Botan 2.1.0 Crypto and TLS for C++11

- Main Page
- Namespaces
- Classes
- Files

- File List
- File Members

openssl_ec.cpp
Go to the documentation of this file.
1 /*
2 * ECDSA and ECDH via OpenSSL
3 * (C) 2015,2016 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7
8 #include <botan/internal/openssl.h>
9
10 #if defined(BOTAN_HAS_ECC_PUBLIC_KEY_CRYPTO)
11 #include <botan/der_enc.h>
12 #include <botan/pkcs8.h>
13 #include <botan/oids.h>
14 #include <botan/internal/pk_ops_impl.h>
15 #endif
16
17 #if defined(BOTAN_HAS_ECDSA)
18 #include <botan/ecdsa.h>
19 #endif
20
21 #if defined(BOTAN_HAS_ECDH)
22 #include <botan/ecdh.h>
23 #endif
24
25 #include <openssl/x509.h>
26 #include <openssl/objects.h>
27
28 #if !defined(OPENSSL_NO_EC)
29 #include <openssl/ec.h>
30 #endif
31
32 #if !defined(OPENSSL_NO_ECDSA)
33 #include <openssl/ecdsa.h>
34 #endif
35
36 #if !defined(OPENSSL_NO_ECDH)
37 #include <openssl/ecdh.h>
38 #endif
39
40 namespace Botan {
41
42 #if defined(BOTAN_HAS_ECC_PUBLIC_KEY_CRYPTO)
43
44 namespace {
45
46 secure_vector<uint8_t> PKCS8_for_openssl(const EC_PrivateKey& ec)
47 {
48 const PointGFp& pub_key = ec.public_point();
49 const BigInt& priv_key = ec.private_value();
50
51 return DER_Encoder()
52 .start_cons(SEQUENCE)
53 .encode(static_cast<size_t>(1))
54 .encode(BigInt::encode_1363(priv_key, priv_key.bytes()), OCTET_STRING)
55 .start_cons(ASN1_Tag(0), PRIVATE)
56 .raw_bytes(ec.domain().DER_encode(EC_DOMPAR_ENC_OID))
57 .end_cons()
58 .start_cons(ASN1_Tag(1), PRIVATE)
59 .encode(EC2OSP(pub_key, PointGFp::UNCOMPRESSED), BIT_STRING)
60 .end_cons()
61 .end_cons()
62 .get_contents();
63 }
64
65 int OpenSSL_EC_nid_for(const OID& oid)
66 {
67 if(oid.empty())
68 return -1;
69
70 const std::string name = OIDS::lookup(oid);
71
72 if(name == "secp192r1")
73 return NID_X9_62_prime192v1;
74 if(name == "secp224r1")
75 return NID_secp224r1;
76 if(name == "secp256r1")
77 return NID_X9_62_prime256v1;
78 if(name == "secp384r1")
79 return NID_secp384r1;
80 if(name == "secp521r1")
81 return NID_secp521r1;
82
83 // OpenSSL 1.0.2 added brainpool curves
84 #if OPENSSL_VERSION_NUMBER >= 0x1000200fL
85 if(name == "brainpool160r1")
86 return NID_brainpoolP160r1;
87 if(name == "brainpool192r1")
88 return NID_brainpoolP192r1;
89 if(name == "brainpool224r1")
90 return NID_brainpoolP224r1;
91 if(name == "brainpool256r1")
92 return NID_brainpoolP256r1;
93 if(name == "brainpool320r1")
94 return NID_brainpoolP320r1;
95 if(name == "brainpool384r1")
96 return NID_brainpoolP384r1;
97 if(name == "brainpool512r1")
98 return NID_brainpoolP512r1;
99 #endif
100
101 return -1;
102 }
103
104 }
105
106 #endif
107
108 #if defined(BOTAN_HAS_ECDSA) && !defined(OPENSSL_NO_ECDSA)
109
110 namespace {
111
112 class OpenSSL_ECDSA_Verification_Operation : public PK_Ops::Verification_with_EMSA
113 {
114 public:
115 OpenSSL_ECDSA_Verification_Operation(const ECDSA_PublicKey& ecdsa, const std::string& emsa, int nid) :
116 PK_Ops::Verification_with_EMSA(emsa), m_ossl_ec(::EC_KEY_new(), ::EC_KEY_free)
117 {
118 std::unique_ptr<::EC_GROUP, std::function<void (::EC_GROUP*)>> grp(::EC_GROUP_new_by_curve_name(nid),
119 ::EC_GROUP_free);
120
121 if(!grp)
122 throw OpenSSL_Error("EC_GROUP_new_by_curve_name");
123
124 ::EC_KEY_set_group(m_ossl_ec.get(), grp.get());
125
126 const secure_vector<uint8_t> enc = EC2OSP(ecdsa.public_point(), PointGFp::UNCOMPRESSED);
127 const uint8_t* enc_ptr = enc.data();
128 EC_KEY* key_ptr = m_ossl_ec.get();
129 if(!::o2i_ECPublicKey(&key_ptr, &enc_ptr, enc.size()))
130 throw OpenSSL_Error("o2i_ECPublicKey");
131
132 const EC_GROUP* group = ::EC_KEY_get0_group(m_ossl_ec.get());
133 m_order_bits = ::EC_GROUP_get_degree(group);
134 }
135
136 size_t max_input_bits() const override { return m_order_bits; }
137
138 bool with_recovery() const override { return false; }
139
140 bool verify(const uint8_t msg[], size_t msg_len,
141 const uint8_t sig_bytes[], size_t sig_len) override
142 {
143 const size_t order_bytes = (m_order_bits + 7) / 8;
144 if(sig_len != 2 * order_bytes)
145 return false;
146
147 std::unique_ptr<ECDSA_SIG, std::function<void (ECDSA_SIG*)>> sig(nullptr, ECDSA_SIG_free);
148 sig.reset(::ECDSA_SIG_new());
149
150 sig->r = BN_bin2bn(sig_bytes , sig_len / 2, nullptr);
151 sig->s = BN_bin2bn(sig_bytes + sig_len / 2, sig_len / 2, nullptr);
152
153 const int res = ECDSA_do_verify(msg, msg_len, sig.get(), m_ossl_ec.get());
154 if(res < 0)
155 throw OpenSSL_Error("ECDSA_do_verify");
156 return (res == 1);
157 }
158
159 private:
160 std::unique_ptr<EC_KEY, std::function<void (EC_KEY*)>> m_ossl_ec;
161 size_t m_order_bits = 0;
162 };
163
164 class OpenSSL_ECDSA_Signing_Operation : public PK_Ops::Signature_with_EMSA
165 {
166 public:
167 OpenSSL_ECDSA_Signing_Operation(const ECDSA_PrivateKey& ecdsa, const std::string& emsa) :
168 PK_Ops::Signature_with_EMSA(emsa),
169 m_ossl_ec(nullptr, ::EC_KEY_free)
170 {
171 const secure_vector<uint8_t> der = PKCS8_for_openssl(ecdsa);
172 const uint8_t* der_ptr = der.data();
173 m_ossl_ec.reset(d2i_ECPrivateKey(nullptr, &der_ptr, der.size()));
174 if(!m_ossl_ec)
175 throw OpenSSL_Error("d2i_ECPrivateKey");
176
177 const EC_GROUP* group = ::EC_KEY_get0_group(m_ossl_ec.get());
178 m_order_bits = ::EC_GROUP_get_degree(group);
179 }
180
181 secure_vector<uint8_t> raw_sign(const uint8_t msg[], size_t msg_len,
182 RandomNumberGenerator&) override
183 {
184 std::unique_ptr<ECDSA_SIG, std::function<void (ECDSA_SIG*)>> sig(nullptr, ECDSA_SIG_free);
185 sig.reset(::ECDSA_do_sign(msg, msg_len, m_ossl_ec.get()));
186
187 if(!sig)
188 throw OpenSSL_Error("ECDSA_do_sign");
189
190 const size_t order_bytes = (m_order_bits + 7) / 8;
191 const size_t r_bytes = BN_num_bytes(sig->r);
192 const size_t s_bytes = BN_num_bytes(sig->s);
193 secure_vector<uint8_t> sigval(2*order_bytes);
194 BN_bn2bin(sig->r, &sigval[order_bytes - r_bytes]);
195 BN_bn2bin(sig->s, &sigval[2*order_bytes - s_bytes]);
196 return sigval;
197 }
198
199 size_t max_input_bits() const override { return m_order_bits; }
200
201 private:
202 std::unique_ptr<EC_KEY, std::function<void (EC_KEY*)>> m_ossl_ec;
203 size_t m_order_bits = 0;
204 };
205
206 }
207
208 std::unique_ptr<PK_Ops::Verification>
209 make_openssl_ecdsa_ver_op(const ECDSA_PublicKey& key, const std::string& params)
210 {
211 const int nid = OpenSSL_EC_nid_for(key.domain().get_oid());
212 if(nid < 0)
213 {
214 throw Lookup_Error("OpenSSL ECDSA does not support this curve");
215 }
216 return std::unique_ptr<PK_Ops::Verification>(new OpenSSL_ECDSA_Verification_Operation(key, params, nid));
217 }
218
219 std::unique_ptr<PK_Ops::Signature>
220 make_openssl_ecdsa_sig_op(const ECDSA_PrivateKey& key, const std::string& params)
221 {
222 const int nid = OpenSSL_EC_nid_for(key.domain().get_oid());
223 if(nid < 0)
224 {
225 throw Lookup_Error("OpenSSL ECDSA does not support this curve");
226 }
227 return std::unique_ptr<PK_Ops::Signature>(new OpenSSL_ECDSA_Signing_Operation(key, params));
228 }
229
230 #endif
231
232 #if defined(BOTAN_HAS_ECDH) && !defined(OPENSSL_NO_ECDH)
233
234 namespace {
235
236 class OpenSSL_ECDH_KA_Operation : public PK_Ops::Key_Agreement_with_KDF
237 {
238 public:
239
240 OpenSSL_ECDH_KA_Operation(const ECDH_PrivateKey& ecdh, const std::string& kdf) :
241 PK_Ops::Key_Agreement_with_KDF(kdf), m_ossl_ec(::EC_KEY_new(), ::EC_KEY_free)
242 {
243 const secure_vector<uint8_t> der = PKCS8_for_openssl(ecdh);
244 const uint8_t* der_ptr = der.data();
245 m_ossl_ec.reset(d2i_ECPrivateKey(nullptr, &der_ptr, der.size()));
246 if(!m_ossl_ec)
247 throw OpenSSL_Error("d2i_ECPrivateKey");
248 }
249
250 secure_vector<uint8_t> raw_agree(const uint8_t w[], size_t w_len) override
251 {
252 const EC_GROUP* group = ::EC_KEY_get0_group(m_ossl_ec.get());
253 const size_t out_len = (::EC_GROUP_get_degree(group) + 7) / 8;
254 secure_vector<uint8_t> out(out_len);
255 EC_POINT* pub_key = ::EC_POINT_new(group);
256
257 if(!pub_key)
258 throw OpenSSL_Error("EC_POINT_new");
259
260 const int os2ecp_rc =
261 ::EC_POINT_oct2point(group, pub_key, w, w_len, nullptr);
262
263 if(os2ecp_rc != 1)
264 throw OpenSSL_Error("EC_POINT_oct2point");
265
266 const int ecdh_rc = ::ECDH_compute_key(out.data(),
267 out.size(),
268 pub_key,
269 m_ossl_ec.get(),
270 /*KDF*/nullptr);
271
272 if(ecdh_rc <= 0)
273 throw OpenSSL_Error("ECDH_compute_key");
274
275 const size_t ecdh_sz = static_cast<size_t>(ecdh_rc);
276
277 if(ecdh_sz > out.size())
278 throw Internal_Error("OpenSSL ECDH returned more than requested");
279
280 out.resize(ecdh_sz);
281 return out;
282 }
283
284 private:
285 std::unique_ptr<EC_KEY, std::function<void (EC_KEY*)>> m_ossl_ec;
286 };
287
288 }
289
290 std::unique_ptr<PK_Ops::Key_Agreement>
291 make_openssl_ecdh_ka_op(const ECDH_PrivateKey& key, const std::string& params)
292 {
293 const int nid = OpenSSL_EC_nid_for(key.domain().get_oid());
294 if(nid < 0)
295 {
296 throw Lookup_Error("OpenSSL ECDH does not support this curve");
297 }
298
299 return std::unique_ptr<PK_Ops::Key_Agreement>(new OpenSSL_ECDH_KA_Operation(key, params));
300 }
301
302 #endif
303
304 }
305
Botan::PointGFp::UNCOMPRESSED
Definition: point_gfp.h:45
Botan::EC2OSP
secure_vector< uint8_t > EC2OSP(const PointGFp &point, uint8_t format)
Definition: point_gfp.cpp:470
Botan::OCTET_STRING
Definition: asn1_obj.h:35
Botan::PRIVATE
Definition: asn1_obj.h:29
Botan::OIDS::lookup
std::string lookup(const OID &oid)
Definition: oids.cpp:18
Botan::ASN1_Tag
ASN1_Tag
Definition: asn1_obj.h:22
Botan::SEQUENCE
Definition: asn1_obj.h:39
Botan
Definition: alg_id.cpp:13
Botan::EC_DOMPAR_ENC_OID
Definition: ec_group.h:25
Botan::BIT_STRING
Definition: asn1_obj.h:34
Botan::BigInt::encode_1363
static secure_vector< uint8_t > encode_1363(const BigInt &n, size_t bytes)
Definition: big_code.cpp:82