X-Git-Url: http://wagner.pp.ru/gitweb/?a=blobdiff_plain;f=ctypescrypto%2Fcipher.py;h=a0a9ac33edc3912021a2f826cf04edad660fb788;hb=ec92bf04b008b0401014cae90fa2dfca18efa02c;hp=91c5283a659f70767620826ef81ae4fd7e1b33a2;hpb=48ddb5373a0a8b0481ed1c72ece36b5973fd3da5;p=oss%2Fctypescrypto.git

diff --git a/ctypescrypto/cipher.py b/ctypescrypto/cipher.py
index 91c5283..a0a9ac3 100644
--- a/ctypescrypto/cipher.py
+++ b/ctypescrypto/cipher.py
@@ -1,3 +1,7 @@
+"""
+access to symmetric ciphers from libcrypto
+
+"""
 from ctypes import create_string_buffer,c_char_p,c_void_p,c_int,c_long,byref,POINTER
 from ctypescrypto import libcrypto
 from ctypescrypto.exception import LibCryptoError
@@ -8,6 +12,8 @@ CIPHER_MODES = ("STREAM","ECB","CBC", "CFB", "OFB", "CTR","GCM")
 
 #
 
+__all__ = ['CipherError','new','Cipher','CipherType']
+
 class CipherError(LibCryptoError):
 	pass
 
@@ -38,7 +44,7 @@ class CipherType:
 		"""
 		self.cipher = libcrypto.EVP_get_cipherbyname(cipher_name)
 		if self.cipher is None:
-			raise CipherError, "Unknown cipher: %s" % cipher_name
+			raise CipherError("Unknown cipher: %s" % cipher_name)
 
 	def __del__(self):
 		pass
@@ -73,7 +79,7 @@ class CipherType:
 		"""
 			Return cipher's algorithm name, derived from OID
 		"""
-		return self.oid().short_name() 
+		return self.oid().shortname() 
 	def oid(self):
 		"""
 			Returns ASN.1 object identifier of the cipher as
@@ -109,29 +115,28 @@ class Cipher:
 		iv_ptr = c_char_p(iv)
 		self.ctx = libcrypto.EVP_CIPHER_CTX_new()
 		if self.ctx == 0:
-			raise CipherError, "Unable to create cipher context"
+			raise CipherError("Unable to create cipher context")
 		self.encrypt = encrypt
-		if encrypt: 
-			enc = 1
-		else: 
-			enc = 0
+		enc=1 if encrypt else 0
 		if not iv is None and len(iv) != cipher_type.iv_length():
 			raise ValueError("Invalid IV length for this algorithm")
 			
 		if len(key) != cipher_type.key_length():
 			if (cipher_type.flags() & 8) != 0:
 				# Variable key length cipher.
-				result = libcrypto.EVP_CipherInit_ex(self.ctx,cipher_type.cipher,None,None,None,c_int(enc))
-				result=libcrypto.EVP_CIPHER_CTX_set_key_length(self.ctx,len(key))
+				result = libcrypto.EVP_CipherInit_ex(self.ctx, cipher_type.cipher, None, None, None, c_int(enc))
+				result = libcrypto.EVP_CIPHER_CTX_set_key_length(self.ctx,len(key))
 				if result == 0:
 					self._clean_ctx()
 					raise CipherError("Unable to set key length")
+				result = libcrypto.EVP_CipherInit_ex(self.ctx, None, None, key_ptr, iv_ptr, c_int(enc))
 			else:
 				raise ValueError("Invalid key length for this algorithm")
-		result = libcrypto.EVP_CipherInit_ex(self.ctx, cipher_type.cipher, None, key_ptr, iv_ptr, c_int(enc))
+		else:
+			result = libcrypto.EVP_CipherInit_ex(self.ctx, cipher_type.cipher, None, key_ptr, iv_ptr, c_int(enc))
 		if result == 0:
 			self._clean_ctx()
-			raise CipherError, "Unable to initialize cipher"
+			raise CipherError("Unable to initialize cipher")
 		self.cipher_type = cipher_type
 		self.block_size = self.cipher_type.block_size()
 		self.cipher_finalized = False
@@ -143,10 +148,7 @@ class Cipher:
 		"""
 			Sets padding mode of the cipher
 		"""
-		if padding:
-			padding_flag = 1
-		else:
-			padding_flag = 0
+		padding_flag=1 if padding else 0
 		libcrypto.EVP_CIPHER_CTX_set_padding(self.ctx, padding_flag)
 
 	def update(self, data):
@@ -162,10 +164,10 @@ class Cipher:
 			called
 		"""
 		if self.cipher_finalized :
-			raise CipherError, "No updates allowed"
-		if type(data) != type(""):
-			raise TypeError, "A string is expected"
-		if len(data) <= 0:
+			raise CipherError("No updates allowed")
+		if not isinstance(data,str):
+			raise TypeError("A string is expected")
+		if len(data) == 0:
 			return ""
 		outbuf=create_string_buffer(self.block_size+len(data))
 		outlen=c_int(0)
@@ -184,14 +186,14 @@ class Cipher:
 			state, they would be processed and returned.
 		"""
 		if self.cipher_finalized :
-			raise CipherError, "Cipher operation is already completed"
+			raise CipherError("Cipher operation is already completed")
 		outbuf=create_string_buffer(self.block_size)
 		self.cipher_finalized = True
-		outlen=c_int()
+		outlen=c_int(0)
 		result = libcrypto.EVP_CipherFinal_ex(self.ctx,outbuf , byref(outlen))
 		if result == 0:
 			self._clean_ctx()
-			raise CipherError, "Unable to finalize cipher"
+			raise CipherError("Unable to finalize cipher")
 		if outlen.value>0:
 			return outbuf.raw[:outlen.value]
 		else:
@@ -200,8 +202,8 @@ class Cipher:
 	def _clean_ctx(self):
 		try:
 			if self.ctx is not None:
-				self.libcrypto.EVP_CIPHER_CTX_cleanup(self.ctx)
-				self.libcrypto.EVP_CIPHER_CTX_free(self.ctx)
+				libcrypto.EVP_CIPHER_CTX_cleanup(self.ctx)
+				libcrypto.EVP_CIPHER_CTX_free(self.ctx)
 				del(self.ctx)
 		except AttributeError:
 			pass
@@ -225,4 +227,4 @@ libcrypto.EVP_CIPHER_nid.argtypes=(c_void_p,)
 libcrypto.EVP_CipherUpdate.argtypes=(c_void_p,c_char_p,POINTER(c_int),c_char_p,c_int)
 libcrypto.EVP_get_cipherbyname.restype=c_void_p
 libcrypto.EVP_get_cipherbyname.argtypes=(c_char_p,)
-
+libcrypto.EVP_CIPHER_CTX_set_key_length.argtypes=(c_void_p,c_int)