1 /* 2 * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved. 3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved. 4 * 5 * Licensed under the OpenSSL license (the "License"). You may not use 6 * this file except in compliance with the License. You can obtain a copy 7 * in the file LICENSE in the source distribution or at 8 * https://www.openssl.org/source/license.html 9 */ 10 11 #ifndef OPENSSL_HEADER_EC_KEY_H 12 #define OPENSSL_HEADER_EC_KEY_H 13 14 #include <openssl/base.h> 15 16 #include <openssl/ec.h> 17 #include <openssl/engine.h> 18 #include <openssl/ex_data.h> 19 20 #if defined(__cplusplus) 21 extern "C" { 22 #endif 23 24 25 // ec_key.h contains functions that handle elliptic-curve points that are 26 // public/private keys. 27 28 29 // EC key objects. 30 // 31 // An |EC_KEY| object represents a public or private EC key. A given object may 32 // be used concurrently on multiple threads by non-mutating functions, provided 33 // no other thread is concurrently calling a mutating function. Unless otherwise 34 // documented, functions which take a |const| pointer are non-mutating and 35 // functions which take a non-|const| pointer are mutating. 36 37 // EC_KEY_new returns a fresh |EC_KEY| object or NULL on error. 38 OPENSSL_EXPORT EC_KEY *EC_KEY_new(void); 39 40 // EC_KEY_new_method acts the same as |EC_KEY_new|, but takes an explicit 41 // |ENGINE|. 42 OPENSSL_EXPORT EC_KEY *EC_KEY_new_method(const ENGINE *engine); 43 44 // EC_KEY_new_by_curve_name returns a fresh EC_KEY for group specified by |nid| 45 // or NULL on error. 46 OPENSSL_EXPORT EC_KEY *EC_KEY_new_by_curve_name(int nid); 47 48 // EC_KEY_free frees all the data owned by |key| and |key| itself. 49 OPENSSL_EXPORT void EC_KEY_free(EC_KEY *key); 50 51 // EC_KEY_dup returns a fresh copy of |src| or NULL on error. 52 OPENSSL_EXPORT EC_KEY *EC_KEY_dup(const EC_KEY *src); 53 54 // EC_KEY_up_ref increases the reference count of |key| and returns one. It does 55 // not mutate |key| for thread-safety purposes and may be used concurrently. 56 OPENSSL_EXPORT int EC_KEY_up_ref(EC_KEY *key); 57 58 // EC_KEY_is_opaque returns one if |key| is opaque and doesn't expose its key 59 // material. Otherwise it return zero. 60 OPENSSL_EXPORT int EC_KEY_is_opaque(const EC_KEY *key); 61 62 // EC_KEY_get0_group returns a pointer to the |EC_GROUP| object inside |key|. 63 OPENSSL_EXPORT const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key); 64 65 // EC_KEY_set_group sets the |EC_GROUP| object that |key| will use to |group|. 66 // It returns one on success and zero if |key| is already configured with a 67 // different group. 68 OPENSSL_EXPORT int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group); 69 70 // EC_KEY_get0_private_key returns a pointer to the private key inside |key|. 71 OPENSSL_EXPORT const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key); 72 73 // EC_KEY_set_private_key sets the private key of |key| to |priv|. It returns 74 // one on success and zero otherwise. |key| must already have had a group 75 // configured (see |EC_KEY_set_group| and |EC_KEY_new_by_curve_name|). 76 OPENSSL_EXPORT int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv); 77 78 // EC_KEY_get0_public_key returns a pointer to the public key point inside 79 // |key|. 80 OPENSSL_EXPORT const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key); 81 82 // EC_KEY_set_public_key sets the public key of |key| to |pub|, by copying it. 83 // It returns one on success and zero otherwise. |key| must already have had a 84 // group configured (see |EC_KEY_set_group| and |EC_KEY_new_by_curve_name|), and 85 // |pub| must also belong to that group. 86 OPENSSL_EXPORT int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub); 87 88 #define EC_PKEY_NO_PARAMETERS 0x001 89 #define EC_PKEY_NO_PUBKEY 0x002 90 91 // EC_KEY_get_enc_flags returns the encoding flags for |key|, which is a 92 // bitwise-OR of |EC_PKEY_*| values. 93 OPENSSL_EXPORT unsigned EC_KEY_get_enc_flags(const EC_KEY *key); 94 95 // EC_KEY_set_enc_flags sets the encoding flags for |key|, which is a 96 // bitwise-OR of |EC_PKEY_*| values. 97 OPENSSL_EXPORT void EC_KEY_set_enc_flags(EC_KEY *key, unsigned flags); 98 99 // EC_KEY_get_conv_form returns the conversation form that will be used by 100 // |key|. 101 OPENSSL_EXPORT point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key); 102 103 // EC_KEY_set_conv_form sets the conversion form to be used by |key|. 104 OPENSSL_EXPORT void EC_KEY_set_conv_form(EC_KEY *key, 105 point_conversion_form_t cform); 106 107 // EC_KEY_check_key performs several checks on |key| (possibly including an 108 // expensive check that the public key is in the primary subgroup). It returns 109 // one if all checks pass and zero otherwise. If it returns zero then detail 110 // about the problem can be found on the error stack. 111 OPENSSL_EXPORT int EC_KEY_check_key(const EC_KEY *key); 112 113 // EC_KEY_check_fips performs both a signing pairwise consistency test 114 // (FIPS 140-2 4.9.2) and the consistency test from SP 800-56Ar3 section 115 // 5.6.2.1.4. It returns one if it passes and zero otherwise. 116 OPENSSL_EXPORT int EC_KEY_check_fips(const EC_KEY *key); 117 118 // EC_KEY_set_public_key_affine_coordinates sets the public key in |key| to 119 // (|x|, |y|). It returns one on success and zero on error. It's considered an 120 // error if |x| and |y| do not represent a point on |key|'s curve. 121 OPENSSL_EXPORT int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, 122 const BIGNUM *x, 123 const BIGNUM *y); 124 125 // EC_KEY_oct2key decodes |len| bytes from |in| as an EC public key in X9.62 126 // form. |key| must already have a group configured. On success, it sets the 127 // public key in |key| to the result and returns one. Otherwise, it returns 128 // zero. 129 OPENSSL_EXPORT int EC_KEY_oct2key(EC_KEY *key, const uint8_t *in, size_t len, 130 BN_CTX *ctx); 131 132 // EC_KEY_key2buf behaves like |EC_POINT_point2buf|, except it encodes the 133 // public key in |key|. 134 OPENSSL_EXPORT size_t EC_KEY_key2buf(const EC_KEY *key, 135 point_conversion_form_t form, 136 uint8_t **out_buf, BN_CTX *ctx); 137 138 // EC_KEY_oct2priv decodes a big-endian, zero-padded integer from |len| bytes 139 // from |in| and sets |key|'s private key to the result. It returns one on 140 // success and zero on error. The input must be padded to the size of |key|'s 141 // group order. 142 OPENSSL_EXPORT int EC_KEY_oct2priv(EC_KEY *key, const uint8_t *in, size_t len); 143 144 // EC_KEY_priv2oct serializes |key|'s private key as a big-endian integer, 145 // zero-padded to the size of |key|'s group order and writes the result to at 146 // most |max_out| bytes of |out|. It returns the number of bytes written on 147 // success and zero on error. If |out| is NULL, it returns the number of bytes 148 // needed without writing anything. 149 OPENSSL_EXPORT size_t EC_KEY_priv2oct(const EC_KEY *key, uint8_t *out, 150 size_t max_out); 151 152 // EC_KEY_priv2buf behaves like |EC_KEY_priv2oct| but sets |*out_buf| to a 153 // newly-allocated buffer containing the result. It returns the size of the 154 // result on success and zero on error. The caller must release |*out_buf| with 155 // |OPENSSL_free| when done. 156 OPENSSL_EXPORT size_t EC_KEY_priv2buf(const EC_KEY *key, uint8_t **out_buf); 157 158 159 // Key generation. 160 161 // EC_KEY_generate_key generates a random, private key, calculates the 162 // corresponding public key and stores both in |key|. It returns one on success 163 // or zero otherwise. 164 OPENSSL_EXPORT int EC_KEY_generate_key(EC_KEY *key); 165 166 // EC_KEY_generate_key_fips behaves like |EC_KEY_generate_key| but performs 167 // additional checks for FIPS compliance. This function is applicable when 168 // generating keys for either signing/verification or key agreement because 169 // both types of consistency check (PCT) are performed. 170 OPENSSL_EXPORT int EC_KEY_generate_key_fips(EC_KEY *key); 171 172 // EC_KEY_derive_from_secret deterministically derives a private key for |group| 173 // from an input secret using HKDF-SHA256. It returns a newly-allocated |EC_KEY| 174 // on success or NULL on error. |secret| must not be used in any other 175 // algorithm. If using a base secret for multiple operations, derive separate 176 // values with a KDF such as HKDF first. 177 // 178 // Note this function implements an arbitrary derivation scheme, rather than any 179 // particular standard one. New protocols are recommended to use X25519 and 180 // Ed25519, which have standard byte import functions. See 181 // |X25519_public_from_private| and |ED25519_keypair_from_seed|. 182 OPENSSL_EXPORT EC_KEY *EC_KEY_derive_from_secret(const EC_GROUP *group, 183 const uint8_t *secret, 184 size_t secret_len); 185 186 187 // Serialisation. 188 189 // EC_KEY_parse_private_key parses a DER-encoded ECPrivateKey structure (RFC 190 // 5915) from |cbs| and advances |cbs|. It returns a newly-allocated |EC_KEY| or 191 // NULL on error. If |group| is non-null, the parameters field of the 192 // ECPrivateKey may be omitted (but must match |group| if present). Otherwise, 193 // the parameters field is required. 194 OPENSSL_EXPORT EC_KEY *EC_KEY_parse_private_key(CBS *cbs, 195 const EC_GROUP *group); 196 197 // EC_KEY_marshal_private_key marshals |key| as a DER-encoded ECPrivateKey 198 // structure (RFC 5915) and appends the result to |cbb|. It returns one on 199 // success and zero on failure. |enc_flags| is a combination of |EC_PKEY_*| 200 // values and controls whether corresponding fields are omitted. 201 OPENSSL_EXPORT int EC_KEY_marshal_private_key(CBB *cbb, const EC_KEY *key, 202 unsigned enc_flags); 203 204 // EC_KEY_parse_curve_name parses a DER-encoded OBJECT IDENTIFIER as a curve 205 // name from |cbs| and advances |cbs|. It returns the decoded |EC_GROUP| or NULL 206 // on error. 207 // 208 // This function returns a non-const pointer which may be passed to 209 // |EC_GROUP_free|. However, the resulting object is actually static and calling 210 // |EC_GROUP_free| is optional. 211 // 212 // TODO(davidben): Make this return a const pointer, if it does not break too 213 // many callers. 214 OPENSSL_EXPORT EC_GROUP *EC_KEY_parse_curve_name(CBS *cbs); 215 216 // EC_KEY_marshal_curve_name marshals |group| as a DER-encoded OBJECT IDENTIFIER 217 // and appends the result to |cbb|. It returns one on success and zero on 218 // failure. 219 OPENSSL_EXPORT int EC_KEY_marshal_curve_name(CBB *cbb, const EC_GROUP *group); 220 221 // EC_KEY_parse_parameters parses a DER-encoded ECParameters structure (RFC 222 // 5480) from |cbs| and advances |cbs|. It returns the resulting |EC_GROUP| or 223 // NULL on error. It supports the namedCurve and specifiedCurve options, but use 224 // of specifiedCurve is deprecated. Use |EC_KEY_parse_curve_name| instead. 225 // 226 // This function returns a non-const pointer which may be passed to 227 // |EC_GROUP_free|. However, the resulting object is actually static and calling 228 // |EC_GROUP_free| is optional. 229 // 230 // TODO(davidben): Make this return a const pointer, if it does not break too 231 // many callers. 232 OPENSSL_EXPORT EC_GROUP *EC_KEY_parse_parameters(CBS *cbs); 233 234 235 // ex_data functions. 236 // 237 // These functions are wrappers. See |ex_data.h| for details. 238 239 OPENSSL_EXPORT int EC_KEY_get_ex_new_index(long argl, void *argp, 240 CRYPTO_EX_unused *unused, 241 CRYPTO_EX_dup *dup_unused, 242 CRYPTO_EX_free *free_func); 243 OPENSSL_EXPORT int EC_KEY_set_ex_data(EC_KEY *r, int idx, void *arg); 244 OPENSSL_EXPORT void *EC_KEY_get_ex_data(const EC_KEY *r, int idx); 245 246 247 // ECDSA method. 248 249 // ECDSA_FLAG_OPAQUE specifies that this ECDSA_METHOD does not expose its key 250 // material. This may be set if, for instance, it is wrapping some other crypto 251 // API, like a platform key store. 252 #define ECDSA_FLAG_OPAQUE 1 253 254 // ecdsa_method_st is a structure of function pointers for implementing ECDSA. 255 // See engine.h. 256 struct ecdsa_method_st { 257 struct openssl_method_common_st common; 258 259 void *app_data; 260 261 int (*init)(EC_KEY *key); 262 int (*finish)(EC_KEY *key); 263 264 // group_order_size returns the number of bytes needed to represent the order 265 // of the group. This is used to calculate the maximum size of an ECDSA 266 // signature in |ECDSA_size|. 267 size_t (*group_order_size)(const 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