/* * DSA * (C) 1999-2010 Jack Lloyd * * Distributed under the terms of the Botan license */ #ifndef BOTAN_DSA_H__ #define BOTAN_DSA_H__ #include #include #include #include namespace Botan { /** * DSA Public Key */ class BOTAN_DLL DSA_PublicKey : public virtual DL_Scheme_PublicKey { public: std::string algo_name() const { return "DSA"; } DL_Group::Format group_format() const { return DL_Group::ANSI_X9_57; } u32bit message_parts() const { return 2; } u32bit message_part_size() const { return group_q().bytes(); } u32bit max_input_bits() const { return group_q().bits(); } DSA_PublicKey(const AlgorithmIdentifier& alg_id, const MemoryRegion& key_bits) : DL_Scheme_PublicKey(alg_id, key_bits, DL_Group::ANSI_X9_57) { } DSA_PublicKey(const DL_Group& group, const BigInt& y); protected: DSA_PublicKey() {} }; /** * DSA Private Key */ class BOTAN_DLL DSA_PrivateKey : public DSA_PublicKey, public virtual DL_Scheme_PrivateKey { public: DSA_PrivateKey(const AlgorithmIdentifier& alg_id, const MemoryRegion& key_bits, RandomNumberGenerator& rng); DSA_PrivateKey(RandomNumberGenerator& rng, const DL_Group& group, const BigInt& private_key = 0); bool check_key(RandomNumberGenerator& rng, bool strong) const; }; /** * Object that can create a DSA signature */ class BOTAN_DLL DSA_Signature_Operation : public PK_Ops::Signature { public: DSA_Signature_Operation(const DSA_PrivateKey& dsa); u32bit message_parts() const { return 2; } u32bit message_part_size() const { return q.bytes(); } u32bit max_input_bits() const { return q.bits(); } SecureVector sign(const byte msg[], u32bit msg_len, RandomNumberGenerator& rng); private: const BigInt& q; const BigInt& x; Fixed_Base_Power_Mod powermod_g_p; Modular_Reducer mod_q; }; /** * Object that can verify a DSA signature */ class BOTAN_DLL DSA_Verification_Operation : public PK_Ops::Verification { public: DSA_Verification_Operation(const DSA_PublicKey& dsa); u32bit message_parts() const { return 2; } u32bit message_part_size() const { return q.bytes(); } u32bit max_input_bits() const { return q.bits(); } bool with_recovery() const { return false; } bool verify(const byte msg[], u32bit msg_len, const byte sig[], u32bit sig_len); private: const BigInt& q; const BigInt& y; Fixed_Base_Power_Mod powermod_g_p, powermod_y_p; Modular_Reducer mod_p, mod_q; }; } #endif