ctypescrypto/pbkdf2.py

   1 """
   2 PKCS5 PBKDF2 function.
   3
   4 """
   5
   6 from ctypes import c_char_p,c_int, c_void_p, create_string_buffer
   7 from ctypescrypto import libcrypto
   8 from ctypescrypto.digest import DigestType
   9
  10 def pbkdf2(password,salt,outlen,digesttype="sha1",iterations=2000):
  11         """
  12                 Interface to PKCS5_PBKDF2_HMAC function
  13                 Parameters:
  14
  15                                 @param password - password to derive key from
  16                                 @param salt - random salt to use for key derivation
  17                                 @param outlen - number of bytes to derive
  18                                 @param digesttype - name of digest to use to use (default sha1)
  19                                 @param iterations - number of iterations to use
  20
  21                                 @returns outlen bytes of key material derived from password and salt
  22         """
  23         dt=DigestType(digesttype)
  24         out=create_string_buffer(outlen)
  25         res=libcrypto.PKCS5_PBKDF2_HMAC(password,len(password),salt,len(salt),
  26                 iterations,dt.digest,outlen,out)
  27         if res<=0:
  28                 raise LibCryptoError("error computing PBKDF2")
  29         return out.raw
  30
  31 libcrypto.PKCS5_PBKDF2_HMAC.argtypes=(c_char_p,c_int,c_char_p,c_int,c_int,
  32         c_void_p,c_int,c_char_p)
  33 libcrypto.PKCS5_PBKDF2_HMAC.restupe=c_int