1 --- libmicrohttpd-0.9.24/doc/ecos.texi.orig 1970-01-01 01:00:00.000000000 +0100
2 +++ libmicrohttpd-0.9.24/doc/ecos.texi 2013-01-03 19:01:45.646387769 +0100
4 +@cindex GPL, GNU General Public License
5 +@cindex eCos, GNU General Public License with eCos Extension
6 +@center Version 2, June 1991
9 +Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
10 +59 Temple Place -- Suite 330, Boston, MA 02111-1307, USA
12 +Everyone is permitted to copy and distribute verbatim copies
13 +of this license document, but changing it is not allowed.
21 + The licenses for most software are designed to take away your
22 +freedom to share and change it. By contrast, the GNU General Public
23 +License is intended to guarantee your freedom to share and change free
24 +software---to make sure the software is free for all its users. This
25 +General Public License applies to most of the Free Software
26 +Foundation's software and to any other program whose authors commit to
27 +using it. (Some other Free Software Foundation software is covered by
28 +the GNU Library General Public License instead.) You can apply it to
31 + When we speak of free software, we are referring to freedom, not
32 +price. Our General Public Licenses are designed to make sure that you
33 +have the freedom to distribute copies of free software (and charge for
34 +this service if you wish), that you receive source code or can get it
35 +if you want it, that you can change the software or use pieces of it
36 +in new free programs; and that you know you can do these things.
38 + To protect your rights, we need to make restrictions that forbid
39 +anyone to deny you these rights or to ask you to surrender the rights.
40 +These restrictions translate to certain responsibilities for you if you
41 +distribute copies of the software, or if you modify it.
43 + For example, if you distribute copies of such a program, whether
44 +gratis or for a fee, you must give the recipients all the rights that
45 +you have. You must make sure that they, too, receive or can get the
46 +source code. And you must show them these terms so they know their
49 + We protect your rights with two steps: (1) copyright the software, and
50 +(2) offer you this license which gives you legal permission to copy,
51 +distribute and/or modify the software.
53 + Also, for each author's protection and ours, we want to make certain
54 +that everyone understands that there is no warranty for this free
55 +software. If the software is modified by someone else and passed on, we
56 +want its recipients to know that what they have is not the original, so
57 +that any problems introduced by others will not reflect on the original
58 +authors' reputations.
60 + Finally, any free program is threatened constantly by software
61 +patents. We wish to avoid the danger that redistributors of a free
62 +program will individually obtain patent licenses, in effect making the
63 +program proprietary. To prevent this, we have made it clear that any
64 +patent must be licensed for everyone's free use or not licensed at all.
66 + The precise terms and conditions for copying, distribution and
70 +@subheading TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
73 +@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
78 +This License applies to any program or other work which contains
79 +a notice placed by the copyright holder saying it may be distributed
80 +under the terms of this General Public License. The ``Program'', below,
81 +refers to any such program or work, and a ``work based on the Program''
82 +means either the Program or any derivative work under copyright law:
83 +that is to say, a work containing the Program or a portion of it,
84 +either verbatim or with modifications and/or translated into another
85 +language. (Hereinafter, translation is included without limitation in
86 +the term ``modification''.) Each licensee is addressed as ``you''.
88 +Activities other than copying, distribution and modification are not
89 +covered by this License; they are outside its scope. The act of
90 +running the Program is not restricted, and the output from the Program
91 +is covered only if its contents constitute a work based on the
92 +Program (independent of having been made by running the Program).
93 +Whether that is true depends on what the Program does.
96 +You may copy and distribute verbatim copies of the Program's
97 +source code as you receive it, in any medium, provided that you
98 +conspicuously and appropriately publish on each copy an appropriate
99 +copyright notice and disclaimer of warranty; keep intact all the
100 +notices that refer to this License and to the absence of any warranty;
101 +and give any other recipients of the Program a copy of this License
102 +along with the Program.
104 +You may charge a fee for the physical act of transferring a copy, and
105 +you may at your option offer warranty protection in exchange for a fee.
108 +You may modify your copy or copies of the Program or any portion
109 +of it, thus forming a work based on the Program, and copy and
110 +distribute such modifications or work under the terms of Section 1
111 +above, provided that you also meet all of these conditions:
115 +You must cause the modified files to carry prominent notices
116 +stating that you changed the files and the date of any change.
119 +You must cause any work that you distribute or publish, that in
120 +whole or in part contains or is derived from the Program or any
121 +part thereof, to be licensed as a whole at no charge to all third
122 +parties under the terms of this License.
125 +If the modified program normally reads commands interactively
126 +when run, you must cause it, when started running for such
127 +interactive use in the most ordinary way, to print or display an
128 +announcement including an appropriate copyright notice and a
129 +notice that there is no warranty (or else, saying that you provide
130 +a warranty) and that users may redistribute the program under
131 +these conditions, and telling the user how to view a copy of this
132 +License. (Exception: if the Program itself is interactive but
133 +does not normally print such an announcement, your work based on
134 +the Program is not required to print an announcement.)
137 +These requirements apply to the modified work as a whole. If
138 +identifiable sections of that work are not derived from the Program,
139 +and can be reasonably considered independent and separate works in
140 +themselves, then this License, and its terms, do not apply to those
141 +sections when you distribute them as separate works. But when you
142 +distribute the same sections as part of a whole which is a work based
143 +on the Program, the distribution of the whole must be on the terms of
144 +this License, whose permissions for other licensees extend to the
145 +entire whole, and thus to each and every part regardless of who wrote it.
147 +Thus, it is not the intent of this section to claim rights or contest
148 +your rights to work written entirely by you; rather, the intent is to
149 +exercise the right to control the distribution of derivative or
150 +collective works based on the Program.
152 +In addition, mere aggregation of another work not based on the Program
153 +with the Program (or with a work based on the Program) on a volume of
154 +a storage or distribution medium does not bring the other work under
155 +the scope of this License.
158 +You may copy and distribute the Program (or a work based on it,
159 +under Section 2) in object code or executable form under the terms of
160 +Sections 1 and 2 above provided that you also do one of the following:
164 +Accompany it with the complete corresponding machine-readable
165 +source code, which must be distributed under the terms of Sections
166 +1 and 2 above on a medium customarily used for software interchange; or,
169 +Accompany it with a written offer, valid for at least three
170 +years, to give any third party, for a charge no more than your
171 +cost of physically performing source distribution, a complete
172 +machine-readable copy of the corresponding source code, to be
173 +distributed under the terms of Sections 1 and 2 above on a medium
174 +customarily used for software interchange; or,
177 +Accompany it with the information you received as to the offer
178 +to distribute corresponding source code. (This alternative is
179 +allowed only for noncommercial distribution and only if you
180 +received the program in object code or executable form with such
181 +an offer, in accord with Subsection b above.)
184 +The source code for a work means the preferred form of the work for
185 +making modifications to it. For an executable work, complete source
186 +code means all the source code for all modules it contains, plus any
187 +associated interface definition files, plus the scripts used to
188 +control compilation and installation of the executable. However, as a
189 +special exception, the source code distributed need not include
190 +anything that is normally distributed (in either source or binary
191 +form) with the major components (compiler, kernel, and so on) of the
192 +operating system on which the executable runs, unless that component
193 +itself accompanies the executable.
195 +If distribution of executable or object code is made by offering
196 +access to copy from a designated place, then offering equivalent
197 +access to copy the source code from the same place counts as
198 +distribution of the source code, even though third parties are not
199 +compelled to copy the source along with the object code.
202 +You may not copy, modify, sublicense, or distribute the Program
203 +except as expressly provided under this License. Any attempt
204 +otherwise to copy, modify, sublicense or distribute the Program is
205 +void, and will automatically terminate your rights under this License.
206 +However, parties who have received copies, or rights, from you under
207 +this License will not have their licenses terminated so long as such
208 +parties remain in full compliance.
211 +You are not required to accept this License, since you have not
212 +signed it. However, nothing else grants you permission to modify or
213 +distribute the Program or its derivative works. These actions are
214 +prohibited by law if you do not accept this License. Therefore, by
215 +modifying or distributing the Program (or any work based on the
216 +Program), you indicate your acceptance of this License to do so, and
217 +all its terms and conditions for copying, distributing or modifying
218 +the Program or works based on it.
221 +Each time you redistribute the Program (or any work based on the
222 +Program), the recipient automatically receives a license from the
223 +original licensor to copy, distribute or modify the Program subject to
224 +these terms and conditions. You may not impose any further
225 +restrictions on the recipients' exercise of the rights granted herein.
226 +You are not responsible for enforcing compliance by third parties to
230 +If, as a consequence of a court judgment or allegation of patent
231 +infringement or for any other reason (not limited to patent issues),
232 +conditions are imposed on you (whether by court order, agreement or
233 +otherwise) that contradict the conditions of this License, they do not
234 +excuse you from the conditions of this License. If you cannot
235 +distribute so as to satisfy simultaneously your obligations under this
236 +License and any other pertinent obligations, then as a consequence you
237 +may not distribute the Program at all. For example, if a patent
238 +license would not permit royalty-free redistribution of the Program by
239 +all those who receive copies directly or indirectly through you, then
240 +the only way you could satisfy both it and this License would be to
241 +refrain entirely from distribution of the Program.
243 +If any portion of this section is held invalid or unenforceable under
244 +any particular circumstance, the balance of the section is intended to
245 +apply and the section as a whole is intended to apply in other
248 +It is not the purpose of this section to induce you to infringe any
249 +patents or other property right claims or to contest validity of any
250 +such claims; this section has the sole purpose of protecting the
251 +integrity of the free software distribution system, which is
252 +implemented by public license practices. Many people have made
253 +generous contributions to the wide range of software distributed
254 +through that system in reliance on consistent application of that
255 +system; it is up to the author/donor to decide if he or she is willing
256 +to distribute software through any other system and a licensee cannot
259 +This section is intended to make thoroughly clear what is believed to
260 +be a consequence of the rest of this License.
263 +If the distribution and/or use of the Program is restricted in
264 +certain countries either by patents or by copyrighted interfaces, the
265 +original copyright holder who places the Program under this License
266 +may add an explicit geographical distribution limitation excluding
267 +those countries, so that distribution is permitted only in or among
268 +countries not thus excluded. In such case, this License incorporates
269 +the limitation as if written in the body of this License.
272 +The Free Software Foundation may publish revised and/or new versions
273 +of the General Public License from time to time. Such new versions will
274 +be similar in spirit to the present version, but may differ in detail to
275 +address new problems or concerns.
277 +Each version is given a distinguishing version number. If the Program
278 +specifies a version number of this License which applies to it and ``any
279 +later version'', you have the option of following the terms and conditions
280 +either of that version or of any later version published by the Free
281 +Software Foundation. If the Program does not specify a version number of
282 +this License, you may choose any version ever published by the Free Software
286 +If you wish to incorporate parts of the Program into other free
287 +programs whose distribution conditions are different, write to the author
288 +to ask for permission. For software which is copyrighted by the Free
289 +Software Foundation, write to the Free Software Foundation; we sometimes
290 +make exceptions for this. Our decision will be guided by the two goals
291 +of preserving the free status of all derivatives of our free software and
292 +of promoting the sharing and reuse of software generally.
295 +@heading NO WARRANTY
302 +BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
303 +FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
304 +OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
305 +PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
306 +OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
307 +MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
308 +TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
309 +PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
310 +REPAIR OR CORRECTION.
313 +IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
314 +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
315 +REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
316 +INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
317 +OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
318 +TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
319 +YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
320 +PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
321 +POSSIBILITY OF SUCH DAMAGES.
324 +@heading ECOS EXTENSION
327 +@center ECOS EXTENSION
332 +As a special exception, if other files instantiate templates or use
333 +macros or inline functions from this file, or you compile this file
334 +and link it with other works to produce a work based on this file,
335 +this file does not by itself cause the resulting work to be covered by
336 +the GNU General Public License. However the source code for this file
337 +must still be made available in accordance with section (3) of the GNU
338 +General Public License v2.
340 +This exception does not invalidate any other reasons why a work based
341 +on this file might be covered by the GNU General Public License.
347 +@heading END OF TERMS AND CONDITIONS
350 +@center END OF TERMS AND CONDITIONS
354 +@unnumberedsec How to Apply These Terms to Your New Programs
356 + If you develop a new program, and you want it to be of the greatest
357 +possible use to the public, the best way to achieve this is to make it
358 +free software which everyone can redistribute and change under these terms.
360 + To do so, attach the following notices to the program. It is safest
361 +to attach them to the start of each source file to most effectively
362 +convey the exclusion of warranty; and each file should have at least
363 +the ``copyright'' line and a pointer to where the full notice is found.
366 +@var{one line to give the program's name and an idea of what it does.}
367 +Copyright (C) 19@var{yy} @var{name of author}
369 +This program is free software; you can redistribute it and/or
370 +modify it under the terms of the GNU General Public License
371 +as published by the Free Software Foundation; either version 2
372 +of the License, or (at your option) any later version.
374 +This program is distributed in the hope that it will be useful,
375 +but WITHOUT ANY WARRANTY; without even the implied warranty of
376 +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
377 +GNU General Public License for more details.
379 +You should have received a copy of the GNU General Public License along
380 +with this program; if not, write to the Free Software Foundation, Inc.,
381 +59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
384 +Also add information on how to contact you by electronic and paper mail.
386 +If the program is interactive, make it output a short notice like this
387 +when it starts in an interactive mode:
390 +Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author}
391 +Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
392 +type `show w'. This is free software, and you are welcome
393 +to redistribute it under certain conditions; type `show c'
397 +The hypothetical commands @samp{show w} and @samp{show c} should show
398 +the appropriate parts of the General Public License. Of course, the
399 +commands you use may be called something other than @samp{show w} and
400 +@samp{show c}; they could even be mouse-clicks or menu items---whatever
403 +You should also get your employer (if you work as a programmer) or your
404 +school, if any, to sign a ``copyright disclaimer'' for the program, if
405 +necessary. Here is a sample; alter the names:
409 +Yoyodyne, Inc., hereby disclaims all copyright
410 +interest in the program `Gnomovision'
411 +(which makes passes at compilers) written
414 +@var{signature of Ty Coon}, 1 April 1989
415 +Ty Coon, President of Vice
419 +This General Public License does not permit incorporating your program into
420 +proprietary programs. If your program is a subroutine library, you may
421 +consider it more useful to permit linking proprietary applications with the
422 +library. If this is what you want to do, use the GNU Library General
423 +Public License instead of this License.
424 --- libmicrohttpd-0.9.24/doc/fdl-1.3.texi.orig 1970-01-01 01:00:00.000000000 +0100
425 +++ libmicrohttpd-0.9.24/doc/fdl-1.3.texi 2013-01-03 19:01:45.646387769 +0100
427 +@c The GNU Free Documentation License.
428 +@center Version 1.3, 3 November 2008
430 +@c This file is intended to be included within another document,
431 +@c hence no sectioning command or @node.
434 +Copyright @copyright{} 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
435 +@uref{http://fsf.org/}
437 +Everyone is permitted to copy and distribute verbatim copies
438 +of this license document, but changing it is not allowed.
445 +The purpose of this License is to make a manual, textbook, or other
446 +functional and useful document @dfn{free} in the sense of freedom: to
447 +assure everyone the effective freedom to copy and redistribute it,
448 +with or without modifying it, either commercially or noncommercially.
449 +Secondarily, this License preserves for the author and publisher a way
450 +to get credit for their work, while not being considered responsible
451 +for modifications made by others.
453 +This License is a kind of ``copyleft'', which means that derivative
454 +works of the document must themselves be free in the same sense. It
455 +complements the GNU General Public License, which is a copyleft
456 +license designed for free software.
458 +We have designed this License in order to use it for manuals for free
459 +software, because free software needs free documentation: a free
460 +program should come with manuals providing the same freedoms that the
461 +software does. But this License is not limited to software manuals;
462 +it can be used for any textual work, regardless of subject matter or
463 +whether it is published as a printed book. We recommend this License
464 +principally for works whose purpose is instruction or reference.
467 +APPLICABILITY AND DEFINITIONS
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470 +contains a notice placed by the copyright holder saying it can be
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476 +copy, modify or distribute the work in a way requiring permission
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479 +A ``Modified Version'' of the Document means any work containing the
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551 +The Document may include Warranty Disclaimers next to the notice which
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577 +If you publish printed copies (or copies in media that commonly have
578 +printed covers) of the Document, numbering more than 100, and the
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610 +them a chance to provide you with an updated version of the Document.
615 +You may copy and distribute a Modified Version of the Document under
616 +the conditions of sections 2 and 3 above, provided that you release
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624 +Use in the Title Page (and on the covers, if any) a title distinct
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638 +State on the Title page the name of the publisher of the
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642 +Preserve all the copyright notices of the Document.
645 +Add an appropriate copyright notice for your modifications
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649 +Include, immediately after the copyright notices, a license notice
650 +giving the public permission to use the Modified Version under the
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658 +Include an unaltered copy of this License.
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934 +++ libmicrohttpd-0.9.24/doc/lgpl.texi 2013-01-03 19:01:45.646387769 +0100
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1496 +That's all there is to it!
1497 --- libmicrohttpd-0.9.24/doc/chapters.orig/basicauthentication.inc 1970-01-01 01:00:00.000000000 +0100
1498 +++ libmicrohttpd-0.9.24/doc/chapters/basicauthentication.inc 2013-01-03 19:12:00.176374962 +0100
1500 +With the small exception of IP address based access control,
1501 +requests from all connecting clients where served equally until now.
1502 +This chapter discusses a first method of client's authentication and
1505 +A very simple approach feasible with the means already discussed would
1506 +be to expect the password in the @emph{URI} string before granting access to
1507 +the secured areas. The password could be separated from the actual resource identifier
1508 +by a certain character, thus the request line might look like
1510 +GET /picture.png?mypassword
1514 +In the rare situation where the client is customized enough and the connection occurs
1515 +through secured lines (e.g., a embedded device directly attached to another via wire)
1516 +and where the ability to embedd a password in the URI or to pass on a URI with a
1517 +password are desired, this can be a reasonable choice.
1519 +But when it is assumed that the user connecting does so with an ordinary Internet browser,
1520 +this implementation brings some problems about. For example, the URI including the password
1521 +stays in the address field or at least in the history of the browser for anybody near enough to see.
1522 +It will also be inconvenient to add the password manually to any new URI when the browser does
1523 +not know how to compose this automatically.
1525 +At least the convenience issue can be addressed by employing the simplest built-in password
1526 +facilities of HTTP compliant browsers, hence we want to start there. It will however turn out
1527 +to have still severe weaknesses in terms of security which need consideration.
1529 +Before we will start implementing @emph{Basic Authentication} as described in @emph{RFC 2617},
1530 +we should finally abandon the bad practice of responding every request the first time our callback
1531 +is called for a given connection. This is becoming more important now because the client and
1532 +the server will have to talk in a more bi-directional way than before to
1534 +But how can we tell whether the callback has been called before for the particular connection?
1535 +Initially, the pointer this parameter references is set by @emph{MHD} in the callback. But it will
1536 +also be "remembered" on the next call (for the same connection).
1537 +Thus, we will generate no response until the parameter is non-null---implying the callback was
1538 +called before at least once. We do not need to share information between different calls of the callback,
1539 +so we can set the parameter to any adress that is assured to be not null. The pointer to the
1540 +@code{connection} structure will be pointing to a legal address, so we take this.
1542 +The first time @code{answer_to_connection} is called, we will not even look at the headers.
1546 +answer_to_connection (void *cls, struct MHD_Connection *connection,
1547 + const char *url, const char *method, const char *version,
1548 + const char *upload_data, size_t *upload_data_size,
1551 + if (0 != strcmp(method, "GET")) return MHD_NO;
1552 + if (NULL == *con_cls) {*con_cls = connection; return MHD_YES;}
1555 + /* else respond accordingly */
1561 +Note how we lop off the connection on the first condition (no "GET" request), but return asking for more on
1562 +the other one with @code{MHD_YES}.
1563 +With this minor change, we can proceed to implement the actual authentication process.
1565 +@heading Request for authentication
1567 +Let us assume we had only files not intended to be handed out without the correct username/password,
1568 +so every "GET" request will be challenged.
1569 +@emph{RFC 2617} describes how the server shall ask for authentication by adding a
1570 +@emph{WWW-Authenticate} response header with the name of the @emph{realm} protected.
1571 +MHD can generate and queue such a failure response for you using
1572 +the @code{MHD_queue_basic_auth_fail_response} API. The only thing you need to do
1573 +is construct a response with the error page to be shown to the user
1574 +if he aborts basic authentication. But first, you should check if the
1575 +proper credentials were already supplied using the
1576 +@code{MHD_basic_auth_get_username_password} call.
1578 +Your code would then look like this:
1581 +answer_to_connection (void *cls, struct MHD_Connection *connection,
1582 + const char *url, const char *method,
1583 + const char *version, const char *upload_data,
1584 + size_t *upload_data_size, void **con_cls)
1589 + struct MHD_Response *response;
1591 + if (0 != strcmp (method, MHD_HTTP_METHOD_GET))
1593 + if (NULL == *con_cls)
1595 + *con_cls = connection;
1599 + user = MHD_basic_auth_get_username_password (connection, &pass);
1600 + fail = ( (user == NULL) ||
1601 + (0 != strcmp (user, "root")) ||
1602 + (0 != strcmp (pass, "pa$$w0rd") ) );
1603 + if (user != NULL) free (user);
1604 + if (pass != NULL) free (pass);
1607 + const char *page = "<html><body>Go away.</body></html>";
1609 + MHD_create_response_from_buffer (strlen (page), (void *) page,
1610 + MHD_RESPMEM_PERSISTENT);
1611 + ret = MHD_queue_basic_auth_fail_response (connection,
1617 + const char *page = "<html><body>A secret.</body></html>";
1619 + MHD_create_response_from_buffer (strlen (page), (void *) page,
1620 + MHD_RESPMEM_PERSISTENT);
1621 + ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
1623 + MHD_destroy_response (response);
1628 +See the @code{examples} directory for the complete example file.
1631 +For a proper server, the conditional statements leading to a return of @code{MHD_NO} should yield a
1632 +response with a more precise status code instead of silently closing the connection. For example,
1633 +failures of memory allocation are best reported as @emph{internal server error} and unexpected
1634 +authentication methods as @emph{400 bad request}.
1639 +Make the server respond to wrong credentials (but otherwise well-formed requests) with the recommended
1640 +@emph{401 unauthorized} status code. If the client still does not authenticate correctly within the
1641 +same connection, close it and store the client's IP address for a certain time. (It is OK to check for
1642 +expiration not until the main thread wakes up again on the next connection.) If the client fails
1643 +authenticating three times during this period, add it to another list for which the
1644 +@code{AcceptPolicyCallback} function denies connection (temporally).
1647 +With the network utility @code{netcat} connect and log the response of a "GET" request as you
1648 +did in the exercise of the first example, this time to a file. Now stop the server and let @emph{netcat}
1649 +listen on the same port the server used to listen on and have it fake being the proper server by giving
1650 +the file's content as the response (e.g. @code{cat log | nc -l -p 8888}). Pretending to think your were
1651 +connecting to the actual server, browse to the eavesdropper and give the correct credentials.
1653 +Copy and paste the encoded string you see in @code{netcat}'s output to some of the Base64 decode tools available online
1654 +and see how both the user's name and password could be completely restored.
1659 --- libmicrohttpd-0.9.24/doc/chapters.orig/bibliography.inc 1970-01-01 01:00:00.000000000 +0100
1660 +++ libmicrohttpd-0.9.24/doc/chapters/bibliography.inc 2013-01-03 19:12:00.176374962 +0100
1662 +@heading API reference
1665 +The @emph{GNU libmicrohttpd} manual by Marco Maggi and Christian Grothoff 2008
1666 +@uref{http://gnunet.org/libmicrohttpd/microhttpd.html}
1669 +All referenced RFCs can be found on the website of @emph{The Internet Engineering Task Force}
1670 +@uref{http://www.ietf.org/}
1673 +@emph{RFC 2616}: Fielding, R., Gettys, J., Mogul, J., Frystyk, H., and T. Berners-Lee,
1674 +"Hypertext Transfer Protocol -- HTTP/1.1", RFC 2016, January 1997.
1677 +@emph{RFC 2617}: Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., Leach, P.,
1678 +Luotonen, A., and L. Stewart, "HTTP Authentication: Basic and Digest Access Authentication", RFC 2617, June 1999.
1682 +A well--structured @emph{HTML} reference can be found on
1683 +@uref{http://www.echoecho.com/html.htm}
1685 +For those readers understanding German or French, there is an excellent document both for learning
1686 +@emph{HTML} and for reference, whose English version unfortunately has been discontinued.
1687 +@uref{http://de.selfhtml.org/} and @uref{http://fr.selfhtml.org/}
1691 --- libmicrohttpd-0.9.24/doc/chapters.orig/exploringrequests.inc 1970-01-01 01:00:00.000000000 +0100
1692 +++ libmicrohttpd-0.9.24/doc/chapters/exploringrequests.inc 2013-01-03 19:12:00.176374962 +0100
1694 +This chapter will deal with the information which the client sends to the
1695 +server at every request. We are going to examine the most useful fields of such an request
1696 +and print them out in a readable manner. This could be useful for logging facilities.
1698 +The starting point is the @emph{hellobrowser} program with the former response removed.
1700 +This time, we just want to collect information in the callback function, thus we will
1701 +just return MHD_NO after we have probed the request. This way, the connection is closed
1702 +without much ado by the server.
1706 +answer_to_connection (void *cls, struct MHD_Connection *connection,
1708 + const char *method, const char *version,
1709 + const char *upload_data,
1710 + size_t *upload_data_size, void **con_cls)
1717 +The ellipsis marks the position where the following instructions shall be inserted.
1720 +We begin with the most obvious information available to the server, the request line. You should
1721 +already have noted that a request consists of a command (or "HTTP method") and a URI (e.g. a filename).
1722 +It also contains a string for the version of the protocol which can be found in @code{version}.
1723 +To call it a "new request" is justified because we return only @code{MHD_NO}, thus ensuring the
1724 +function will not be called again for this connection.
1726 +printf ("New %s request for %s using version %s\n", method, url, version);
1730 +The rest of the information is a bit more hidden. Nevertheless, there is lot of it sent from common
1731 +Internet browsers. It is stored in "key-value" pairs and we want to list what we find in the header.
1732 +As there is no mandatory set of keys a client has to send, each key-value pair is printed out one by
1733 +one until there are no more left. We do this by writing a separate function which will be called for
1734 +each pair just like the above function is called for each HTTP request.
1735 +It can then print out the content of this pair.
1737 +int print_out_key (void *cls, enum MHD_ValueKind kind,
1738 + const char *key, const char *value)
1740 + printf ("%s: %s\n", key, value);
1746 +To start the iteration process that calls our new function for every key, the line
1748 +MHD_get_connection_values (connection, MHD_HEADER_KIND, &print_out_key, NULL);
1751 +needs to be inserted in the connection callback function too. The second parameter tells the function
1752 +that we are only interested in keys from the general HTTP header of the request. Our iterating
1753 +function @code{print_out_key} does not rely on any additional information to fulfill its duties
1754 +so the last parameter can be NULL.
1756 +All in all, this constitutes the complete @code{logging.c} program for this chapter which can be
1757 +found in the @code{examples} section.
1759 +Connecting with any modern Internet browser should yield a handful of keys. You should try to
1760 +interpret them with the aid of @emph{RFC 2616}.
1761 +Especially worth mentioning is the "Host" key which is often used to serve several different websites
1762 +hosted under one single IP address but reachable by different domain names (this is called virtual hosting).
1764 +@heading Conclusion
1765 +The introduced capabilities to itemize the content of a simple GET request---especially the
1766 +URI---should already allow the server to satisfy clients' requests for small specific resources
1767 +(e.g. files) or even induce alteration of server state. However, the latter is not
1768 +recommended as the GET method (including its header data) is by convention considered a "safe"
1769 +operation, which should not change the server's state in a significant way. By convention,
1770 +GET operations can thus be performed by crawlers and other automatic software. Naturally
1771 +actions like searching for a passed string are fine.
1773 +Of course, no transmission can occur while the return value is still set to @code{MHD_NO} in the
1779 +By parsing the @code{url} string and delivering responses accordingly, implement a small server for
1780 +"virtual" files. When asked for @code{/index.htm@{l@}}, let the response consist of a HTML page
1781 +containing a link to @code{/another.html} page which is also to be created "on the fly" in case of
1782 +being requested. If neither of these two pages are requested, @code{MHD_HTTP_NOT_FOUND} shall be
1783 +returned accompanied by an informative message.
1786 +A very interesting information has still been ignored by our logger---the client's IP address.
1787 +Implement a callback function
1789 +static int on_client_connect (void *cls,
1790 + const struct sockaddr *addr,
1791 + socklen_t addrlen)
1794 +that prints out the IP address in an appropriate format. You might want to use the POSIX function
1795 +@code{inet_ntoa} but bear in mind that @code{addr} is actually just a structure containing other
1796 +substructures and is @emph{not} the variable this function expects.
1797 +Make sure to return @code{MHD_YES} so that the library knows the client is allowed to connect
1798 +(and to then process the request). If one wanted to limit access basing on IP addresses, this would be the place
1799 +to do it. The address of your @code{on_client_connect} function must be passed as the third parameter to the
1800 +@code{MHD_start_daemon} call.
1803 --- libmicrohttpd-0.9.24/doc/chapters.orig/hellobrowser.inc 1970-01-01 01:00:00.000000000 +0100
1804 +++ libmicrohttpd-0.9.24/doc/chapters/hellobrowser.inc 2013-01-03 19:12:00.176374962 +0100
1806 +The most basic task for a HTTP server is to deliver a static text message to any client connecting to it.
1807 +Given that this is also easy to implement, it is an excellent problem to start with.
1809 +For now, the particular URI the client asks for shall have no effect on the message that will
1810 +be returned. In addition, the server shall end the connection after the message has been sent so that
1811 +the client will know there is nothing more to expect.
1813 +The C program @code{hellobrowser.c}, which is to be found in the examples section, does just that.
1814 +If you are very eager, you can compile and start it right away but it is advisable to type the
1815 +lines in by yourself as they will be discussed and explained in detail.
1817 +After the necessary includes and the definition of the port which our server should listen on
1819 +#include <sys/types.h>
1820 +#include <sys/select.h>
1821 +#include <sys/socket.h>
1822 +#include <microhttpd.h>
1829 +the desired behaviour of our server when HTTP request arrive has to be implemented. We already have
1830 +agreed that it should not care about the particular details of the request, such as who is requesting
1831 +what. The server will respond merely with the same small HTML page to every request.
1833 +The function we are going to write now will be called by @emph{GNU libmicrohttpd} every time an
1834 +appropriate request comes in. While the name of this callback function is arbitrary, its parameter
1835 +list has to follow a certain layout. So please, ignore the lot of parameters for now, they will be
1836 +explained at the point they are needed. We have to use only one of them,
1837 +@code{struct MHD_Connection *connection}, for the minimalistic functionality we want to archive at the moment.
1839 +This parameter is set by the @emph{libmicrohttpd} daemon and holds the necessary information to
1840 +relate the call with a certain connection. Keep in mind that a server might have to satisfy hundreds
1841 +of concurrent connections and we have to make sure that the correct data is sent to the destined
1842 +client. Therefore, this variable is a means to refer to a particular connection if we ask the
1843 +daemon to sent the reply.
1845 +Talking about the reply, it is defined as a string right after the function header
1847 +int answer_to_connection (void *cls, struct MHD_Connection *connection,
1849 + const char *method, const char *version,
1850 + const char *upload_data,
1851 + size_t *upload_data_size, void **con_cls)
1853 + const char *page = "<html><body>Hello, browser!</body></html>";
1858 +HTTP is a rather strict protocol and the client would certainly consider it "inappropriate" if we
1859 +just sent the answer string "as is". Instead, it has to be wrapped with additional information stored in so-called headers and footers. Most of the work in this area is done by the library for us---we
1860 +just have to ask. Our reply string packed in the necessary layers will be called a "response".
1861 +To obtain such a response we hand our data (the reply--string) and its size over to the
1862 +@code{MHD_create_response_from_buffer} function. The last two parameters basically tell @emph{MHD}
1863 +that we do not want it to dispose the message data for us when it has been sent and there also needs
1864 +no internal copy to be done because the @emph{constant} string won't change anyway.
1867 + struct MHD_Response *response;
1870 + response = MHD_create_response_from_buffer (strlen (page),
1871 + (void*) page, MHD_RESPMEM_PERSISTENT);
1876 +Now that the the response has been laced up, it is ready for delivery and can be queued for sending.
1877 +This is done by passing it to another @emph{GNU libmicrohttpd} function. As all our work was done in
1878 +the scope of one function, the recipient is without doubt the one associated with the
1879 +local variable @code{connection} and consequently this variable is given to the queue function.
1880 +Every HTTP response is accompanied by a status code, here "OK", so that the client knows
1881 +this response is the intended result of his request and not due to some error or malfunction.
1883 +Finally, the packet is destroyed and the return value from the queue returned,
1884 +already being set at this point to either MHD_YES or MHD_NO in case of success or failure.
1887 + ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
1888 + MHD_destroy_response (response);
1896 +With the primary task of our server implemented, we can start the actual server daemon which will listen
1897 +on @code{PORT} for connections. This is done in the main function.
1901 + struct MHD_Daemon *daemon;
1903 + daemon = MHD_start_daemon (MHD_USE_SELECT_INTERNALLY, PORT, NULL, NULL,
1904 + &answer_to_connection, NULL, MHD_OPTION_END);
1905 + if (NULL == daemon) return 1;
1910 +The first parameter is one of three possible modes of operation. Here we want the daemon to run in
1911 +a separate thread and to manage all incoming connections in the same thread. This means that while
1912 +producing the response for one connection, the other connections will be put on hold. In this
1913 +example, where the reply is already known and therefore the request is served quickly, this poses no problem.
1915 +We will allow all clients to connect regardless of their name or location, therefore we do not check
1916 +them on connection and set the forth and fifth parameter to NULL.
1918 +Parameter six is the address of the function we want to be called whenever a new connection has been
1919 +established. Our @code{answer_to_connection} knows best what the client wants and needs no additional
1920 +information (which could be passed via the next parameter) so the next parameter is NULL. Likewise,
1921 +we do not need to pass extra options to the daemon so we just write the MHD_OPTION_END as the last parameter.
1923 +As the server daemon runs in the background in its own thread, the execution flow in our main
1924 +function will contine right after the call. Because of this, we must delay the execution flow in the
1925 +main thread or else the program will terminate prematurely. We let it pause in a processing-time
1926 +friendly manner by waiting for the enter key to be pressed. In the end, we stop the daemon so it can
1927 +do its cleanup tasks.
1931 + MHD_stop_daemon (daemon);
1938 +The first example is now complete.
1942 +cc hellobrowser.c -o hellobrowser -I$PATH_TO_LIBMHD_INCLUDES
1943 + -L$PATH_TO_LIBMHD_LIBS -lmicrohttpd
1945 +with the two paths set accordingly and run it.
1947 +Now open your favorite Internet browser and go to the address @code{http://localhost:8888/}, provided that 8888
1948 +is the port you chose. If everything works as expected, the browser will present the message of the
1949 +static HTML page it got from our minimal server.
1952 +To keep this first example as small as possible, some drastic shortcuts were taken and are to be
1955 +Firstly, there is no distinction made between the kinds of requests a client could send. We implied
1956 +that the client sends a GET request, that means, that he actually asked for some data. Even when
1957 +it is not intended to accept POST requests, a good server should at least recognize that this
1958 +request does not constitute a legal request and answer with an error code. This can be easily
1959 +implemented by checking if the parameter @code{method} equals the string "GET" and returning a
1960 +@code{MHD_NO} if not so.
1962 +Secondly, the above practice of queuing a response upon the first call of the callback function
1963 +brings with it some limitations. This is because the content of the message body will not be
1964 +received if a response is queued in the first iteration. Furthermore, the connection will be closed
1965 +right after the response has been transferred then. This is typically not what you want as it
1966 +disables HTTP pipelining. The correct approach is to simply not queue a message on the first
1967 +callback unless there is an error. The @code{void**} argument to the callback provides a location
1968 +for storing information about the history of the connection; for the first call, the pointer
1969 +will point to NULL. A simplistic way to differenciate the first call from others is to check
1970 +if the pointer is NULL and set it to a non-NULL value during the first call.
1972 +Both of these issues you will find addressed in the official @code{minimal_example.c} residing in
1973 +the @code{src/examples} directory of the @emph{MHD} package. The source code of this
1974 +program should look very familiar to you by now and easy to understand.
1976 +For our example, the @code{must_copy} and @code{must_free} parameter at the response construction
1977 +function could be set to @code{MHD_NO}. In the usual case, responses cannot be sent immediately
1978 +after being queued. For example, there might be other data on the system that needs to be sent with
1979 +a higher priority. Nevertheless, the queue function will return successfully---raising the problem
1980 +that the data we have pointed to may be invalid by the time it is about being sent. This is not an
1981 +issue here because we can expect the @code{page} string, which is a constant @emph{string literal}
1982 +here, to be static. That means it will be present and unchanged for as long as the program runs.
1983 +For dynamic data, one could choose to either have @emph{MHD} free the memory @code{page} points
1984 +to itself when it is not longer needed or, alternatively, have the library to make and manage
1985 +its own copy of it.
1990 +While the server is running, use a program like @code{telnet} or @code{netcat} to connect to it. Try to form a
1991 +valid HTTP 1.1 request yourself like
1993 +GET /dontcare HTTP/1.1
1998 +and see what the server returns to you.
2002 +Also, try other requests, like POST, and see how our server does not mind and why.
2003 +How far in malforming a request can you go before the builtin functionality of @emph{MHD} intervenes
2004 +and an altered response is sent? Make sure you read about the status codes in the @emph{RFC}.
2008 +Add the option @code{MHD_USE_PEDANTIC_CHECKS} to the start function of the daemon in @code{main}.
2009 +Mind the special format of the parameter list here which is described in the manual. How indulgent
2010 +is the server now to your input?
2014 +Let the main function take a string as the first command line argument and pass @code{argv[1]} to
2015 +the @code{MHD_start_daemon} function as the sixth parameter. The address of this string will be
2016 +passed to the callback function via the @code{cls} variable. Decorate the text given at the command
2017 +line when the server is started with proper HTML tags and send it as the response instead of the
2018 +former static string.
2022 +@emph{Demanding:} Write a separate function returning a string containing some useful information,
2023 +for example, the time. Pass the function's address as the sixth parameter and evaluate this function
2024 +on every request anew in @code{answer_to_connection}. Remember to free the memory of the string
2025 +every time after satisfying the request.
2028 --- libmicrohttpd-0.9.24/doc/chapters.orig/introduction.inc 1970-01-01 01:00:00.000000000 +0100
2029 +++ libmicrohttpd-0.9.24/doc/chapters/introduction.inc 2013-01-03 19:12:00.176374962 +0100
2031 +This tutorial is for developers who want to learn how they can add HTTP serving
2032 +capabilities to their applications with the @emph{GNU libmicrohttpd} library,
2033 +abbreviated @emph{MHD}. The reader will learn how to
2034 +implement basic HTTP functions from simple executable
2035 +sample programs that implement various features.
2037 +The text is supposed to be a supplement to the API reference manual of
2038 +@emph{GNU libmicrohttpd} and for that reason does not explain many of the parameters.
2039 +Therefore, the reader should always consult the manual to find the exact meaning
2040 +of the functions used in the tutorial. Furthermore, the reader is
2041 +encouraged to study the relevant @emph{RFCs}, which document the HTTP standard.
2043 +@emph{GNU libmicrohttpd} is assumed to be already installed. This tutorial
2044 +is written for version @value{VERSION}. At the time being,
2045 +this tutorial has only been tested on @emph{GNU/Linux} machines even though
2046 +efforts were made not to rely on anything that would prevent the samples from being
2047 +built on similar systems.
2051 +This tutorial was originally written by Sebastian Gerhardt for MHD
2052 +0.4.0. It was slighly polished and updated to MHD 0.9.0 by Christian
2054 --- libmicrohttpd-0.9.24/doc/chapters.orig/largerpost.inc 1970-01-01 01:00:00.000000000 +0100
2055 +++ libmicrohttpd-0.9.24/doc/chapters/largerpost.inc 2013-01-03 19:12:00.176374962 +0100
2057 +The previous chapter introduced a way to upload data to the server, but the developed example program
2058 +has some shortcomings, such as not being able to handle larger chunks of data. In this chapter, we
2059 +are going to discuss a more advanced server program that allows clients to upload a file in order to
2060 +have it stored on the server's filesystem. The server shall also watch and limit the number of
2061 +clients concurrently uploading, responding with a proper busy message if necessary.
2064 +@heading Prepared answers
2065 +We choose to operate the server with the @code{SELECT_INTERNALLY} method. This makes it easier to
2066 +synchronize the global states at the cost of possible delays for other connections if the processing
2067 +of a request is too slow. One of these variables that needs to be shared for all connections is the
2068 +total number of clients that are uploading.
2071 +#define MAXCLIENTS 2
2072 +static unsigned int nr_of_uploading_clients = 0;
2076 +If there are too many clients uploading, we want the server to respond to all requests with a busy
2079 +const char* busypage =
2080 + "<html><body>This server is busy, please try again later.</body></html>";
2084 +Otherwise, the server will send a @emph{form} that informs the user of the current number of uploading clients,
2085 +and ask her to pick a file on her local filesystem which is to be uploaded.
2087 +const char* askpage = "<html><body>\n\
2088 + Upload a file, please!<br>\n\
2089 + There are %u clients uploading at the moment.<br>\n\
2090 + <form action=\"/filepost\" method=\"post\" \
2091 + enctype=\"multipart/form-data\">\n\
2092 + <input name=\"file\" type=\"file\">\n\
2093 + <input type=\"submit\" value=\" Send \"></form>\n\
2098 +If the upload has succeeded, the server will respond with a message saying so.
2100 +const char* completepage = "<html><body>The upload has been completed.</body></html>";
2104 +We want the server to report internal errors, such as memory shortage or file access problems,
2107 +const char* servererrorpage
2108 + = "<html><body>An internal server error has occured.</body></html>";
2109 +const char* fileexistspage
2110 + = "<html><body>This file already exists.</body></html>";
2114 +It would be tolerable to send all these responses undifferentiated with a @code{200 HTTP_OK}
2115 +status code but in order to improve the @code{HTTP} conformance of our server a bit, we extend the
2116 +@code{send_page} function so that it accepts individual status codes.
2120 +send_page (struct MHD_Connection *connection,
2121 + const char* page, int status_code)
2124 + struct MHD_Response *response;
2126 + response = MHD_create_response_from_buffer (strlen (page), (void*) page,
2127 + MHD_RESPMEM_MUST_COPY);
2128 + if (!response) return MHD_NO;
2130 + ret = MHD_queue_response (connection, status_code, response);
2131 + MHD_destroy_response (response);
2138 +Note how we ask @emph{MHD} to make its own copy of the message data. The reason behind this will
2139 +become clear later.
2142 +@heading Connection cycle
2143 +The decision whether the server is busy or not is made right at the beginning of the connection. To
2144 +do that at this stage is especially important for @emph{POST} requests because if no response is
2145 +queued at this point, and @code{MHD_YES} returned, @emph{MHD} will not sent any queued messages until
2146 +a postprocessor has been created and the post iterator is called at least once.
2150 +answer_to_connection (void *cls, struct MHD_Connection *connection,
2152 + const char *method, const char *version,
2153 + const char *upload_data,
2154 + size_t *upload_data_size, void **con_cls)
2156 + if (NULL == *con_cls)
2158 + struct connection_info_struct *con_info;
2160 + if (nr_of_uploading_clients >= MAXCLIENTS)
2161 + return send_page(connection, busypage, MHD_HTTP_SERVICE_UNAVAILABLE);
2165 +If the server is not busy, the @code{connection_info} structure is initialized as usual, with
2166 +the addition of a filepointer for each connection.
2169 + con_info = malloc (sizeof (struct connection_info_struct));
2170 + if (NULL == con_info) return MHD_NO;
2173 + if (0 == strcmp (method, "POST"))
2177 + else con_info->connectiontype = GET;
2179 + *con_cls = (void*) con_info;
2186 +For @emph{POST} requests, the postprocessor is created and we register a new uploading client. From
2187 +this point on, there are many possible places for errors to occur that make it necessary to interrupt
2188 +the uploading process. We need a means of having the proper response message ready at all times.
2189 +Therefore, the @code{connection_info} structure is extended to hold the most current response
2190 +message so that whenever a response is sent, the client will get the most informative message. Here,
2191 +the structure is initialized to "no error".
2193 + if (0 == strcmp (method, "POST"))
2195 + con_info->postprocessor
2196 + = MHD_create_post_processor (connection, POSTBUFFERSIZE,
2197 + iterate_post, (void*) con_info);
2199 + if (NULL == con_info->postprocessor)
2205 + nr_of_uploading_clients++;
2207 + con_info->connectiontype = POST;
2208 + con_info->answercode = MHD_HTTP_OK;
2209 + con_info->answerstring = completepage;
2211 + else con_info->connectiontype = GET;
2215 +If the connection handler is called for the second time, @emph{GET} requests will be answered with
2216 +the @emph{form}. We can keep the buffer under function scope, because we asked @emph{MHD} to make its
2217 +own copy of it for as long as it is needed.
2219 + if (0 == strcmp (method, "GET"))
2222 + char buffer[1024];
2224 + sprintf (buffer, askpage, nr_of_uploading_clients);
2225 + return send_page (connection, buffer, MHD_HTTP_OK);
2231 +The rest of the @code{answer_to_connection} function is very similar to the @code{simplepost.c}
2232 +example, except the more flexible content of the responses. The @emph{POST} data is processed until
2233 +there is none left and the execution falls through to return an error page if the connection
2234 +constituted no expected request method.
2236 + if (0 == strcmp (method, "POST"))
2238 + struct connection_info_struct *con_info = *con_cls;
2240 + if (0 != *upload_data_size)
2242 + MHD_post_process (con_info->postprocessor,
2243 + upload_data, *upload_data_size);
2244 + *upload_data_size = 0;
2249 + return send_page (connection, con_info->answerstring,
2250 + con_info->answercode);
2253 + return send_page(connection, errorpage, MHD_HTTP_BAD_REQUEST);
2259 +@heading Storing to data
2260 +Unlike the @code{simplepost.c} example, here it is to be expected that post iterator will be called
2261 +several times now. This means that for any given connection (there might be several concurrent of them)
2262 +the posted data has to be written to the correct file. That is why we store a file handle in every
2263 +@code{connection_info}, so that the it is preserved between successive iterations.
2266 +iterate_post (void *coninfo_cls, enum MHD_ValueKind kind,
2268 + const char *filename, const char *content_type,
2269 + const char *transfer_encoding, const char *data,
2270 + uint64_t off, size_t size)
2272 + struct connection_info_struct *con_info = coninfo_cls;
2276 +Because the following actions depend heavily on correct file processing, which might be error prone,
2277 +we default to reporting internal errors in case anything will go wrong.
2280 +con_info->answerstring = servererrorpage;
2281 +con_info->answercode = MHD_HTTP_INTERNAL_SERVER_ERROR;
2285 +In the "askpage" @emph{form}, we told the client to label its post data with the "file" key. Anything else
2289 + if (0 != strcmp (key, "file")) return MHD_NO;
2293 +If the iterator is called for the first time, no file will have been opened yet. The @code{filename}
2294 +string contains the name of the file (without any paths) the user selected on his system. We want to
2295 +take this as the name the file will be stored on the server and make sure no file of that name exists
2296 +(or is being uploaded) before we create one (note that the code below technically contains a
2297 +race between the two "fopen" calls, but we will overlook this for portability sake).
2299 + if (!con_info->fp)
2301 + if (NULL != (fp = fopen (filename, "rb")) )
2304 + con_info->answerstring = fileexistspage;
2305 + con_info->answercode = MHD_HTTP_FORBIDDEN;
2309 + con_info->fp = fopen (filename, "ab");
2310 + if (!con_info->fp) return MHD_NO;
2316 +Occasionally, the iterator function will be called even when there are 0 new bytes to process. The
2317 +server only needs to write data to the file if there is some.
2321 + if (!fwrite (data, size, sizeof(char), con_info->fp))
2327 +If this point has been reached, everything worked well for this iteration and the response can
2328 +be set to success again. If the upload has finished, this iterator function will not be called again.
2330 + con_info->answerstring = completepage;
2331 + con_info->answercode = MHD_HTTP_OK;
2339 +The new client was registered when the postprocessor was created. Likewise, we unregister the client
2340 +on destroying the postprocessor when the request is completed.
2342 +void request_completed (void *cls, struct MHD_Connection *connection,
2344 + enum MHD_RequestTerminationCode toe)
2346 + struct connection_info_struct *con_info = *con_cls;
2348 + if (NULL == con_info) return;
2350 + if (con_info->connectiontype == POST)
2352 + if (NULL != con_info->postprocessor)
2354 + MHD_destroy_post_processor (con_info->postprocessor);
2355 + nr_of_uploading_clients--;
2358 + if (con_info->fp) fclose (con_info->fp);
2368 +This is essentially the whole example @code{largepost.c}.
2372 +Now that the clients are able to create files on the server, security aspects are becoming even more
2373 +important than before. Aside from proper client authentication, the server should always make sure
2374 +explicitly that no files will be created outside of a dedicated upload directory. In particular,
2375 +filenames must be checked to not contain strings like "../".
2376 --- libmicrohttpd-0.9.24/doc/chapters.orig/processingpost.inc 1970-01-01 01:00:00.000000000 +0100
2377 +++ libmicrohttpd-0.9.24/doc/chapters/processingpost.inc 2013-01-03 19:12:00.176374962 +0100
2379 +The previous chapters already have demonstrated a variety of possibilities to send information
2380 +to the HTTP server, but it is not recommended that the @emph{GET} method is used to alter the way
2381 +the server operates. To induce changes on the server, the @emph{POST} method is preferred over
2382 +and is much more powerful than @emph{GET} and will be introduced in this chapter.
2384 +We are going to write an application that asks for the visitor's name and, after the user has posted it,
2385 +composes an individual response text. Even though it was not mandatory to use the @emph{POST} method here,
2386 +as there is no permanent change caused by the POST, it is an illustrative example on how to share data
2387 +between different functions for the same connection. Furthermore, the reader should be able to extend
2390 +@heading GET request
2391 +When the first @emph{GET} request arrives, the server shall respond with a HTML page containing an
2392 +edit field for the name.
2395 +const char* askpage = "<html><body>\
2396 + What's your name, Sir?<br>\
2397 + <form action=\"/namepost\" method=\"post\">\
2398 + <input name=\"name\" type=\"text\"\
2399 + <input type=\"submit\" value=\" Send \"></form>\
2404 +The @code{action} entry is the @emph{URI} to be called by the browser when posting, and the
2405 +@code{name} will be used later to be sure it is the editbox's content that has been posted.
2407 +We also prepare the answer page, where the name is to be filled in later, and an error page
2408 +as the response for anything but proper @emph{GET} and @emph{POST} requests:
2411 +const char* greatingpage="<html><body><h1>Welcome, %s!</center></h1></body></html>";
2413 +const char* errorpage="<html><body>This doesn't seem to be right.</body></html>";
2417 +Whenever we need to send a page, we use an extra function
2418 +@code{int send_page(struct MHD_Connection *connection, const char* page)}
2419 +for this, which does not contain anything new and whose implementation is therefore
2420 +not discussed further in the tutorial.
2423 +@heading POST request
2424 +Posted data can be of arbitrary and considerable size; for example, if a user uploads a big
2425 +image to the server. Similar to the case of the header fields, there may also be different streams
2426 +of posted data, such as one containing the text of an editbox and another the state of a button.
2427 +Likewise, we will have to register an iterator function that is going to be called maybe several times
2428 +not only if there are different POSTs but also if one POST has only been received partly yet and
2429 +needs processing before another chunk can be received.
2431 +Such an iterator function is called by a @emph{postprocessor}, which must be created upon arriving
2432 +of the post request. We want the iterator function to read the first post data which is tagged
2433 +@code{name} and to create an individual greeting string based on the template and the name.
2434 +But in order to pass this string to other functions and still be able to differentiate different
2435 +connections, we must first define a structure to share the information, holding the most import entries.
2438 +struct connection_info_struct
2440 + int connectiontype;
2441 + char *answerstring;
2442 + struct MHD_PostProcessor *postprocessor;
2447 +With these information available to the iterator function, it is able to fulfill its task.
2448 +Once it has composed the greeting string, it returns @code{MHD_NO} to inform the post processor
2449 +that it does not need to be called again. Note that this function does not handle processing
2450 +of data for the same @code{key}. If we were to expect that the name will be posted in several
2451 +chunks, we had to expand the namestring dynamically as additional parts of it with the same @code{key}
2452 +came in. But in this example, the name is assumed to fit entirely inside one single packet.
2456 +iterate_post (void *coninfo_cls, enum MHD_ValueKind kind, const char *key,
2457 + const char *filename, const char *content_type,
2458 + const char *transfer_encoding, const char *data,
2459 + uint64_t off, size_t size)
2461 + struct connection_info_struct *con_info = coninfo_cls;
2463 + if (0 == strcmp (key, "name"))
2465 + if ((size > 0) && (size <= MAXNAMESIZE))
2467 + char *answerstring;
2468 + answerstring = malloc (MAXANSWERSIZE);
2469 + if (!answerstring) return MHD_NO;
2471 + snprintf (answerstring, MAXANSWERSIZE, greatingpage, data);
2472 + con_info->answerstring = answerstring;
2474 + else con_info->answerstring = NULL;
2484 +Once a connection has been established, it can be terminated for many reasons. As these
2485 +reasons include unexpected events, we have to register another function that cleans up any resources
2486 +that might have been allocated for that connection by us, namely the post processor and the greetings
2487 +string. This cleanup function must take into account that it will also be called for finished
2488 +requests other than @emph{POST} requests.
2491 +void request_completed (void *cls, struct MHD_Connection *connection,
2493 + enum MHD_RequestTerminationCode toe)
2495 + struct connection_info_struct *con_info = *con_cls;
2497 + if (NULL == con_info) return;
2498 + if (con_info->connectiontype == POST)
2500 + MHD_destroy_post_processor (con_info->postprocessor);
2501 + if (con_info->answerstring) free (con_info->answerstring);
2510 +@emph{GNU libmicrohttpd} is informed that it shall call the above function when the daemon is started
2511 +in the main function.
2515 +daemon = MHD_start_daemon (MHD_USE_SELECT_INTERNALLY, PORT, NULL, NULL,
2516 + &answer_to_connection, NULL,
2517 + MHD_OPTION_NOTIFY_COMPLETED, &request_completed, NULL,
2523 +@heading Request handling
2524 +With all other functions prepared, we can now discuss the actual request handling.
2526 +On the first iteration for a new request, we start by allocating a new instance of a
2527 +@code{struct connection_info_struct} structure, which will store all necessary information for later
2528 +iterations and other functions.
2532 +answer_to_connection (void *cls, struct MHD_Connection *connection,
2534 + const char *method, const char *version,
2535 + const char *upload_data,
2536 + size_t *upload_data_size, void **con_cls)
2538 + if(NULL == *con_cls)
2540 + struct connection_info_struct *con_info;
2542 + con_info = malloc (sizeof (struct connection_info_struct));
2543 + if (NULL == con_info) return MHD_NO;
2544 + con_info->answerstring = NULL;
2548 +If the new request is a @emph{POST}, the postprocessor must be created now. In addition, the type
2549 +of the request is stored for convenience.
2551 + if (0 == strcmp (method, "POST"))
2553 + con_info->postprocessor
2554 + = MHD_create_post_processor (connection, POSTBUFFERSIZE,
2555 + iterate_post, (void*) con_info);
2557 + if (NULL == con_info->postprocessor)
2562 + con_info->connectiontype = POST;
2564 + else con_info->connectiontype = GET;
2568 +The address of our structure will both serve as the indicator for successive iterations and to remember
2569 +the particular details about the connection.
2571 + *con_cls = (void*) con_info;
2577 +The rest of the function will not be executed on the first iteration. A @emph{GET} request is easily
2578 +satisfied by sending the question form.
2580 + if (0 == strcmp (method, "GET"))
2582 + return send_page (connection, askpage);
2587 +In case of @emph{POST}, we invoke the post processor for as long as data keeps incoming, setting
2588 +@code{*upload_data_size} to zero in order to indicate that we have processed---or at least have
2589 +considered---all of it.
2591 + if (0 == strcmp (method, "POST"))
2593 + struct connection_info_struct *con_info = *con_cls;
2595 + if (*upload_data_size != 0)
2597 + MHD_post_process (con_info->postprocessor, upload_data,
2598 + *upload_data_size);
2599 + *upload_data_size = 0;
2603 + else if (NULL != con_info->answerstring)
2604 + return send_page (connection, con_info->answerstring);
2609 +Finally, if they are neither @emph{GET} nor @emph{POST} requests, the error page is returned.
2611 + return send_page(connection, errorpage);
2616 +These were the important parts of the program @code{simplepost.c}.
2617 --- libmicrohttpd-0.9.24/doc/chapters.orig/responseheaders.inc 1970-01-01 01:00:00.000000000 +0100
2618 +++ libmicrohttpd-0.9.24/doc/chapters/responseheaders.inc 2013-01-03 19:12:00.176374962 +0100
2620 +Now that we are able to inspect the incoming request in great detail,
2621 +this chapter discusses the means to enrich the outgoing responses likewise.
2623 +As you have learned in the @emph{Hello, Browser} chapter, some obligatory
2624 +header fields are added and set automatically for simple responses by the library
2625 +itself but if more advanced features are desired, additional fields have to be created.
2626 +One of the possible fields is the content type field and an example will be developed around it.
2627 +This will lead to an application capable of correctly serving different types of files.
2630 +When we responded with HTML page packed in the static string previously, the client had no choice
2631 +but guessing about how to handle the response, because the server had not told him.
2632 +What if we had sent a picture or a sound file? Would the message have been understood
2633 +or merely been displayed as an endless stream of random characters in the browser?
2634 +This is what the mime content types are for. The header of the response is extended
2635 +by certain information about how the data is to be interpreted.
2637 +To introduce the concept, a picture of the format @emph{PNG} will be sent to the client
2638 +and labeled accordingly with @code{image/png}.
2639 +Once again, we can base the new example on the @code{hellobrowser} program.
2642 +#define FILENAME "picture.png"
2643 +#define MIMETYPE "image/png"
2646 +answer_to_connection (void *cls, struct MHD_Connection *connection,
2648 + const char *method, const char *version,
2649 + const char *upload_data,
2650 + size_t *upload_data_size, void **con_cls)
2652 + unsigned char *buffer = NULL;
2653 + struct MHD_Response *response;
2657 +We want the program to open the file for reading and determine its size:
2663 + if (0 != strcmp (method, "GET"))
2665 + if ( (-1 == (fd = open (FILENAME, O_RDONLY))) ||
2666 + (0 != fstat (fd, &sbuf)) )
2668 + /* error accessing file */
2669 + /* ... (see below) */
2671 + /* ... (see below) */
2675 +When dealing with files, there is a lot that could go wrong on the
2676 +server side and if so, the client should be informed with @code{MHD_HTTP_INTERNAL_SERVER_ERROR}.
2679 + /* error accessing file */
2680 + if (fd != -1) close (fd);
2681 + const char *errorstr =
2682 + "<html><body>An internal server error has occured!\
2685 + MHD_create_response_from_buffer (strlen (errorstr),
2686 + (void *) errorstr,
2687 + MHD_RESPMEM_PERSISTENT);
2691 + MHD_queue_response (connection, MHD_HTTP_INTERNAL_SERVER_ERROR,
2693 + MHD_destroy_response (response);
2701 + const char *errorstr = "<html><body>An internal server error has occured!\
2704 + if (buffer) free(buffer);
2706 + response = MHD_create_response_from_buffer (strlen(errorstr), (void*) errorstr,
2707 + MHD_RESPMEM_PERSISTENT);
2711 + ret = MHD_queue_response (connection,
2712 + MHD_HTTP_INTERNAL_SERVER_ERROR,
2714 + MHD_destroy_response (response);
2718 + else return MHD_NO;
2723 +Note that we nevertheless have to create a response object even for sending a simple error code.
2724 +Otherwise, the connection would just be closed without comment, leaving the client curious about
2727 +But in the case of success a response will be constructed directly from the file descriptor:
2730 + /* error accessing file */
2731 + /* ... (see above) */
2735 + MHD_create_response_from_fd_at_offset (sbuf.st_size, fd, 0);
2736 + MHD_add_response_header (response, "Content-Type", MIMETYPE);
2737 + ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
2738 + MHD_destroy_response (response);
2742 +Note that the response object will take care of closing the file desciptor for us.
2744 +Up to this point, there was little new. The actual novelty is that we enhance the header with the
2745 +meta data about the content. Aware of the field's name we want to add, it is as easy as that:
2747 +MHD_add_response_header(response, "Content-Type", MIMETYPE);
2750 +We do not have to append a colon expected by the protocol behind the first
2751 +field---@emph{GNU libhttpdmicro} will take care of this.
2753 +The function finishes with the well-known lines
2755 + ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
2756 + MHD_destroy_response (response);
2762 +The complete program @code{responseheaders.c} is in the @code{examples} section as usual.
2763 +Find a @emph{PNG} file you like and save it to the directory the example is run from under the name
2764 +@code{picture.png}. You should find the image displayed on your browser if everything worked well.
2767 +The include file of the @emph{MHD} library comes with the header types mentioned in @emph{RFC 2616}
2768 +already defined as macros. Thus, we could have written @code{MHD_HTTP_HEADER_CONTENT_TYPE} instead
2769 +of @code{"Content-Type"} as well. However, one is not limited to these standard headers and could
2770 +add custom response headers without violating the protocol. Whether, and how, the client would react
2771 +to these custom header is up to the receiver. Likewise, the client is allowed to send custom request
2772 +headers to the server as well, opening up yet more possibilities how client and server could
2773 +communicate with each other.
2775 +The method of creating the response from a file on disk only works for static content.
2776 +Serving dynamically created responses will be a topic of a future chapter.
2782 +Remember that the original program was written under a few assumptions---a static response
2783 +using a local file being one of them. In order to simulate a very large or hard to reach file that cannot be provided
2784 +instantly, postpone the queuing in the callback with the @code{sleep} function for 30 seconds
2785 +@emph{if} the file @code{/big.png} is requested (but deliver the same as above). A request for
2786 +@code{/picture.png} should provide just the same but without any artificial delays.
2788 +Now start two instances of your browser (or even use two machines) and see how the second client
2789 +is put on hold while the first waits for his request on the slow file to be fulfilled.
2791 +Finally, change the sourcecode to use @code{MHD_USE_THREAD_PER_CONNECTION} when the daemon is
2792 +started and try again.
2796 +Did you succeed in implementing the clock exercise yet? This time, let the server save the
2797 +program's start time @code{t} and implement a response simulating a countdown that reaches 0 at
2798 +@code{t+60}. Returning a message saying on which point the countdown is, the response should
2799 +ultimately be to reply "Done" if the program has been running long enough,
2801 +An unofficial, but widely understood, response header line is @code{Refresh: DELAY; url=URL} with
2802 +the uppercase words substituted to tell the client it should request the given resource after
2803 +the given delay again. Improve your program in that the browser (any modern browser should work)
2804 +automatically reconnects and asks for the status again every 5 seconds or so. The URL would have
2805 +to be composed so that it begins with "http://", followed by the @emph{URI} the server is reachable
2806 +from the client's point of view.
2808 +Maybe you want also to visualize the countdown as a status bar by creating a
2809 +@code{<table>} consisting of one row and @code{n} columns whose fields contain small images of either
2810 +a red or a green light.
2813 --- libmicrohttpd-0.9.24/doc/chapters.orig/sessions.inc 1970-01-01 01:00:00.000000000 +0100
2814 +++ libmicrohttpd-0.9.24/doc/chapters/sessions.inc 2013-01-03 19:12:00.176374962 +0100
2816 +This chapter discusses how one should manage sessions, that is, share state between multiple
2817 +HTTP requests from the same user. We use a simple example where the user submits multiple
2818 +forms and the server is supposed to accumulate state from all of these forms. Naturally, as
2819 +this is a network protocol, our session mechanism must support having many users with
2820 +many concurrent sessions at the same time.
2822 +In order to track users, we use a simple session cookie. A session cookie expires when the
2823 +user closes the browser. Changing from session cookies to persistent cookies only requires
2824 +adding an expiration time to the cookie. The server creates a fresh session cookie whenever
2825 +a request without a cookie is received, or if the supplied session cookie is not known to
2828 +@heading Looking up the cookie
2830 +Since MHD parses the HTTP cookie header for us, looking up an existing cookie
2831 +is straightforward:
2837 +Here, FIXME is the name we chose for our session cookie.
2840 +@heading Setting the cookie header
2842 +MHD requires the user to provide the full cookie format string in order to set
2843 +cookies. In order to generate a unique cookie, our example creates a random
2844 +64-character text string to be used as the value of the cookie:
2850 +Given this cookie value, we can then set the cookie header in our HTTP response
2858 +@heading Remark: Session expiration
2860 +It is of course possible that clients stop their interaction with the
2861 +server at any time. In order to avoid using too much storage, the
2862 +server must thus discard inactive sessions at some point. Our example
2863 +implements this by discarding inactive sessions after a certain amount
2864 +of time. Alternatively, the implementation may limit the total number
2865 +of active sessions. Which bounds are used for idle sessions or the
2866 +total number of sessions obviously depends largely on the type of
2867 +the application and available server resources.
2869 +@heading Example code
2871 +A sample application implementing a website with multiple
2872 +forms (which are dynamically created using values from previous
2873 +POST requests from the same session) is available
2874 +as the example @code{sessions.c}.
2876 +Note that the example uses a simple, $O(n)$ linked list traversal to
2877 +look up sessions and to expire old sessions. Using a hash table and a
2878 +heap would be more appropriate if a large number of concurrent
2879 +sessions is expected.
2883 +Naturally, it is quite conceivable to store session data in a database
2884 +instead of in memory. Still, having mechanisms to expire data
2885 +associated with long-time idle sessions (where the business process
2886 +has still not finished) is likely a good idea.
2887 --- libmicrohttpd-0.9.24/doc/chapters.orig/tlsauthentication.inc 1970-01-01 01:00:00.000000000 +0100
2888 +++ libmicrohttpd-0.9.24/doc/chapters/tlsauthentication.inc 2013-01-03 19:12:00.176374962 +0100
2890 +We left the basic authentication chapter with the unsatisfactory conclusion that
2891 +any traffic, including the credentials, could be intercepted by anyone between
2892 +the browser client and the server. Protecting the data while it is sent over
2893 +unsecured lines will be the goal of this chapter.
2895 +Since version 0.4, the @emph{MHD} library includes support for encrypting the
2896 +traffic by employing SSL/TSL. If @emph{GNU libmicrohttpd} has been configured to
2897 +support these, encryption and decryption can be applied transparently on the
2898 +data being sent, with only minimal changes to the actual source code of the example.
2901 +@heading Preparation
2903 +First, a private key for the server will be generated. With this key, the server
2904 +will later be able to authenticate itself to the client---preventing anyone else
2905 +from stealing the password by faking its identity. The @emph{OpenSSL} suite, which
2906 +is available on many operating systems, can generate such a key. For the scope of
2907 +this tutorial, we will be content with a 1024 bit key:
2909 +> openssl genrsa -out server.key 1024
2913 +In addition to the key, a certificate describing the server in human readable tokens
2914 +is also needed. This certificate will be attested with our aforementioned key. In this way,
2915 +we obtain a self-signed certificate, valid for one year.
2918 +> openssl req -days 365 -out server.pem -new -x509 -key server.key
2922 +To avoid unnecessary error messages in the browser, the certificate needs to
2923 +have a name that matches the @emph{URI}, for example, "localhost" or the domain.
2924 +If you plan to have a publicly reachable server, you will need to ask a trusted third party,
2925 +called @emph{Certificate Authority}, or @emph{CA}, to attest the certificate for you. This way,
2926 +any visitor can make sure the server's identity is real.
2928 +Whether the server's certificate is signed by us or a third party, once it has been accepted
2929 +by the client, both sides will be communicating over encrypted channels. From this point on,
2930 +it is the client's turn to authenticate itself. But this has already been implemented in the basic
2931 +authentication scheme.
2934 +@heading Changing the source code
2936 +We merely have to extend the server program so that it loads the two files into memory,
2942 + struct MHD_Daemon *daemon;
2946 + key_pem = load_file (SERVERKEYFILE);
2947 + cert_pem = load_file (SERVERCERTFILE);
2949 + if ((key_pem == NULL) || (cert_pem == NULL))
2951 + printf ("The key/certificate files could not be read.\n");
2957 +and then we point the @emph{MHD} daemon to it upon initalization.
2960 + daemon = MHD_start_daemon (MHD_USE_SELECT_INTERNALLY | MHD_USE_SSL,
2962 + &answer_to_connection, NULL,
2963 + MHD_OPTION_HTTPS_MEM_KEY, key_pem,
2964 + MHD_OPTION_HTTPS_MEM_CERT, cert_pem,
2967 + if (NULL == daemon)
2969 + printf ("%s\n", cert_pem);
2980 +The rest consists of little new besides some additional memory cleanups.
2985 + MHD_stop_daemon (daemon);
2995 +The rather unexciting file loader can be found in the complete example @code{tlsauthentication.c}.
3001 +While the standard @emph{HTTP} port is 80, it is 443 for @emph{HTTPS}. The common internet browsers assume
3002 +standard @emph{HTTP} if they are asked to access other ports than these. Therefore, you will have to type
3003 +@code{https://localhost:8888} explicitly when you test the example, or the browser will not know how to
3004 +handle the answer properly.
3007 +The remaining weak point is the question how the server will be trusted initially. Either a @emph{CA} signs the
3008 +certificate or the client obtains the key over secure means. Anyway, the clients have to be aware (or configured)
3009 +that they should not accept certificates of unknown origin.
3012 +The introduced method of certificates makes it mandatory to set an expiration date---making it less feasible to
3013 +hardcode certificates in embedded devices.
3016 +The cryptographic facilities consume memory space and computing time. For this reason, websites usually consists
3017 +both of uncritically @emph{HTTP} parts and secured @emph{HTTPS}.
3022 +@heading Client authentication
3024 +You can also use MHD to authenticate the client via SSL/TLS certificates
3025 +(as an alternative to using the password-based Basic or Digest authentication).
3026 +To do this, you will need to link your application against @emph{gnutls}.
3027 +Next, when you start the MHD daemon, you must specify the root CA that you're
3030 + daemon = MHD_start_daemon (MHD_USE_SELECT_INTERNALLY | MHD_USE_SSL,
3032 + &answer_to_connection, NULL,
3033 + MHD_OPTION_HTTPS_MEM_KEY, key_pem,
3034 + MHD_OPTION_HTTPS_MEM_CERT, cert_pem,
3035 + MHD_OPTION_HTTPS_MEM_TRUST, root_ca_pem,
3039 +With this, you can then obtain client certificates for each session.
3040 +In order to obtain the identity of the client, you first need to
3041 +obtain the raw GnuTLS session handle from @emph{MHD} using
3042 +@code{MHD_get_connection_info}.
3045 +#include <gnutls/gnutls.h>
3046 +#include <gnutls/x509.h>
3048 +gnutls_session_t tls_session;
3049 +union MHD_ConnectionInfo *ci;
3051 +ci = MHD_get_connection_info (connection,
3052 + MHD_CONNECTION_INFO_GNUTLS_SESSION);
3053 +tls_session = ci->tls_session;
3056 +You can then extract the client certificate:
3060 + * Get the client's certificate
3062 + * @param tls_session the TLS session
3063 + * @return NULL if no valid client certificate could be found, a pointer
3064 + * to the certificate if found
3066 +static gnutls_x509_crt_t
3067 +get_client_certificate (gnutls_session_t tls_session)
3069 + unsigned int listsize;
3070 + const gnutls_datum_t * pcert;
3071 + gnutls_certificate_status_t client_cert_status;
3072 + gnutls_x509_crt_t client_cert;
3074 + if (tls_session == NULL)
3076 + if (gnutls_certificate_verify_peers2(tls_session,
3077 + &client_cert_status))
3079 + pcert = gnutls_certificate_get_peers(tls_session,
3081 + if ( (pcert == NULL) ||
3085 + "Failed to retrieve client certificate chain\n");
3088 + if (gnutls_x509_crt_init(&client_cert))
3091 + "Failed to initialize client certificate\n");
3094 + /* Note that by passing values between 0 and listsize here, you
3095 + can get access to the CA's certs */
3096 + if (gnutls_x509_crt_import(client_cert,
3098 + GNUTLS_X509_FMT_DER))
3101 + "Failed to import client certificate\n");
3102 + gnutls_x509_crt_deinit(client_cert);
3105 + return client_cert;
3109 +Using the client certificate, you can then get the client's distinguished name
3110 +and alternative names:
3114 + * Get the distinguished name from the client's certificate
3116 + * @param client_cert the client certificate
3117 + * @return NULL if no dn or certificate could be found, a pointer
3118 + * to the dn if found
3121 +cert_auth_get_dn(gnutls_x509_crt_c client_cert)
3127 + gnutls_x509_crt_get_dn(client_cert, NULL, &lbuf);
3128 + buf = malloc(lbuf);
3132 + "Failed to allocate memory for certificate dn\n");
3135 + gnutls_x509_crt_get_dn(client_cert, buf, &lbuf);
3141 + * Get the alternative name of specified type from the client's certificate
3143 + * @param client_cert the client certificate
3144 + * @param nametype The requested name type
3145 + * @param index The position of the alternative name if multiple names are
3146 + * matching the requested type, 0 for the first matching name
3147 + * @return NULL if no matching alternative name could be found, a pointer
3148 + * to the alternative name if found
3151 +MHD_cert_auth_get_alt_name(gnutls_x509_crt_t client_cert,
3153 + unsigned int index)
3158 + unsigned int subseq;
3159 + unsigned int type;
3163 + for (seq=0;;seq++)
3166 + result = gnutls_x509_crt_get_subject_alt_name2(client_cert, seq, NULL, &lbuf,
3168 + if (result == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
3170 + if (nametype != (int) type)
3172 + if (subseq == index)
3176 + buf = malloc(lbuf);
3180 + "Failed to allocate memory for certificate alt name\n");
3183 + result = gnutls_x509_crt_get_subject_alt_name2(client_cert,
3188 + if (result != nametype)
3191 + "Unexpected return value from gnutls: %d\n",
3200 +Finally, you should release the memory associated with the client
3204 +gnutls_x509_crt_deinit (client_cert);