Changes between Version 6 and Version 7 of AnnouncerPlugin/MessageEncryption


Ignore:
Timestamp:
Mar 11, 2010 10:27:02 PM (5 years ago)
Author:
hasienda
Comment:

updated information according to latest development, some changes to page structure

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  • AnnouncerPlugin/MessageEncryption

    v6 v7  
    55=== Where === 
    66Where to kick in and mangle the message body is of course an essential decision. 
    7 Reading the current code from trunk I found this in ./announcerplugin_trunk/announcer/distributors/mail.py 
     7My initial assumption that I could add cryptographically functions right before inserting recipient addresses to the message was wrong. 
     8  
     9Now I add the following into code of ./announcerplugin_trunk/announcer/distributors/mail.py from trunk of AnnouncerPlugin: 
    810{{{ 
    9         parentMessage.attach(msgText) 
    10         decorators = self._get_decorators() 
    11         if len(decorators) > 0: 
    12             decorator = decorators.pop() 
    13             decorator.decorate_message(event, rootMessage, decorators) 
    14 --> 
    15         recip_adds = [x[2] for x in recipients if x] 
    16         # Append any to, cc or bccs added to the recipient list 
    17         for field in ('To', 'Cc', 'Bcc'): 
     11         return msgid 
    1812  
     13     def _do_send(self, transport, event, format, recipients, formatter): 
     14         output = formatter.format(transport, event.realm, format, event) 
     15+ 
     16+        email_encrypt = True 
     17+        if email_encrypt: 
     18+            output = encrypt_txt(output) 
     19+            self.log.debug("EmailDistributor successfully encrypted msg.") 
     20+ 
     21         alternate_style = formatter.alternative_style_for( 
     22             transport,  
     23             event.realm, 
    1924}}} 
    20 --> Here I'll add some code to make encryption just work (1st step). Encryption/signing key ID hard-coded, growing number of variables I'd like to see as options in [annoucer] section of trac.ini and other ugliness. This will evolve over time, i.e. code will be moved out into a separate python script file and it's function will be imported into mail.py. 
    21  
    22 [FIXME: add more Q+A here to help with code design evaluation and code review]   
    23  ?: Why not implement encryption as another IAnnouncementEmailDecorator 
    24   A: Decorators are called without guaranteed order. Encryption needs control, that it'll be the last message body mangling action. 
    25  ?: Why not implement encryption as another IAnnouncementFormatter 
    26   A: Encryption is not about encoding etc. 
    2725 
    2826=== What === 
     
    3735 
    3836=== How === 
     37==== The interface ==== 
    3938To make it more difficult for me to start I've found not one but several candidates for interacting with GnuPG from Python (http://wiki.python.org/moin/GnuPrivacyGuard has a listing with some more comments): 
    4039 * [http://code.google.com/p/python-gnupg/ python-gnupg] 
     
    4443   * download and local install without issues, 
    4544   * function list_keys() ~~doesn't "just work"~~ works on a known-good gpg keyfile directory - got it 
    46    * beware: "gnupghome" directory will be created silently (including parents), if something is not there exactly as specified, __init__ will need to prevent creation of unwanted directories by (worst case: repeated) mis-configuration 
    47    *  
     45   * beware: "gnupghome" directory will be created silently (including parents), if something is not there exactly as specified, init function will need to prevent creation of unwanted directories by (worst case: repeated) mis-configuration 
    4846 * [http://py-gnupg.sourceforge.net/ Python GnuPGInterface] 
    4947  * PRO: Debian package python-gnupginterface-0.3.2-9 
     
    5553  * PRO: interface to C GPGME library, not limited to gpg by design, other backends planned, works on Windows as well as Unix/Linux, latest release v0.8.1 from 26-11-2008, Debian package python-pyme-0.8.1+clean-1 
    5654  * CON: complex dependencies because built on GPGME + Python + SWIG 
     55  * '''TEST''' 
     56   * Debian package needed upgrade to python-pyme-0.8.1+clean-3+b1 to fix error on GnuPG interface setup call 
     57   * much more complex API compared to python-gnupg 
     58   * on halt for now, but still considered nice-to-have, since it would allow additional crypto-backends i.e. working with X.509 certificates etc. 
    5759 * [http://pypi.python.org/pypi/OpenPGP/ OpenPGP] 
    5860  * PRO: ? 
     
    6466hints, recommendations? known-good code references or popular applications? 
    6567 
     68==== The code ==== 
     69 1. step: add some code to make encryption just work '''done'''[[BR]] 
     70  * expect encryption/signing key ID hard-coded, some fixed values for variables I'd like to see as options in [annoucer] section of trac.ini and other ugliness 
     71 2. step: code evolution over time, i.e. 
     72  a. put code into separate python script and import function into distributors/mail.py '''done'''[[BR]] 
     73   * add new reference 
     74{{{ 
     75from announcer.util.mail_encrypt import encrypt_txt 
     76}}} 
     77   * add ./announcerplugin_trunk/announcer/'''util/mail_encrypt.py''' containing new cryptographic functions 
     78  b. consider invention of a new class, i.e. to allow for reusable code, gpg interface initialization before sign and encrypt actions would profit among others 
     79  c. add a minimal set of new options to [annoucer] section of trac.ini and replace formerly fixed values to gain planned control about new cryptographic functions 
     80 3. step: extend web_ui of AnnouncerPlugin to remote-control new options from user and/or administration settings 
     81 
     82[FIXME: add more Q+A here to help with code design evaluation and code review]   
     83 ?: Why not implement encryption as another IAnnouncementEmailDecorator 
     84  A: Decorators are called without guaranteed order. Encryption needs control, that it'll be the last message body mangling action. 
     85 ?: Why not implement encryption as another IAnnouncementFormatter 
     86  A: Encryption is not about encoding etc. 
     87 
    6688=== Sources (ideas and code) === 
    6789 * Intro to python-gnupg at http://groups.google.de/group/comp.lang.python/browse_thread/thread/f2b97a2c11e1df63 
     
    6991 * Python e-mail test server http://docs.djangoproject.com/en/1.1/topics/email/#topics-email 
    7092 * How Django, another Python based system handles e-mail-encryption with [http://code.google.com/p/django-email-extras/ django-email-extras] ([http://code.google.com/p/django-email-extras/source/browse/trunk/email_extras/ browse the code]) 
     93 * Python tutorial at http://www.python.org/doc/current/tutorial/index.html to help some newbie like me opening the world of Python code 
    7194some more real-world implementations of python-gnupg, hints? 
    7295