1 // Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved. 2 // Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved. 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // https://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 16 #ifndef OPENSSL_HEADER_EC_KEY_H 17 #define OPENSSL_HEADER_EC_KEY_H 18 19 #include <openssl/base.h> // IWYU pragma: export 20 21 #include <openssl/ec.h> 22 #include <openssl/engine.h> 23 #include <openssl/ex_data.h> 24 25 #if defined(__cplusplus) 26 extern "C" { 27 #endif 28 29 30 // ec_key.h contains functions that handle elliptic-curve points that are 31 // public/private keys. 32 33 34 // EC key objects. 35 // 36 // An |EC_KEY| object represents a public or private EC key. A given object may 37 // be used concurrently on multiple threads by non-mutating functions, provided 38 // no other thread is concurrently calling a mutating function. Unless otherwise 39 // documented, functions which take a |const| pointer are non-mutating and 40 // functions which take a non-|const| pointer are mutating. 41 42 // EC_KEY_new returns a fresh |EC_KEY| object or NULL on error. 43 OPENSSL_EXPORT EC_KEY *EC_KEY_new(void); 44 45 // EC_KEY_new_method acts the same as |EC_KEY_new|, but takes an explicit 46 // |ENGINE|. 47 OPENSSL_EXPORT EC_KEY *EC_KEY_new_method(const ENGINE *engine); 48 49 // EC_KEY_new_by_curve_name returns a fresh EC_KEY for group specified by |nid| 50 // or NULL on error. 51 OPENSSL_EXPORT EC_KEY *EC_KEY_new_by_curve_name(int nid); 52 53 // EC_KEY_free frees all the data owned by |key| and |key| itself. 54 OPENSSL_EXPORT void EC_KEY_free(EC_KEY *key); 55 56 // EC_KEY_dup returns a fresh copy of |src| or NULL on error. 57 OPENSSL_EXPORT EC_KEY *EC_KEY_dup(const EC_KEY *src); 58 59 // EC_KEY_up_ref increases the reference count of |key| and returns one. It does 60 // not mutate |key| for thread-safety purposes and may be used concurrently. 61 OPENSSL_EXPORT int EC_KEY_up_ref(EC_KEY *key); 62 63 // EC_KEY_is_opaque returns one if |key| is opaque and doesn't expose its key 64 // material. Otherwise it return zero. 65 OPENSSL_EXPORT int EC_KEY_is_opaque(const EC_KEY *key); 66 67 // EC_KEY_get0_group returns a pointer to the |EC_GROUP| object inside |key|. 68 OPENSSL_EXPORT const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key); 69 70 // EC_KEY_set_group sets the |EC_GROUP| object that |key| will use to |group|. 71 // It returns one on success and zero if |key| is already configured with a 72 // different group. 73 OPENSSL_EXPORT int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group); 74 75 // EC_KEY_get0_private_key returns a pointer to the private key inside |key|. 76 OPENSSL_EXPORT const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key); 77 78 // EC_KEY_set_private_key sets the private key of |key| to |priv|. It returns 79 // one on success and zero otherwise. |key| must already have had a group 80 // configured (see |EC_KEY_set_group| and |EC_KEY_new_by_curve_name|). 81 OPENSSL_EXPORT int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv); 82 83 // EC_KEY_get0_public_key returns a pointer to the public key point inside 84 // |key|. 85 OPENSSL_EXPORT const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key); 86 87 // EC_KEY_set_public_key sets the public key of |key| to |pub|, by copying it. 88 // It returns one on success and zero otherwise. |key| must already have had a 89 // group configured (see |EC_KEY_set_group| and |EC_KEY_new_by_curve_name|), and 90 // |pub| must also belong to that group. 91 OPENSSL_EXPORT int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub); 92 93 #define EC_PKEY_NO_PARAMETERS 0x001 94 #define EC_PKEY_NO_PUBKEY 0x002 95 96 // EC_KEY_get_enc_flags returns the encoding flags for |key|, which is a 97 // bitwise-OR of |EC_PKEY_*| values. 98 OPENSSL_EXPORT unsigned EC_KEY_get_enc_flags(const EC_KEY *key); 99 100 // EC_KEY_set_enc_flags sets the encoding flags for |key|, which is a 101 // bitwise-OR of |EC_PKEY_*| values. 102 OPENSSL_EXPORT void EC_KEY_set_enc_flags(EC_KEY *key, unsigned flags); 103 104 // EC_KEY_get_conv_form returns the conversation form that will be used by 105 // |key|. 106 OPENSSL_EXPORT point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key); 107 108 // EC_KEY_set_conv_form sets the conversion form to be used by |key|. 109 OPENSSL_EXPORT void EC_KEY_set_conv_form(EC_KEY *key, 110 point_conversion_form_t cform); 111 112 // EC_KEY_check_key performs several checks on |key| (possibly including an 113 // expensive check that the public key is in the primary subgroup). It returns 114 // one if all checks pass and zero otherwise. If it returns zero then detail 115 // about the problem can be found on the error stack. 116 OPENSSL_EXPORT int EC_KEY_check_key(const EC_KEY *key); 117 118 // EC_KEY_check_fips performs both a signing pairwise consistency test 119 // (FIPS 140-2 4.9.2) and the consistency test from SP 800-56Ar3 section 120 // 5.6.2.1.4. It returns one if it passes and zero otherwise. 121 OPENSSL_EXPORT int EC_KEY_check_fips(const EC_KEY *key); 122 123 // EC_KEY_set_public_key_affine_coordinates sets the public key in |key| to 124 // (|x|, |y|). It returns one on success and zero on error. It's considered an 125 // error if |x| and |y| do not represent a point on |key|'s curve. 126 OPENSSL_EXPORT int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, 127 const BIGNUM *x, 128 const BIGNUM *y); 129 130 // EC_KEY_oct2key decodes |len| bytes from |in| as an EC public key in X9.62 131 // form. |key| must already have a group configured. On success, it sets the 132 // public key in |key| to the result and returns one. Otherwise, it returns 133 // zero. |ctx| may be NULL. 134 OPENSSL_EXPORT int EC_KEY_oct2key(EC_KEY *key, const uint8_t *in, size_t len, 135 BN_CTX *ctx); 136 137 // EC_KEY_key2buf behaves like |EC_POINT_point2buf|, except it encodes the 138 // public key in |key|. |ctx| is ignored and may be NULL. 139 OPENSSL_EXPORT size_t EC_KEY_key2buf(const EC_KEY *key, 140 point_conversion_form_t form, 141 uint8_t **out_buf, BN_CTX *ctx); 142 143 // EC_KEY_oct2priv decodes a big-endian, zero-padded integer from |len| bytes 144 // from |in| and sets |key|'s private key to the result. It returns one on 145 // success and zero on error. The input must be padded to the size of |key|'s 146 // group order. 147 OPENSSL_EXPORT int EC_KEY_oct2priv(EC_KEY *key, const uint8_t *in, size_t len); 148 149 // EC_KEY_priv2oct serializes |key|'s private key as a big-endian integer, 150 // zero-padded to the size of |key|'s group order and writes the result to at 151 // most |max_out| bytes of |out|. It returns the number of bytes written on 152 // success and zero on error. If |out| is NULL, it returns the number of bytes 153 // needed without writing anything. 154 OPENSSL_EXPORT size_t EC_KEY_priv2oct(const EC_KEY *key, uint8_t *out, 155 size_t max_out); 156 157 // EC_KEY_priv2buf behaves like |EC_KEY_priv2oct| but sets |*out_buf| to a 158 // newly-allocated buffer containing the result. It returns the size of the 159 // result on success and zero on error. The caller must release |*out_buf| with 160 // |OPENSSL_free| when done. 161 OPENSSL_EXPORT size_t EC_KEY_priv2buf(const EC_KEY *key, uint8_t **out_buf); 162 163 164 // Key generation. 165 166 // EC_KEY_generate_key generates a random, private key, calculates the 167 // corresponding public key and stores both in |key|. It returns one on success 168 // or zero otherwise. 169 OPENSSL_EXPORT int EC_KEY_generate_key(EC_KEY *key); 170 171 // EC_KEY_generate_key_fips behaves like |EC_KEY_generate_key| but performs 172 // additional checks for FIPS compliance. This function is applicable when 173 // generating keys for either signing/verification or key agreement because 174 // both types of consistency check (PCT) are performed. 175 OPENSSL_EXPORT int EC_KEY_generate_key_fips(EC_KEY *key); 176 177 // EC_KEY_derive_from_secret deterministically derives a private key for |group| 178 // from an input secret using HKDF-SHA256. It returns a newly-allocated |EC_KEY| 179 // on success or NULL on error. |secret| must not be used in any other 180 // algorithm. If using a base secret for multiple operations, derive separate 181 // values with a KDF such as HKDF first. 182 // 183 // Note this function implements an arbitrary derivation scheme, rather than any 184 // particular standard one. New protocols are recommended to use X25519 and 185 // Ed25519, which have standard byte import functions. See 186 // |X25519_public_from_private| and |ED25519_keypair_from_seed|. 187 OPENSSL_EXPORT EC_KEY *EC_KEY_derive_from_secret(const EC_GROUP *group, 188 const uint8_t *secret, 189 size_t secret_len); 190 191 192 // Serialisation. 193 194 // EC_KEY_parse_private_key parses a DER-encoded ECPrivateKey structure (RFC 195 // 5915) from |cbs| and advances |cbs|. It returns a newly-allocated |EC_KEY| or 196 // NULL on error. If |group| is non-null, the parameters field of the 197 // ECPrivateKey may be omitted (but must match |group| if present). Otherwise, 198 // the parameters field is required. 199 OPENSSL_EXPORT EC_KEY *EC_KEY_parse_private_key(CBS *cbs, 200 const EC_GROUP *group); 201 202 // EC_KEY_marshal_private_key marshals |key| as a DER-encoded ECPrivateKey 203 // structure (RFC 5915) and appends the result to |cbb|. It returns one on 204 // success and zero on failure. |enc_flags| is a combination of |EC_PKEY_*| 205 // values and controls whether corresponding fields are omitted. 206 OPENSSL_EXPORT int EC_KEY_marshal_private_key(CBB *cbb, const EC_KEY *key, 207 unsigned enc_flags); 208 209 // EC_KEY_parse_curve_name parses a DER-encoded OBJECT IDENTIFIER as a curve 210 // name from |cbs| and advances |cbs|. It returns the decoded |EC_GROUP| or NULL 211 // on error. 212 // 213 // This function returns a non-const pointer which may be passed to 214 // |EC_GROUP_free|. However, the resulting object is actually static and calling 215 // |EC_GROUP_free| is optional. 216 // 217 // TODO(davidben): Make this return a const pointer, if it does not break too 218 // many callers. 219 OPENSSL_EXPORT EC_GROUP *EC_KEY_parse_curve_name(CBS *cbs); 220 221 // EC_KEY_marshal_curve_name marshals |group| as a DER-encoded OBJECT IDENTIFIER 222 // and appends the result to |cbb|. It returns one on success and zero on 223 // failure. 224 OPENSSL_EXPORT int EC_KEY_marshal_curve_name(CBB *cbb, const EC_GROUP *group); 225 226 // EC_KEY_parse_parameters parses a DER-encoded ECParameters structure (RFC 227 // 5480) from |cbs| and advances |cbs|. It returns the resulting |EC_GROUP| or 228 // NULL on error. It supports the namedCurve and specifiedCurve options, but use 229 // of specifiedCurve is deprecated. Use |EC_KEY_parse_curve_name| instead. 230 // 231 // This function returns a non-const pointer which may be passed to 232 // |EC_GROUP_free|. However, the resulting object is actually static and calling 233 // |EC_GROUP_free| is optional. 234 // 235 // TODO(davidben): Make this return a const pointer, if it does not break too 236 // many callers. 237 OPENSSL_EXPORT EC_GROUP *EC_KEY_parse_parameters(CBS *cbs); 238 239 240 // ex_data functions. 241 // 242 // These functions are wrappers. See |ex_data.h| for details. 243 244 OPENSSL_EXPORT int EC_KEY_get_ex_new_index(long argl, void *argp, 245 CRYPTO_EX_unused *unused, 246 CRYPTO_EX_dup *dup_unused, 247 CRYPTO_EX_free *free_func); 248 OPENSSL_EXPORT int EC_KEY_set_ex_data(EC_KEY *r, int idx, void *arg); 249 OPENSSL_EXPORT void *EC_KEY_get_ex_data(const EC_KEY *r, int idx); 250 251 252 // ECDSA method. 253 254 // ECDSA_FLAG_OPAQUE specifies that this ECDSA_METHOD does not expose its key 255 // material. This may be set if, for instance, it is wrapping some other crypto 256 // API, like a platform key store. 257 #define ECDSA_FLAG_OPAQUE 1 258 259 // ecdsa_method_st is a structure of function pointers for implementing ECDSA. 260 // See engine.h. 261 struct ecdsa_method_st { 262 struct openssl_method_common_st common; 263 264 void *app_data; 265 266 int (*init)(EC_KEY *key); 267 int (*finish)(EC_KEY *key); 268 269 // sign matches the arguments and behaviour of |ECDSA_sign|. 270 int (*sign)(const uint8_t *digest, size_t digest_len, uint8_t *sig, 271 unsigned int *sig_len, EC_KEY *eckey); 272 273 int flags; 274 }; 275 276 277 // Deprecated functions. 278 279 // EC_KEY_set_asn1_flag does nothing. 280 OPENSSL_EXPORT void EC_KEY_set_asn1_flag(EC_KEY *key, int flag); 281 282 // d2i_ECPrivateKey parses a DER-encoded ECPrivateKey structure (RFC 5915) from 283 // |len| bytes at |*inp|, as described in |d2i_SAMPLE|. On input, if |*out_key| 284 // is non-NULL and has a group configured, the parameters field may be omitted 285 // but must match that group if present. 286 // 287 // Use |EC_KEY_parse_private_key| instead. 288 OPENSSL_EXPORT EC_KEY *d2i_ECPrivateKey(EC_KEY **out_key, const uint8_t **inp, 289 long len); 290 291 // i2d_ECPrivateKey marshals |key| as a DER-encoded ECPrivateKey structure (RFC 292 // 5915), as described in |i2d_SAMPLE|. 293 // 294 // Use |EC_KEY_marshal_private_key| instead. 295 OPENSSL_EXPORT int i2d_ECPrivateKey(const EC_KEY *key, uint8_t **outp); 296 297 // d2i_ECPKParameters parses a DER-encoded ECParameters structure (RFC 5480) 298 // from |len| bytes at |*inp|, as described in |d2i_SAMPLE|. For legacy reasons, 299 // it recognizes the specifiedCurve form, but only for curves that are already 300 // supported as named curves. 301 // 302 // Use |EC_KEY_parse_parameters| or |EC_KEY_parse_curve_name| instead. 303 OPENSSL_EXPORT EC_GROUP *d2i_ECPKParameters(EC_GROUP **out, const uint8_t **inp, 304 long len); 305 306 // i2d_ECPKParameters marshals |group| as a DER-encoded ECParameters structure 307 // (RFC 5480), as described in |i2d_SAMPLE|. 308 // 309 // Use |EC_KEY_marshal_curve_name| instead. 310 OPENSSL_EXPORT int i2d_ECPKParameters(const EC_GROUP *group, uint8_t **outp); 311 312 // d2i_ECParameters parses a DER-encoded ECParameters structure (RFC 5480) from 313 // |len| bytes at |*inp|, as described in |d2i_SAMPLE|. It returns the result as 314 // an |EC_KEY| with parameters, but no key, configured. 315 // 316 // Use |EC_KEY_parse_parameters| or |EC_KEY_parse_curve_name| instead. 317 OPENSSL_EXPORT EC_KEY *d2i_ECParameters(EC_KEY **out_key, const uint8_t **inp, 318 long len); 319 320 // i2d_ECParameters marshals |key|'s parameters as a DER-encoded OBJECT 321 // IDENTIFIER, as described in |i2d_SAMPLE|. 322 // 323 // Use |EC_KEY_marshal_curve_name| instead. 324 OPENSSL_EXPORT int i2d_ECParameters(const EC_KEY *key, uint8_t **outp); 325 326 // o2i_ECPublicKey parses an EC point from |len| bytes at |*inp| into 327 // |*out_key|. Note that this differs from the d2i format in that |*out_key| 328 // must be non-NULL with a group set. On successful exit, |*inp| is advanced by 329 // |len| bytes. It returns |*out_key| or NULL on error. 330 // 331 // Use |EC_POINT_oct2point| instead. 332 OPENSSL_EXPORT EC_KEY *o2i_ECPublicKey(EC_KEY **out_key, const uint8_t **inp, 333 long len); 334 335 // i2o_ECPublicKey marshals an EC point from |key|, as described in 336 // |i2d_SAMPLE|, except it returns zero on error instead of a negative value. 337 // 338 // Use |EC_POINT_point2cbb| instead. 339 OPENSSL_EXPORT int i2o_ECPublicKey(const EC_KEY *key, unsigned char **outp); 340 341 342 #if defined(__cplusplus) 343 } // extern C 344 345 extern "C++" { 346 347 BSSL_NAMESPACE_BEGIN 348 349 BORINGSSL_MAKE_DELETER(EC_KEY, EC_KEY_free) 350 BORINGSSL_MAKE_UP_REF(EC_KEY, EC_KEY_up_ref) 351 352 BSSL_NAMESPACE_END 353 354 } // extern C++ 355 356 #endif 357 358 #endif // OPENSSL_HEADER_EC_KEY_H 359