/usr/share/gocode/src/golang.org/x/crypto/openpgp/armor/encode.go is in golang-golang-x-crypto-dev 1:0.0~git20170629.0.5ef0053-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 | // Copyright 2010 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 armor
import (
"encoding/base64"
"io"
)
var armorHeaderSep = []byte(": ")
var blockEnd = []byte("\n=")
var newline = []byte("\n")
var armorEndOfLineOut = []byte("-----\n")
// writeSlices writes its arguments to the given Writer.
func writeSlices(out io.Writer, slices ...[]byte) (err error) {
for _, s := range slices {
_, err = out.Write(s)
if err != nil {
return err
}
}
return
}
// lineBreaker breaks data across several lines, all of the same byte length
// (except possibly the last). Lines are broken with a single '\n'.
type lineBreaker struct {
lineLength int
line []byte
used int
out io.Writer
haveWritten bool
}
func newLineBreaker(out io.Writer, lineLength int) *lineBreaker {
return &lineBreaker{
lineLength: lineLength,
line: make([]byte, lineLength),
used: 0,
out: out,
}
}
func (l *lineBreaker) Write(b []byte) (n int, err error) {
n = len(b)
if n == 0 {
return
}
if l.used == 0 && l.haveWritten {
_, err = l.out.Write([]byte{'\n'})
if err != nil {
return
}
}
if l.used+len(b) < l.lineLength {
l.used += copy(l.line[l.used:], b)
return
}
l.haveWritten = true
_, err = l.out.Write(l.line[0:l.used])
if err != nil {
return
}
excess := l.lineLength - l.used
l.used = 0
_, err = l.out.Write(b[0:excess])
if err != nil {
return
}
_, err = l.Write(b[excess:])
return
}
func (l *lineBreaker) Close() (err error) {
if l.used > 0 {
_, err = l.out.Write(l.line[0:l.used])
if err != nil {
return
}
}
return
}
// encoding keeps track of a running CRC24 over the data which has been written
// to it and outputs a OpenPGP checksum when closed, followed by an armor
// trailer.
//
// It's built into a stack of io.Writers:
// encoding -> base64 encoder -> lineBreaker -> out
type encoding struct {
out io.Writer
breaker *lineBreaker
b64 io.WriteCloser
crc uint32
blockType []byte
}
func (e *encoding) Write(data []byte) (n int, err error) {
e.crc = crc24(e.crc, data)
return e.b64.Write(data)
}
func (e *encoding) Close() (err error) {
err = e.b64.Close()
if err != nil {
return
}
e.breaker.Close()
var checksumBytes [3]byte
checksumBytes[0] = byte(e.crc >> 16)
checksumBytes[1] = byte(e.crc >> 8)
checksumBytes[2] = byte(e.crc)
var b64ChecksumBytes [4]byte
base64.StdEncoding.Encode(b64ChecksumBytes[:], checksumBytes[:])
return writeSlices(e.out, blockEnd, b64ChecksumBytes[:], newline, armorEnd, e.blockType, armorEndOfLine)
}
// Encode returns a WriteCloser which will encode the data written to it in
// OpenPGP armor.
func Encode(out io.Writer, blockType string, headers map[string]string) (w io.WriteCloser, err error) {
bType := []byte(blockType)
err = writeSlices(out, armorStart, bType, armorEndOfLineOut)
if err != nil {
return
}
for k, v := range headers {
err = writeSlices(out, []byte(k), armorHeaderSep, []byte(v), newline)
if err != nil {
return
}
}
_, err = out.Write(newline)
if err != nil {
return
}
e := &encoding{
out: out,
breaker: newLineBreaker(out, 64),
crc: crc24Init,
blockType: bType,
}
e.b64 = base64.NewEncoder(base64.StdEncoding, e.breaker)
return e, nil
}
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