11#include <botan/internal/divide.h>
12#include <botan/internal/dl_scheme.h>
13#include <botan/internal/keypair.h>
14#include <botan/internal/pk_ops_impl.h>
16#if defined(BOTAN_HAS_RFC6979_GENERATOR)
17 #include <botan/internal/rfc6979.h>
23 return m_public_key->group().q_bytes();
27 return m_public_key->estimated_strength();
31 return m_public_key->p_bits();
35 return m_public_key->get_int_field(
algo_name(), field);
43 return m_public_key->public_key_as_bytes();
47 return m_public_key->DER_encode();
51 return m_public_key->check_key(rng, strong);
55 return std::make_unique<DSA_PrivateKey>(rng, m_public_key->group());
61 BOTAN_ARG_CHECK(m_public_key->group().has_q(),
"Q parameter must be set for DSA");
65 m_public_key = std::make_shared<DL_PublicKey>(group, y);
67 BOTAN_ARG_CHECK(m_public_key->group().has_q(),
"Q parameter must be set for DSA");
73 m_private_key = std::make_shared<DL_PrivateKey>(group, rng);
74 m_public_key = m_private_key->public_key();
80 m_private_key = std::make_shared<DL_PrivateKey>(group, x);
81 m_public_key = m_private_key->public_key();
86 m_public_key = m_private_key->public_key();
88 BOTAN_ARG_CHECK(m_private_key->group().has_q(),
"Q parameter must be set for DSA");
92 if(!m_private_key->check_key(rng, strong)) {
96 if(m_private_key->private_key() >= m_private_key->group().get_q()) {
104 return m_private_key->DER_encode();
108 return m_private_key->raw_private_key_bits();
112 return m_private_key->get_int_field(
algo_name(), field);
117 return std::unique_ptr<DSA_PublicKey>(
new DSA_PublicKey(m_public_key));
127 DSA_Signature_Operation(
const std::shared_ptr<const DL_PrivateKey>& key,
128 std::string_view emsa,
130 PK_Ops::Signature_with_Hash(emsa), m_key(key) {
132 m_b_inv = m_key->group().inverse_mod_q(m_b);
135 size_t signature_length()
const override {
return 2 * m_key->group().q_bytes(); }
137 std::vector<uint8_t> raw_sign(std::span<const uint8_t> msg, RandomNumberGenerator& rng)
override;
139 AlgorithmIdentifier algorithm_identifier()
const override;
142 std::shared_ptr<const DL_PrivateKey> m_key;
146AlgorithmIdentifier DSA_Signature_Operation::algorithm_identifier()
const {
147 const std::string full_name =
"DSA/" + hash_function();
148 const OID oid = OID::from_string(full_name);
149 return AlgorithmIdentifier(oid, AlgorithmIdentifier::USE_EMPTY_PARAM);
152std::vector<uint8_t> DSA_Signature_Operation::raw_sign(std::span<const uint8_t> msg, RandomNumberGenerator& rng) {
153 const DL_Group& group = m_key->group();
154 const BigInt& q = group.get_q();
156 BigInt m = BigInt::from_bytes_with_max_bits(msg.data(), msg.size(), group.q_bits());
162#if defined(BOTAN_HAS_RFC6979_GENERATOR)
166 const BigInt k = BigInt::random_integer(rng, 1, q);
169 const BigInt k_inv = group.inverse_mod_q(group.mod_q(m_b * k)) * m_b;
180 const BigInt r =
ct_modulo(group.power_g_p(k, group.q_bits()), group.get_q());
185 m_b = group.square_mod_q(m_b);
186 m_b_inv = group.square_mod_q(m_b_inv);
188 m = group.multiply_mod_q(m_b, m);
189 const BigInt xr = group.multiply_mod_q(m_b, m_key->private_key(), r);
191 const BigInt s = group.multiply_mod_q(m_b_inv, k_inv, group.mod_q(xr + m));
194 if(r.is_zero() || s.is_zero()) {
198 return unlock(BigInt::encode_fixed_length_int_pair(r, s, q.bytes()));
204class DSA_Verification_Operation
final :
public PK_Ops::Verification_with_Hash {
206 DSA_Verification_Operation(
const std::shared_ptr<const DL_PublicKey>& key, std::string_view emsa) :
207 PK_Ops::Verification_with_Hash(emsa), m_key(key) {}
209 DSA_Verification_Operation(
const std::shared_ptr<const DL_PublicKey>& key,
const AlgorithmIdentifier& alg_id) :
210 PK_Ops::Verification_with_Hash(alg_id,
"DSA"), m_key(key) {}
212 bool verify(std::span<const uint8_t> input, std::span<const uint8_t> sig)
override;
215 std::shared_ptr<const DL_PublicKey> m_key;
218bool DSA_Verification_Operation::verify(std::span<const uint8_t> input, std::span<const uint8_t> sig) {
219 const auto group = m_key->group();
221 const BigInt& q = group.get_q();
222 const size_t q_bytes = q.bytes();
224 if(sig.size() != 2 * q_bytes) {
228 BigInt r(sig.first(q_bytes));
229 BigInt s(sig.last(q_bytes));
231 if(r == 0 || r >= q || s == 0 || s >= q) {
235 BigInt i = BigInt::from_bytes_with_max_bits(input.data(), input.size(), group.q_bits());
240 s = group.inverse_mod_q(s);
242 const BigInt sr = group.multiply_mod_q(s, r);
243 const BigInt si = group.multiply_mod_q(s, i);
245 s = group.multi_exponentiate(si, m_key->public_key(), sr);
248 return (s % group.get_q() == r);
254 std::string_view provider)
const {
255 if(provider ==
"base" || provider.empty()) {
256 return std::make_unique<DSA_Verification_Operation>(this->m_public_key, params);
263 if(provider ==
"base" || provider.empty()) {
264 return std::make_unique<DSA_Verification_Operation>(this->m_public_key, signature_algorithm);
271 std::string_view params,
272 std::string_view provider)
const {
273 if(provider ==
"base" || provider.empty()) {
274 return std::make_unique<DSA_Signature_Operation>(this->m_private_key, params, rng);
#define BOTAN_ARG_CHECK(expr, msg)
virtual OID object_identifier() const
static BigInt random_integer(RandomNumberGenerator &rng, const BigInt &min, const BigInt &max)
secure_vector< uint8_t > private_key_bits() const override
bool check_key(RandomNumberGenerator &rng, bool strong) const override
std::unique_ptr< PK_Ops::Signature > create_signature_op(RandomNumberGenerator &rng, std::string_view params, std::string_view provider) const override
secure_vector< uint8_t > raw_private_key_bits() const override
std::unique_ptr< Public_Key > public_key() const override
const BigInt & get_int_field(std::string_view field) const override
std::optional< size_t > _signature_element_size_for_DER_encoding() const override
std::vector< uint8_t > raw_public_key_bits() const override
size_t estimated_strength() const override
std::unique_ptr< PK_Ops::Verification > create_x509_verification_op(const AlgorithmIdentifier &signature_algorithm, std::string_view provider) const override
friend class DSA_PrivateKey
bool check_key(RandomNumberGenerator &rng, bool strong) const override
std::vector< uint8_t > public_key_bits() const override
AlgorithmIdentifier algorithm_identifier() const override
const BigInt & get_int_field(std::string_view field) const override
std::string algo_name() const override
std::unique_ptr< Private_Key > generate_another(RandomNumberGenerator &rng) const final
size_t key_length() const override
std::unique_ptr< PK_Ops::Verification > create_verification_op(std::string_view params, std::string_view provider) const override
int(* final)(unsigned char *, CTX *)
bool signature_consistency_check(RandomNumberGenerator &rng, const Private_Key &private_key, const Public_Key &public_key, std::string_view padding)
BigInt generate_rfc6979_nonce(const BigInt &x, const BigInt &q, const BigInt &h, std::string_view hash)
BigInt ct_modulo(const BigInt &x, const BigInt &y)
std::vector< T > unlock(const secure_vector< T > &in)
std::vector< T, secure_allocator< T > > secure_vector