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Diffstat (limited to 'comm/third_party/botan/src/lib/base/sym_algo.h')
-rw-r--r-- | comm/third_party/botan/src/lib/base/sym_algo.h | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/base/sym_algo.h b/comm/third_party/botan/src/lib/base/sym_algo.h new file mode 100644 index 0000000000..41d9992927 --- /dev/null +++ b/comm/third_party/botan/src/lib/base/sym_algo.h @@ -0,0 +1,190 @@ +/* +* Symmetric Algorithm Base Class +* (C) 1999-2007 Jack Lloyd +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#ifndef BOTAN_SYMMETRIC_ALGORITHM_H_ +#define BOTAN_SYMMETRIC_ALGORITHM_H_ + +#include <botan/symkey.h> +#include <botan/types.h> + +namespace Botan { + +/** +* Represents the length requirements on an algorithm key +*/ +class BOTAN_PUBLIC_API(2,0) Key_Length_Specification final + { + public: + /** + * Constructor for fixed length keys + * @param keylen the supported key length + */ + explicit Key_Length_Specification(size_t keylen) : + m_min_keylen(keylen), + m_max_keylen(keylen), + m_keylen_mod(1) + { + } + + /** + * Constructor for variable length keys + * @param min_k the smallest supported key length + * @param max_k the largest supported key length + * @param k_mod the number of bytes the key must be a multiple of + */ + Key_Length_Specification(size_t min_k, + size_t max_k, + size_t k_mod = 1) : + m_min_keylen(min_k), + m_max_keylen(max_k ? max_k : min_k), + m_keylen_mod(k_mod) + { + } + + /** + * @param length is a key length in bytes + * @return true iff this length is a valid length for this algo + */ + bool valid_keylength(size_t length) const + { + return ((length >= m_min_keylen) && + (length <= m_max_keylen) && + (length % m_keylen_mod == 0)); + } + + /** + * @return minimum key length in bytes + */ + size_t minimum_keylength() const + { + return m_min_keylen; + } + + /** + * @return maximum key length in bytes + */ + size_t maximum_keylength() const + { + return m_max_keylen; + } + + /** + * @return key length multiple in bytes + */ + size_t keylength_multiple() const + { + return m_keylen_mod; + } + + /* + * Multiplies all length requirements with the given factor + * @param n the multiplication factor + * @return a key length specification multiplied by the factor + */ + Key_Length_Specification multiple(size_t n) const + { + return Key_Length_Specification(n * m_min_keylen, + n * m_max_keylen, + n * m_keylen_mod); + } + + private: + size_t m_min_keylen, m_max_keylen, m_keylen_mod; + }; + +/** +* This class represents a symmetric algorithm object. +*/ +class BOTAN_PUBLIC_API(2,0) SymmetricAlgorithm + { + public: + virtual ~SymmetricAlgorithm() = default; + + /** + * Reset the state. + */ + virtual void clear() = 0; + + /** + * @return object describing limits on key size + */ + virtual Key_Length_Specification key_spec() const = 0; + + /** + * @return maximum allowed key length + */ + size_t maximum_keylength() const + { + return key_spec().maximum_keylength(); + } + + /** + * @return minimum allowed key length + */ + size_t minimum_keylength() const + { + return key_spec().minimum_keylength(); + } + + /** + * 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(size_t length) const + { + return key_spec().valid_keylength(length); + } + + /** + * Set the symmetric key of this object. + * @param key the SymmetricKey to be set. + */ + void set_key(const SymmetricKey& key) + { + set_key(key.begin(), key.length()); + } + + template<typename Alloc> + void set_key(const std::vector<uint8_t, Alloc>& key) + { + set_key(key.data(), key.size()); + } + + /** + * Set the symmetric key of this object. + * @param key the to be set as a byte array. + * @param length in bytes of key param + */ + void set_key(const uint8_t key[], size_t length); + + /** + * @return the algorithm name + */ + virtual std::string name() const = 0; + + protected: + void verify_key_set(bool cond) const + { + if(cond == false) + throw_key_not_set_error(); + } + + private: + void throw_key_not_set_error() const; + + /** + * Run the key schedule + * @param key the key + * @param length of key + */ + virtual void key_schedule(const uint8_t key[], size_t length) = 0; + }; + +} + +#endif |