developer.intra2net.com Git - python-delta-tar/blob - file_crypt.py

   1 #!/usr/bin/env python3
   2
   3 """ Encrypt a single file
   4
   5 low-cost quick-devel badly-documented
   6
   7 .. codeauthor:: Intra2net <info@intra2net.com>
   8 """
   9
  10 import sys
  11 from deltatar import tarfile
  12 from traceback import print_exc
  13
  14
  15 def main(do_encrypt, in_file, out_file, password, comptype='gz', enctype='aes',
  16          key_length=128, bufsize=tarfile.RECORDSIZE, encoding='UTF-8'):
  17     """ Main function, called when running file as script
  18
  19     see module doc for more info
  20     """
  21
  22     write_handle = read_handle = None
  23     return_code = 4
  24
  25     try:
  26         # open file to read
  27         if do_encrypt:
  28             read_handle = open(in_file, 'rt')
  29         else:
  30             read_handle = tarfile._Stream(name=in_file, mode='r',
  31                                           comptype=comptype, bufsize=bufsize,
  32                                           fileobj=None, enctype=enctype,
  33                                           key_length=key_length,
  34                                           password=password)
  35         return_code = 3
  36
  37         # open file to write
  38         if do_encrypt:
  39             write_handle = tarfile._Stream(name=out_file, mode='w',
  40                                            comptype=comptype, bufsize=bufsize,
  41                                            fileobj=None, enctype=enctype,
  42                                            key_length=key_length,
  43                                            password=password)
  44         else:
  45             write_handle = open(out_file, 'wt')
  46         return_code = 1
  47
  48         # convert
  49         while True:
  50             buf = read_handle.read(bufsize)
  51             print('.', end='')
  52             if do_encrypt:
  53                 write_handle.write(buf.encode(encoding, errors='strict'))
  54             else:
  55                 write_handle.write(buf.decode(encoding, errors='replace'))
  56             if len(buf) < bufsize:
  57                 if do_encrypt:
  58                     print('successfully encrypted {} into {}'
  59                           .format(in_file, out_file))
  60                 else:
  61                     print('successfully decrypted {} into {}'
  62                           .format(in_file, out_file))
  63                 break   # reached EOF
  64
  65         return_code = 0
  66
  67     except Exception:
  68         print('error encrypting file')
  69         print_exc()
  70
  71     finally:
  72         # close everything
  73         if write_handle:
  74             try:
  75                 write_handle.close()
  76             except Exception:
  77                 return_code += 8
  78                 print('error closing out file')
  79                 print_exc()
  80
  81         if read_handle:
  82             try:
  83                 read_handle.close()
  84             except Exception:
  85                 return_code += 16
  86                 print('error closing in file')
  87                 print_exc()
  88
  89     # done
  90     return return_code
  91
  92
  93 if __name__ == '__main__':
  94     if len(sys.argv) < 4:
  95         print('file_crypt.py {enc|dec} [-c] INFILE OUTFILE PASSWORD')
  96         sys.exit(2)
  97     elif sys.argv[1] == '-h':
  98         print('encrypt_file.py {enc|dec} [-c] INFILE OUTFILE PASSWORD')
  99         sys.exit(0)
 100
 101     comptype = 'tar'  # auto-detect, not sure whether this would work
 102     idx = 1
 103     if sys.argv[idx] == '-c':
 104         print('assuming gzip compression')
 105         comptype = 'gz'
 106         idx += 1
 107
 108     do_encrypt = None
 109     if sys.argv[idx] == 'enc':
 110         do_encrypt = True
 111     elif sys.argv[idx] == 'dec':
 112         do_encrypt = False
 113     else:
 114         print('encrypt_file.py {enc|dec} [-c] INFILE OUTFILE PASSWORD')
 115         sys.exit(2)
 116
 117     if len(sys.argv) != idx+4:
 118         print('encrypt_file.py {enc|dec} [-c] INFILE OUTFILE PASSWORD')
 119         sys.exit(2)
 120
 121     sys.exit(main(do_encrypt, sys.argv[idx+1], sys.argv[idx+2],
 122                   sys.argv[idx+3], comptype))