64(n2)<<52 |
+ uint64(n3)<<46 |
+ uint64(n4)<<40 |
+ uint64(n5)<<34 |
+ uint64(n6)<<28 |
+ uint64(n7)<<22 |
+ uint64(n8)<<16,
+ true
+}
+
+type newlineFilteringReader struct {
+ wrapped io.Reader
+}
+
+func (r *newlineFilteringReader) Read(p []byte) (int, error) {
+ n, err := r.wrapped.Read(p)
+ for n > 0 {
+ offset := 0
+ for i, b := range p[:n] {
+ if b != '\r' && b != '\n' {
+ if i != offset {
+ p[offset] = b
+ }
+ offset++
+ }
+ }
+ if offset > 0 {
+ return offset, err
+ }
+ // Previous buffer entirely whitespace, read again
+ n, err = r.wrapped.Read(p)
+ }
+ return n, err
+}
+
+// NewDecoder constructs a new base64 stream decoder.
+func NewDecoder(enc *Encoding, r io.Reader) io.Reader {
+ return &decoder{enc: enc, r: &newlineFilteringReader{r}}
+}
+
+// DecodedLen returns the maximum length in bytes of the decoded data
+// corresponding to n bytes of base64-encoded data.
+func (enc *Encoding) DecodedLen(n int) int {
+ if enc.padChar == NoPadding {
+ // Unpadded data may end with partial block of 2-3 characters.
+ return n * 6 / 8
+ }
+ // Padded base64 should always be a multiple of 4 characters in length.
+ return n / 4 * 3
+}
diff --git a/src/encoding/base64/base64_test.go b/src/encoding/base64/base64_test.go
new file mode 100644
index 0000000..57256a3
--- /dev/null
+++ b/src/encoding/base64/base64_test.go
@@ -0,0 +1,530 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package base64
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+ "io"
+ "reflect"
+ "runtime/debug"
+ "strings"
+ "testing"
+ "time"
+)
+
+type testpair struct {
+ decoded, encoded string
+}
+
+var pairs = []testpair{
+ // RFC 3548 examples
+ {"\x14\xfb\x9c\x03\xd9\x7e", "FPucA9l+"},
+ {"\x14\xfb\x9c\x03\xd9", "FPucA9k="},
+ {"\x14\xfb\x9c\x03", "FPucAw=="},
+
+ // RFC 4648 examples
+ {"", ""},
+ {"f", "Zg=="},
+ {"fo", "Zm8="},
+ {"foo", "Zm9v"},
+ {"foob", "Zm9vYg=="},
+ {"fooba", "Zm9vYmE="},
+ {"foobar", "Zm9vYmFy"},
+
+ // Wikipedia examples
+ {"sure.", "c3VyZS4="},
+ {"sure", "c3VyZQ=="},
+ {"sur", "c3Vy"},
+ {"su", "c3U="},
+ {"leasure.", "bGVhc3VyZS4="},
+ {"easure.", "ZWFzdXJlLg=="},
+ {"asure.", "YXN1cmUu"},
+ {"sure.", "c3VyZS4="},
+}
+
+// Do nothing to a reference base64 string (leave in standard format)
+func stdRef(ref string) string {
+ return ref
+}
+
+// Convert a reference string to URL-encoding
+func urlRef(ref string) string {
+ ref = strings.ReplaceAll(ref, "+", "-")
+ ref = strings.ReplaceAll(ref, "/", "_")
+ return ref
+}
+
+// Convert a reference string to raw, unpadded format
+func rawRef(ref string) string {
+ return strings.TrimRight(ref, "=")
+}
+
+// Both URL and unpadding conversions
+func rawURLRef(ref string) string {
+ return rawRef(urlRef(ref))
+}
+
+// A nonstandard encoding with a funny padding character, for testing
+var funnyEncoding = NewEncoding(encodeStd).WithPadding(rune('@'))
+
+func funnyRef(ref string) string {
+ return strings.ReplaceAll(ref, "=", "@")
+}
+
+type encodingTest struct {
+ enc *Encoding // Encoding to test
+ conv func(string) string // Reference string converter
+}
+
+var encodingTests = []encodingTest{
+ {StdEncoding, stdRef},
+ {URLEncoding, urlRef},
+ {RawStdEncoding, rawRef},
+ {RawURLEncoding, rawURLRef},
+ {funnyEncoding, funnyRef},
+ {StdEncoding.Strict(), stdRef},
+ {URLEncoding.Strict(), urlRef},
+ {RawStdEncoding.Strict(), rawRef},
+ {RawURLEncoding.Strict(), rawURLRef},
+ {funnyEncoding.Strict(), funnyRef},
+}
+
+var bigtest = testpair{
+ "Twas brillig, and the slithy toves",
+ "VHdhcyBicmlsbGlnLCBhbmQgdGhlIHNsaXRoeSB0b3Zlcw==",
+}
+
+func testEqual(t *testing.T, msg string, args ...any) bool {
+ t.Helper()
+ if args[len(args)-2] != args[len(args)-1] {
+ t.Errorf(msg, args...)
+ return false
+ }
+ return true
+}
+
+func TestEncode(t *testing.T) {
+ for _, p := range pairs {
+ for _, tt := range encodingTests {
+ got := tt.enc.EncodeToString([]byte(p.decoded))
+ testEqual(t, "Encode(%q) = %q, want %q", p.decoded,
+ got, tt.conv(p.encoded))
+ }
+ }
+}
+
+func TestEncoder(t *testing.T) {
+ for _, p := range pairs {
+ bb := &bytes.Buffer{}
+ encoder := NewEncoder(StdEncoding, bb)
+ encoder.Write([]byte(p.decoded))
+ encoder.Close()
+ testEqual(t, "Encode(%q) = %q, want %q", p.decoded, bb.String(), p.encoded)
+ }
+}
+
+func TestEncoderBuffering(t *testing.T) {
+ input := []byte(bigtest.decoded)
+ for bs := 1; bs <= 12; bs++ {
+ bb := &bytes.Buffer{}
+ encoder := NewEncoder(StdEncoding, bb)
+ for pos := 0; pos < len(input); pos += bs {
+ end := pos + bs
+ if end > len(input) {
+ end = len(input)
+ }
+ n, err := encoder.Write(input[pos:end])
+ testEqual(t, "Write(%q) gave error %v, want %v", input[pos:end], err, error(nil))
+ testEqual(t, "Write(%q) gave length %v, want %v", input[pos:end], n, end-pos)
+ }
+ err := encoder.Close()
+ testEqual(t, "Close gave error %v, want %v", err, error(nil))
+ testEqual(t, "Encoding/%d of %q = %q, want %q", bs, bigtest.decoded, bb.String(), bigtest.encoded)
+ }
+}
+
+func TestDecode(t *testing.T) {
+ for _, p := range pairs {
+ for _, tt := range encodingTests {
+ encoded := tt.conv(p.encoded)
+ dbuf := make([]byte, tt.enc.DecodedLen(len(encoded)))
+ count, err := tt.enc.Decode(dbuf, []byte(encoded))
+ testEqual(t, "Decode(%q) = error %v, want %v", encoded, err, error(nil))
+ testEqual(t, "Decode(%q) = length %v, want %v", encoded, count, len(p.decoded))
+ testEqual(t, "Decode(%q) = %q, want %q", encoded, string(dbuf[0:count]), p.decoded)
+
+ dbuf, err = tt.enc.DecodeString(encoded)
+ testEqual(t, "DecodeString(%q) = error %v, want %v", encoded, err, error(nil))
+ testEqual(t, "DecodeString(%q) = %q, want %q", encoded, string(dbuf), p.decoded)
+ }
+ }
+}
+
+func TestDecoder(t *testing.T) {
+ for _, p := range pairs {
+ decoder := NewDecoder(StdEncoding, strings.NewReader(p.encoded))
+ dbuf := make([]byte, StdEncoding.DecodedLen(len(p.encoded)))
+ count, err := decoder.Read(dbuf)
+ if err != nil && err != io.EOF {
+ t.Fatal("Read failed", err)
+ }
+ testEqual(t, "Read from %q = length %v, want %v", p.encoded, count, len(p.decoded))
+ testEqual(t, "Decoding of %q = %q, want %q", p.encoded, string(dbuf[0:count]), p.decoded)
+ if err != io.EOF {
+ _, err = decoder.Read(dbuf)
+ }
+ testEqual(t, "Read from %q = %v, want %v", p.encoded, err, io.EOF)
+ }
+}
+
+func TestDecoderBuffering(t *testing.T) {
+ for bs := 1; bs <= 12; bs++ {
+ decoder := NewDecoder(StdEncoding, strings.NewReader(bigtest.encoded))
+ buf := make([]byte, len(bigtest.decoded)+12)
+ var total int
+ var n int
+ var err error
+ for total = 0; total < len(bigtest.decoded) && err == nil; {
+ n, err = decoder.Read(buf[total : total+bs])
+ total += n
+ }
+ if err != nil && err != io.EOF {
+ t.Errorf("Read from %q at pos %d = %d, unexpected error %v", bigtest.encoded, total, n, err)
+ }
+ testEqual(t, "Decoding/%d of %q = %q, want %q", bs, bigtest.encoded, string(buf[0:total]), bigtest.decoded)
+ }
+}
+
+func TestDecodeCorrupt(t *testing.T) {
+ testCases := []struct {
+ input string
+ offset int // -1 means no corruption.
+ }{
+ {"", -1},
+ {"\n", -1},
+ {"AAA=\n", -1},
+ {"AAAA\n", -1},
+ {"!!!!", 0},
+ {"====", 0},
+ {"x===", 1},
+ {"=AAA", 0},
+ {"A=AA", 1},
+ {"AA=A", 2},
+ {"AA==A", 4},
+ {"AAA=AAAA", 4},
+ {"AAAAA", 4},
+ {"AAAAAA", 4},
+ {"A=", 1},
+ {"A==", 1},
+ {"AA=", 3},
+ {"AA==", -1},
+ {"AAA=", -1},
+ {"AAAA", -1},
+ {"AAAAAA=", 7},
+ {"YWJjZA=====", 8},
+ {"A!\n", 1},
+ {"A=\n", 1},
+ }
+ for _, tc := range testCases {
+ dbuf := make([]byte, StdEncoding.DecodedLen(len(tc.input)))
+ _, err := StdEncoding.Decode(dbuf, []byte(tc.input))
+ if tc.offset == -1 {
+ if err != nil {
+ t.Error("Decoder wrongly detected corruption in", tc.input)
+ }
+ continue
+ }
+ switch err := err.(type) {
+ case CorruptInputError:
+ testEqual(t, "Corruption in %q at offset %v, want %v", tc.input, int(err), tc.offset)
+ default:
+ t.Error("Decoder failed to detect corruption in", tc)
+ }
+ }
+}
+
+func TestDecodeBounds(t *testing.T) {
+ var buf [32]byte
+ s := StdEncoding.EncodeToString(buf[:])
+ defer func() {
+ if err := recover(); err != nil {
+ t.Fatalf("Decode panicked unexpectedly: %v\n%s", err, debug.Stack())
+ }
+ }()
+ n, err := StdEncoding.Decode(buf[:], []byte(s))
+ if n != len(buf) || err != nil {
+ t.Fatalf("StdEncoding.Decode = %d, %v, want %d, nil", n, err, len(buf))
+ }
+}
+
+func TestEncodedLen(t *testing.T) {
+ for _, tt := range []struct {
+ enc *Encoding
+ n int
+ want int
+ }{
+ {RawStdEncoding, 0, 0},
+ {RawStdEncoding, 1, 2},
+ {RawStdEncoding, 2, 3},
+ {RawStdEncoding, 3, 4},
+ {RawStdEncoding, 7, 10},
+ {StdEncoding, 0, 0},
+ {StdEncoding, 1, 4},
+ {StdEncoding, 2, 4},
+ {StdEncoding, 3, 4},
+ {StdEncoding, 4, 8},
+ {StdEncoding, 7, 12},
+ } {
+ if got := tt.enc.EncodedLen(tt.n); got != tt.want {
+ t.Errorf("EncodedLen(%d): got %d, want %d", tt.n, got, tt.want)
+ }
+ }
+}
+
+func TestDecodedLen(t *testing.T) {
+ for _, tt := range []struct {
+ enc *Encoding
+ n int
+ want int
+ }{
+ {RawStdEncoding, 0, 0},
+ {RawStdEncoding, 2, 1},
+ {RawStdEncoding, 3, 2},
+ {RawStdEncoding, 4, 3},
+ {RawStdEncoding, 10, 7},
+ {StdEncoding, 0, 0},
+ {StdEncoding, 4, 3},
+ {StdEncoding, 8, 6},
+ } {
+ if got := tt.enc.DecodedLen(tt.n); got != tt.want {
+ t.Errorf("DecodedLen(%d): got %d, want %d", tt.n, got, tt.want)
+ }
+ }
+}
+
+func TestBig(t *testing.T) {
+ n := 3*1000 + 1
+ raw := make([]byte, n)
+ const alpha = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ for i := 0; i < n; i++ {
+ raw[i] = alpha[i%len(alpha)]
+ }
+ encoded := new(bytes.Buffer)
+ w := NewEncoder(StdEncoding, encoded)
+ nn, err := w.Write(raw)
+ if nn != n || err != nil {
+ t.Fatalf("Encoder.Write(raw) = %d, %v want %d, nil", nn, err, n)
+ }
+ err = w.Close()
+ if err != nil {
+ t.Fatalf("Encoder.Close() = %v want nil", err)
+ }
+ decoded, err := io.ReadAll(NewDecoder(StdEncoding, encoded))
+ if err != nil {
+ t.Fatalf("io.ReadAll(NewDecoder(...)): %v", err)
+ }
+
+ if !bytes.Equal(raw, decoded) {
+ var i int
+ for i = 0; i < len(decoded) && i < len(raw); i++ {
+ if decoded[i] != raw[i] {
+ break
+ }
+ }
+ t.Errorf("Decode(Encode(%d-byte string)) failed at offset %d", n, i)
+ }
+}
+
+func TestNewLineCharacters(t *testing.T) {
+ // Each of these should decode to the string "sure", without errors.
+ const expected = "sure"
+ examples := []string{
+ "c3VyZQ==",
+ "c3VyZQ==\r",
+ "c3VyZQ==\n",
+ "c3VyZQ==\r\n",
+ "c3VyZ\r\nQ==",
+ "c3V\ryZ\nQ==",
+ "c3V\nyZ\rQ==",
+ "c3VyZ\nQ==",
+ "c3VyZQ\n==",
+ "c3VyZQ=\n=",
+ "c3VyZQ=\r\n\r\n=",
+ }
+ for _, e := range examples {
+ buf, err := StdEncoding.DecodeString(e)
+ if err != nil {
+ t.Errorf("Decode(%q) failed: %v", e, err)
+ continue
+ }
+ if s := string(buf); s != expected {
+ t.Errorf("Decode(%q) = %q, want %q", e, s, expected)
+ }
+ }
+}
+
+type nextRead struct {
+ n int // bytes to return
+ err error // error to return
+}
+
+// faultInjectReader returns data from source, rate-limited
+// and with the errors as written to nextc.
+type faultInjectReader struct {
+ source string
+ nextc <-chan nextRead
+}
+
+func (r *faultInjectReader) Read(p []byte) (int, error) {
+ nr := <-r.nextc
+ if len(p) > nr.n {
+ p = p[:nr.n]
+ }
+ n := copy(p, r.source)
+ r.source = r.source[n:]
+ return n, nr.err
+}
+
+// tests that we don't ignore errors from our underlying reader
+func TestDecoderIssue3577(t *testing.T) {
+ next := make(chan nextRead, 10)
+ wantErr := errors.New("my error")
+ next <- nextRead{5, nil}
+ next <- nextRead{10, wantErr}
+ next <- nextRead{0, wantErr}
+ d := NewDecoder(StdEncoding, &faultInjectReader{
+ source: "VHdhcyBicmlsbGlnLCBhbmQgdGhlIHNsaXRoeSB0b3Zlcw==", // twas brillig...
+ nextc: next,
+ })
+ errc := make(chan error, 1)
+ go func() {
+ _, err := io.ReadAll(d)
+ errc <- err
+ }()
+ select {
+ case err := <-errc:
+ if err != wantErr {
+ t.Errorf("got error %v; want %v", err, wantErr)
+ }
+ case <-time.After(5 * time.Second):
+ t.Errorf("timeout; Decoder blocked without returning an error")
+ }
+}
+
+func TestDecoderIssue4779(t *testing.T) {
+ encoded := `CP/EAT8AAAEF
+AQEBAQEBAAAAAAAAAAMAAQIEBQYHCAkKCwEAAQUBAQEBAQEAAAAAAAAAAQACAwQFBgcICQoLEAAB
+BAEDAgQCBQcGCAUDDDMBAAIRAwQhEjEFQVFhEyJxgTIGFJGhsUIjJBVSwWIzNHKC0UMHJZJT8OHx
+Y3M1FqKygyZEk1RkRcKjdDYX0lXiZfKzhMPTdePzRieUpIW0lcTU5PSltcXV5fVWZnaGlqa2xtbm
+9jdHV2d3h5ent8fX5/cRAAICAQIEBAMEBQYHBwYFNQEAAhEDITESBEFRYXEiEwUygZEUobFCI8FS
+0fAzJGLhcoKSQ1MVY3M08SUGFqKygwcmNcLSRJNUoxdkRVU2dGXi8rOEw9N14/NGlKSFtJXE1OT0
+pbXF1eX1VmZ2hpamtsbW5vYnN0dXZ3eHl6e3x//aAAwDAQACEQMRAD8A9VSSSSUpJJJJSkkkJ+Tj
+1kiy1jCJJDnAcCTykpKkuQ6p/jN6FgmxlNduXawwAzaGH+V6jn/R/wCt71zdn+N/qL3kVYFNYB4N
+ji6PDVjWpKp9TSXnvTf8bFNjg3qOEa2n6VlLpj/rT/pf567DpX1i6L1hs9Py67X8mqdtg/rUWbbf
++gkp0kkkklKSSSSUpJJJJT//0PVUkkklKVLq3WMDpGI7KzrNjADtYNXvI/Mqr/Pd/q9W3vaxjnvM
+NaCXE9gNSvGPrf8AWS3qmba5jjsJhoB0DAf0NDf6sevf+/lf8Hj0JJATfWT6/dV6oXU1uOLQeKKn
+EQP+Hubtfe/+R7Mf/g7f5xcocp++Z11JMCJPgFBxOg7/AOuqDx8I/ikpkXkmSdU8mJIJA/O8EMAy
+j+mSARB/17pKVXYWHXjsj7yIex0PadzXMO1zT5KHoNA3HT8ietoGhgjsfA+CSnvvqh/jJtqsrwOv
+2b6NGNzXfTYexzJ+nU7/ALkf4P8Awv6P9KvTQQ4AgyDqCF85Pho3CTB7eHwXoH+LT65uZbX9X+o2
+bqbPb06551Y4
+`
+ encodedShort := strings.ReplaceAll(encoded, "\n", "")
+
+ dec := NewDecoder(StdEncoding, strings.NewReader(encoded))
+ res1, err := io.ReadAll(dec)
+ if err != nil {
+ t.Errorf("ReadAll failed: %v", err)
+ }
+
+ dec = NewDecoder(StdEncoding, strings.NewReader(encodedShort))
+ var res2 []byte
+ res2, err = io.ReadAll(dec)
+ if err != nil {
+ t.Errorf("ReadAll failed: %v", err)
+ }
+
+ if !bytes.Equal(res1, res2) {
+ t.Error("Decoded results not equal")
+ }
+}
+
+func TestDecoderIssue7733(t *testing.T) {
+ s, err := StdEncoding.DecodeString("YWJjZA=====")
+ want := CorruptInputError(8)
+ if !reflect.DeepEqual(want, err) {
+ t.Errorf("Error = %v; want CorruptInputError(8)", err)
+ }
+ if string(s) != "abcd" {
+ t.Errorf("DecodeString = %q; want abcd", s)
+ }
+}
+
+func TestDecoderIssue15656(t *testing.T) {
+ _, err := StdEncoding.Strict().DecodeString("WvLTlMrX9NpYDQlEIFlnDB==")
+ want := CorruptInputError(22)
+ if !reflect.DeepEqual(want, err) {
+ t.Errorf("Error = %v; want CorruptInputError(22)", err)
+ }
+ _, err = StdEncoding.Strict().DecodeString("WvLTlMrX9NpYDQlEIFlnDA==")
+ if err != nil {
+ t.Errorf("Error = %v; want nil", err)
+ }
+ _, err = StdEncoding.DecodeString("WvLTlMrX9NpYDQlEIFlnDB==")
+ if err != nil {
+ t.Errorf("Error = %v; want nil", err)
+ }
+}
+
+func BenchmarkEncodeToString(b *testing.B) {
+ data := make([]byte, 8192)
+ b.SetBytes(int64(len(data)))
+ for i := 0; i < b.N; i++ {
+ StdEncoding.EncodeToString(data)
+ }
+}
+
+func BenchmarkDecodeString(b *testing.B) {
+ sizes := []int{2, 4, 8, 64, 8192}
+ benchFunc := func(b *testing.B, benchSize int) {
+ data := StdEncoding.EncodeToString(make([]byte, benchSize))
+ b.SetBytes(int64(len(data)))
+ b.ResetTimer()
+ for i := 0; i < b.N; i++ {
+ StdEncoding.DecodeString(data)
+ }
+ }
+ for _, size := range sizes {
+ b.Run(fmt.Sprintf("%d", size), func(b *testing.B) {
+ benchFunc(b, size)
+ })
+ }
+}
+
+func TestDecoderRaw(t *testing.T) {
+ source := "AAAAAA"
+ want := []byte{0, 0, 0, 0}
+
+ // Direct.
+ dec1, err := RawURLEncoding.DecodeString(source)
+ if err != nil || !bytes.Equal(dec1, want) {
+ t.Errorf("RawURLEncoding.DecodeString(%q) = %x, %v, want %x, nil", source, dec1, err, want)
+ }
+
+ // Through reader. Used to fail.
+ r := NewDecoder(RawURLEncoding, bytes.NewReader([]byte(source)))
+ dec2, err := io.ReadAll(io.LimitReader(r, 100))
+ if err != nil || !bytes.Equal(dec2, want) {
+ t.Errorf("reading NewDecoder(RawURLEncoding, %q) = %x, %v, want %x, nil", source, dec2, err, want)
+ }
+
+ // Should work with padding.
+ r = NewDecoder(URLEncoding, bytes.NewReader([]byte(source+"==")))
+ dec3, err := io.ReadAll(r)
+ if err != nil || !bytes.Equal(dec3, want) {
+ t.Errorf("reading NewDecoder(URLEncoding, %q) = %x, %v, want %x, nil", source+"==", dec3, err, want)
+ }
+}
diff --git a/src/encoding/base64/example_test.go b/src/encoding/base64/example_test.go
new file mode 100644
index 0000000..61a3adc
--- /dev/null
+++ b/src/encoding/base64/example_test.go
@@ -0,0 +1,83 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Keep in sync with ../base32/example_test.go.
+
+package base64_test
+
+import (
+ "encoding/base64"
+ "fmt"
+ "os"
+)
+
+func Example() {
+ msg := "Hello, 世界"
+ encoded := base64.StdEncoding.EncodeToString([]byte(msg))
+ fmt.Println(encoded)
+ decoded, err := base64.StdEncoding.DecodeString(encoded)
+ if err != nil {
+ fmt.Println("decode error:", err)
+ return
+ }
+ fmt.Println(string(decoded))
+ // Output:
+ // SGVsbG8sIOS4lueVjA==
+ // Hello, 世界
+}
+
+func ExampleEncoding_EncodeToString() {
+ data := []byte("any + old & data")
+ str := base64.StdEncoding.EncodeToString(data)
+ fmt.Println(str)
+ // Output:
+ // YW55ICsgb2xkICYgZGF0YQ==
+}
+
+func ExampleEncoding_Encode() {
+ data := []byte("Hello, world!")
+ dst := make([]byte, base64.StdEncoding.EncodedLen(len(data)))
+ base64.StdEncoding.Encode(dst, data)
+ fmt.Println(string(dst))
+ // Output:
+ // SGVsbG8sIHdvcmxkIQ==
+}
+
+func ExampleEncoding_DecodeString() {
+ str := "c29tZSBkYXRhIHdpdGggACBhbmQg77u/"
+ data, err := base64.StdEncoding.DecodeString(str)
+ if err != nil {
+ fmt.Println("error:", err)
+ return
+ }
+ fmt.Printf("%q\n", data)
+ // Output:
+ // "some data with \x00 and \ufeff"
+}
+
+func ExampleEncoding_Decode() {
+ str := "SGVsbG8sIHdvcmxkIQ=="
+ dst := make([]byte, base64.StdEncoding.DecodedLen(len(str)))
+ n, err := base64.StdEncoding.Decode(dst, []byte(str))
+ if err != nil {
+ fmt.Println("decode error:", err)
+ return
+ }
+ dst = dst[:n]
+ fmt.Printf("%q\n", dst)
+ // Output:
+ // "Hello, world!"
+}
+
+func ExampleNewEncoder() {
+ input := []byte("foo\x00bar")
+ encoder := base64.NewEncoder(base64.StdEncoding, os.Stdout)
+ encoder.Write(input)
+ // Must close the encoder when finished to flush any partial blocks.
+ // If you comment out the following line, the last partial block "r"
+ // won't be encoded.
+ encoder.Close()
+ // Output:
+ // Zm9vAGJhcg==
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 22:42:05 +0000