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
161
162
163
164
165
166
167
168
169
170
171
|
require 'digest/md5'
module SASL
##
# RFC 2831:
# http://tools.ietf.org/html/rfc2831
class DigestMD5 < Mechanism
attr_writer :cnonce
def initialize(*a)
super
@nonce_count = 0
end
def start
@state = nil
unless defined? @nonce
['auth', nil]
else
# reauthentication
receive('challenge', '')
end
end
def receive(message_name, content)
if message_name == 'challenge'
c = decode_challenge(content)
unless c['rspauth']
response = {}
if defined?(@nonce) && response['nonce'].nil?
# Could be reauth
else
# No reauth:
@nonce_count = 0
end
@nonce ||= c['nonce']
response['nonce'] = @nonce
response['charset'] = 'utf-8'
response['username'] = preferences.username
response['realm'] = c['realm'] || preferences.realm
@cnonce = generate_nonce unless defined? @cnonce
response['cnonce'] = @cnonce
@nc = next_nc
response['nc'] = @nc
@qop = c['qop'] || 'auth'
response['qop'] = 'auth' #@qop
response['digest-uri'] = preferences.digest_uri
response['response'] = response_value(response['nonce'], response['nc'], response['cnonce'], response['qop'], response['realm'])
['response', encode_response(response)]
else
rspauth_expected = response_value(@nonce, @nc, @cnonce, @qop, '')
#p :rspauth_received=>c['rspauth'], :rspauth_expected=>rspauth_expected
if c['rspauth'] == rspauth_expected
['response', nil]
else
# Bogus server?
@state = :failure
['failure', nil]
end
end
else
# No challenge? Might be success or failure
super
end
end
private
def decode_challenge(text)
challenge = {}
state = :key
key = ''
value = ''
text.scan(/./) do |ch|
if state == :key
if ch == '='
state = :value
elsif ch =~ /\S/
key += ch
end
elsif state == :value
if ch == ','
challenge[key] = value
key = ''
value = ''
state = :key
elsif ch == '"' and value == ''
state = :quote
else
value += ch
end
elsif state == :quote
if ch == '"'
state = :value
else
value += ch
end
end
end
challenge[key] = value unless key == ''
#p :decode_challenge => challenge
challenge
end
def encode_response(response)
#p :encode_response => response
response.collect do |k,v|
if ['username', 'cnonce', 'digest-uri', 'authzid','realm','qop'].include? k
v.sub!('\\', '\\\\')
v.sub!('"', '\\"')
"#{k}=\"#{v}\""
else
"#{k}=#{v}"
end
end.join(',')
end
def generate_nonce
nonce = ''
while nonce.length < 32
c = rand(128).chr
nonce += c if c =~ /^[a-zA-Z0-9]$/
end
nonce
end
##
# Function from RFC2831
def h(s); Digest::MD5.digest(s); end
##
# Function from RFC2831
def hh(s); Digest::MD5.hexdigest(s); end
##
# Calculate the value for the response field
def response_value(nonce, nc, cnonce, qop, realm, a2_prefix='AUTHENTICATE')
#p :response_value => {:nonce=>nonce,
# :cnonce=>cnonce,
# :qop=>qop,
# :username=>preferences.username,
# :realm=>preferences.realm,
# :password=>preferences.password,
# :authzid=>preferences.authzid}
a1_h = h("#{preferences.username}:#{realm}:#{preferences.password}")
a1 = "#{a1_h}:#{nonce}:#{cnonce}"
if preferences.authzid
a1 += ":#{preferences.authzid}"
end
if qop && (qop.downcase == 'auth-int' || qop.downcase == 'auth-conf')
a2 = "#{a2_prefix}:#{preferences.digest_uri}:00000000000000000000000000000000"
else
a2 = "#{a2_prefix}:#{preferences.digest_uri}"
end
hh("#{hh(a1)}:#{nonce}:#{nc}:#{cnonce}:#{qop}:#{hh(a2)}")
end
def next_nc
@nonce_count += 1
s = @nonce_count.to_s
s = "0#{s}" while s.length < 8
s
end
end
end
|
