/************************************************* * KDF1/KDF2 Source File * * (C) 1999-2007 Jack Lloyd * *************************************************/ #include #include #include #include #include namespace Botan { /************************************************* * Derive a key * *************************************************/ SecureVector KDF::derive_key(u32bit key_len, const MemoryRegion& secret, const std::string& salt) const { return derive_key(key_len, secret, secret.size(), reinterpret_cast(salt.data()), salt.length()); } /************************************************* * Derive a key * *************************************************/ SecureVector KDF::derive_key(u32bit key_len, const MemoryRegion& secret, const byte salt[], u32bit salt_len) const { return derive_key(key_len, secret.begin(), secret.size(), salt, salt_len); } /************************************************* * Derive a key * *************************************************/ SecureVector KDF::derive_key(u32bit key_len, const MemoryRegion& secret, const MemoryRegion& salt) const { return derive_key(key_len, secret.begin(), secret.size(), salt.begin(), salt.size()); } /************************************************* * Derive a key * *************************************************/ SecureVector KDF::derive_key(u32bit key_len, const byte secret[], u32bit secret_len, const std::string& salt) const { return derive_key(key_len, secret, secret_len, reinterpret_cast(salt.data()), salt.length()); } /************************************************* * Derive a key * *************************************************/ SecureVector KDF::derive_key(u32bit key_len, const byte secret[], u32bit secret_len, const byte salt[], u32bit salt_len) const { return derive(key_len, secret, secret_len, salt, salt_len); } /************************************************* * KDF1 Key Derivation Mechanism * *************************************************/ SecureVector KDF1::derive(u32bit, const byte secret[], u32bit secret_len, const byte P[], u32bit P_len) const { std::auto_ptr hash(get_hash(hash_name)); hash->update(secret, secret_len); hash->update(P, P_len); return hash->final(); } /************************************************* * KDF1 Constructor * *************************************************/ KDF1::KDF1(const std::string& h_name) : hash_name(h_name) { if(!have_hash(hash_name)) throw Algorithm_Not_Found(hash_name); } /************************************************* * KDF2 Key Derivation Mechanism * *************************************************/ SecureVector KDF2::derive(u32bit out_len, const byte secret[], u32bit secret_len, const byte P[], u32bit P_len) const { SecureVector output; u32bit counter = 1; std::auto_ptr hash(get_hash(hash_name)); while(out_len && counter) { hash->update(secret, secret_len); for(u32bit j = 0; j != 4; ++j) hash->update(get_byte(j, counter)); hash->update(P, P_len); SecureVector hash_result = hash->final(); u32bit added = std::min(hash_result.size(), out_len); output.append(hash_result, added); out_len -= added; ++counter; } return output; } /************************************************* * KDF2 Constructor * *************************************************/ KDF2::KDF2(const std::string& h_name) : hash_name(h_name) { if(!have_hash(hash_name)) throw Algorithm_Not_Found(hash_name); } }