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
|
#--
# =============================================================================
# Copyright (c) 2004,2005 Jamis Buck (jamis@37signals.com)
# All rights reserved.
#
# This source file is distributed as part of the Net::SSH Secure Shell Client
# library for Ruby. This file (and the library as a whole) may be used only as
# allowed by either the BSD license, or the Ruby license (or, by association
# with the Ruby license, the GPL). See the "doc" subdirectory of the Net::SSH
# distribution for the texts of these licenses.
# -----------------------------------------------------------------------------
# net-ssh website : http://net-ssh.rubyforge.org
# project website: http://rubyforge.org/projects/net-ssh
# =============================================================================
#++
require 'net/ssh/errors'
require 'net/ssh/userauth/constants'
module Net
module SSH
module UserAuth
module Methods
# Implements the "publickey" SSH authentication method.
class PublicKey
include Net::SSH::UserAuth::Constants
# The messenger instance to use to send and receive messages
attr_writer :messenger
# The session id of the current SSH session
attr_writer :session_id
# Create a new PublicKey instance that uses the given buffer
# factory to produce new buffer instances.
def initialize( buffers )
@buffers = buffers
end
# Attempts to perform public-key authentication for the given
# username, trying each identity known to the key manager. If any of
# them succeed, returns +true+, otherwise returns +false+. The data
# hash must contain a UserKeyManager instance under the
# <tt>:key_manager</tt> key.
def authenticate( next_service, username, data={} )
key_manager = data[:key_manager]
return false unless key_manager
key_manager.identities.each do |identity|
return true if authenticate_with( identity, next_service,
username, key_manager )
end
return false
ensure
key_manager.finish if key_manager
end
# Builds a Net::SSH::Util::WriterBuffer that contains the request
# formatted for sending a public-key request to the server.
def build_request( pub_key, username, next_service, has_sig,
buffer=nil )
# begin
buffer ||= @buffers.writer
buffer.write_byte USERAUTH_REQUEST
buffer.write_string username
buffer.write_string next_service
buffer.write_string "publickey"
buffer.write_bool has_sig
buffer.write_string pub_key.ssh_type
blob = @buffers.writer
blob.write_key pub_key
buffer.write_string blob.to_s
return buffer
end
private :build_request
# Builds and sends a request formatted for a public-key
# authentication request.
def send_request( pub_key, username, next_service, signature=nil )
msg = build_request( pub_key, username, next_service, signature )
msg.write_string signature if signature
@messenger.send_message msg
end
private :send_request
# Attempts to perform public-key authentication for the given
# username, with the given identity (public key). Returns +true+ if
# successful, or +false+ otherwise.
def authenticate_with( identity, next_service, username, key_manager )
send_request identity, username, next_service
message = @messenger.wait_for_message
case message.message_type
when USERAUTH_PK_OK
sig_data = @buffers.writer
sig_data.write_string @session_id
build_request identity, username, next_service, true, sig_data
sig_blob = key_manager.sign( identity, sig_data )
send_request identity, username, next_service, sig_blob.to_s
message = @messenger.wait_for_message
case message.message_type
when USERAUTH_SUCCESS
return true
when USERAUTH_FAILURE
return false
else
raise Net::SSH::Exception,
"unexpected server response to USERAUTH_REQUEST: " +
message.inspect
end
when USERAUTH_FAILURE
return false
else
raise Net::SSH::Exception,
"unexpected reply to USERAUTH_REQUEST: #{message.inspect}"
end
end
private :authenticate_with
end
end
end
end
end
|
