diff options
Diffstat (limited to 'botan/src/pubkey/ecdsa/ecdsa.cpp')
-rw-r--r-- | botan/src/pubkey/ecdsa/ecdsa.cpp | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/botan/src/pubkey/ecdsa/ecdsa.cpp b/botan/src/pubkey/ecdsa/ecdsa.cpp new file mode 100644 index 0000000..9640c63 --- /dev/null +++ b/botan/src/pubkey/ecdsa/ecdsa.cpp @@ -0,0 +1,230 @@ +/* +* ECDSA implemenation +* (C) 2007 Manuel Hartl, FlexSecure GmbH +* 2007 Falko Strenzke, FlexSecure GmbH +* 2008 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#include <botan/ecdsa.h> +#include <botan/numthry.h> +#include <botan/util.h> +#include <botan/der_enc.h> +#include <botan/ber_dec.h> +#include <botan/secmem.h> +#include <botan/point_gfp.h> + +namespace Botan { + +ECDSA_PrivateKey::ECDSA_PrivateKey(RandomNumberGenerator& rng, + const EC_Domain_Params& dom_pars) + { + mp_dom_pars = std::auto_ptr<EC_Domain_Params>(new EC_Domain_Params(dom_pars)); + generate_private_key(rng); + + try + { + mp_public_point->check_invariants(); + } + catch(Illegal_Point& e) + { + throw Invalid_State("ECDSA key generation failed"); + } + + m_ecdsa_core = ECDSA_Core(*mp_dom_pars, m_private_value, *mp_public_point); + } + +/* +* ECDSA_PublicKey +*/ +void ECDSA_PublicKey::affirm_init() const // virtual + { + EC_PublicKey::affirm_init(); + } + +void ECDSA_PublicKey::set_domain_parameters(const EC_Domain_Params& dom_pars) + { + if(mp_dom_pars.get()) + { + // they are already set, we must ensure that they are equal to the arg + if(dom_pars != *mp_dom_pars.get()) + throw Invalid_Argument("EC_PublicKey::set_domain_parameters - cannot reset to a new value"); + + return; + } + + if(m_enc_public_point.size() == 0) + throw Invalid_State("EC_PublicKey::set_domain_parameters(): encoded public point isn't set"); + + // now try to decode the public key ... + PointGFp tmp_pp(OS2ECP(m_enc_public_point, dom_pars.get_curve())); + try + { + tmp_pp.check_invariants(); + } + catch(Illegal_Point e) + { + throw Invalid_State("EC_PublicKey::set_domain_parameters(): point does not lie on provided curve"); + } + + std::auto_ptr<EC_Domain_Params> p_tmp_pars(new EC_Domain_Params(dom_pars)); + ECDSA_Core tmp_ecdsa_core(*p_tmp_pars, BigInt(0), tmp_pp); + mp_public_point.reset(new PointGFp(tmp_pp)); + m_ecdsa_core = tmp_ecdsa_core; + mp_dom_pars = p_tmp_pars; + } + +void ECDSA_PublicKey::set_all_values(const ECDSA_PublicKey& other) + { + m_param_enc = other.m_param_enc; + m_ecdsa_core = other.m_ecdsa_core; + m_enc_public_point = other.m_enc_public_point; + if(other.mp_dom_pars.get()) + mp_dom_pars.reset(new EC_Domain_Params(other.domain_parameters())); + + if(other.mp_public_point.get()) + mp_public_point.reset(new PointGFp(other.public_point())); + } + +ECDSA_PublicKey::ECDSA_PublicKey(const ECDSA_PublicKey& other) + : Public_Key(), + EC_PublicKey(), + PK_Verifying_wo_MR_Key() + { + set_all_values(other); + } + +const ECDSA_PublicKey& ECDSA_PublicKey::operator=(const ECDSA_PublicKey& rhs) + { + set_all_values(rhs); + return *this; + } + +bool ECDSA_PublicKey::verify(const byte message[], + u32bit mess_len, + const byte signature[], + u32bit sig_len) const + { + affirm_init(); + + BigInt r, s; + + BER_Decoder(signature, sig_len) + .start_cons(SEQUENCE) + .decode(r) + .decode(s) + .end_cons() + .verify_end(); + + u32bit enc_len = std::max(r.bytes(), s.bytes()); + + SecureVector<byte> sv_plain_sig; + + sv_plain_sig.append(BigInt::encode_1363(r, enc_len)); + sv_plain_sig.append(BigInt::encode_1363(s, enc_len)); + + return m_ecdsa_core.verify(sv_plain_sig, sv_plain_sig.size(), + message, mess_len); + } + +ECDSA_PublicKey::ECDSA_PublicKey(const EC_Domain_Params& dom_par, + const PointGFp& public_point) + { + mp_dom_pars = std::auto_ptr<EC_Domain_Params>(new EC_Domain_Params(dom_par)); + mp_public_point = std::auto_ptr<PointGFp>(new PointGFp(public_point)); + m_param_enc = ENC_EXPLICIT; + m_ecdsa_core = ECDSA_Core(*mp_dom_pars, BigInt(0), *mp_public_point); + } + +void ECDSA_PublicKey::X509_load_hook() + { + EC_PublicKey::X509_load_hook(); + EC_PublicKey::affirm_init(); + m_ecdsa_core = ECDSA_Core ( *mp_dom_pars, BigInt ( 0 ), *mp_public_point ); + } + +u32bit ECDSA_PublicKey::max_input_bits() const + { + if(!mp_dom_pars.get()) + { + throw Invalid_State("ECDSA_PublicKey::max_input_bits(): domain parameters not set"); + } + return mp_dom_pars->get_order().bits(); + } + +/************************* +* ECDSA_PrivateKey +*************************/ +void ECDSA_PrivateKey::affirm_init() const // virtual + { + EC_PrivateKey::affirm_init(); + } + +void ECDSA_PrivateKey::PKCS8_load_hook(bool generated) + { + EC_PrivateKey::PKCS8_load_hook(generated); + EC_PrivateKey::affirm_init(); + m_ecdsa_core = ECDSA_Core(*mp_dom_pars, m_private_value, *mp_public_point); + } + +void ECDSA_PrivateKey::set_all_values(const ECDSA_PrivateKey& other) + { + m_private_value = other.m_private_value; + m_param_enc = other.m_param_enc; + m_ecdsa_core = other.m_ecdsa_core; + m_enc_public_point = other.m_enc_public_point; + + if(other.mp_dom_pars.get()) + mp_dom_pars.reset(new EC_Domain_Params(other.domain_parameters())); + + if(other.mp_public_point.get()) + mp_public_point.reset(new PointGFp(other.public_point())); + } + +ECDSA_PrivateKey::ECDSA_PrivateKey(ECDSA_PrivateKey const& other) + : Public_Key(), + EC_PublicKey(), + Private_Key(), + ECDSA_PublicKey(), + EC_PrivateKey(), + PK_Signing_Key() + { + set_all_values(other); + } + + +const ECDSA_PrivateKey& ECDSA_PrivateKey::operator=(const ECDSA_PrivateKey& rhs) + { + set_all_values(rhs); + return *this; + } + +SecureVector<byte> ECDSA_PrivateKey::sign(const byte message[], + u32bit mess_len, + RandomNumberGenerator& rng) const + { + affirm_init(); + + SecureVector<byte> sv_sig = m_ecdsa_core.sign(message, mess_len, rng); + + if(sv_sig.size() % 2 != 0) + throw Invalid_Argument("Erroneous length of signature"); + + u32bit rs_len = sv_sig.size() / 2; + SecureVector<byte> sv_r, sv_s; + sv_r.set(sv_sig.begin(), rs_len); + sv_s.set(&sv_sig[rs_len], rs_len); + + BigInt r = BigInt::decode(sv_r, sv_r.size()); + BigInt s = BigInt::decode(sv_s, sv_s.size()); + + return DER_Encoder() + .start_cons(SEQUENCE) + .encode(r) + .encode(s) + .end_cons() + .get_contents(); + } + +} |