1 /* Originally written by Bodo Moeller for the OpenSSL project. 2 * ==================================================================== 3 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in 14 * the documentation and/or other materials provided with the 15 * distribution. 16 * 17 * 3. All advertising materials mentioning features or use of this 18 * software must display the following acknowledgment: 19 * "This product includes software developed by the OpenSSL Project 20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 21 * 22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 23 * endorse or promote products derived from this software without 24 * prior written permission. For written permission, please contact 25 * [email protected]. 26 * 27 * 5. Products derived from this software may not be called "OpenSSL" 28 * nor may "OpenSSL" appear in their names without prior written 29 * permission of the OpenSSL Project. 30 * 31 * 6. Redistributions of any form whatsoever must retain the following 32 * acknowledgment: 33 * "This product includes software developed by the OpenSSL Project 34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 35 * 36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 47 * OF THE POSSIBILITY OF SUCH DAMAGE. 48 * ==================================================================== 49 * 50 * This product includes cryptographic software written by Eric Young 51 * ([email protected]). This product includes software written by Tim 52 * Hudson ([email protected]). 53 * 54 */ 55 /* ==================================================================== 56 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. 57 * 58 * Portions of the attached software ("Contribution") are developed by 59 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. 60 * 61 * The Contribution is licensed pursuant to the OpenSSL open source 62 * license provided above. 63 * 64 * The elliptic curve binary polynomial software is originally written by 65 * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems 66 * Laboratories. */ 67 68 #ifndef OPENSSL_HEADER_EC_KEY_H 69 #define OPENSSL_HEADER_EC_KEY_H 70 71 #include <openssl/base.h> 72 73 #include <openssl/ec.h> 74 #include <openssl/engine.h> 75 #include <openssl/ex_data.h> 76 77 #if defined(__cplusplus) 78 extern "C" { 79 #endif 80 81 82 // ec_key.h contains functions that handle elliptic-curve points that are 83 // public/private keys. 84 85 86 // EC key objects. 87 // 88 // An |EC_KEY| object represents a public or private EC key. A given object may 89 // be used concurrently on multiple threads by non-mutating functions, provided 90 // no other thread is concurrently calling a mutating function. Unless otherwise 91 // documented, functions which take a |const| pointer are non-mutating and 92 // functions which take a non-|const| pointer are mutating. 93 94 // EC_KEY_new returns a fresh |EC_KEY| object or NULL on error. 95 OPENSSL_EXPORT EC_KEY *EC_KEY_new(void); 96 97 // EC_KEY_new_method acts the same as |EC_KEY_new|, but takes an explicit 98 // |ENGINE|. 99 OPENSSL_EXPORT EC_KEY *EC_KEY_new_method(const ENGINE *engine); 100 101 // EC_KEY_new_by_curve_name returns a fresh EC_KEY for group specified by |nid| 102 // or NULL on error. 103 OPENSSL_EXPORT EC_KEY *EC_KEY_new_by_curve_name(int nid); 104 105 // EC_KEY_free frees all the data owned by |key| and |key| itself. 106 OPENSSL_EXPORT void EC_KEY_free(EC_KEY *key); 107 108 // EC_KEY_dup returns a fresh copy of |src| or NULL on error. 109 OPENSSL_EXPORT EC_KEY *EC_KEY_dup(const EC_KEY *src); 110 111 // EC_KEY_up_ref increases the reference count of |key| and returns one. It does 112 // not mutate |key| for thread-safety purposes and may be used concurrently. 113 OPENSSL_EXPORT int EC_KEY_up_ref(EC_KEY *key); 114 115 // EC_KEY_is_opaque returns one if |key| is opaque and doesn't expose its key 116 // material. Otherwise it return zero. 117 OPENSSL_EXPORT int EC_KEY_is_opaque(const EC_KEY *key); 118 119 // EC_KEY_get0_group returns a pointer to the |EC_GROUP| object inside |key|. 120 OPENSSL_EXPORT const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key); 121 122 // EC_KEY_set_group sets the |EC_GROUP| object that |key| will use to |group|. 123 // It returns one on success and zero if |key| is already configured with a 124 // different group. 125 OPENSSL_EXPORT int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group); 126 127 // EC_KEY_get0_private_key returns a pointer to the private key inside |key|. 128 OPENSSL_EXPORT const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key); 129 130 // EC_KEY_set_private_key sets the private key of |key| to |priv|. It returns 131 // one on success and zero otherwise. |key| must already have had a group 132 // configured (see |EC_KEY_set_group| and |EC_KEY_new_by_curve_name|). 133 OPENSSL_EXPORT int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv); 134 135 // EC_KEY_get0_public_key returns a pointer to the public key point inside 136 // |key|. 137 OPENSSL_EXPORT const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key); 138 139 // EC_KEY_set_public_key sets the public key of |key| to |pub|, by copying it. 140 // It returns one on success and zero otherwise. |key| must already have had a 141 // group configured (see |EC_KEY_set_group| and |EC_KEY_new_by_curve_name|), and 142 // |pub| must also belong to that group. 143 OPENSSL_EXPORT int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub); 144 145 #define EC_PKEY_NO_PARAMETERS 0x001 146 #define EC_PKEY_NO_PUBKEY 0x002 147 148 // EC_KEY_get_enc_flags returns the encoding flags for |key|, which is a 149 // bitwise-OR of |EC_PKEY_*| values. 150 OPENSSL_EXPORT unsigned EC_KEY_get_enc_flags(const EC_KEY *key); 151 152 // EC_KEY_set_enc_flags sets the encoding flags for |key|, which is a 153 // bitwise-OR of |EC_PKEY_*| values. 154 OPENSSL_EXPORT void EC_KEY_set_enc_flags(EC_KEY *key, unsigned flags); 155 156 // EC_KEY_get_conv_form returns the conversation form that will be used by 157 // |key|. 158 OPENSSL_EXPORT point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key); 159 160 // EC_KEY_set_conv_form sets the conversion form to be used by |key|. 161 OPENSSL_EXPORT void EC_KEY_set_conv_form(EC_KEY *key, 162 point_conversion_form_t cform); 163 164 // EC_KEY_check_key performs several checks on |key| (possibly including an 165 // expensive check that the public key is in the primary subgroup). It returns 166 // one if all checks pass and zero otherwise. If it returns zero then detail 167 // about the problem can be found on the error stack. 168 OPENSSL_EXPORT int EC_KEY_check_key(const EC_KEY *key); 169 170 // EC_KEY_check_fips performs both a signing pairwise consistency test 171 // (FIPS 140-2 4.9.2) and the consistency test from SP 800-56Ar3 section 172 // 5.6.2.1.4. It returns one if it passes and zero otherwise. 173 OPENSSL_EXPORT int EC_KEY_check_fips(const EC_KEY *key); 174 175 // EC_KEY_set_public_key_affine_coordinates sets the public key in |key| to 176 // (|x|, |y|). It returns one on success and zero on error. It's considered an 177 // error if |x| and |y| do not represent a point on |key|'s curve. 178 OPENSSL_EXPORT int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, 179 const BIGNUM *x, 180 const BIGNUM *y); 181 182 // EC_KEY_oct2key decodes |len| bytes from |in| as an EC public key in X9.62 183 // form. |key| must already have a group configured. On success, it sets the 184 // public key in |key| to the result and returns one. Otherwise, it returns 185 // zero. 186 OPENSSL_EXPORT int EC_KEY_oct2key(EC_KEY *key, const uint8_t *in, size_t len, 187 BN_CTX *ctx); 188 189 // EC_KEY_key2buf behaves like |EC_POINT_point2buf|, except it encodes the 190 // public key in |key|. 191 OPENSSL_EXPORT size_t EC_KEY_key2buf(const EC_KEY *key, 192 point_conversion_form_t form, 193 uint8_t **out_buf, BN_CTX *ctx); 194 195 // EC_KEY_oct2priv decodes a big-endian, zero-padded integer from |len| bytes 196 // from |in| and sets |key|'s private key to the result. It returns one on 197 // success and zero on error. The input must be padded to the size of |key|'s 198 // group order. 199 OPENSSL_EXPORT int EC_KEY_oct2priv(EC_KEY *key, const uint8_t *in, size_t len); 200 201 // EC_KEY_priv2oct serializes |key|'s private key as a big-endian integer, 202 // zero-padded to the size of |key|'s group order and writes the result to at 203 // most |max_out| bytes of |out|. It returns the number of bytes written on 204 // success and zero on error. If |out| is NULL, it returns the number of bytes 205 // needed without writing anything. 206 OPENSSL_EXPORT size_t EC_KEY_priv2oct(const EC_KEY *key, uint8_t *out, 207 size_t max_out); 208 209 // EC_KEY_priv2buf behaves like |EC_KEY_priv2oct| but sets |*out_buf| to a 210 // newly-allocated buffer containing the result. It returns the size of the 211 // result on success and zero on error. The caller must release |*out_buf| with 212 // |OPENSSL_free| when done. 213 OPENSSL_EXPORT size_t EC_KEY_priv2buf(const EC_KEY *key, uint8_t **out_buf); 214 215 216 // Key generation. 217 218 // EC_KEY_generate_key generates a random, private key, calculates the 219 // corresponding public key and stores both in |key|. It returns one on success 220 // or zero otherwise. 221 OPENSSL_EXPORT int EC_KEY_generate_key(EC_KEY *key); 222 223 // EC_KEY_generate_key_fips behaves like |EC_KEY_generate_key| but performs 224 // additional checks for FIPS compliance. This function is applicable when 225 // generating keys for either signing/verification or key agreement because 226 // both types of consistency check (PCT) are performed. 227 OPENSSL_EXPORT int EC_KEY_generate_key_fips(EC_KEY *key); 228 229 // EC_KEY_derive_from_secret deterministically derives a private key for |group| 230 // from an input secret using HKDF-SHA256. It returns a newly-allocated |EC_KEY| 231 // on success or NULL on error. |secret| must not be used in any other 232 // algorithm. If using a base secret for multiple operations, derive separate 233 // values with a KDF such as HKDF first. 234 // 235 // Note this function implements an arbitrary derivation scheme, rather than any 236 // particular standard one. New protocols are recommended to use X25519 and 237 // Ed25519, which have standard byte import functions. See 238 // |X25519_public_from_private| and |ED25519_keypair_from_seed|. 239 OPENSSL_EXPORT EC_KEY *EC_KEY_derive_from_secret(const EC_GROUP *group, 240 const uint8_t *secret, 241 size_t secret_len); 242 243 244 // Serialisation. 245 246 // EC_KEY_parse_private_key parses a DER-encoded ECPrivateKey structure (RFC 247 // 5915) from |cbs| and advances |cbs|. It returns a newly-allocated |EC_KEY| or 248 // NULL on error. If |group| is non-null, the parameters field of the 249 // ECPrivateKey may be omitted (but must match |group| if present). Otherwise, 250 // the parameters field is required. 251 OPENSSL_EXPORT EC_KEY *EC_KEY_parse_private_key(CBS *cbs, 252 const EC_GROUP *group); 253 254 // EC_KEY_marshal_private_key marshals |key| as a DER-encoded ECPrivateKey 255 // structure (RFC 5915) and appends the result to |cbb|. It returns one on 256 // success and zero on failure. |enc_flags| is a combination of |EC_PKEY_*| 257 // values and controls whether corresponding fields are omitted. 258 OPENSSL_EXPORT int EC_KEY_marshal_private_key(CBB *cbb, const EC_KEY *key, 259 unsigned enc_flags); 260 261 // EC_KEY_parse_curve_name parses a DER-encoded OBJECT IDENTIFIER as a curve 262 // name from |cbs| and advances |cbs|. It returns the decoded |EC_GROUP| or NULL 263 // on error. 264 // 265 // This function returns a non-const pointer which may be passed to 266 // |EC_GROUP_free|. However, the resulting object is actually static and calling 267 // |EC_GROUP_free| is optional. 268 // 269 // TODO(davidben): Make this return a const pointer, if it does not break too 270 // many callers. 271 OPENSSL_EXPORT EC_GROUP *EC_KEY_parse_curve_name(CBS *cbs); 272 273 // EC_KEY_marshal_curve_name marshals |group| as a DER-encoded OBJECT IDENTIFIER 274 // and appends the result to |cbb|. It returns one on success and zero on 275 // failure. 276 OPENSSL_EXPORT int EC_KEY_marshal_curve_name(CBB *cbb, const EC_GROUP *group); 277 278 // EC_KEY_parse_parameters parses a DER-encoded ECParameters structure (RFC 279 // 5480) from |cbs| and advances |cbs|. It returns the resulting |EC_GROUP| or 280 // NULL on error. It supports the namedCurve and specifiedCurve options, but use 281 // of specifiedCurve is deprecated. Use |EC_KEY_parse_curve_name| instead. 282 // 283 // This function returns a non-const pointer which may be passed to 284 // |EC_GROUP_free|. However, the resulting object is actually static and calling 285 // |EC_GROUP_free| is optional. 286 // 287 // TODO(davidben): Make this return a const pointer, if it does not break too 288 // many callers. 289 OPENSSL_EXPORT EC_GROUP *EC_KEY_parse_parameters(CBS *cbs); 290 291 292 // ex_data functions. 293 // 294 // These functions are wrappers. See |ex_data.h| for details. 295 296 OPENSSL_EXPORT int EC_KEY_get_ex_new_index(long argl, void *argp, 297 CRYPTO_EX_unused *unused, 298 CRYPTO_EX_dup *dup_unused, 299 CRYPTO_EX_free *free_func); 300 OPENSSL_EXPORT int EC_KEY_set_ex_data(EC_KEY *r, int idx, void *arg); 301 OPENSSL_EXPORT void *EC_KEY_get_ex_data(const EC_KEY *r, int idx); 302 303 304 // ECDSA method. 305 306 // ECDSA_FLAG_OPAQUE specifies that this ECDSA_METHOD does not expose its key 307 // material. This may be set if, for instance, it is wrapping some other crypto 308 // API, like a platform key store. 309 #define ECDSA_FLAG_OPAQUE 1 310 311 // ecdsa_method_st is a structure of function pointers for implementing ECDSA. 312 // See engine.h. 313 struct ecdsa_method_st { 314 struct openssl_method_common_st common; 315 316 void *app_data; 317 318 int (*init)(EC_KEY *key); 319 int (*finish)(EC_KEY *key); 320 321 // group_order_size returns the number of bytes needed to represent the order 322 // of the group. This is used to calculate the maximum size of an ECDSA 323 // signature in |ECDSA_size|. 324 size_t (*group_order_size)(const EC_KEY *key); 325 326 // sign matches the arguments and behaviour of |ECDSA_sign|. 327 int (*sign)(const uint8_t *digest, size_t digest_len, uint8_t *sig, 328 unsigned int *sig_len, EC_KEY *eckey); 329 330 int flags; 331 }; 332 333 334 // Deprecated functions. 335 336 // EC_KEY_set_asn1_flag does nothing. 337 OPENSSL_EXPORT void EC_KEY_set_asn1_flag(EC_KEY *key, int flag); 338 339 // d2i_ECPrivateKey parses a DER-encoded ECPrivateKey structure (RFC 5915) from 340 // |len| bytes at |*inp|, as described in |d2i_SAMPLE|. On input, if |*out_key| 341 // is non-NULL and has a group configured, the parameters field may be omitted 342 // but must match that group if present. 343 // 344 // Use |EC_KEY_parse_private_key| instead. 345 OPENSSL_EXPORT EC_KEY *d2i_ECPrivateKey(EC_KEY **out_key, const uint8_t **inp, 346 long len); 347 348 // i2d_ECPrivateKey marshals |key| as a DER-encoded ECPrivateKey structure (RFC 349 // 5915), as described in |i2d_SAMPLE|. 350 // 351 // Use |EC_KEY_marshal_private_key| instead. 352 OPENSSL_EXPORT int i2d_ECPrivateKey(const EC_KEY *key, uint8_t **outp); 353 354 // d2i_ECParameters parses a DER-encoded ECParameters structure (RFC 5480) from 355 // |len| bytes at |*inp|, as described in |d2i_SAMPLE|. 356 // 357 // Use |EC_KEY_parse_parameters| or |EC_KEY_parse_curve_name| instead. 358 OPENSSL_EXPORT EC_KEY *d2i_ECParameters(EC_KEY **out_key, const uint8_t **inp, 359 long len); 360 361 // i2d_ECParameters marshals |key|'s parameters as a DER-encoded OBJECT 362 // IDENTIFIER, as described in |i2d_SAMPLE|. 363 // 364 // Use |EC_KEY_marshal_curve_name| instead. 365 OPENSSL_EXPORT int i2d_ECParameters(const EC_KEY *key, uint8_t **outp); 366 367 // o2i_ECPublicKey parses an EC point from |len| bytes at |*inp| into 368 // |*out_key|. Note that this differs from the d2i format in that |*out_key| 369 // must be non-NULL with a group set. On successful exit, |*inp| is advanced by 370 // |len| bytes. It returns |*out_key| or NULL on error. 371 // 372 // Use |EC_POINT_oct2point| instead. 373 OPENSSL_EXPORT EC_KEY *o2i_ECPublicKey(EC_KEY **out_key, const uint8_t **inp, 374 long len); 375 376 // i2o_ECPublicKey marshals an EC point from |key|, as described in 377 // |i2d_SAMPLE|, except it returns zero on error instead of a negative value. 378 // 379 // Use |EC_POINT_point2cbb| instead. 380 OPENSSL_EXPORT int i2o_ECPublicKey(const EC_KEY *key, unsigned char **outp); 381 382 383 #if defined(__cplusplus) 384 } // extern C 385 386 extern "C++" { 387 388 BSSL_NAMESPACE_BEGIN 389 390 BORINGSSL_MAKE_DELETER(EC_KEY, EC_KEY_free) 391 BORINGSSL_MAKE_UP_REF(EC_KEY, EC_KEY_up_ref) 392 393 BSSL_NAMESPACE_END 394 395 } // extern C++ 396 397 #endif 398 399 #endif // OPENSSL_HEADER_EC_KEY_H 400