diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/openpgp/armor/encode.go')
-rw-r--r-- | vendor/golang.org/x/crypto/openpgp/armor/encode.go | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/armor/encode.go b/vendor/golang.org/x/crypto/openpgp/armor/encode.go new file mode 100644 index 0000000..6f07582 --- /dev/null +++ b/vendor/golang.org/x/crypto/openpgp/armor/encode.go | |||
@@ -0,0 +1,160 @@ | |||
1 | // Copyright 2010 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 armor | ||
6 | |||
7 | import ( | ||
8 | "encoding/base64" | ||
9 | "io" | ||
10 | ) | ||
11 | |||
12 | var armorHeaderSep = []byte(": ") | ||
13 | var blockEnd = []byte("\n=") | ||
14 | var newline = []byte("\n") | ||
15 | var armorEndOfLineOut = []byte("-----\n") | ||
16 | |||
17 | // writeSlices writes its arguments to the given Writer. | ||
18 | func writeSlices(out io.Writer, slices ...[]byte) (err error) { | ||
19 | for _, s := range slices { | ||
20 | _, err = out.Write(s) | ||
21 | if err != nil { | ||
22 | return err | ||
23 | } | ||
24 | } | ||
25 | return | ||
26 | } | ||
27 | |||
28 | // lineBreaker breaks data across several lines, all of the same byte length | ||
29 | // (except possibly the last). Lines are broken with a single '\n'. | ||
30 | type lineBreaker struct { | ||
31 | lineLength int | ||
32 | line []byte | ||
33 | used int | ||
34 | out io.Writer | ||
35 | haveWritten bool | ||
36 | } | ||
37 | |||
38 | func newLineBreaker(out io.Writer, lineLength int) *lineBreaker { | ||
39 | return &lineBreaker{ | ||
40 | lineLength: lineLength, | ||
41 | line: make([]byte, lineLength), | ||
42 | used: 0, | ||
43 | out: out, | ||
44 | } | ||
45 | } | ||
46 | |||
47 | func (l *lineBreaker) Write(b []byte) (n int, err error) { | ||
48 | n = len(b) | ||
49 | |||
50 | if n == 0 { | ||
51 | return | ||
52 | } | ||
53 | |||
54 | if l.used == 0 && l.haveWritten { | ||
55 | _, err = l.out.Write([]byte{'\n'}) | ||
56 | if err != nil { | ||
57 | return | ||
58 | } | ||
59 | } | ||
60 | |||
61 | if l.used+len(b) < l.lineLength { | ||
62 | l.used += copy(l.line[l.used:], b) | ||
63 | return | ||
64 | } | ||
65 | |||
66 | l.haveWritten = true | ||
67 | _, err = l.out.Write(l.line[0:l.used]) | ||
68 | if err != nil { | ||
69 | return | ||
70 | } | ||
71 | excess := l.lineLength - l.used | ||
72 | l.used = 0 | ||
73 | |||
74 | _, err = l.out.Write(b[0:excess]) | ||
75 | if err != nil { | ||
76 | return | ||
77 | } | ||
78 | |||
79 | _, err = l.Write(b[excess:]) | ||
80 | return | ||
81 | } | ||
82 | |||
83 | func (l *lineBreaker) Close() (err error) { | ||
84 | if l.used > 0 { | ||
85 | _, err = l.out.Write(l.line[0:l.used]) | ||
86 | if err != nil { | ||
87 | return | ||
88 | } | ||
89 | } | ||
90 | |||
91 | return | ||
92 | } | ||
93 | |||
94 | // encoding keeps track of a running CRC24 over the data which has been written | ||
95 | // to it and outputs a OpenPGP checksum when closed, followed by an armor | ||
96 | // trailer. | ||
97 | // | ||
98 | // It's built into a stack of io.Writers: | ||
99 | // encoding -> base64 encoder -> lineBreaker -> out | ||
100 | type encoding struct { | ||
101 | out io.Writer | ||
102 | breaker *lineBreaker | ||
103 | b64 io.WriteCloser | ||
104 | crc uint32 | ||
105 | blockType []byte | ||
106 | } | ||
107 | |||
108 | func (e *encoding) Write(data []byte) (n int, err error) { | ||
109 | e.crc = crc24(e.crc, data) | ||
110 | return e.b64.Write(data) | ||
111 | } | ||
112 | |||
113 | func (e *encoding) Close() (err error) { | ||
114 | err = e.b64.Close() | ||
115 | if err != nil { | ||
116 | return | ||
117 | } | ||
118 | e.breaker.Close() | ||
119 | |||
120 | var checksumBytes [3]byte | ||
121 | checksumBytes[0] = byte(e.crc >> 16) | ||
122 | checksumBytes[1] = byte(e.crc >> 8) | ||
123 | checksumBytes[2] = byte(e.crc) | ||
124 | |||
125 | var b64ChecksumBytes [4]byte | ||
126 | base64.StdEncoding.Encode(b64ChecksumBytes[:], checksumBytes[:]) | ||
127 | |||
128 | return writeSlices(e.out, blockEnd, b64ChecksumBytes[:], newline, armorEnd, e.blockType, armorEndOfLine) | ||
129 | } | ||
130 | |||
131 | // Encode returns a WriteCloser which will encode the data written to it in | ||
132 | // OpenPGP armor. | ||
133 | func Encode(out io.Writer, blockType string, headers map[string]string) (w io.WriteCloser, err error) { | ||
134 | bType := []byte(blockType) | ||
135 | err = writeSlices(out, armorStart, bType, armorEndOfLineOut) | ||
136 | if err != nil { | ||
137 | return | ||
138 | } | ||
139 | |||
140 | for k, v := range headers { | ||
141 | err = writeSlices(out, []byte(k), armorHeaderSep, []byte(v), newline) | ||
142 | if err != nil { | ||
143 | return | ||
144 | } | ||
145 | } | ||
146 | |||
147 | _, err = out.Write(newline) | ||
148 | if err != nil { | ||
149 | return | ||
150 | } | ||
151 | |||
152 | e := &encoding{ | ||
153 | out: out, | ||
154 | breaker: newLineBreaker(out, 64), | ||
155 | crc: crc24Init, | ||
156 | blockType: bType, | ||
157 | } | ||
158 | e.b64 = base64.NewEncoder(base64.StdEncoding, e.breaker) | ||
159 | return e, nil | ||
160 | } | ||