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