1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
-
-
-
+
|
<!doctype html public "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type"
content="text/html; charset=iso-8859-1">
<meta name="Author"
content="Matt Newman <[email protected]>">
<meta name="Copyright" content="1999 Matt Newman.">
|
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
-
-
+
+
|
<dd>Forces handshake to take place, and returns 0 if
handshake is still in progress (non-blocking), or 1 if
the handshake was successful. If the handshake failed
this routine will throw an error.</dd>
<dt> </dt>
<dt><a name="tls::status"><strong>tls::status</strong>
<em>?-local? channel</em></a></dt>
<dd>Returns the current security status of a SSL channel. The
result is a list of key value pairs describing the
<dd>Returns the current security status of an SSL channel. The
result is a list of key-value pairs describing the
connected peer. If the result is an empty list then the
SSL handshake has not yet completed.
If <em>-local</em> is given, then the certificate information
is the one used locally.</dd>
</dl>
<blockquote>
|
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
|
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
|
-
+
-
+
-
-
-
+
-
+
+
|
<dd>SSL-enable a regular Tcl channel - it need not be a
socket, but must provide bi-directional flow. Also
setting session parameters for SSL handshake.</dd>
</dl>
<blockquote>
<dl>
<dt>-<strong>cadir</strong> <em>dir</em></dt>
<dt><strong>-cadir</strong> <em>dir</em></dt>
<dd>Provide the directory containing the CA certificates.</dd>
<dt><strong>-cafile </strong><em>filename</em></dt>
<dd>Provide the CA file.</dd>
<dt><strong>-certfile</strong> <em>filename</em></dt>
<dd>Provide the certificate to use.</dd>
<dt><strong>-cipher </strong><em>string</em></dt>
<dd>Provide the cipher suites to use. Syntax is as per
OpenSSL.</dd>
<dt><strong>-command</strong><em> callback</em></dt>
<dt><strong>-command</strong> <em>callback</em></dt>
<dd>If specified, this callback will be invoked at several points
during the OpenSSL handshake. It can pass errors and tracing
information, and it can allow Tcl scripts to perform
their own validation of the certificate in place of the
default validation provided by OpenSSL.
The callback should return an integer whose interpretation
depends on context.
<dt><strong>-password</strong><em> callback</em></dt>
<dt><strong>-password</strong> <em>callback</em></dt>
<dd>If supplied, this callback will be invoked when OpenSSL needs
to obtain a password, typically for a certificate.
to obtain a password, typically to unlock the private key of
a certificate.
The callback should return a string which represents the
password to be used.
<br>
See <a href="#CALLBACK OPTIONS">CALLBACK OPTIONS</a> for
further discussion.</dd>
<dt><strong>-request </strong><em>bool</em></dt>
<dd>Request a certificate from peer during SSL handshake.
|
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
|
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
|
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-
-
-
-
-
+
+
+
+
+
+
-
-
+
-
-
-
-
-
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-
+
|
<p>
As indicated above, individual channels can be given their own callbacks
to handle intermediate processing by the OpenSSL library, using the
<em>-command</em> and <em>-password</em> options passed to either of
<strong>tls::socket</strong> or <strong>tls::import</strong>.
</p>
<blockquote>
<dl>
<dt><strong>-command</strong> <em>callback</em></dt>
<dd>
Invokes the specified <em>callback</em> script at
several points during the OpenSSL handshake.
Except as indicated below, values returned from the
callback are ignored.
Arguments appended to the script upon callback take one of the
following forms:
<br>
<br>
<dl>
<!-- This form of callback is disabled.
<dt>
<strong>error</strong> <em>channel message</em>
</dt>
<dd>
The <em>message</em> argument contains an error message generated
by the OpenSSL function
<code>ERR_reason_error_string()</code>.
</dd>
<br>
-->
<dt>
<strong>info</strong> <em>channel major minor message</em>
</dt>
<dd>
This form of callback is invoked by the OpenSSL function
<code>SSL_CTX_set_info_callback()</code>.
<br>
The <em>major</em> and <em>minor</em> arguments are used to
represent the state information bitmask.
<dl>
<dt>Possible values for <em>major</em> are:</dt>
<dd><code>handshake, alert, connect, accept</code>.</dd>
<dt>Possible values for <em>minor</em> are:</dt>
<dd><code>start, done, read, write, loop, exit</code>.</dd>
</dl>
The <em>message</em> argument is a descriptive string which may
be generated either by
<code>SSL_state_string_long()</code> or by
<code>SSL_alert_desc_string_long()</code>,
depending on context.
</dd>
<br>
<dt>
<strong>verify</strong> <em>channel depth cert status error</em>
</dt>
<dd>
This form of callback is invoked by the OpenSSL function
<code>SSL_set_verify()</code>.
<br>
The <em>depth</em> argument is an integer representing the
current depth on the certificate chain, with
<code>0</code> as the subject certificate and higher values
denoting progressively more indirect issuer certificates.
<br>
The <em>cert</em> argument is a list of key-value pairs similar
to those returned by
<a href="#tls::status"><strong>tls::status</strong></a>.
<br>
The <em>status</em> argument is an integer representing the
current validity of the certificate.
A value of <code>0</code> means the certificate is deemed invalid.
A value of <code>1</code> means the certificate is deemed valid.
<br>
The <em>error</em> argument supplies the message, if any, generated
by
<code>X509_STORE_CTX_get_error()</code>.
<br>
<br>
The callback may override normal validation processing by explicitly
returning one of the above <em>status</em> values.
</dd>
</dl>
</dd>
<br>
<dt><strong>-password</strong> <em>callback</em></dt>
<dd>
Invokes the specified <em>callback</em> script when OpenSSL needs to
obtain a password. The callback should return a string which
represents the password to be used.
No arguments are appended to the script upon callback.
</dd>
</dl>
</blockquote>
<p>
Reference implementations of these callbacks are provided in the distribution
as <strong>tls::callback</strong> and <strong>tls::password</strong>.
Note that these are <em>sample</em> implementations only. In a more realistic
deployment you would substitute your own callbacks, typically by configuring
the <em>-command</em> and <em>-password</em> options on each channel with
Reference implementations of these callbacks are provided in the
distribution as <strong>tls::callback</strong> and
<strong>tls::password</strong> respectively. Note that these are
<em>sample</em> implementations only. In a more realistic deployment
you would specify your own callback scripts on each TLS channel
using the <em>-command</em> and <em>-password</em> options.
scripts to be executed when the callbacks are invoked.
compatibility with earlier implementations. The use of implied callbacks
compatibility with earlier implementations.
is not recommended.
The <strong>tls::debug</strong> variable provides some additional control
over the default commands. Its value is zero by default. Higher values
produce more diagnostic output. Setting this value greater than zero
will also force the default verify method in <strong>tls::callback</strong>
to accept the certificate, even if it is invalid.
The <strong>tls::debug</strong> variable provides some additional
control over these reference callbacks. Its value is zero by default.
Higher values produce more diagnostic output, and will also force the
verify method in <strong>tls::callback</strong> to accept the
certificate, even when it is invalid.
</p>
<p>
<em>
The use of the reference callbacks <strong>tls::callback</strong> and
<strong>tls::password</strong> is not recommended. They may be removed
from future releases.
</em>
</p>
<p>
<em>
The use of the variable <strong>tls::debug</strong> is not recommended.
It may be removed from future releases.
</em>
</p>
<h3><a name="HTTPS EXAMPLE">HTTPS EXAMPLE</a></h3>
<p>This example requires a patch to the <strong>http</strong>
module that ships with Tcl - this patch has been submitted for
inclusion in Tcl 8.2.1, but is also provided in the tls directory
if needed. A sample server.pem is provided with the TLS release,
courtesy of the <strong>OpenSSL</strong> project.</p>
<pre><code>
<pre><code>package require http
|
300
301
302
303
304
305
306
307
308
309
|
412
413
414
415
416
417
418
419
420
421
422
|
+
|
<p><strong>socket</strong>, <strong>fileevent, </strong><a
href="http://www.openssl.org/"><strong>OpenSSL</strong></a></p>
<hr>
<pre>
Copyright © 1999 Matt Newman.
Copyright © 2004 Starfish Systems.
</pre>
</body>
</html>
|