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path: root/src/pkg/encoding/base64/base64.go
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Diffstat (limited to 'src/pkg/encoding/base64/base64.go')
-rw-r--r--src/pkg/encoding/base64/base64.go393
1 files changed, 0 insertions, 393 deletions
diff --git a/src/pkg/encoding/base64/base64.go b/src/pkg/encoding/base64/base64.go
deleted file mode 100644
index e38c26d0e..000000000
--- a/src/pkg/encoding/base64/base64.go
+++ /dev/null
@@ -1,393 +0,0 @@
-// 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 (
- "bytes"
- "io"
- "strconv"
- "strings"
-)
-
-/*
- * 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 string
- decodeMap [256]byte
-}
-
-const encodeStd = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
-const encodeURL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
-
-// NewEncoding returns a new Encoding defined by the given alphabet,
-// which must be a 64-byte string.
-func NewEncoding(encoder string) *Encoding {
- e := new(Encoding)
- 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
-}
-
-// 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)
-
-var removeNewlinesMapper = func(r rune) rune {
- if r == '\r' || r == '\n' {
- return -1
- }
- return r
-}
-
-/*
- * 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
- }
-
- for len(src) > 0 {
- dst[0] = 0
- dst[1] = 0
- dst[2] = 0
- dst[3] = 0
-
- // Unpack 4x 6-bit source blocks into a 4 byte
- // destination quantum
- switch len(src) {
- default:
- dst[3] |= src[2] & 0x3F
- dst[2] |= src[2] >> 6
- fallthrough
- case 2:
- dst[2] |= (src[1] << 2) & 0x3F
- dst[1] |= src[1] >> 4
- fallthrough
- case 1:
- dst[1] |= (src[0] << 4) & 0x3F
- dst[0] |= src[0] >> 2
- }
-
- // Encode 6-bit blocks using the base64 alphabet
- for j := 0; j < 4; j++ {
- dst[j] = enc.encode[dst[j]]
- }
-
- // Pad the final quantum
- if len(src) < 3 {
- dst[3] = '='
- if len(src) < 2 {
- dst[2] = '='
- }
- break
- }
-
- src = src[3:]
- dst = dst[4:]
- }
-}
-
-// 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[0:], e.buf[0:])
- if _, e.err = e.w.Write(e.out[0:4]); 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[0:], p[0: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.
- for i := 0; i < len(p); i++ {
- e.buf[i] = p[i]
- }
- 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[0:], e.buf[0:e.nbuf])
- e.nbuf = 0
- _, e.err = e.w.Write(e.out[0:4])
- }
- 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 { return (n + 2) / 3 * 4 }
-
-/*
- * Decoder
- */
-
-type CorruptInputError int64
-
-func (e CorruptInputError) Error() string {
- return "illegal base64 data at input byte " + strconv.FormatInt(int64(e), 10)
-}
-
-// decode is like Decode but returns an additional 'end' value, which
-// indicates if end-of-message padding was encountered and thus any
-// additional data is an error. This method assumes that src has been
-// stripped of all supported whitespace ('\r' and '\n').
-func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
- olen := len(src)
- for len(src) > 0 && !end {
- // Decode quantum using the base64 alphabet
- var dbuf [4]byte
- dlen := 4
-
- for j := range dbuf {
- if len(src) == 0 {
- return n, false, CorruptInputError(olen - len(src) - j)
- }
- in := src[0]
- src = src[1:]
- if in == '=' {
- // We've reached the end and there's padding
- switch j {
- case 0, 1:
- // incorrect padding
- return n, false, CorruptInputError(olen - len(src) - 1)
- case 2:
- // "==" is expected, the first "=" is already consumed.
- if len(src) == 0 {
- // not enough padding
- return n, false, CorruptInputError(olen)
- }
- if src[0] != '=' {
- // incorrect padding
- return n, false, CorruptInputError(olen - len(src) - 1)
- }
- src = src[1:]
- }
- if len(src) > 0 {
- // trailing garbage
- err = CorruptInputError(olen - len(src))
- }
- dlen, end = j, true
- break
- }
- dbuf[j] = enc.decodeMap[in]
- if dbuf[j] == 0xFF {
- return n, false, CorruptInputError(olen - len(src) - 1)
- }
- }
-
- // Pack 4x 6-bit source blocks into 3 byte destination
- // quantum
- switch dlen {
- case 4:
- dst[2] = dbuf[2]<<6 | dbuf[3]
- fallthrough
- case 3:
- dst[1] = dbuf[1]<<4 | dbuf[2]>>2
- fallthrough
- case 2:
- dst[0] = dbuf[0]<<2 | dbuf[1]>>4
- }
- dst = dst[3:]
- n += dlen - 1
- }
-
- return n, end, 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) {
- src = bytes.Map(removeNewlinesMapper, src)
- n, _, err = enc.decode(dst, src)
- return
-}
-
-// DecodeString returns the bytes represented by the base64 string s.
-func (enc *Encoding) DecodeString(s string) ([]byte, error) {
- s = strings.Map(removeNewlinesMapper, s)
- dbuf := make([]byte, enc.DecodedLen(len(s)))
- n, err := enc.Decode(dbuf, []byte(s))
- return dbuf[:n], err
-}
-
-type decoder struct {
- err error
- enc *Encoding
- r io.Reader
- end bool // saw end of message
- 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) {
- if d.err != nil {
- return 0, d.err
- }
-
- // 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
- }
-
- // Read a chunk.
- nn := len(p) / 3 * 4
- if nn < 4 {
- nn = 4
- }
- if nn > len(d.buf) {
- nn = len(d.buf)
- }
- nn, d.err = io.ReadAtLeast(d.r, d.buf[d.nbuf:nn], 4-d.nbuf)
- d.nbuf += nn
- if d.err != nil || d.nbuf < 4 {
- 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.end, d.err = d.enc.decode(d.outbuf[0:], d.buf[0:nr])
- d.out = d.outbuf[0:nw]
- n = copy(p, d.out)
- d.out = d.out[n:]
- } else {
- n, d.end, d.err = d.enc.decode(p, d.buf[0:nr])
- }
- d.nbuf -= nr
- for i := 0; i < d.nbuf; i++ {
- d.buf[i] = d.buf[i+nr]
- }
-
- if d.err == nil {
- d.err = err
- }
- return n, d.err
-}
-
-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[0: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 { return n / 4 * 3 }
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-29 11:46:44 +0000