/************************************************* * DSA Source File * * (C) 1999-2007 Jack Lloyd * *************************************************/ #include #include #include namespace Botan { /************************************************* * DSA_PublicKey Constructor * *************************************************/ DSA_PublicKey::DSA_PublicKey(const DL_Group& grp, const BigInt& y1) { group = grp; y = y1; X509_load_hook(); } /************************************************* * Algorithm Specific X.509 Initialization Code * *************************************************/ void DSA_PublicKey::X509_load_hook() { core = DSA_Core(group, y); load_check(); } /************************************************* * DSA Verification Function * *************************************************/ bool DSA_PublicKey::verify(const byte msg[], u32bit msg_len, const byte sig[], u32bit sig_len) const { return core.verify(msg, msg_len, sig, sig_len); } /************************************************* * Return the maximum input size in bits * *************************************************/ u32bit DSA_PublicKey::max_input_bits() const { return group_q().bits(); } /************************************************* * Return the size of each portion of the sig * *************************************************/ u32bit DSA_PublicKey::message_part_size() const { return group_q().bytes(); } /************************************************* * Create a DSA private key * *************************************************/ DSA_PrivateKey::DSA_PrivateKey(const DL_Group& grp) { group = grp; x = random_integer(2, group_q() - 1); PKCS8_load_hook(true); } /************************************************* * DSA_PrivateKey Constructor * *************************************************/ DSA_PrivateKey::DSA_PrivateKey(const DL_Group& grp, const BigInt& x1, const BigInt& y1) { group = grp; y = y1; x = x1; PKCS8_load_hook(); } /************************************************* * Algorithm Specific PKCS #8 Initialization Code * *************************************************/ void DSA_PrivateKey::PKCS8_load_hook(bool generated) { if(y == 0) y = power_mod(group_g(), x, group_p()); core = DSA_Core(group, y, x); if(generated) gen_check(); else load_check(); } /************************************************* * DSA Signature Operation * *************************************************/ SecureVector DSA_PrivateKey::sign(const byte in[], u32bit length) const { const BigInt& q = group_q(); BigInt k; do k.randomize(q.bits()); while(k >= q); return core.sign(in, length, k); } /************************************************* * Check Private DSA Parameters * *************************************************/ bool DSA_PrivateKey::check_key(bool strong) const { if(!DL_Scheme_PrivateKey::check_key(strong) || x >= group_q()) return false; if(!strong) return true; try { KeyPair::check_key(get_pk_signer(*this, "EMSA1(SHA-1)"), get_pk_verifier(*this, "EMSA1(SHA-1)") ); } catch(Self_Test_Failure) { return false; } return true; } }