Project

General

Profile

Alternativecustom authentication HowTo » History » Version 10

Andrew R Jackson, 2014-04-08 21:01
Updated auth_sources table info to reflect schema as of Redmine 2.4.1

1 1 Andrew R Jackson
h1. Alternative (custom) Authentication HowTo
2
3 9 Mischa The Evil
{{>toc}}
4
5 1 Andrew R Jackson
h2. Intro
6
7
This page explains how to get Redmine to authenticate users against a different database. Perhaps you're running (and even wrote) an app that already stores account records, and you want Redmine to use those. Presumably that app doesn't support OpenID, else you'd be configuring that.
8
9
Having Redmine defer authentication to your other app is helpful to users--they only have to remember one set of passwords and the accounts can't get out-of-sync. And if they are registered with your main app, Redmine can be configured to automatically add them to its own table (without storing any password info) when they first log in there.
10
11
h2. Redmine Support For Alternative Authentication
12
13
Redmine has specific support for alternative/custom authentication which makes implementing it very easy.
14
* +@auth_sources@ table+
15
** You will add a record here specific to your custom authentication.
16
* +@AuthSource@ class+
17
** You will create your own subclass of this, and implement the @authenticate()@ method.
18
19
Redmine's authentication process is along these lines (LDAP & OpenID assumed to be disabled):
20
# First, try to authenticate @login@ & @password@ against Redmine's internal table (@users@).
21
# If that fails, try each alternative authentication source registered in the @auth_sources@ table, stopping when one of the sources succeeds.
22
# If that fails, reject the login attempt.
23
24
_Note: Redmine will make a note of which source successfully authenticated a specific user. That source will be tried first the next time that user tries to login. Administrators can manually set/override that on a user-by-user basis via @Administration -> Users -> {user} -> Authentication mode@._
25
26
h2. Implementing An Alternative Authentication Source
27
28
This article assumes the alternative authentication involves querying a table (or tables) in some other database. However, the approach can be generalized to authenticate against pretty much anything else (some secret file, some network service, whatever fun scenario you have); you may want to examine the Redmine code in @app/models/auth_source_ldap.rb@ for a non-database alternative authentication example.
29
30
h3. Insert a Sensible @auth_sources@ Record
31
32
First, we should decide what our @auth_sources@ record will look like. Redmine core and our @AuthSource@ subclass code will make use of that info, so it's good to figure this out up front.
33
34 10 Andrew R Jackson
For reference, here is the (Redmine 2.4.1) @auth_sources@ table:
35 1 Andrew R Jackson
36
<pre>
37
+-------------------+--------------+------+-----+---------+----------------+
38
| Field             | Type         | Null | Key | Default | Extra          |
39
+-------------------+--------------+------+-----+---------+----------------+
40
| id                | int(11)      | NO   | PRI | NULL    | auto_increment |
41
| type              | varchar(30)  | NO   |     |         |                |
42
| name              | varchar(60)  | NO   |     |         |                |
43
| host              | varchar(60)  | YES  |     | NULL    |                |
44
| port              | int(11)      | YES  |     | NULL    |                |
45
| account           | varchar(255) | YES  |     | NULL    |                |
46 10 Andrew R Jackson
| account_password  | varchar(255) | YES  |     |         |                |
47 1 Andrew R Jackson
| base_dn           | varchar(255) | YES  |     | NULL    |                |
48
| attr_login        | varchar(30)  | YES  |     | NULL    |                |
49
| attr_firstname    | varchar(30)  | YES  |     | NULL    |                |
50
| attr_lastname     | varchar(30)  | YES  |     | NULL    |                |
51
| attr_mail         | varchar(30)  | YES  |     | NULL    |                |
52
| onthefly_register | tinyint(1)   | NO   |     | 0       |                |
53
| tls               | tinyint(1)   | NO   |     | 0       |                |
54 10 Andrew R Jackson
| filter            | varchar(255) | YES  |     | NULL    |                |
55
| timeout           | int(11)      | YES  |     | NULL    |                |
56 1 Andrew R Jackson
+-------------------+--------------+------+-----+---------+----------------+
57
</pre>
58
59 10 Andrew R Jackson
This schema has been relatively stable, although older Redmine versions may be missing the last 2 columns (e.g. Redmine 0.9 doesn't have them).
60
61 1 Andrew R Jackson
How our @AuthSource@ subclass code will make use of these fields is more-or-less up to us, but there are two key constraints from Redmine:
62
# +@type@ must be the name of your @AuthSource@ subclass+
63
#* Redmine will use this field to instantiate your class and call its @authenticate()@ method when attempting to authenticate a login attempt using your custom source.
64
#* This class name should begin with @AuthSource@.
65
#* We'll put "@AuthSourceMyCustomApp@"
66
# +@onthefly_register has a 1 or 0@+
67
#* Redmine will use this field to determine if unknown users (logins Redmine doesn't know about yet) can be registered within Redmine using this authentication source. Otherwise, if you put "0" here, an Administrator will first have to register the user manually (and presumably set their @Authentication mode@)--Redmine won't add them automatically.
68
69
Here's how we'll use these fields (substitute your own values):
70
71
| *Field* | *Our Value* | *Comment* |
72
| id | @NULL@ | Let the database engine provide the id. |
73
| type | "AuthSourceMyCustomApp" | Name of your @AuthSource@ subclass |
74
| name | "MyCustomApp" | Name of this alternative authentication source. Will be displayed in Administration UI pages.|
75
| host | "myApp.other.host.edu" | Host name where the other database lives. This article doesn't assume that's the same host as where your Redmine database is. |
76
| port | 3306 | Port for the database on that other host. |
77
| account | "myDbUser" | Account name for accessing that other database. |
78
| account_password | "myDbPass" | Password for that account for accessing the other database. |
79 8 Olivier Pinette
| base_dn | "mysql:myApp" | This field sounds very LDAP-ish. Sorry. We will interpret it to mean "BASic Database Name data" and store within a string of the form "@{dbAdapterName}:{dbName}@".|
80 1 Andrew R Jackson
| attr_login | "name" | What field in your other database table contains the login? |
81
| attr_firstname | "firstName" | What field in your other database table contains the user's first name? |
82
| attr_lastname | "lastName" | What field in your other database table contains the user's last name? |
83
| attr_mail | "email" | What field in your other database table contains the user's email? |
84
| onthefly_register | 1 | Yes, if this source authenticates the user then Redmine should create an internal record for them (w/o password info). |
85
| tls | 0 | Dunno. 0 for "no". |
86 10 Andrew R Jackson
| filter | NULL | Dunno. NULL is the default though. |
87
| timeout | NULL | Dunno. Timeout while waiting for alternative authenticator? NULL is the default though. |
88 1 Andrew R Jackson
89
_Note: The @attr_*@ fields are not always needed. They are used by the LDAP authentication source to map LDAP attributes to Redmine attributes. I recommend using them, however, since they make the @authentication()@ code more widely applicable (fewer changes necessary for you to use the code in your specific situation)._
90
91 10 Andrew R Jackson
So we insert the record into our Redmine's (v2.4.1) @auth_sources@ table with SQL like the following:
92 1 Andrew R Jackson
93
<pre>
94
<code class="Sql">
95 10 Andrew R Jackson
INSERT INTO auth_sources VALUES
96
  (NULL, 'AuthSourceMyCustomApp', 'MyCustomApp', 'myApp.other.host.edu', 3306,
97
  'myDbUser', 'myDbPass', 'mysql:myApp', 'name', 'firstName', 'lastName', 'email',
98
  1, 0, null, null)
99 1 Andrew R Jackson
</code>
100
</pre>
101
102
h3. Implement Your @AuthSource@ Subclass
103
104
Create a new file for your @AuthSource@ subclass in @app/models/@, following the naming scheme of the existing @auth_source.rb@ and @auth_source_ldap.rb@.
105
* Here we'll use @app/models/auth_source_myApp.rb@
106
107
Implement the class such that a call to its @authenticate()@ method will contact the other database and use the table there to check the provided login credentials. The values in your @auth_sources@ table record above are available via instances variables (e.g. @self.host@, @self.base_dn@, @self.attr_firstname@). 
108
109
Here's our commented class:
110
111
<pre>
112
<code class="ruby">
113
# Redmine MyApp Authentication Source
114
#
115
# Copyright (C) 2010 Andrew R Jackson
116
#
117
# This program is free software; you can redistribute it and/or
118
# modify it under the terms of the GNU General Public License
119
# as published by the Free Software Foundation; either version 2
120
# of the License, or (at your option) any later version.
121
#
122
# This program is distributed in the hope that it will be useful,
123
# but WITHOUT ANY WARRANTY; without even the implied warranty of
124
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
125
# GNU General Public License for more details.
126
#
127
# You should have received a copy of the GNU General Public License
128
# along with this program; if not, write to the Free Software
129
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
130
131
# Let's have a new class for our ActiveRecord-based connection
132
# to our alternative authentication database. Remember that we're
133
# not assuming that the alternative authentication database is on
134
# the same host (and/or port) as Redmine's database. So its current
135
# database connection may be of no use to us. ActiveRecord uses class
136
# variables to store state (yay) like current connections and such; thus,
137
# dedicated class...
138
class MyAppCustomDB_ActiveRecord < ActiveRecord::Base
139
  PAUSE_RETRIES = 5
140
  MAX_RETRIES = 50
141
end
142
143
# Subclass AuthSource
144
class AuthSourceMyCustomApp < AuthSource
145
146
  # authentication() implementation
147
  # - Redmine will call this method, passing the login and password entered
148
  #   on the Sign In form.
149
  #
150
  # +login+ : what user entered for their login
151
  # +password+ : what user entered for their password
152
  def authenticate(login, password)
153
    retVal = nil
154
    unless(login.blank? or password.blank?)
155
      # Get a connection to the authenticating database.
156
      # - Don't use ActiveRecord::Base when using establish_connection() to get at
157
      #   your alternative database (leave Redmine's current connection alone).
158
      #   Use class you prepped above.
159
      # - Recall that the values stored in the fields of your auth_sources
160
      #   record are available as self.fieldName
161
162
      # First, get the DB Adapter name and database to use for connecting:
163
      adapter, dbName = self.base_dn.split(':')
164
165
      # Second, try to get a connection, safely dealing with the MySQL<->ActiveRecord
166
      # failed connection bug that can still arise to this day (regardless of 
167
      # reconnect, oddly).
168
      retryCount = 0
169
      begin
170
        connPool = MyAppCustomDB_ActiveRecord.establish_connection(
171
          :adapter  => adapter,
172
          :host     => self.host,
173
          :port     => self.port,
174
          :username => self.account,
175
          :password => self.account_password,
176
          :database => dbName,
177
          :reconnect => true
178
        )
179
        db = connPool.checkout()
180
      rescue => err # for me, always due to dead connection; must retry bunch-o-times to get a good one if this happens
181
        if(retryCount < MyAppCustomDB_ActiveRecord::MAX_RETRIES)
182
          sleep(1) if(retryCount < MyAppCustomDB_ActiveRecord::PAUSE_RETRIES)
183
          retryCount += 1
184
          connPool.disconnect!
185
          retry # start again at begin
186
        else # too many retries, serious, reraise error and let it fall through as it normally would in Rails.
187
          raise
188
        end
189
      end
190
191
      # Third, query the alternative authentication database for needed info. SQL
192
      # sufficient, obvious, and doesn't require other setup/LoC. Even more the
193
      # case if we have our database engine compute our digests (here, the whole
194
      # username is a salt). SQL also nice if your alt auth database doesn't have
195
      # AR classes and is not part of a Rails app, etc.
196
      resultRow = db.select_one(
197
        "SELECT #{self.attr_login}, #{self.attr_firstname}, #{self.attr_lastname}, #{self.attr_mail} " +
198
        "FROM genboreeuser " +
199
        "WHERE SHA1(CONCAT(#{self.attr_login}, password)) = SHA1(CONCAT('#{db.quote_string(login)}', '#{db.quote_string(password)}'))"
200
      )
201
202
      unless(resultRow.nil? or resultRow.empty?)
203
        user = resultRow[self.attr_login]
204
        unless(user.nil? or user.empty?)
205
          # Found a record whose login & password digest matches that computed
206
          # from Sign Inform parameters. If allowing Redmine to automatically
207
          # register such accounts in its internal table, return account
208
          # information to Redmine based on record found.
209
          retVal =
210 6 Anibal Sanchez
          {
211 1 Andrew R Jackson
            :firstname => resultRow[self.attr_firstname],
212
            :lastname => resultRow[self.attr_lastname],
213
            :mail => resultRow[self.attr_mail],
214
            :auth_source_id => self.id
215 6 Anibal Sanchez
          } if(onthefly_register?)
216 1 Andrew R Jackson
        end
217
      end
218
    end
219
    # Check connection back into pool.
220
    connPool.checkin(db)
221
    return retVal
222
  end
223
224
  def auth_method_name
225
    "MyCustomApp"
226
  end
227
end
228
229
</code>
230
</pre>
231
232
h2. Deploy & Test
233
234
Save your new class in @app/model/@ and restart Redmine.
235
236
* You ought to be able to try to log in as a use that exists in your alternative database but that doesn't exist in your Redmine instance.
237
* Existing Redmine accounts (and passwords) should continue to work.
238
* If you examine Redmine's @users@ table, you should see records appear after each successful login that used your alternative database.
239
** @hashed_password@ will be empty for those records.
240
** @auth_source_id@ will have the @id@ from @auth_sources@ which worked to authenticate the user; @NULL@ means "use internal Redmine authentication". The Administrator can also manually set this value via the @Authentication mode@ UI widget I mentioned above.
241
* Users authenticated with an alternative source will not be able to change their passwords using Redmine (great check by the core code) and will see an error message if they try to do so.
242
243
h2. Follow-Up
244
245
If you want to ONLY use your alternative authentication source for Redmine Sign In, remove the "Register" button. We did this by removing the @menu.push :register@ line in @lib/redmine.rb@. And we turned off the "Lost Password" feature via @Administration -> Settings -> Authentication -> Lost password@.
246
247 4 Paco Alcaide
<pre>
248 1 Andrew R Jackson
This was all pretty fast and simple to set up, thanks to how Redmine is organized and that some thought about permitting this kind of thing had been made. Quality. I hope I didn't get anything too wrong.
249
</pre>
250
251 6 Anibal Sanchez
h2. Joomla
252
253 7 Glen Vanderhel
We've customized the code to integrate Redmine with Joomla. Please, check the attachment to review an implementation for Joomla 2.5 and Redmine 2.0.3.
254 6 Anibal Sanchez
255
As Joomla does not have lastname in the users table, we have added a Html tag to show an icon in Redmine.
256
257
Remember to change the DB prefix (line 84) and the lastname customization (line 98).
258
259 5 Julien Recurt
h2. Bugs
260
261
 * In 1.0.1 if you got an error like "undefined method `stringify_keys!' for #<Array:...>) when logging" in see #6196
262
<pre>
263
<code class="ruby">
264
# Lines 97 from previous script
265
          retVal =
266
          {
267
            :firstname => resultRow[self.attr_firstname],
268
            :lastname => resultRow[self.attr_lastname],
269
            :mail => resultRow[self.attr_mail],
270
            :auth_source_id => self.id
271
          } if(onthefly_register?)
272
# ...
273 1 Andrew R Jackson
</code>
274
</pre>
275 6 Anibal Sanchez
276
 * In 2.0.3, the codefix for #6196 is still required, we've fixed the original code.