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,)