1 #! /usr/bin/env python

     2 

     3 """Mimification and unmimification of mail messages.

     4 

     5 Decode quoted-printable parts of a mail message or encode using

     6 quoted-printable.

     7 

     8 Usage:

     9         mimify(input, output)

    10         unmimify(input, output, decode_base64 = 0)

    11 to encode and decode respectively.  Input and output may be the name

    12 of a file or an open file object.  Only a readline() method is used

    13 on the input file, only a write() method is used on the output file.

    14 When using file names, the input and output file names may be the

    15 same.

    16 

    17 Interactive usage:

    18         mimify.py -e [infile [outfile]]

    19         mimify.py -d [infile [outfile]]

    20 to encode and decode respectively.  Infile defaults to standard

    21 input and outfile to standard output.

    22 """

    23 

    24 # Configure

    25 MAXLEN = 200    # if lines longer than this, encode as quoted-printable

    26 CHARSET = 'ISO-8859-1'  # default charset for non-US-ASCII mail

    27 QUOTE = '> '            # string replies are quoted with

    28 # End configure

    29 

    30 import re

    31 

    32 import warnings

    33 warnings.warn("the mimify module is deprecated; use the email package instead",

    34                 DeprecationWarning, 2)

    35 

    36 __all__ = ["mimify","unmimify","mime_encode_header","mime_decode_header"]

    37 

    38 qp = re.compile('^content-transfer-encoding:\\s*quoted-printable', re.I)

    39 base64_re = re.compile('^content-transfer-encoding:\\s*base64', re.I)

    40 mp = re.compile('^content-type:.*multipart/.*boundary="?([^;"\n]*)', re.I|re.S)

    41 chrset = re.compile('^(content-type:.*charset=")(us-ascii|iso-8859-[0-9]+)(".*)', re.I|re.S)

    42 he = re.compile('^-*\n')

    43 mime_code = re.compile('=([0-9a-f][0-9a-f])', re.I)

    44 mime_head = re.compile('=\\?iso-8859-1\\?q\\?([^? \t\n]+)\\?=', re.I)

    45 repl = re.compile('^subject:\\s+re: ', re.I)

    46 

    47 class File:

    48     """A simple fake file object that knows about limited read-ahead and

    49     boundaries.  The only supported method is readline()."""

    50 

    51     def __init__(self, file, boundary):

    52         self.file = file

    53         self.boundary = boundary

    54         self.peek = None

    55 

    56     def readline(self):

    57         if self.peek is not None:

    58             return ''

    59         line = self.file.readline()

    60         if not line:

    61             return line

    62         if self.boundary:

    63             if line == self.boundary + '\n':

    64                 self.peek = line

    65                 return ''

    66             if line == self.boundary + '--\n':

    67                 self.peek = line

    68                 return ''

    69         return line

    70 

    71 class HeaderFile:

    72     def __init__(self, file):

    73         self.file = file

    74         self.peek = None

    75 

    76     def readline(self):

    77         if self.peek is not None:

    78             line = self.peek

    79             self.peek = None

    80         else:

    81             line = self.file.readline()

    82         if not line:

    83             return line

    84         if he.match(line):

    85             return line

    86         while 1:

    87             self.peek = self.file.readline()

    88             if len(self.peek) == 0 or \

    89                (self.peek[0] != ' ' and self.peek[0] != '\t'):

    90                 return line

    91             line = line + self.peek

    92             self.peek = None

    93 

    94 def mime_decode(line):

    95     """Decode a single line of quoted-printable text to 8bit."""

    96     newline = ''

    97     pos = 0

    98     while 1:

    99         res = mime_code.search(line, pos)

   100         if res is None:

   101             break

   102         newline = newline + line[pos:res.start(0)] + \

   103                   chr(int(res.group(1), 16))

   104         pos = res.end(0)

   105     return newline + line[pos:]

   106 

   107 def mime_decode_header(line):

   108     """Decode a header line to 8bit."""

   109     newline = ''

   110     pos = 0

   111     while 1:

   112         res = mime_head.search(line, pos)

   113         if res is None:

   114             break

   115         match = res.group(1)

   116         # convert underscores to spaces (before =XX conversion!)

   117         match = ' '.join(match.split('_'))

   118         newline = newline + line[pos:res.start(0)] + mime_decode(match)

   119         pos = res.end(0)

   120     return newline + line[pos:]

   121 

   122 def unmimify_part(ifile, ofile, decode_base64 = 0):

   123     """Convert a quoted-printable part of a MIME mail message to 8bit."""

   124     multipart = None

   125     quoted_printable = 0

   126     is_base64 = 0

   127     is_repl = 0

   128     if ifile.boundary and ifile.boundary[:2] == QUOTE:

   129         prefix = QUOTE

   130     else:

   131         prefix = ''

   132 

   133     # read header

   134     hfile = HeaderFile(ifile)

   135     while 1:

   136         line = hfile.readline()

   137         if not line:

   138             return

   139         if prefix and line[:len(prefix)] == prefix:

   140             line = line[len(prefix):]

   141             pref = prefix

   142         else:

   143             pref = ''

   144         line = mime_decode_header(line)

   145         if qp.match(line):

   146             quoted_printable = 1

   147             continue        # skip this header

   148         if decode_base64 and base64_re.match(line):

   149             is_base64 = 1

   150             continue

   151         ofile.write(pref + line)

   152         if not prefix and repl.match(line):

   153             # we're dealing with a reply message

   154             is_repl = 1

   155         mp_res = mp.match(line)

   156         if mp_res:

   157             multipart = '--' + mp_res.group(1)

   158         if he.match(line):

   159             break

   160     if is_repl and (quoted_printable or multipart):

   161         is_repl = 0

   162 

   163     # read body

   164     while 1:

   165         line = ifile.readline()

   166         if not line:

   167             return

   168         line = re.sub(mime_head, '\\1', line)

   169         if prefix and line[:len(prefix)] == prefix:

   170             line = line[len(prefix):]

   171             pref = prefix

   172         else:

   173             pref = ''

   174 ##              if is_repl and len(line) >= 4 and line[:4] == QUOTE+'--' and line[-3:] != '--\n':

   175 ##                      multipart = line[:-1]

   176         while multipart:

   177             if line == multipart + '--\n':

   178                 ofile.write(pref + line)

   179                 multipart = None

   180                 line = None

   181                 break

   182             if line == multipart + '\n':

   183                 ofile.write(pref + line)

   184                 nifile = File(ifile, multipart)

   185                 unmimify_part(nifile, ofile, decode_base64)

   186                 line = nifile.peek

   187                 if not line:

   188                     # premature end of file

   189                     break

   190                 continue

   191             # not a boundary between parts

   192             break

   193         if line and quoted_printable:

   194             while line[-2:] == '=\n':

   195                 line = line[:-2]

   196                 newline = ifile.readline()

   197                 if newline[:len(QUOTE)] == QUOTE:

   198                     newline = newline[len(QUOTE):]

   199                 line = line + newline

   200             line = mime_decode(line)

   201         if line and is_base64 and not pref:

   202             import base64

   203             line = base64.decodestring(line)

   204         if line:

   205             ofile.write(pref + line)

   206 

   207 def unmimify(infile, outfile, decode_base64 = 0):

   208     """Convert quoted-printable parts of a MIME mail message to 8bit."""

   209     if type(infile) == type(''):

   210         ifile = open(infile)

   211         if type(outfile) == type('') and infile == outfile:

   212             import os

   213             d, f = os.path.split(infile)

   214             os.rename(infile, os.path.join(d, ',' + f))

   215     else:

   216         ifile = infile

   217     if type(outfile) == type(''):

   218         ofile = open(outfile, 'w')

   219     else:

   220         ofile = outfile

   221     nifile = File(ifile, None)

   222     unmimify_part(nifile, ofile, decode_base64)

   223     ofile.flush()

   224 

   225 mime_char = re.compile('[=\177-\377]') # quote these chars in body

   226 mime_header_char = re.compile('[=?\177-\377]') # quote these in header

   227 

   228 def mime_encode(line, header):

   229     """Code a single line as quoted-printable.

   230     If header is set, quote some extra characters."""

   231     if header:

   232         reg = mime_header_char

   233     else:

   234         reg = mime_char

   235     newline = ''

   236     pos = 0

   237     if len(line) >= 5 and line[:5] == 'From ':

   238         # quote 'From ' at the start of a line for stupid mailers

   239         newline = ('=%02x' % ord('F')).upper()

   240         pos = 1

   241     while 1:

   242         res = reg.search(line, pos)

   243         if res is None:

   244             break

   245         newline = newline + line[pos:res.start(0)] + \

   246                   ('=%02x' % ord(res.group(0))).upper()

   247         pos = res.end(0)

   248     line = newline + line[pos:]

   249 

   250     newline = ''

   251     while len(line) >= 75:

   252         i = 73

   253         while line[i] == '=' or line[i-1] == '=':

   254             i = i - 1

   255         i = i + 1

   256         newline = newline + line[:i] + '=\n'

   257         line = line[i:]

   258     return newline + line

   259 

   260 mime_header = re.compile('([ \t(]|^)([-a-zA-Z0-9_+]*[\177-\377][-a-zA-Z0-9_+\177-\377]*)(?=[ \t)]|\n)')

   261 

   262 def mime_encode_header(line):

   263     """Code a single header line as quoted-printable."""

   264     newline = ''

   265     pos = 0

   266     while 1:

   267         res = mime_header.search(line, pos)

   268         if res is None:

   269             break

   270         newline = '%s%s%s=?%s?Q?%s?=' % \

   271                   (newline, line[pos:res.start(0)], res.group(1),

   272                    CHARSET, mime_encode(res.group(2), 1))

   273         pos = res.end(0)

   274     return newline + line[pos:]

   275 

   276 mv = re.compile('^mime-version:', re.I)

   277 cte = re.compile('^content-transfer-encoding:', re.I)

   278 iso_char = re.compile('[\177-\377]')

   279 

   280 def mimify_part(ifile, ofile, is_mime):

   281     """Convert an 8bit part of a MIME mail message to quoted-printable."""

   282     has_cte = is_qp = is_base64 = 0

   283     multipart = None

   284     must_quote_body = must_quote_header = has_iso_chars = 0

   285 

   286     header = []

   287     header_end = ''

   288     message = []

   289     message_end = ''

   290     # read header

   291     hfile = HeaderFile(ifile)

   292     while 1:

   293         line = hfile.readline()

   294         if not line:

   295             break

   296         if not must_quote_header and iso_char.search(line):

   297             must_quote_header = 1

   298         if mv.match(line):

   299             is_mime = 1

   300         if cte.match(line):

   301             has_cte = 1

   302             if qp.match(line):

   303                 is_qp = 1

   304             elif base64_re.match(line):

   305                 is_base64 = 1

   306         mp_res = mp.match(line)

   307         if mp_res:

   308             multipart = '--' + mp_res.group(1)

   309         if he.match(line):

   310             header_end = line

   311             break

   312         header.append(line)

   313 

   314     # read body

   315     while 1:

   316         line = ifile.readline()

   317         if not line:

   318             break

   319         if multipart:

   320             if line == multipart + '--\n':

   321                 message_end = line

   322                 break

   323             if line == multipart + '\n':

   324                 message_end = line

   325                 break

   326         if is_base64:

   327             message.append(line)

   328             continue

   329         if is_qp:

   330             while line[-2:] == '=\n':

   331                 line = line[:-2]

   332                 newline = ifile.readline()

   333                 if newline[:len(QUOTE)] == QUOTE:

   334                     newline = newline[len(QUOTE):]

   335                 line = line + newline

   336             line = mime_decode(line)

   337         message.append(line)

   338         if not has_iso_chars:

   339             if iso_char.search(line):

   340                 has_iso_chars = must_quote_body = 1

   341         if not must_quote_body:

   342             if len(line) > MAXLEN:

   343                 must_quote_body = 1

   344 

   345     # convert and output header and body

   346     for line in header:

   347         if must_quote_header:

   348             line = mime_encode_header(line)

   349         chrset_res = chrset.match(line)

   350         if chrset_res:

   351             if has_iso_chars:

   352                 # change us-ascii into iso-8859-1

   353                 if chrset_res.group(2).lower() == 'us-ascii':

   354                     line = '%s%s%s' % (chrset_res.group(1),

   355                                        CHARSET,

   356                                        chrset_res.group(3))

   357             else:

   358                 # change iso-8859-* into us-ascii

   359                 line = '%sus-ascii%s' % chrset_res.group(1, 3)

   360         if has_cte and cte.match(line):

   361             line = 'Content-Transfer-Encoding: '

   362             if is_base64:

   363                 line = line + 'base64\n'

   364             elif must_quote_body:

   365                 line = line + 'quoted-printable\n'

   366             else:

   367                 line = line + '7bit\n'

   368         ofile.write(line)

   369     if (must_quote_header or must_quote_body) and not is_mime:

   370         ofile.write('Mime-Version: 1.0\n')

   371         ofile.write('Content-Type: text/plain; ')

   372         if has_iso_chars:

   373             ofile.write('charset="%s"\n' % CHARSET)

   374         else:

   375             ofile.write('charset="us-ascii"\n')

   376     if must_quote_body and not has_cte:

   377         ofile.write('Content-Transfer-Encoding: quoted-printable\n')

   378     ofile.write(header_end)

   379 

   380     for line in message:

   381         if must_quote_body:

   382             line = mime_encode(line, 0)

   383         ofile.write(line)

   384     ofile.write(message_end)

   385 

   386     line = message_end

   387     while multipart:

   388         if line == multipart + '--\n':

   389             # read bit after the end of the last part

   390             while 1:

   391                 line = ifile.readline()

   392                 if not line:

   393                     return

   394                 if must_quote_body:

   395                     line = mime_encode(line, 0)

   396                 ofile.write(line)

   397         if line == multipart + '\n':

   398             nifile = File(ifile, multipart)

   399             mimify_part(nifile, ofile, 1)

   400             line = nifile.peek

   401             if not line:

   402                 # premature end of file

   403                 break

   404             ofile.write(line)

   405             continue

   406         # unexpectedly no multipart separator--copy rest of file

   407         while 1:

   408             line = ifile.readline()

   409             if not line:

   410                 return

   411             if must_quote_body:

   412                 line = mime_encode(line, 0)

   413             ofile.write(line)

   414 

   415 def mimify(infile, outfile):

   416     """Convert 8bit parts of a MIME mail message to quoted-printable."""

   417     if type(infile) == type(''):

   418         ifile = open(infile)

   419         if type(outfile) == type('') and infile == outfile:

   420             import os

   421             d, f = os.path.split(infile)

   422             os.rename(infile, os.path.join(d, ',' + f))

   423     else:

   424         ifile = infile

   425     if type(outfile) == type(''):

   426         ofile = open(outfile, 'w')

   427     else:

   428         ofile = outfile

   429     nifile = File(ifile, None)

   430     mimify_part(nifile, ofile, 0)

   431     ofile.flush()

   432 

   433 import sys

   434 if __name__ == '__main__' or (len(sys.argv) > 0 and sys.argv[0] == 'mimify'):

   435     import getopt

   436     usage = 'Usage: mimify [-l len] -[ed] [infile [outfile]]'

   437 

   438     decode_base64 = 0

   439     opts, args = getopt.getopt(sys.argv[1:], 'l:edb')

   440     if len(args) not in (0, 1, 2):

   441         print usage

   442         sys.exit(1)

   443     if (('-e', '') in opts) == (('-d', '') in opts) or \

   444        ((('-b', '') in opts) and (('-d', '') not in opts)):

   445         print usage

   446         sys.exit(1)

   447     for o, a in opts:

   448         if o == '-e':

   449             encode = mimify

   450         elif o == '-d':

   451             encode = unmimify

   452         elif o == '-l':

   453             try:

   454                 MAXLEN = int(a)

   455             except (ValueError, OverflowError):

   456                 print usage

   457                 sys.exit(1)

   458         elif o == '-b':

   459             decode_base64 = 1

   460     if len(args) == 0:

   461         encode_args = (sys.stdin, sys.stdout)

   462     elif len(args) == 1:

   463         encode_args = (args[0], sys.stdout)

   464     else:

   465         encode_args = (args[0], args[1])

   466     if decode_base64:

   467         encode_args = encode_args + (decode_base64,)

   468     encode(*encode_args)