/************************************************* * EMSA3 Source File * * (C) 1999-2007 Jack Lloyd * *************************************************/ #include #include #include namespace Botan { /************************************************* * EMSA3 Update Operation * *************************************************/ void EMSA3::update(const byte input[], u32bit length) { hash->update(input, length); } /************************************************* * Return the raw (unencoded) data * *************************************************/ SecureVector EMSA3::raw_data() { return hash->final(); } /************************************************* * EMSA3 Encode Operation * *************************************************/ SecureVector EMSA3::encoding_of(const MemoryRegion& msg, u32bit output_bits) { if(msg.size() != hash->OUTPUT_LENGTH) throw Encoding_Error("EMSA3::encoding_of: Bad input length"); u32bit output_length = output_bits / 8; if(output_length < hash_id.size() + hash->OUTPUT_LENGTH + 10) throw Encoding_Error("EMSA3::pad: Output length is too small"); SecureVector T(output_length); const u32bit P_LENGTH = output_length - hash->OUTPUT_LENGTH - hash_id.size() - 2; T[0] = 0x01; set_mem(T+1, P_LENGTH, 0xFF); T[P_LENGTH+1] = 0x00; T.copy(P_LENGTH+2, hash_id, hash_id.size()); T.copy(output_length-hash->OUTPUT_LENGTH, msg, msg.size()); return T; } /************************************************* * EMSA3 Constructor * *************************************************/ EMSA3::EMSA3(const std::string& hash_name) { hash_id = pkcs_hash_id(hash_name); hash = get_hash(hash_name); } }