ctypescrypto/engine.py

   1 """
   2 engine loading and configuration
   3 """
   4 from ctypes import *
   5 from ctypescrypto import libcrypto
   6 from ctypescrypto.exception import LibCryptoError
   7
   8 __all__=['default','set_default']
   9
  10 default=None
  11
  12 def set_default(engine):
  13     """
  14         Loads specified engine and sets it as default for all
  15         algorithms, supported by it
  16     """
  17     global default
  18     e=libcrypto.ENGINE_by_id(engine)
  19     if e is None:
  20         # Try load engine
  21         e = libcrypto.ENGINE_by_id("dynamic")
  22         if  e is None:
  23             raise LibCryptoError("Cannot get 'dynamic' engine")
  24         if not libcrypto.ENGINE_ctrl_cmd_string(e,"SO_PATH",engine,0):
  25             raise LibCryptoError("Cannot execute ctrl cmd SO_PATH")
  26         if not libcrypto.ENGINE_ctrl_cmd_string(e,"LOAD",None,0):
  27             raise LibCryptoError("Cannot execute ctrl cmd LOAD")
  28     if e is None:
  29         raise ValueError("Cannot find engine "+engine)
  30     libcrypto.ENGINE_set_default(e,c_int(0xFFFF))
  31     default=e
  32
  33 # Declare function result and arguments for used functions
  34 libcrypto.ENGINE_by_id.restype=c_void_p
  35 libcrypto.ENGINE_by_id.argtypes=(c_char_p,)
  36 libcrypto.ENGINE_set_default.argtypes=(c_void_p,c_int)
  37 libcrypto.ENGINE_ctrl_cmd_string.argtypes=(c_void_p,c_char_p,c_char_p,c_int)
  38 libcrypto.ENGINE_finish.argtypes=(c_char_p,)