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Diffstat (limited to 'old/botan/build/botan/sym_algo.h')
-rw-r--r-- | old/botan/build/botan/sym_algo.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/old/botan/build/botan/sym_algo.h b/old/botan/build/botan/sym_algo.h new file mode 100644 index 0000000..1c8b816 --- /dev/null +++ b/old/botan/build/botan/sym_algo.h @@ -0,0 +1,101 @@ +/** +* Symmetric Algorithm Base Class +* (C) 1999-2007 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#ifndef BOTAN_SYMMETRIC_ALGORITHM_H__ +#define BOTAN_SYMMETRIC_ALGORITHM_H__ + +#include <botan/types.h> +#include <botan/exceptn.h> +#include <botan/symkey.h> + +namespace Botan { + +/** +* This class represents a symmetric algorithm object. +*/ +class BOTAN_DLL SymmetricAlgorithm + { + public: + + /** + * The maximum allowed key length. + */ + const u32bit MAXIMUM_KEYLENGTH; + + /** + * The minimal allowed key length. + */ + const u32bit MINIMUM_KEYLENGTH; + + /** + * A valid keylength is a multiple of this value. + */ + const u32bit KEYLENGTH_MULTIPLE; + + /** + * The name of the algorithm. + * @return the name of the algorithm + */ + virtual std::string name() const = 0; + + /** + * Set the symmetric key of this object. + * @param key the SymmetricKey to be set. + */ + void set_key(const SymmetricKey& key) throw(Invalid_Key_Length) + { set_key(key.begin(), key.length()); } + + /** + * Set the symmetric key of this object. + * @param key the to be set as a byte array. + * @param the length of the byte array. + */ + void set_key(const byte key[], u32bit length) throw(Invalid_Key_Length) + { + if(!valid_keylength(length)) + throw Invalid_Key_Length(name(), length); + key_schedule(key, length); + } + + /** + * Check whether a given key length is valid for this algorithm. + * @param length the key length to be checked. + * @return true if the key length is valid. + */ + bool valid_keylength(u32bit length) const + { + return ((length >= MINIMUM_KEYLENGTH) && + (length <= MAXIMUM_KEYLENGTH) && + (length % KEYLENGTH_MULTIPLE == 0)); + } + + /** + * Construct a SymmetricAlgorithm. + * @param key_min the minimum allowed key length + * @param key_max the maximum allowed key length + * @param key_mod any valid key length must be a multiple of this value + */ + SymmetricAlgorithm(u32bit key_min, u32bit key_max, u32bit key_mod) : + MAXIMUM_KEYLENGTH(key_max ? key_max : key_min), + MINIMUM_KEYLENGTH(key_min), + KEYLENGTH_MULTIPLE(key_mod) + {} + + virtual ~SymmetricAlgorithm() {} + private: + virtual void key_schedule(const byte[], u32bit) = 0; + }; + +/** +* The two possible directions for cipher filters, determining whether they +* actually perform encryption or decryption. +*/ +enum Cipher_Dir { ENCRYPTION, DECRYPTION }; + +} + +#endif |