diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/openpgp/armor/armor.go')
-rw-r--r-- | vendor/golang.org/x/crypto/openpgp/armor/armor.go | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/armor/armor.go b/vendor/golang.org/x/crypto/openpgp/armor/armor.go new file mode 100644 index 0000000..592d186 --- /dev/null +++ b/vendor/golang.org/x/crypto/openpgp/armor/armor.go | |||
@@ -0,0 +1,219 @@ | |||
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 implements OpenPGP ASCII Armor, see RFC 4880. OpenPGP Armor is | ||
6 | // very similar to PEM except that it has an additional CRC checksum. | ||
7 | package armor // import "golang.org/x/crypto/openpgp/armor" | ||
8 | |||
9 | import ( | ||
10 | "bufio" | ||
11 | "bytes" | ||
12 | "encoding/base64" | ||
13 | "golang.org/x/crypto/openpgp/errors" | ||
14 | "io" | ||
15 | ) | ||
16 | |||
17 | // A Block represents an OpenPGP armored structure. | ||
18 | // | ||
19 | // The encoded form is: | ||
20 | // -----BEGIN Type----- | ||
21 | // Headers | ||
22 | // | ||
23 | // base64-encoded Bytes | ||
24 | // '=' base64 encoded checksum | ||
25 | // -----END Type----- | ||
26 | // where Headers is a possibly empty sequence of Key: Value lines. | ||
27 | // | ||
28 | // Since the armored data can be very large, this package presents a streaming | ||
29 | // interface. | ||
30 | type Block struct { | ||
31 | Type string // The type, taken from the preamble (i.e. "PGP SIGNATURE"). | ||
32 | Header map[string]string // Optional headers. | ||
33 | Body io.Reader // A Reader from which the contents can be read | ||
34 | lReader lineReader | ||
35 | oReader openpgpReader | ||
36 | } | ||
37 | |||
38 | var ArmorCorrupt error = errors.StructuralError("armor invalid") | ||
39 | |||
40 | const crc24Init = 0xb704ce | ||
41 | const crc24Poly = 0x1864cfb | ||
42 | const crc24Mask = 0xffffff | ||
43 | |||
44 | // crc24 calculates the OpenPGP checksum as specified in RFC 4880, section 6.1 | ||
45 | func crc24(crc uint32, d []byte) uint32 { | ||
46 | for _, b := range d { | ||
47 | crc ^= uint32(b) << 16 | ||
48 | for i := 0; i < 8; i++ { | ||
49 | crc <<= 1 | ||
50 | if crc&0x1000000 != 0 { | ||
51 | crc ^= crc24Poly | ||
52 | } | ||
53 | } | ||
54 | } | ||
55 | return crc | ||
56 | } | ||
57 | |||
58 | var armorStart = []byte("-----BEGIN ") | ||
59 | var armorEnd = []byte("-----END ") | ||
60 | var armorEndOfLine = []byte("-----") | ||
61 | |||
62 | // lineReader wraps a line based reader. It watches for the end of an armor | ||
63 | // block and records the expected CRC value. | ||
64 | type lineReader struct { | ||
65 | in *bufio.Reader | ||
66 | buf []byte | ||
67 | eof bool | ||
68 | crc uint32 | ||
69 | } | ||
70 | |||
71 | func (l *lineReader) Read(p []byte) (n int, err error) { | ||
72 | if l.eof { | ||
73 | return 0, io.EOF | ||
74 | } | ||
75 | |||
76 | if len(l.buf) > 0 { | ||
77 | n = copy(p, l.buf) | ||
78 | l.buf = l.buf[n:] | ||
79 | return | ||
80 | } | ||
81 | |||
82 | line, isPrefix, err := l.in.ReadLine() | ||
83 | if err != nil { | ||
84 | return | ||
85 | } | ||
86 | if isPrefix { | ||
87 | return 0, ArmorCorrupt | ||
88 | } | ||
89 | |||
90 | if len(line) == 5 && line[0] == '=' { | ||
91 | // This is the checksum line | ||
92 | var expectedBytes [3]byte | ||
93 | var m int | ||
94 | m, err = base64.StdEncoding.Decode(expectedBytes[0:], line[1:]) | ||
95 | if m != 3 || err != nil { | ||
96 | return | ||
97 | } | ||
98 | l.crc = uint32(expectedBytes[0])<<16 | | ||
99 | uint32(expectedBytes[1])<<8 | | ||
100 | uint32(expectedBytes[2]) | ||
101 | |||
102 | line, _, err = l.in.ReadLine() | ||
103 | if err != nil && err != io.EOF { | ||
104 | return | ||
105 | } | ||
106 | if !bytes.HasPrefix(line, armorEnd) { | ||
107 | return 0, ArmorCorrupt | ||
108 | } | ||
109 | |||
110 | l.eof = true | ||
111 | return 0, io.EOF | ||
112 | } | ||
113 | |||
114 | if len(line) > 96 { | ||
115 | return 0, ArmorCorrupt | ||
116 | } | ||
117 | |||
118 | n = copy(p, line) | ||
119 | bytesToSave := len(line) - n | ||
120 | if bytesToSave > 0 { | ||
121 | if cap(l.buf) < bytesToSave { | ||
122 | l.buf = make([]byte, 0, bytesToSave) | ||
123 | } | ||
124 | l.buf = l.buf[0:bytesToSave] | ||
125 | copy(l.buf, line[n:]) | ||
126 | } | ||
127 | |||
128 | return | ||
129 | } | ||
130 | |||
131 | // openpgpReader passes Read calls to the underlying base64 decoder, but keeps | ||
132 | // a running CRC of the resulting data and checks the CRC against the value | ||
133 | // found by the lineReader at EOF. | ||
134 | type openpgpReader struct { | ||
135 | lReader *lineReader | ||
136 | b64Reader io.Reader | ||
137 | currentCRC uint32 | ||
138 | } | ||
139 | |||
140 | func (r *openpgpReader) Read(p []byte) (n int, err error) { | ||
141 | n, err = r.b64Reader.Read(p) | ||
142 | r.currentCRC = crc24(r.currentCRC, p[:n]) | ||
143 | |||
144 | if err == io.EOF { | ||
145 | if r.lReader.crc != uint32(r.currentCRC&crc24Mask) { | ||
146 | return 0, ArmorCorrupt | ||
147 | } | ||
148 | } | ||
149 | |||
150 | return | ||
151 | } | ||
152 | |||
153 | // Decode reads a PGP armored block from the given Reader. It will ignore | ||
154 | // leading garbage. If it doesn't find a block, it will return nil, io.EOF. The | ||
155 | // given Reader is not usable after calling this function: an arbitrary amount | ||
156 | // of data may have been read past the end of the block. | ||
157 | func Decode(in io.Reader) (p *Block, err error) { | ||
158 | r := bufio.NewReaderSize(in, 100) | ||
159 | var line []byte | ||
160 | ignoreNext := false | ||
161 | |||
162 | TryNextBlock: | ||
163 | p = nil | ||
164 | |||
165 | // Skip leading garbage | ||
166 | for { | ||
167 | ignoreThis := ignoreNext | ||
168 | line, ignoreNext, err = r.ReadLine() | ||
169 | if err != nil { | ||
170 | return | ||
171 | } | ||
172 | if ignoreNext || ignoreThis { | ||
173 | continue | ||
174 | } | ||
175 | line = bytes.TrimSpace(line) | ||
176 | if len(line) > len(armorStart)+len(armorEndOfLine) && bytes.HasPrefix(line, armorStart) { | ||
177 | break | ||
178 | } | ||
179 | } | ||
180 | |||
181 | p = new(Block) | ||
182 | p.Type = string(line[len(armorStart) : len(line)-len(armorEndOfLine)]) | ||
183 | p.Header = make(map[string]string) | ||
184 | nextIsContinuation := false | ||
185 | var lastKey string | ||
186 | |||
187 | // Read headers | ||
188 | for { | ||
189 | isContinuation := nextIsContinuation | ||
190 | line, nextIsContinuation, err = r.ReadLine() | ||
191 | if err != nil { | ||
192 | p = nil | ||
193 | return | ||
194 | } | ||
195 | if isContinuation { | ||
196 | p.Header[lastKey] += string(line) | ||
197 | continue | ||
198 | } | ||
199 | line = bytes.TrimSpace(line) | ||
200 | if len(line) == 0 { | ||
201 | break | ||
202 | } | ||
203 | |||
204 | i := bytes.Index(line, []byte(": ")) | ||
205 | if i == -1 { | ||
206 | goto TryNextBlock | ||
207 | } | ||
208 | lastKey = string(line[:i]) | ||
209 | p.Header[lastKey] = string(line[i+2:]) | ||
210 | } | ||
211 | |||
212 | p.lReader.in = r | ||
213 | p.oReader.currentCRC = crc24Init | ||
214 | p.oReader.lReader = &p.lReader | ||
215 | p.oReader.b64Reader = base64.NewDecoder(base64.StdEncoding, &p.lReader) | ||
216 | p.Body = &p.oReader | ||
217 | |||
218 | return | ||
219 | } | ||