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
|
package sshd
import "encoding/binary"
// Helpers below are borrowed from go.crypto circa 2011:
// parsePtyRequest parses the payload of the pty-req message and extracts the
// dimensions of the terminal. See RFC 4254, section 6.2.
func parsePtyRequest(s []byte) (width, height int, ok bool) {
_, s, ok = parseString(s)
if !ok {
return
}
width32, s, ok := parseUint32(s)
if !ok {
return
}
height32, _, ok := parseUint32(s)
width = int(width32)
height = int(height32)
if width < 1 {
ok = false
}
if height < 1 {
ok = false
}
return
}
func parseWinchRequest(s []byte) (width, height int, ok bool) {
width32, _, ok := parseUint32(s)
if !ok {
return
}
height32, _, ok := parseUint32(s)
if !ok {
return
}
width = int(width32)
height = int(height32)
if width < 1 {
ok = false
}
if height < 1 {
ok = false
}
return
}
func parseString(in []byte) (out string, rest []byte, ok bool) {
if len(in) < 4 {
return
}
length := binary.BigEndian.Uint32(in)
if uint32(len(in)) < 4+length {
return
}
out = string(in[4 : 4+length])
rest = in[4+length:]
ok = true
return
}
func parseUint32(in []byte) (uint32, []byte, bool) {
if len(in) < 4 {
return 0, nil, false
}
return binary.BigEndian.Uint32(in), in[4:], true
}
|
