summaryrefslogtreecommitdiffstats
path: root/doc/swiftkerbauth_guide.md
blob: ef76ad0311f954f3c36290585d4e5b63ffa39e05 (plain)
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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
#swiftkerbauth

* [Installing Kerberos module for Apache on IPA client] (#httpd-kerb-install)
* [Creating HTTP Service Principal on IPA server] (#http-principal)
* [Installing and configuring swiftkerbauth on IPA client] (#install-swiftkerbauth)
* [Using swiftkerbauth] (#use-swiftkerbauth)

<a name="httpd-kerb-install" />
## Installing Kerberos module for Apache on IPA client

Install httpd server with kerberos module:
> yum install httpd mod_auth_kerb
>
> service httpd restart

Check if auth_kerb_module is loaded :
> httpd -M | grep kerb

Change httpd log level to debug by adding/changing the following in
*/etc/httpd/conf/httpd.conf* file

    LogLevel debug

httpd logs are at */var/log/httpd/error_log* for troubleshooting

If SELinux is enabled, allow Apache to connect to memcache and
activate the changes by running
>setsebool -P httpd_can_network_connect 1
>
>setsebool -P httpd_can_network_memcache 1

*****

<a name="http-principal" />
## Creating HTTP Service Principal on IPA server

Add a HTTP Kerberos service principal :
> ipa service-add HTTP/client.rhelbox.com@RHELBOX.COM

Retrieve the HTTP service principal to a keytab file:
> ipa-getkeytab -s server.rhelbox.com -p HTTP/client.rhelbox.com@RHELBOX.COM -k /tmp/http.keytab

Copy keytab file to client:
> scp /tmp/http.keytab root@192.168.56.101:/etc/httpd/conf/http.keytab

## Creating HTTP Service Principal on Windows AD server

Add a HTTP Kerberos service principal:
> c:\>ktpass.exe -princ HTTP/fcclient.winad.com@WINAD.COM -mapuser
> auth_admin@WINAD.COM -pass Redhat*123 -out c:\HTTP.keytab

Use winscp to copy HTTP.ketab file to /etc/httpd/conf/http.keytab

*****

<a name="install-swiftkerbauth" />
##Installing and configuring swiftkerbauth on IPA client

Prerequisites for installing swiftkerbauth
* swift (havana)
* gluster-swift (optional)

You can install swiftkerbauth using one of these three ways:

Installing swiftkerbauth from source:
> python setup.py install

Installing swiftkerbauth using pip:
> pip install swiftkerbauth

Installing swiftkerbauth from RPMs:
> ./makerpm.sh
>
> rpm -ivh dist/swiftkerbauth-1.0.0-1.noarch.rpm

Edit */etc/httpd/conf.d/swift-auth.conf* and change KrbServiceName, KrbAuthRealms and Krb5KeyTab parameters accordingly.
More detail on configuring kerberos for apache can be found at:
[auth_kerb_module Configuration][]

Make /etc/httpd/conf/http.keytab readable by any user :
> chmod 644 /etc/httpd/conf/http.keytab

And preferably change owner of keytab file to apache :
> chown apache:apache /etc/httpd/conf/http.keytab

Reload httpd
> service httpd reload

Make authentication script executable:
> chmod +x /var/www/cgi-bin/swift-auth

*****

<a name="#use-swiftkerbauth" />
##Using swiftkerbauth

### Adding kerbauth filter in swift pipeline

Edit */etc/swift/proxy-server.conf* and add a new filter section as follows:

    [filter:kerbauth]
    use = egg:swiftkerbauth#kerbauth
    ext_authentication_url = http://client.rhelbox.com/cgi-bin/swift-auth

Add kerbauth to pipeline

    [pipeline:main]
    pipeline = catch_errors healthcheck proxy-logging cache proxy-logging kerbauth proxy-server

If the Swift server is not one of your Gluster nodes, edit
*/etc/swift/fs.conf* and change the following lines in the DEFAULT
section:

    mount_ip = RHS_NODE_HOSTNAME
    remote_cluster = yes

Restart swift to activate kerbauth filer
> swift-init main restart


###Examples

####Authenticate user and get Kerberos ticket

> kinit auth_admin

NOTE: curl ignores user specified in -u option. All further curl commands
will use the currently authenticated auth_admin user.

####Get an authentication token:
> curl -v -u : --negotiate --location-trusted http://client.rhelbox.com:8080/auth/v1.0

    * About to connect() to client.rhelbox.com port 8080 (#0)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 8080 (#0)
    > GET /auth/v1.0 HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com:8080
    > Accept: */*
    >
    < HTTP/1.1 303 See Other
    < Content-Type: text/html; charset=UTF-8
    < Location: http://client.rhelbox.com/cgi-bin/swift-auth
    < Content-Length: 0
    < X-Trans-Id: txecd415aae89b4320b6145-0052417ea5
    < Date: Tue, 24 Sep 2013 11:59:33 GMT
    <
    * Connection #0 to host client.rhelbox.com left intact
    * Issue another request to this URL: 'http://client.rhelbox.com/cgi-bin/swift-auth'
    * About to connect() to client.rhelbox.com port 80 (#1)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 80 (#1)
    > GET /cgi-bin/swift-auth HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com
    > Accept: */*
    >
    < HTTP/1.1 401 Unauthorized
    < Date: Tue, 24 Sep 2013 11:59:33 GMT
    < Server: Apache/2.4.6 (Fedora) mod_auth_kerb/5.4
    < WWW-Authenticate: Negotiate
    < WWW-Authenticate: Basic realm="Swift Authentication"
    < Content-Length: 381
    < Content-Type: text/html; charset=iso-8859-1
    <
    * Ignoring the response-body
    * Connection #1 to host client.rhelbox.com left intact
    * Issue another request to this URL: 'http://client.rhelbox.com/cgi-bin/swift-auth'
    * Re-using existing connection! (#1) with host (nil)
    * Connected to (nil) (192.168.56.101) port 80 (#1)
    * Server auth using GSS-Negotiate with user ''
    > GET /cgi-bin/swift-auth HTTP/1.1
    > Authorization: Negotiate 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
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com
    > Accept: */*
    >
    < HTTP/1.1 200 OK
    < Date: Tue, 24 Sep 2013 11:59:33 GMT
    < Server: Apache/2.4.6 (Fedora) mod_auth_kerb/5.4
    < WWW-Authenticate: Negotiate YIGZBgkqhkiG9xIBAgICAG+BiTCBhqADAgEFoQMCAQ+iejB4oAMCARKicQRveeZTV/QRJSIOoOWPbZkEmtdug9V5ZcMGXWqAJvCAnrvw9gHbklMyLl8f8jU2e0wU3ehtchLEL4dVeAYgKsnUgw4wGhHu59AZBwSbHRKSpv3I6gWEZqC4NAEuZJFW9ipdUHOiclBQniVXXCsRF/5Y
    < X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a
    < X-Debug-Remote-User: auth_admin
    < X-Debug-Groups: auth_admin,auth_reseller_admin
    < X-Debug-Token-Life: 86400s
    < X-Debug-Token-Expires: Wed Sep 25 17:29:33 2013
    < Content-Length: 0
    < Content-Type: text/html; charset=UTF-8
    <
    * Connection #1 to host (nil) left intact
    * Closing connection #0
    * Closing connection #1

The header *X-Auth-Token* in response contains the token *AUTH_tk083b8abc92f4a514f34224a181ed568a*.

####PUT a container
>curl -v -X PUT -H 'X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a' http://client.rhelbox.com:8080/v1/AUTH_myvolume/c1

    * About to connect() to client.rhelbox.com port 8080 (#0)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 8080 (#0)
    > PUT /v1/AUTH_myvolume/c1 HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com:8080
    > Accept: */*
    > X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a
    >
    < HTTP/1.1 201 Created
    < Content-Length: 0
    < Content-Type: text/html; charset=UTF-8
    < X-Trans-Id: txc420b0ebf9714445900e8-0052418863
    < Date: Tue, 24 Sep 2013 12:41:07 GMT
    <
    * Connection #0 to host client.rhelbox.com left intact
    * Closing connection #0

####GET a container listing
> curl -v -X GET -H 'X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a' http://client.rhelbox.com:8080/v1/AUTH_myvolume

    * About to connect() to client.rhelbox.com port 8080 (#0)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 8080 (#0)
    > GET /v1/AUTH_myvolume HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com:8080
    > Accept: */*
    > X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a
    >
    < HTTP/1.1 200 OK
    < Content-Length: 3
    < X-Account-Container-Count: 0
    < Accept-Ranges: bytes
    < X-Account-Object-Count: 0
    < X-Bytes-Used: 0
    < X-Timestamp: 1379997117.09468
    < X-Object-Count: 0
    < X-Account-Bytes-Used: 0
    < X-Type: Account
    < Content-Type: text/plain; charset=utf-8
    < X-Container-Count: 0
    < X-Trans-Id: tx89826736a1ab4d6aae6e3-00524188dc
    < Date: Tue, 24 Sep 2013 12:43:08 GMT
    <
    c1
    * Connection #0 to host client.rhelbox.com left intact
    * Closing connection #0

####PUT an object in container
> curl -v -X PUT -H 'X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a' http://client.rhelbox.com:8080/v1/AUTH_myvolume/c1/object1 -d'Hello world'

    * About to connect() to client.rhelbox.com port 8080 (#0)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 8080 (#0)
    > PUT /v1/AUTH_myvolume/c1/object1 HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com:8080
    > Accept: */*
    > X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a
    > Content-Length: 11
    > Content-Type: application/x-www-form-urlencoded
    >
    * upload completely sent off: 11 out of 11 bytes
    < HTTP/1.1 201 Created
    < Last-Modified: Wed, 25 Sep 2013 06:08:00 GMT
    < Content-Length: 0
    < Etag: 3e25960a79dbc69b674cd4ec67a72c62
    < Content-Type: text/html; charset=UTF-8
    < X-Trans-Id: tx01f1b5a430cf4af3897be-0052427dc0
    < Date: Wed, 25 Sep 2013 06:08:01 GMT
    <
    * Connection #0 to host client.rhelbox.com left intact
    * Closing connection #0

####Give permission to jsmith to list and download objects from c1 container
> curl -v -X POST -H 'X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a' -H 'X-Container-Read: jsmith' http://client.rhelbox.com:8080/v1/AUTH_myvolume/c1

    * About to connect() to client.rhelbox.com port 8080 (#0)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 8080 (#0)
    > POST /v1/AUTH_myvolume/c1 HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com:8080
    > Accept: */*
    > X-Auth-Token: AUTH_tk083b8abc92f4a514f34224a181ed568a
    > X-Container-Read: jsmith
    >
    < HTTP/1.1 204 No Content
    < Content-Length: 0
    < Content-Type: text/html; charset=UTF-8
    < X-Trans-Id: txcedea3e2557d463eb591d-0052427f60
    < Date: Wed, 25 Sep 2013 06:14:56 GMT
    <
    * Connection #0 to host client.rhelbox.com left intact
    * Closing connection #0

####Access container as jsmith

> kinit jsmith

Get token for jsmith
> curl -v -u : --negotiate --location-trusted http://client.rhelbox.com:8080/auth/v1.0

    * About to connect() to client.rhelbox.com port 8080 (#0)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 8080 (#0)
    > GET /auth/v1.0 HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com:8080
    > Accept: */*
    >
    < HTTP/1.1 303 See Other
    < Content-Type: text/html; charset=UTF-8
    < Location: http://client.rhelbox.com/cgi-bin/swift-auth
    < Content-Length: 0
    < X-Trans-Id: txf51e1bf7f8c5496f8cc93-005242800b
    < Date: Wed, 25 Sep 2013 06:17:47 GMT
    <
    * Connection #0 to host client.rhelbox.com left intact
    * Issue another request to this URL: 'http://client.rhelbox.com/cgi-bin/swift-auth'
    * About to connect() to client.rhelbox.com port 80 (#1)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 80 (#1)
    > GET /cgi-bin/swift-auth HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com
    > Accept: */*
    >
    < HTTP/1.1 401 Unauthorized
    < Date: Wed, 25 Sep 2013 06:17:47 GMT
    < Server: Apache/2.4.6 (Fedora) mod_auth_kerb/5.4
    < WWW-Authenticate: Negotiate
    < WWW-Authenticate: Basic realm="Swift Authentication"
    < Content-Length: 381
    < Content-Type: text/html; charset=iso-8859-1
    <
    * Ignoring the response-body
    * Connection #1 to host client.rhelbox.com left intact
    * Issue another request to this URL: 'http://client.rhelbox.com/cgi-bin/swift-auth'
    * Re-using existing connection! (#1) with host (nil)
    * Connected to (nil) (192.168.56.101) port 80 (#1)
    * Server auth using GSS-Negotiate with user ''
    > GET /cgi-bin/swift-auth HTTP/1.1
    > Authorization: Negotiate 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
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com
    > Accept: */*
    >
    < HTTP/1.1 200 OK
    < Date: Wed, 25 Sep 2013 06:17:47 GMT
    < Server: Apache/2.4.6 (Fedora) mod_auth_kerb/5.4
    < WWW-Authenticate: Negotiate YIGYBgkqhkiG9xIBAgICAG+BiDCBhaADAgEFoQMCAQ+ieTB3oAMCARKicARuH2YpjFrtgIhGr5nO7gh/21EvGH9tayRo5A3pw5pxD1B1036ePLG/x98OdMrSflse5s8ttz8FmvRphCFJa8kfYtnWULgoFLF2F2a1zBdSo2oCA0R05YFwArNhkg6ou5o7wWZkERHK33CKlhudSj8=
    < X-Auth-Token: AUTH_tkb5a20eb8207a819e76619431c8410447
    < X-Debug-Remote-User: jsmith
    < X-Debug-Groups: jsmith
    < X-Debug-Token-Life: 86400s
    < X-Debug-Token-Expires: Thu Sep 26 11:47:47 2013
    < Content-Length: 0
    < Content-Type: text/html; charset=UTF-8
    <
    * Connection #1 to host (nil) left intact
    * Closing connection #0
    * Closing connection #1

List the container using authentication token for jsmith:
> curl -v -X GET -H 'X-Auth-Token: AUTH_tkb5a20eb8207a819e76619431c8410447' http://client.rhelbox.com:8080/v1/AUTH_myvolume/c1

    * About to connect() to client.rhelbox.com port 8080 (#0)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 8080 (#0)
    > GET /v1/AUTH_myvolume/c1 HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com:8080
    > Accept: */*
    > X-Auth-Token: AUTH_tkb5a20eb8207a819e76619431c8410447
    >
    < HTTP/1.1 200 OK
    < Content-Length: 8
    < X-Container-Object-Count: 0
    < Accept-Ranges: bytes
    < X-Timestamp: 1
    < X-Container-Bytes-Used: 0
    < Content-Type: text/plain; charset=utf-8
    < X-Trans-Id: tx575215929c654d9f9f284-00524280a4
    < Date: Wed, 25 Sep 2013 06:20:20 GMT
    <
    object1
    * Connection #0 to host client.rhelbox.com left intact
    * Closing connection #0

Downloading the object as jsmith:
> curl -v -X GET -H 'X-Auth-Token: AUTH_tkb5a20eb8207a819e76619431c8410447' http://client.rhelbox.com:8080/v1/AUTH_myvolume/c1/object1

    * About to connect() to client.rhelbox.com port 8080 (#0)
    *   Trying 192.168.56.101...
    * connected
    * Connected to client.rhelbox.com (192.168.56.101) port 8080 (#0)
    > GET /v1/AUTH_myvolume/c1/object1 HTTP/1.1
    > User-Agent: curl/7.27.0
    > Host: client.rhelbox.com:8080
    > Accept: */*
    > X-Auth-Token: AUTH_tkb5a20eb8207a819e76619431c8410447
    >
    < HTTP/1.1 200 OK
    < Content-Length: 11
    < Accept-Ranges: bytes
    < Last-Modified: Wed, 25 Sep 2013 06:08:00 GMT
    < Etag: 3e25960a79dbc69b674cd4ec67a72c62
    < X-Timestamp: 1380089280.98829
    < Content-Type: application/x-www-form-urlencoded
    < X-Trans-Id: tx19b5cc3847854f40a6ca8-00524281aa
    < Date: Wed, 25 Sep 2013 06:24:42 GMT
    <
    * Connection #0 to host client.rhelbox.com left intact
    Hello world* Closing connection #0

For curl to follow the redirect, you need to specify additional
options. With these, and with a current Kerberos ticket, you should
get the Kerberos user's cached authentication token, or a new one if
the previous token has expired.

> curl -v -u : --negotiate --location-trusted -X GET http://client.rhelbox.com:8080/v1/AUTH_myvolume/c1/object1

The --negotiate option is for curl to perform Kerberos authentication and
--location-trusted is for curl to follow the redirect.

[auth_kerb_module Configuration]: http://modauthkerb.sourceforge.net/configure.html