[fex.git] / doc / concept

F*EX (Frams' Fast File EXchange) is a service to send big (large, huge, giant,
...) files from a user A to a user B, anywhere on the internet.

The sender uploads the file to the F*EX-server and the recipient automatically
gets a notification email with a download-URL.

Main features of F*EX

  * file transfer of virtually unlimited file size
  * recipient and sender only need an email program and a web browser - of any
    kind, they do not have to install any software
  * RESEND and REGET for resuming after link failures at last sent byte
  * auto-notification of recipient
  * auto-deletion after download
  * auto-deletion after expiration date (default: 5 days)
  * full-users can create one time upload URLs for foreign users
  * full-users can create subusers, who can send only to this full-user
  * full-users can create groups, an analogy to mailing lists, but for files
  * self registration possible for internal and external users
  * maintenance-free: no admin interaction necessary 
  * sending to multiple recipients needs storage on the server only once
  * quotas for sending and receiving
  * F*EX is a HTTP web-service and needs no firewall-tunnels
  * support for (personal or public) streams, too (SEX : Stream EXchange)
  * for real UNIX users, there are the shell programs fexsend and fexget to
    avoid annoying web browser usage and for full scripting support
  * adminstration by CLI or Web
  * about 10 times faster than apache
  * authentification modules for LDAP, RADIUS, POP, mailman
  * server based user address books
  * (reverse) proxy support
  * "public upload" similar to "anonymous ftp" possible
  * "anonymous upload" without registration for enabled IP addresses possible
  * localization for many languages
  * authentification by local user database, RADIUS, LDAP, mailman or POP
  * user and admin can throttle bandwith usage
  * admin can restrict access based on email or IP addresses
  * server available for UNIX and Windows hosts
  * protocol and source-code free available

The end user normally uses F*EX with his web browser and the URLs
http://YOURFEXSERVER/fup (file upload) and http://YOURFEXSERVER/fop (file
download). 


F*EX is not an anonymous service (exception: "public upload" and
"anonymous upload", see later).
The admin must register the user with his email address and auth-ID
string (low security password). This task can be done either with the CLI
program "fac" (F*EX admin control) or http://YOURFEXSERVER/fac

Alternativly the users can register theirselves with http://YOURFEXSERVER/fur
(F*EX user registration), if the admin allows them to do so. This is done by
setting the variables @local_domains and @local_hosts in FEXHOME/lib/fex.ph
Example: 

        @local_hosts = qw(127.0.0.1 10.10.100.0-10.10.255.255);
        @local_domains = qw(rus.uni-stuttgart.de flupp.org);

You can also use wildcard "*" in a domain, for example:

        @local_domains = qw(uni-stuttgart.de *.uni-stuttgart.de);

Then all subdomains are allowed.


In addition the administrator can allow external users to fex (only) to
internal users. The F*EX functioning scheme is close related to email
where any external user can send email to an internal user. This is also
possible with F*EX. These users are then called "restricted users". The
administrator has to define via configuration variable @local_rdomains
the local recipient domains. For example:

@local_rdomains = qw(YOURDOMAIN *.YOURDOMAIN OTHERDOMAIN);


F*EX full users can create one time upload URLs with
http://YOURFEXSERVER/fuc 

With such a URL a foreign user can send this F*EX full user a single file.

F*EX full users can theirselves register "subusers" with
http://YOURFEXSERVER/fuc 

Subusers can only fex to their full-user, not to any others, and they
cannot create other subusers.


F*EX full users also can create groups, an analogy to mailing lists, but
for files: every member of a group can send files to the group address.


The administrator can set with fac the CAPTIVE flag for a full user. Then
he cannot change anymore his default settings (KEEP, AUTODELETE, etc)


The F*EX user is the same as the "sender" in the fup CGI and the "from"
parameter in the F*EX URL. 

The (confusing) naming scheme is historically based :-)


The recipient (normally) does not need any registration. He authenticates
himself with his unique download-URL which he gets in the notification
email.


You do not need to build F*EX URLs manually, they are generated by the
F*EX programs. 


A F*EX session is based on unique URL parameters or POST variables (FROM,
TO, ID, etc). For security reasons the URL parameters FROM and ID become a
MD5-hashed access key link (AKEY for regular users, SKEY for subusers,
GKEY for groupusers), generated by the CGIs, to prevent that a third
person could easily read these parameters from the user webbrowser URL
address field. AKEY and SKEY are used as optional cookies, too, for
extending the session life.

A SKEY is made of md5_hex("$mainuser:$subuser:$subuserid")
A GKEY is made of md5_hex("$mainuser:$groupname:$groupuser:$groupuserid")

Note: the AKEY, SKEY and GKEY always can be stolen by a network sniffer!
If you need true security, then you have to use https instead of http! 

After download the file will be deleted after a grace time of 1 minute.
This grace time allows a recipient to get the file again if he had
problems in saving it. 

With the fexsend client the sender can change this behavior:

option -D means "delay autodelete": do not delete the the file directly
after download, but with the nightly fex_cleanup cronjob. More downloads
are possible only from the same client (identified by cookie or ip
address). 

option -K means "keep file": do not delete the file after download, but
only after expiration date (normally 5 days). More downloads are possible
only from the same client (identified by cookie or ip address).


If you fex a file to yourself (sender = recipient), then the resulting
download link is valid for any client and can be downloaded everywhere
and more than once (until expiration date).

If you want "delay autodelete" to be the default behaviour for all users
and each transfer then set
        $autodelete = 'DELAY'; # or 'NO' for no autodelete
in FEXHOME/lib/fex.ph

In addition, you can add to the "Recipient(s)" field of the fup CGI:
":autodelete=delay" or ":autodelete=no" or ":keep=x" (where x is the number
of days). Example:
Recipient(s): framstag@rus.uni-stuttgart.de:keep=10

These options are also possible in the server address book (see CGI fuc).

If you need more security, then set in fex.ph:
$fop_auth = 'yes';
$force_https = 'yes';

With $fop_auth upload is restricted to registered users and download
requires (HTTP) authorization. The credentials are the F*EX user email
and auth-ID.
See extra documentation SSL for using https.

If you want to have encrypted emails, then you need a GPG public key for 
the user fex. Create it with "gpg --gen-key" (use fex@YOURFEXSERVER as the
user or the $bcc address from fex.ph if you have set it, see below). Next,
the user has to upload his public key via webinterface "user config &
operation control" and "Manage e-mail encryption".

"Public upload" is a feature similar to anonymous ftp: the sender does not
to be registered, but may send only to predefined recipients via
http://YOURFEXSERVER/pup

The administrator has to define via configuration variable
@public_recipients the email addresses for which anyone can upload files
without registration (auth-ID is not necessary). For example:

@public_recipients = qw(fexmaster@YOURDOMAIN bunny@OTHERDOMAIN);

With "anonymous upload" one can use F*EX without registration or
authentication. The administrator has to define via configuration variable
@anonymous_upload for which IP addresses this feature is available.

The administrator can globally forbid certain recipient address via fex.ph
configuration (example):

@forbidden_recipients = qw(nobody@* *@microsoft.com);

The administrator can also forbid a user to fex to any recipient address,
but the allowed ones with: fac -r USER


By standard installation the base directory FEXHOME is the same as the
login HOME of user fex, but you can move it if you want. FEXHOME is
determined by the full path of fexsrv as configured in
/etc/xinetd.d/fex . Change this when you move FEXHOME!

You can also add (name based) virtual hosts with fac.

Do not give write permission to any other user to any file in FEXHOME or
below!


FEXHOME contains:

        spool/                          spool directory and user data 
        htdocs/                         directory for generic download files
        bin/                            directory for programs
        cgi-bin/                        directory for CGI programs
        lib/                            directory for library and config files
        doc/                            additional documentation
        locale/                         alternative language installation
        

Files in spool:

        cleanup.log                     log of daily cleanup cronjob
        dkey.log                        log of download keys
        dop.log                         log of HTTP document output
        error.log                       log of errors
        fexsrv.log                      log of all HTTP requests
        fop.log                         log of file downloads
        fup.log                         log of file uploads
        fur.log                         log of user self registrations
        sex.log                         log of stream exchanges
        $user/@                         regular user auth-ID
        $user/@SUBUSER                  subuser addresses and IDs
        $user/@ALLOWED_RECIPIENTS       recipients restrictions for this user
        $user/@ALLOWED_RHOSTS           recipient's hosts restrictions
        $user/@UPLOAD_HOSTS             upload hosts restrictions
        $user/@DOWNLOAD_HOSTS           download hosts restrictions
        $user/@ADDRESS_BOOK             users recipient address book
        $user/@GROUP                    directory of F*EX user groups
        $user/@OKEY                     directory with one time upload keys
        $user/@QUOTA                    sender and recipient quotas
        $user/@AUTODELETE               autodelete default
        $user/@KEEP                     keep default
        $user/@LOCALE                   locale default
        $user/@CAPTIVE                  user must not change his settings
        $user/@FEXYOURSELF              user can only fex to himself via 
                                        web interface
        $to/$from/$file/upload          file data in upload progress
        $to/$from/$file/filename        original file name
        $to/$from/$file/size            original file size
        $to/$from/$file/useragent       HTTP header User-Agent
        $to/$from/$file/uurl            upload URL
        $to/$from/$file/data            file data after complete upload
        $to/$from/$file/keep            keep time (autoexpire) in days
        $to/$from/$file/autodelete      autodelete option: YES NO or DELAY
        $to/$from/$file/comment         comment in notification email
        $to/$from/$file/id              file ID (optional)
        $to/$from/$file/ip              sender ip address
        $to/$from/$file/notify          reminder notify flag
        $to/$from/$file/error           error message if file has gone
        $to/$from/$file/download        log of successful downloads
        $to/$from/$file/restrictions    IP based download restrictions
                                        (see $user/@ALLOWED_RHOSTS)
        $to/$from/$file/dkey            download key
        $to/$from/$file/locale          locale

As you see, the first directory sometimes means sender and sometimes means
recipient! It depends on the case of usage (up/download).

BEWARE: for the special senders fexmail and anonymous $to and $from are
swapped (by fup and fop)! This is to prevent overcrowding of the toplevel
spool directory with _fexmail_$RANDOM and _anonymous_$RANDOM recipients.


A registered full F*EX user is identified by the file $spooldir/$from/@
Only if this file contains his auth-ID this user is able to send files to
others. Otherwise he is just an unpriviledged recipient.

You can customize the upload CGI fup by editing FEXHOME/lib/fup.pl

Additional directories in spool:

        .dkeys/                         download keys lookup directory
        .ukeys/                         upload keys lookup directory
        .akeys/                         authentication keys lookup directory
        .skeys/                         subuser keys lookup directory
        .gkeys/                         groupuser keys lookup directory
        .xkeys/                         extra download keys lookup directory
        .debug/                         directory for debug output (optional)
        .reg/                           temporary data for user selfregistration

The upload keys (UKEY) are necessary to synchronize the file upload by
HTTP POST with the javascript upload status bar which is an asynchronous
HTTP GET. The GET process needs to know the corresponding POST process.
This is done via UKEY, a unique upload identifier.

The download key (DKEY) is a unique identifier for - guess what -
downloading. It also prevents an attacker to get the file, because only
the recipient knows the DKEY as part of the download URL from the
notification email. 

XKEY is an optional extra download key to have a short download URL in
shape http://YOURFEXSERVER//XKEY
The XKEY always starts with // and is provided as a COMMENT by the client.
Example: fexsend schwuppdiwupp.jpg //
The user has to realize that such URLs have very low security.

If you need to trace a F*EX request, then set 
        $debug = 1;
in fex.ph and look in ~/spool/.debug/ for the correspondening files.

The user fex also gets a Bcc of all sent notification emails. This is a
help for debugging purposes. If you want these Bcc mails to another
address then set in fex.ph:

        $bcc = 'other@address';

The sender also get a Bcc if he put the string "!bcc!" in the comment
field.

If you have users within another domain with its own MTA and those users
want to fex each other, then their MTA probably will reject the
notification email. To prevent this problem you can set in fex.ph
@remote_domains = qw(other_domain1 other_domain2 ...);
In this case "From: $admin" will be used in the notification emails.

F*EX comes with its own web server: fexsrv
Standard web servers like apache have been proven problematic, either in
speed or because of a 2-GB-limit. 

It is not possible to use the F*EX CGIs with an alternative web server,
because the F*EX CGIs need special fexsrv features.

xinetd starts fexsrv for every new connection, which then executes the
CGIs fup (file upload), fop (file output), fuc (fex user control), foc
(fex operation control), fac (fex admin control), fur (fex user
registration) and sex (stream exchange). 


SEX has the opposite authorization model of FEX: The sender does not
need any registration. He can send a stream to any registered SEX user,
who must identify himself with his auth-ID. This is because a stream does
not cost resources when it is not bound to a recipient. It will block
otherwise. The client programs for sexing are sexsend and sexget. You can
call them also fuckyou and fuckme :-)


With the F*EX client fexsend you can have a streaming file transfer with 
spooling: on client side there is no temporary buffer file (archive), but
the data is sent directly to the F*EX server. This saves time and disk
space on the client.

Example for a streaming archive upload:

  fexsend -a music+video.tar *mp3 *avi webmaster@flupp.org

Example for a streaming data upload:

  fpg fex /var/log/* | fexsend -s logs fexmaster@flupp.org

The data streaming is implemented via a HTTP extension: the header
Content-Length is given -1 which means: unknown length, read until EOF.

For streaming receiving you can use "fexget -s-" or "wget -O-".


fexsrv also can do generic document output (via dop) like a normal web
server. For this, your files must be under FEXHOME/htdocs and they must
not have the same name as the CGIs under FEXHOME/cgi-bin, because the CGIs
have priority.

For security reasons, documents to be delivered by dop:
- the file must be readable by group or world
- the file must be in FEXHOME/htdocs or a directory specified by @doc_dirs
- the filename must not start with a "."
- the filename must not contain a "@"
- the filename must not end with "~"

To enable HTTP basic authentication, write your access token to a file
named .htauth which will protect all files in this directory. An user will
be prompted for this password by his web browser.

To restrict the access to specific client IP addresses, put these IPs into
a file named .htaccessfrom which will protect all files below this
directory. You can name single IPs, also as IP ranges (example:
129.69.0.0-129.69.255.255)

dop is not a regular CGI program (like fup or fop), but a sub-program of
fexsrv. 

*.html files may contain $VARIABLES$ which will be substituted with the
value of the corresponding environment variable. See example
$SERVER_ADMIN$ in FEXHOME/htdocs/index.html

*.html files may contain <<perl-code>> (even multiline) which will be
evaluated. See example FEXHOME/htdocs/dynamic.html
This perl-code must not contain '>>' strings itself!
Pay attention: do not place security relevant data inside << >> because it
will be delivered to the client if the URL ends with '!'! See example:
http://fex.rus.uni-stuttgart.de/index.html
http://fex.rus.uni-stuttgart.de/index.html!

If you want to hide your code, then you have to write a CGI script and
place it into the cgi-bin directory. Files there will never be delivered
by dop. You also can do "chmod o-r file.html" to prevent source code
delivery.

*.html files may contain conditional blocks:

#if (perl-expression)
   HTML...
#elseif (perl-expression)
   HTML...
#else
   HTML...
#endif

which will be evaluated at run-time (#else and #elseif are optional).

*.html files may contain:
#include "FILE"
which means: load FILE from current directory at this place in code.

dop also can display a directory listing if this directory contains a file
named .htindex
To restrict the listing to specific files, put a matching regular
expression into .htindex
Example: echo 'pdf$' > /home/fex/htdocs/doc/.htindex

dop can output gzipped files on-the-fly as a streaming document. For
example: you have /fex/home/htdocs/big.file but a client requests
http://YOURFEXSERVER/big.file.gz then a corresponding big.file.gz will be
delivered.

dop can also output tar, tgz or zip archives on-the-fly as a streaming
document. Just create a symbolic link with files (or directories) you want
in this archive and enclose them with ":". The symlink name must end with
".stream". Example:

http://fex.rus.uni-stuttgart.de:8080/download/sex.tar

fex@fex:~/htdocs/download: ls -l sex*
lrwxrwxrwx 1 fex fex     7 2011-01-26 11:46 sexget -> sexsend
-rwxr-xr-x 1 fex fex 12110 2012-08-22 09:55 sexsend
lrwxrwxrwx 1 fex fex    22 2012-09-01 12:13 sex.stream -> :sexsend:sexget:sexxx:
lrwxrwxrwx 1 fex fex     7 2012-09-01 11:28 sexxx -> sexsend

It is also possible to create this stream file as a regular file. Then the
content must be the file names you want in the streaming archive.

Note: you may only use relative paths and without "../" elements.

Note: Files beginning with a . or ending with ~ will not be included in
the download stream.

cronjob fex_cleanup is run once a day and deletes expired uploads, removes
inactive accounts and does some other spool houskeeping. See: crontab -l

To detect inactive users you can put in fex.ph:
$account_expire = "365:notify";

This sends an email to $admin when an user is inactive for 365 days.

Or to delete inactive users you can put in fex.ph:
$account_expire = "365:delete";

This deletes user accounts automatically which have been inactive for 365
days. 

Of course you can use any number of days.

Inactive users will get an account reactivation request before.

The address book may contain the optional parameters autodelete and
keep. Address book example entry:

flupp framstag@flupp.org keep=99 autodelete=no

BUT: these address book parameters are only accepted when using the
fexsend or schwuppdiwupp client! They will be ignored when using a
webbrowser!

Nevertheless you may add autodelete and keep parameters using a
webbrowser, but then they are valid for ALL addresses in the "Recipient"
field!

The clients fexsend and schwuppdiwupp can MD5-encrypt the auth-ID together
with a session-ID. The session-ID itself is provided by the server after
an initial "GET SID" HTTP request. This is not possible through a proxy,
because most proxies do not support persistant tcp sessions.

See fex-client_2.pdf for the F*EX protocol specification.

To understand and trace the F*EX protocol you can use fexsend with the -v
option. 

Example (--> means send to server, <-- means receive from server):

framstag@fex:~: fexsend -v X.png framstag@flupp.org
ID data from /home/framstag/.fex/id: http://fex.rus.uni-stuttgart.de framstag@rus.uni-stuttgart.de XXXX
Server/User: http://fex.rus.uni-stuttgart.de/framstag@rus.uni-stuttgart.de
TCPCONNECT to fex.rus.uni-stuttgart.de
--> GET SID HTTP/1.1
-->
<-- HTTP/1.1 201 8p2Y2qa2
<-- X-Features: SID,CHECKRECIPIENT,GROUPS,QUOTA,FILEID,MULTIPOST,XKEY
<-- X-SID: 8p2Y2qa2
<-- X-Timeout: 30
<-- Content-Length: 0
<-- 
--> HEAD /fop/framstag@flupp.org/framstag@fex.rus.uni-stuttgart.de/X.png??ID=MD5H:226e896d0adab86892957aa8158b37ba HTTP/1.1
-->
<-- HTTP/1.1 200 OK
<-- Content-Length: 0
<-- X-Size: 0
<-- X-Features: SID,CHECKRECIPIENT,GROUPS,QUOTA,FILEID,MULTIPOST,XKEY
<-- 
--> POST /fup HTTP/1.1
--> Host: fex.rus.uni-stuttgart.de
--> User-Agent: fexsend (Ubuntu 8.04.4 LTS)
--> Content-Length: 149935162
--> Content-Type: multipart/form-data; boundary=JhUOtQ3sgV5ZcHJzrTny523nBFqgUNvSAOUHoRMTdZfGpAjs
--> 
--> --JhUOtQ3sgV5ZcHJzrTny523nBFqgUNvSAOUHoRMTdZfGpAjs
--> Content-Disposition: form-data; name="FROM"
--> 
--> framstag@fex.rus.uni-stuttgart.de
--> --JhUOtQ3sgV5ZcHJzrTny523nBFqgUNvSAOUHoRMTdZfGpAjs
--> Content-Disposition: form-data; name="TO"
--> 
--> framstag@flupp.org
--> --JhUOtQ3sgV5ZcHJzrTny523nBFqgUNvSAOUHoRMTdZfGpAjs
--> Content-Disposition: form-data; name="ID"
--> 
--> MD5H:226e896d0adab86892957aa8158b37ba
--> --JhUOtQ3sgV5ZcHJzrTny523nBFqgUNvSAOUHoRMTdZfGpAjs
--> Content-Disposition: form-data; name="FILESIZE"
--> 
--> 149934400
--> --JhUOtQ3sgV5ZcHJzrTny523nBFqgUNvSAOUHoRMTdZfGpAjs
--> Content-Disposition: form-data; name="FILE"; filename="X.png"
--> Content-Type: application/octet-stream
--> Content-Length: 149934400
--> X-File-ID: 1283077463
--> 
--> (file content)
--> --JhUOtQ3sgV5ZcHJzrTny523nBFqgUNvSAOUHoRMTdZfGpAjs--
<-- Location: http://fex.rus.uni-stuttgart.de/fop/CoVhikzk/X.png
<-- X-Recipient: framstag@flupp.org (autodelete=YES,keep=5)
<-- 

Comment on the HEAD request above:
The client fexsend sends it to request whether the file has been sent
before and if it was successful or not. On the later case, the server
would reply how many bytes has already been received and the client then
can send only the missing part. Normally the answer to the HEAD request is
0 (see above), which means: nothing of this file has been received so far.

But this is only half of the truth :-)
I have omitted in the example above the requests CHECKRECIPIENT and
GET ADDRESS_BOOK, to keep it simple in the first run.
CHECKRECIPIENT is a HTTP POST request to check whether the recpient's
email address is valid to the server.
GET ADDRESS_BOOK is a HTTP GET request to check if the recipient with a
short address (= address without @) is an alias in the senders server
address book. 
Please use "fexsend -v" by yourself to see the whole protocol dialoge.

Many HTTP proxies have a POST limit, which is often at 2 GB, but sometimes
lower. To overcome this limitation a F*EX client (like fexsend) may
include in the POST the HTTP MIME part "filesize" which indicates the full
file size. All incoming file POSTs with this file name will be appended
until the full file size is reached. Of course the client has to POST all
parts of this file, in the correct order, in asking the server how many
bytes has already been received. Example:

framstag@fex:/tmp: fexsend -vP wwwproxy.uni-stuttgart.de.de:8080:1024 2GB.tmp .
ID data from /home/framstag/.fex/id: http://fex.rus.uni-stuttgart.de:8080 framstag@rus.uni-stuttgart.de xxxxxx
Server/User: http://fex.rus.uni-stuttgart.de:8080/framstag@rus.uni-stuttgart.de
TCPCONNECT to wwwproxy.uni-stuttgart.de.de:8080
--> HEAD http://fex.rus.uni-stuttgart.de:8080/fop/framstag@rus.uni-stuttgart.de/framstag@rus.uni-stuttgart.de/2GB.tmp??&ID=xxxxxx HTTP/1.1
-->
<-- HTTP/1.1 200 OK
<-- X-Size: 0
<-- Content-Length: 0
<-- Proxy-Connection: Keep-Alive
<-- Connection: Keep-Alive
<-- Date: Tue, 08 Jun 2010 15:04:13 GMT
<--
TCPCONNECT to wwwproxy.uni-stuttgart.de.de:8080
--> POST http://fex.rus.uni-stuttgart.de:8080/fup HTTP/1.1
--> Host: fex.rus.uni-stuttgart.de:8080
--> User-Agent: fexsend (Ubuntu 8.04.4 LTS)
--> Content-Length: 1073677143
--> Content-Type: multipart/form-data; boundary=gqhqeU7FCHMl4ohxJ5knK1y9rF75xYTvabPvZTeWnAhaoDsK
-->
--> --gqhqeU7FCHMl4ohxJ5knK1y9rF75xYTvabPvZTeWnAhaoDsK
--> Content-Disposition: form-data; name="FROM"
-->
--> framstag@rus.uni-stuttgart.de
--> --gqhqeU7FCHMl4ohxJ5knK1y9rF75xYTvabPvZTeWnAhaoDsK
--> Content-Disposition: form-data; name="TO"
-->
--> framstag@rus.uni-stuttgart.de
--> --gqhqeU7FCHMl4ohxJ5knK1y9rF75xYTvabPvZTeWnAhaoDsK
--> Content-Disposition: form-data; name="ID"
-->
--> xxxxxx
--> --gqhqeU7FCHMl4ohxJ5knK1y9rF75xYTvabPvZTeWnAhaoDsK
--> Content-Disposition: form-data; name="COMMENT"
-->
--> NOMAIL
--> --gqhqeU7FCHMl4ohxJ5knK1y9rF75xYTvabPvZTeWnAhaoDsK
--> Content-Disposition: form-data; name="FILESIZE"
-->
--> 2147483748
--> --gqhqeU7FCHMl4ohxJ5knK1y9rF75xYTvabPvZTeWnAhaoDsK
--> Content-Disposition: form-data; name="FILE"; filename="2GB.tmp"
--> Content-Type: application/octet-stream
--> Content-Length: 1073676288
--> X-File-ID: 1275549886
-->
--> (file content)
--> --gqhqeU7FCHMl4ohxJ5knK1y9rF75xYTvabPvZTeWnAhaoDsK--
2GB.tmp : 1023 MB in 73 s (14363 kB/s), chunk #1 : 1023 MB
<-- HTTP/1.1 206 Partial OK
<-- X-Message: Partial OK
<-- Server: fexsrv
<-- Expires: 0
<-- Cache-Control: no-cache
<-- Content-Type: text/html; charset=UTF-8
<-- Connection: close
<-- Date: Tue, 08 Jun 2010 15:05:29 GMT
<--
TCPCONNECT to wwwproxy.uni-stuttgart.de.de:8080
--> HEAD http://fex.rus.uni-stuttgart.de:8080/fop/framstag@rus.uni-stuttgart.de/framstag@rus.uni-stuttgart.de/2GB.tmp??&ID=xxxxxx HTTP/1.1
-->
<-- HTTP/1.1 200 OK
<-- X-Size: 2147483748
<-- X-File-ID: 1275549886
<-- Content-Length: 1073676288
<-- Proxy-Connection: Keep-Alive
<-- Connection: Keep-Alive
<-- Date: Tue, 08 Jun 2010 15:05:29 GMT
<--
TCPCONNECT to wwwproxy.uni-stuttgart.de.de:8080
--> POST http://fex.rus.uni-stuttgart.de:8080/fup HTTP/1.1
--> Host: fex.rus.uni-stuttgart.de:8080
--> User-Agent: fexsend (Ubuntu 8.04.4 LTS)
--> Content-Length: 1073677254
--> Content-Type: multipart/form-data; boundary=LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw
-->
--> --LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw
--> Content-Disposition: form-data; name="FROM"
-->
--> framstag@rus.uni-stuttgart.de
--> --LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw
--> Content-Disposition: form-data; name="TO"
-->
--> framstag@rus.uni-stuttgart.de
--> --LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw
--> Content-Disposition: form-data; name="ID"
-->
--> xxxxxx
--> --LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw
--> Content-Disposition: form-data; name="COMMENT"
-->
--> NOMAIL
--> --LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw
--> Content-Disposition: form-data; name="SEEK"
-->
--> 1073676288
--> --LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw
--> Content-Disposition: form-data; name="FILESIZE"
-->
--> 2147483748
--> --LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw
--> Content-Disposition: form-data; name="FILE"; filename="2GB.tmp"
--> Content-Type: application/octet-stream
--> Content-Length: 1073676288
--> X-File-ID: 1275549886
-->
--> (file content)
--> --LofreCkx1GmgWNCHZ9exBQoQhiEF7pXSaPp2KUQVPlnarPAw--
2GB.tmp : 0 MB in 1 s (128 kB/s), total 2048 MB


The default character set for F*EX is UTF-8, because most clients seem to
use it. The problem is, it is nowhere defined which character set HTTP
uses itself.

Important for programmers: The perl variables of the F*EX CGI's (fup, fop,
etc) have their UTF-8 flag turned off. This means, they contain UTF-8 data
in binary representation.

F*EX has support for many languanges. For every language a translated
version will be installed in $HOME/locale/
The switch is done at runtime via locale cookie (by fexsrv).
Some common functions from fex.pp must be present at any time for any
locale in any language, eg notification functions. Therfore there is
$HOME/lib/lf.pl (extracted functions from fex.pp).

I have additional authentication modules for RADIUS, LDAP, mailman and
POP. Please email me if you are interested.

framstag@rus.uni-stuttgart.de