Botan 3.7.1
Crypto and TLS for C&
ecc_key.cpp
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1/*
2* ECC Key implemenation
3* (C) 2007 Manuel Hartl, FlexSecure GmbH
4* Falko Strenzke, FlexSecure GmbH
5* 2008-2010 Jack Lloyd
6*
7* Botan is released under the Simplified BSD License (see license.txt)
8*/
9
10#include <botan/ecc_key.h>
11
12#include <botan/ber_dec.h>
13#include <botan/der_enc.h>
14#include <botan/secmem.h>
15#include <botan/internal/ec_key_data.h>
16#include <botan/internal/fmt.h>
17#include <botan/internal/workfactor.h>
18
19#if defined(BOTAN_HAS_LEGACY_EC_POINT)
20 #include <botan/ec_point.h>
21#endif
22
23namespace Botan {
24
26 return domain().get_p_bits();
27}
28
32
33namespace {
34
35EC_Group_Encoding default_encoding_for(const EC_Group& group) {
36 if(group.get_curve_oid().empty()) {
38 } else {
40 }
41}
42
43} // namespace
44
45#if defined(BOTAN_HAS_LEGACY_EC_POINT)
46EC_PublicKey::EC_PublicKey(EC_Group group, const EC_Point& pub_point) {
47 auto pt = EC_AffinePoint(group, pub_point);
48 m_public_key = std::make_shared<const EC_PublicKey_Data>(std::move(group), std::move(pt));
49 m_domain_encoding = default_encoding_for(domain());
50}
51#endif
52
54 m_public_key = std::make_shared<const EC_PublicKey_Data>(std::move(group), std::move(pub_point));
55 m_domain_encoding = default_encoding_for(domain());
56}
57
58EC_PublicKey::EC_PublicKey(const AlgorithmIdentifier& alg_id, std::span<const uint8_t> key_bits) {
59 m_public_key = std::make_shared<const EC_PublicKey_Data>(EC_Group(alg_id.parameters()), key_bits);
60 m_domain_encoding = default_encoding_for(domain());
61}
62
65 return m_public_key->group();
66}
67
68#if defined(BOTAN_HAS_LEGACY_EC_POINT)
69const EC_Point& EC_PublicKey::public_point() const {
71 return m_public_key->legacy_point();
72}
73#endif
74
77 return m_public_key->public_key();
78}
79
80bool EC_PublicKey::check_key(RandomNumberGenerator& rng, bool /*strong*/) const {
81 // We already checked when deserializing that the point was on the curve
82 return domain().verify_group(rng) && !_public_ec_point().is_identity();
83}
84
88
89std::vector<uint8_t> EC_PublicKey::raw_public_key_bits() const {
91}
92
93std::vector<uint8_t> EC_PublicKey::public_key_bits() const {
94 return raw_public_key_bits();
95}
96
97std::vector<uint8_t> EC_PublicKey::DER_domain() const {
99}
100
103 throw Invalid_Argument("Invalid point encoding for EC_PublicKey");
104 }
105
106 m_point_encoding = enc;
107}
108
110 if(form == EC_Group_Encoding::NamedCurve && domain().get_curve_oid().empty()) {
111 throw Invalid_Argument("Cannot used NamedCurve encoding for a curve without an OID");
112 }
113
114 m_domain_encoding = form;
115}
116
119 return m_private_key->legacy_bigint();
120}
121
124 return m_private_key->private_key();
125}
126
127/**
128* EC_PrivateKey constructor
129*/
131 EC_Group ec_group,
132 const BigInt& x,
133 bool with_modular_inverse) {
134 auto scalar = (x.is_zero()) ? EC_Scalar::random(ec_group, rng) : EC_Scalar::from_bigint(ec_group, x);
135 m_private_key = std::make_shared<EC_PrivateKey_Data>(std::move(ec_group), std::move(scalar));
136 m_public_key = m_private_key->public_key(rng, with_modular_inverse);
137 m_domain_encoding = default_encoding_for(domain());
138}
139
140EC_PrivateKey::EC_PrivateKey(RandomNumberGenerator& rng, EC_Group ec_group, bool with_modular_inverse) {
141 auto scalar = EC_Scalar::random(ec_group, rng);
142 m_private_key = std::make_shared<EC_PrivateKey_Data>(std::move(ec_group), std::move(scalar));
143 m_public_key = m_private_key->public_key(rng, with_modular_inverse);
144 m_domain_encoding = default_encoding_for(domain());
145}
146
147EC_PrivateKey::EC_PrivateKey(EC_Group ec_group, EC_Scalar x, bool with_modular_inverse) {
148 m_private_key = std::make_shared<EC_PrivateKey_Data>(std::move(ec_group), std::move(x));
149 m_public_key = m_private_key->public_key(with_modular_inverse);
150 m_domain_encoding = default_encoding_for(domain());
151}
152
157
159 BOTAN_STATE_CHECK(m_private_key != nullptr && m_public_key != nullptr);
160
161 return DER_Encoder()
163 .encode(static_cast<size_t>(1))
166 .encode(m_public_key->public_key().serialize_uncompressed(), ASN1_Type::BitString)
167 .end_cons()
168 .end_cons()
169 .get_contents();
170}
171
173 std::span<const uint8_t> key_bits,
174 bool with_modular_inverse) {
175 EC_Group group(alg_id.parameters());
176
177 OID key_parameters;
180
181 BER_Decoder(key_bits)
183 .decode_and_check<size_t>(1, "Unknown version code for ECC key")
185 .decode_optional(key_parameters, ASN1_Type(0), ASN1_Class::ExplicitContextSpecific)
187 .end_cons();
188
189 m_private_key = std::make_shared<EC_PrivateKey_Data>(group, private_key_bits);
190
191 if(public_key_bits.empty()) {
192 m_public_key = m_private_key->public_key(with_modular_inverse);
193 } else {
194 m_public_key = std::make_shared<EC_PublicKey_Data>(group, public_key_bits);
195 }
196
197 m_domain_encoding = default_encoding_for(domain());
198}
199
200bool EC_PrivateKey::check_key(RandomNumberGenerator& rng, bool strong) const {
201 if(!m_private_key) {
202 return false;
203 }
204
205 return EC_PublicKey::check_key(rng, strong);
206}
207
208const BigInt& EC_PublicKey::get_int_field(std::string_view field) const {
209 if(field == "public_x" || field == "public_y") {
210 throw Not_Implemented(fmt("EC_PublicKey::get_int_field no longer implements getter for {}", field));
211 } else if(field == "base_x") {
212 return this->domain().get_g_x();
213 } else if(field == "base_y") {
214 return this->domain().get_g_y();
215 } else if(field == "p") {
216 return this->domain().get_p();
217 } else if(field == "a") {
218 return this->domain().get_a();
219 } else if(field == "b") {
220 return this->domain().get_b();
221 } else if(field == "cofactor") {
222 return this->domain().get_cofactor();
223 } else if(field == "order") {
224 return this->domain().get_order();
225 } else {
226 return Public_Key::get_int_field(field);
227 }
228}
229
230const BigInt& EC_PrivateKey::get_int_field(std::string_view field) const {
231 if(field == "x") {
232 return this->private_value();
233 } else {
234 return EC_PublicKey::get_int_field(field);
235 }
236}
237
238} // namespace Botan
#define BOTAN_STATE_CHECK(expr)
Definition assert.h:41
const std::vector< uint8_t > & parameters() const
Definition asn1_obj.h:474
virtual const BigInt & get_int_field(std::string_view field) const
Definition pk_keys.cpp:18
virtual OID object_identifier() const
Definition pk_keys.cpp:22
BER_Decoder start_sequence()
Definition ber_dec.h:123
BER_Decoder & decode_and_check(const T &expected, std::string_view error_msg)
Definition ber_dec.h:272
bool is_zero() const
Definition bigint.h:458
secure_vector< uint8_t > get_contents()
Definition der_enc.cpp:132
DER_Encoder & start_explicit_context_specific(uint32_t tag)
Definition der_enc.h:72
DER_Encoder & start_sequence()
Definition der_enc.h:64
DER_Encoder & end_cons()
Definition der_enc.cpp:171
DER_Encoder & encode(bool b)
Definition der_enc.cpp:250
bool is_identity() const
Return true if this point is the identity element.
std::vector< uint8_t > serialize(EC_Point_Format format) const
Return an encoding depending on the requested format.
const BigInt & get_b() const
Definition ec_group.cpp:522
const BigInt & get_a() const
Definition ec_group.cpp:518
const BigInt & get_g_y() const
Definition ec_group.cpp:570
const BigInt & get_cofactor() const
Definition ec_group.cpp:574
const BigInt & get_p() const
Definition ec_group.cpp:514
bool verify_group(RandomNumberGenerator &rng, bool strong=false) const
Definition ec_group.cpp:654
const BigInt & get_order() const
Definition ec_group.cpp:562
size_t get_p_bits() const
Definition ec_group.cpp:498
const BigInt & get_g_x() const
Definition ec_group.cpp:566
const OID & get_curve_oid() const
Definition ec_group.cpp:582
std::vector< uint8_t > DER_encode(EC_Group_Encoding form) const
Definition ec_group.cpp:604
const EC_Scalar & _private_key() const
Definition ecc_key.cpp:122
const BigInt & private_value() const
Definition ecc_key.cpp:117
secure_vector< uint8_t > raw_private_key_bits() const final
Definition ecc_key.cpp:153
std::shared_ptr< const EC_PrivateKey_Data > m_private_key
Definition ecc_key.h:219
bool check_key(RandomNumberGenerator &rng, bool strong) const override
Definition ecc_key.cpp:200
const BigInt & get_int_field(std::string_view field) const final
Definition ecc_key.cpp:230
secure_vector< uint8_t > private_key_bits() const final
Definition ecc_key.cpp:158
const EC_Group & domain() const
Definition ecc_key.cpp:63
std::vector< uint8_t > DER_domain() const
Definition ecc_key.cpp:97
void set_parameter_encoding(EC_Group_Encoding enc)
Definition ecc_key.cpp:109
EC_Point_Format m_point_encoding
Definition ecc_key.h:137
EC_Group_Encoding m_domain_encoding
Definition ecc_key.h:136
size_t estimated_strength() const override
Definition ecc_key.cpp:29
AlgorithmIdentifier algorithm_identifier() const override
Definition ecc_key.cpp:85
size_t key_length() const override
Definition ecc_key.cpp:25
EC_Group_Encoding domain_format() const
Definition ecc_key.h:92
std::shared_ptr< const EC_PublicKey_Data > m_public_key
Definition ecc_key.h:135
std::vector< uint8_t > raw_public_key_bits() const override
Definition ecc_key.cpp:89
void set_point_encoding(EC_Point_Format enc)
Definition ecc_key.cpp:101
const BigInt & get_int_field(std::string_view field) const override
Definition ecc_key.cpp:208
EC_PublicKey()=default
EC_Point_Format point_encoding() const
Definition ecc_key.h:98
const EC_AffinePoint & _public_ec_point() const
Definition ecc_key.cpp:75
bool check_key(RandomNumberGenerator &rng, bool strong) const override
Definition ecc_key.cpp:80
std::vector< uint8_t > public_key_bits() const override
Definition ecc_key.cpp:93
static EC_Scalar from_bigint(const EC_Group &group, const BigInt &bn)
Definition ec_scalar.cpp:65
static EC_Scalar random(const EC_Group &group, RandomNumberGenerator &rng)
Definition ec_scalar.cpp:57
bool empty() const
Definition asn1_obj.h:266
size_t ecp_work_factor(size_t bits)
std::string fmt(std::string_view format, const T &... args)
Definition fmt.h:53
ASN1_Type
Definition asn1_obj.h:44
std::vector< T, secure_allocator< T > > secure_vector
Definition secmem.h:61
EC_Group_Encoding
Definition ec_group.h:36