Source Code for Module dkim.dkimsign

 1  #!/usr/bin/env python 
 2   
 3  # This software is provided 'as-is', without any express or implied 
 4  # warranty.  In no event will the author be held liable for any damages 
 5  # arising from the use of this software. 
 6  # 
 7  # Permission is granted to anyone to use this software for any purpose, 
 8  # including commercial applications, and to alter it and redistribute it 
 9  # freely, subject to the following restrictions: 
10  # 
11  # 1. The origin of this software must not be misrepresented; you must not 
12  #    claim that you wrote the original software. If you use this software 
13  #    in a product, an acknowledgment in the product documentation would be 
14  #    appreciated but is not required. 
15  # 2. Altered source versions must be plainly marked as such, and must not be 
16  #    misrepresented as being the original software. 
17  # 3. This notice may not be removed or altered from any source distribution. 
18  # 
19  # Copyright (c) 2008 Greg Hewgill http://hewgill.com 
20  # 
21  # This has been modified from the original software. 
22  # Copyright (c) 2011 William Grant <me@williamgrant.id.au> 
23  # Copyright (c) 2017 Scott Kitterman <scott@kitterman.com> 
24   
25  from __future__ import print_function 
26   
27  import sys 
28  import argparse 
29   
30  import dkim 
31   
32   
33 -def main(): 
34      # Backward compatibility hack because argparse doesn't support optional 
35      # positional arguments 
36      arguments=['--'+arg if arg[:8] == 'identity' else arg for arg in sys.argv[1:]] 
37      parser = argparse.ArgumentParser( 
38          description='Produce DKIM signature for email messages.', 
39          epilog="message to be signed follows commands on stdin") 
40      parser.add_argument('selector', action="store") 
41      parser.add_argument('domain', action="store") 
42      parser.add_argument('privatekeyfile', action="store") 
43      parser.add_argument('--hcanon', choices=['simple', 'relaxed'], 
44          default='relaxed', 
45          help='Header canonicalization algorithm: default=relaxed') 
46      parser.add_argument('--bcanon', choices=['simple', 'relaxed'], 
47          default='simple', 
48          help='Body canonicalization algorithm: default=simple') 
49      parser.add_argument('--signalg', choices=['rsa-sha256', 'ed25519-sha256', 'rsa-sha1'], 
50          default='rsa-sha256', 
51          help='Signature algorithm: default=rsa-sha256') 
52      parser.add_argument('--identity', help='Optional value for i= tag.') 
53      args=parser.parse_args(arguments) 
54      include_headers = None 
55      length = None 
56      logger = None 
57   
58      if sys.version_info[0] >= 3: 
59          args.selector = bytes(args.selector, encoding='UTF-8') 
60          args.domain = bytes(args.domain, encoding='UTF-8') 
61          if args.identity is not None: 
62              args.identity = bytes(args.identity, encoding='UTF-8') 
63          args.hcanon = bytes(args.hcanon, encoding='UTF-8') 
64          args.bcanon = bytes(args.bcanon, encoding='UTF-8') 
65          args.signalg = bytes(args.signalg, encoding='UTF-8') 
66          # Make sys.stdin and stdout binary streams. 
67          sys.stdin = sys.stdin.detach() 
68          sys.stdout = sys.stdout.detach() 
69      canonicalize = (args.hcanon, args.bcanon) 
70   
71      message = sys.stdin.read() 
72      try: 
73          d = dkim.DKIM(message,logger=logger, signature_algorithm=args.signalg, 
74                        linesep=dkim.util.get_linesep(message)) 
75          sig = d.sign(args.selector, args.domain, open( 
76                       args.privatekeyfile, "rb").read(), identity = args.identity, 
77                       canonicalize=canonicalize, include_headers=include_headers, 
78                       length=length) 
79          sys.stdout.write(sig) 
80          sys.stdout.write(message) 
81      except Exception as e: 
82          print(e, file=sys.stderr) 
83          sys.stdout.write(message) 
84   
85   
86  if __name__ == "__main__": 
87      main() 
88