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 * openssl-core@openssl.org. 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 * (eay@cryptsoft.com). This product includes software written by Tim 52 * Hudson (tjh@cryptsoft.com). 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_H 69 #define OPENSSL_HEADER_EC_H 70 71 #include <openssl/base.h> 72 73 #if defined(__cplusplus) 74 extern "C" { 75 #endif 76 77 78 // Low-level operations on elliptic curves. 79 80 81 // point_conversion_form_t enumerates forms, as defined in X9.62 (ECDSA), for 82 // the encoding of a elliptic curve point (x,y) 83 typedef enum { 84 // POINT_CONVERSION_COMPRESSED indicates that the point is encoded as z||x, 85 // where the octet z specifies which solution of the quadratic equation y 86 // is. 87 POINT_CONVERSION_COMPRESSED = 2, 88 89 // POINT_CONVERSION_UNCOMPRESSED indicates that the point is encoded as 90 // z||x||y, where z is the octet 0x04. 91 POINT_CONVERSION_UNCOMPRESSED = 4, 92 93 // POINT_CONVERSION_HYBRID indicates that the point is encoded as z||x||y, 94 // where z specifies which solution of the quadratic equation y is. This is 95 // not supported by the code and has never been observed in use. 96 // 97 // TODO(agl): remove once node.js no longer references this. 98 POINT_CONVERSION_HYBRID = 6, 99 } point_conversion_form_t; 100 101 102 // Elliptic curve groups. 103 104 // EC_GROUP_new_by_curve_name returns a fresh EC_GROUP object for the elliptic 105 // curve specified by |nid|, or NULL on unsupported NID or allocation failure. 106 // 107 // The supported NIDs are: 108 // NID_secp224r1 (P-224), 109 // NID_X9_62_prime256v1 (P-256), 110 // NID_secp384r1 (P-384), 111 // NID_secp521r1 (P-521) 112 // 113 // If in doubt, use |NID_X9_62_prime256v1|, or see the curve25519.h header for 114 // more modern primitives. 115 OPENSSL_EXPORT EC_GROUP *EC_GROUP_new_by_curve_name(int nid); 116 117 // EC_GROUP_free releases a reference to |group|. 118 OPENSSL_EXPORT void EC_GROUP_free(EC_GROUP *group); 119 120 // EC_GROUP_dup takes a reference to |a| and returns it. 121 OPENSSL_EXPORT EC_GROUP *EC_GROUP_dup(const EC_GROUP *a); 122 123 // EC_GROUP_cmp returns zero if |a| and |b| are the same group and non-zero 124 // otherwise. 125 OPENSSL_EXPORT int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, 126 BN_CTX *ignored); 127 128 // EC_GROUP_get0_generator returns a pointer to the internal |EC_POINT| object 129 // in |group| that specifies the generator for the group. 130 OPENSSL_EXPORT const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group); 131 132 // EC_GROUP_get0_order returns a pointer to the internal |BIGNUM| object in 133 // |group| that specifies the order of the group. 134 OPENSSL_EXPORT const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group); 135 136 // EC_GROUP_order_bits returns the number of bits of the order of |group|. 137 OPENSSL_EXPORT int EC_GROUP_order_bits(const EC_GROUP *group); 138 139 // EC_GROUP_get_cofactor sets |*cofactor| to the cofactor of |group| using 140 // |ctx|, if it's not NULL. It returns one on success and zero otherwise. 141 OPENSSL_EXPORT int EC_GROUP_get_cofactor(const EC_GROUP *group, 142 BIGNUM *cofactor, BN_CTX *ctx); 143 144 // EC_GROUP_get_curve_GFp gets various parameters about a group. It sets 145 // |*out_p| to the order of the coordinate field and |*out_a| and |*out_b| to 146 // the parameters of the curve when expressed as y² = x³ + ax + b. Any of the 147 // output parameters can be NULL. It returns one on success and zero on 148 // error. 149 OPENSSL_EXPORT int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *out_p, 150 BIGNUM *out_a, BIGNUM *out_b, 151 BN_CTX *ctx); 152 153 // EC_GROUP_get_curve_name returns a NID that identifies |group|. 154 OPENSSL_EXPORT int EC_GROUP_get_curve_name(const EC_GROUP *group); 155 156 // EC_GROUP_get_degree returns the number of bits needed to represent an 157 // element of the field underlying |group|. 158 OPENSSL_EXPORT unsigned EC_GROUP_get_degree(const EC_GROUP *group); 159 160 // EC_curve_nid2nist returns the NIST name of the elliptic curve specified by 161 // |nid|, or NULL if |nid| is not a NIST curve. For example, it returns "P-256" 162 // for |NID_X9_62_prime256v1|. 163 OPENSSL_EXPORT const char *EC_curve_nid2nist(int nid); 164 165 // EC_curve_nist2nid returns the NID of the elliptic curve specified by the NIST 166 // name |name|, or |NID_undef| if |name| is not a recognized name. For example, 167 // it returns |NID_X9_62_prime256v1| for "P-256". 168 OPENSSL_EXPORT int EC_curve_nist2nid(const char *name); 169 170 171 // Points on elliptic curves. 172 173 // EC_POINT_new returns a fresh |EC_POINT| object in the given group, or NULL 174 // on error. 175 OPENSSL_EXPORT EC_POINT *EC_POINT_new(const EC_GROUP *group); 176 177 // EC_POINT_free frees |point| and the data that it points to. 178 OPENSSL_EXPORT void EC_POINT_free(EC_POINT *point); 179 180 // EC_POINT_copy sets |*dest| equal to |*src|. It returns one on success and 181 // zero otherwise. 182 OPENSSL_EXPORT int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src); 183 184 // EC_POINT_dup returns a fresh |EC_POINT| that contains the same values as 185 // |src|, or NULL on error. 186 OPENSSL_EXPORT EC_POINT *EC_POINT_dup(const EC_POINT *src, 187 const EC_GROUP *group); 188 189 // EC_POINT_set_to_infinity sets |point| to be the "point at infinity" for the 190 // given group. 191 OPENSSL_EXPORT int EC_POINT_set_to_infinity(const EC_GROUP *group, 192 EC_POINT *point); 193 194 // EC_POINT_is_at_infinity returns one iff |point| is the point at infinity and 195 // zero otherwise. 196 OPENSSL_EXPORT int EC_POINT_is_at_infinity(const EC_GROUP *group, 197 const EC_POINT *point); 198 199 // EC_POINT_is_on_curve returns one if |point| is an element of |group| and 200 // and zero otherwise or when an error occurs. This is different from OpenSSL, 201 // which returns -1 on error. If |ctx| is non-NULL, it may be used. 202 OPENSSL_EXPORT int EC_POINT_is_on_curve(const EC_GROUP *group, 203 const EC_POINT *point, BN_CTX *ctx); 204 205 // EC_POINT_cmp returns zero if |a| is equal to |b|, greater than zero if 206 // not equal and -1 on error. If |ctx| is not NULL, it may be used. 207 OPENSSL_EXPORT int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, 208 const EC_POINT *b, BN_CTX *ctx); 209 210 211 // Point conversion. 212 213 // EC_POINT_get_affine_coordinates_GFp sets |x| and |y| to the affine value of 214 // |point| using |ctx|, if it's not NULL. It returns one on success and zero 215 // otherwise. 216 // 217 // Either |x| or |y| may be NULL to skip computing that coordinate. This is 218 // slightly faster in the common case where only the x-coordinate is needed. 219 OPENSSL_EXPORT int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group, 220 const EC_POINT *point, 221 BIGNUM *x, BIGNUM *y, 222 BN_CTX *ctx); 223 224 // EC_POINT_set_affine_coordinates_GFp sets the value of |point| to be 225 // (|x|, |y|). The |ctx| argument may be used if not NULL. It returns one 226 // on success or zero on error. Note that, unlike with OpenSSL, it's 227 // considered an error if the point is not on the curve. 228 OPENSSL_EXPORT int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, 229 EC_POINT *point, 230 const BIGNUM *x, 231 const BIGNUM *y, 232 BN_CTX *ctx); 233 234 // EC_POINT_point2oct serialises |point| into the X9.62 form given by |form| 235 // into, at most, |len| bytes at |buf|. It returns the number of bytes written 236 // or zero on error if |buf| is non-NULL, else the number of bytes needed. The 237 // |ctx| argument may be used if not NULL. 238 OPENSSL_EXPORT size_t EC_POINT_point2oct(const EC_GROUP *group, 239 const EC_POINT *point, 240 point_conversion_form_t form, 241 uint8_t *buf, size_t len, BN_CTX *ctx); 242 243 // EC_POINT_point2cbb behaves like |EC_POINT_point2oct| but appends the 244 // serialised point to |cbb|. It returns one on success and zero on error. 245 OPENSSL_EXPORT int EC_POINT_point2cbb(CBB *out, const EC_GROUP *group, 246 const EC_POINT *point, 247 point_conversion_form_t form, 248 BN_CTX *ctx); 249 250 // EC_POINT_oct2point sets |point| from |len| bytes of X9.62 format 251 // serialisation in |buf|. It returns one on success and zero otherwise. The 252 // |ctx| argument may be used if not NULL. 253 OPENSSL_EXPORT int EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *point, 254 const uint8_t *buf, size_t len, 255 BN_CTX *ctx); 256 257 // EC_POINT_set_compressed_coordinates_GFp sets |point| to equal the point with 258 // the given |x| coordinate and the y coordinate specified by |y_bit| (see 259 // X9.62). It returns one on success and zero otherwise. 260 OPENSSL_EXPORT int EC_POINT_set_compressed_coordinates_GFp( 261 const EC_GROUP *group, EC_POINT *point, const BIGNUM *x, int y_bit, 262 BN_CTX *ctx); 263 264 265 // Group operations. 266 267 // EC_POINT_add sets |r| equal to |a| plus |b|. It returns one on success and 268 // zero otherwise. If |ctx| is not NULL, it may be used. 269 OPENSSL_EXPORT int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, 270 const EC_POINT *a, const EC_POINT *b, 271 BN_CTX *ctx); 272 273 // EC_POINT_dbl sets |r| equal to |a| plus |a|. It returns one on success and 274 // zero otherwise. If |ctx| is not NULL, it may be used. 275 OPENSSL_EXPORT int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, 276 const EC_POINT *a, BN_CTX *ctx); 277 278 // EC_POINT_invert sets |a| equal to minus |a|. It returns one on success and 279 // zero otherwise. If |ctx| is not NULL, it may be used. 280 OPENSSL_EXPORT int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, 281 BN_CTX *ctx); 282 283 // EC_POINT_mul sets r = generator*n + q*m. It returns one on success and zero 284 // otherwise. If |ctx| is not NULL, it may be used. 285 OPENSSL_EXPORT int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, 286 const BIGNUM *n, const EC_POINT *q, 287 const BIGNUM *m, BN_CTX *ctx); 288 289 290 // Deprecated functions. 291 292 // EC_GROUP_new_curve_GFp creates a new, arbitrary elliptic curve group based 293 // on the equation y² = x³ + a·x + b. It returns the new group or NULL on 294 // error. 295 // 296 // This new group has no generator. It is an error to use a generator-less group 297 // with any functions except for |EC_GROUP_free|, |EC_POINT_new|, 298 // |EC_POINT_set_affine_coordinates_GFp|, and |EC_GROUP_set_generator|. 299 // 300 // |EC_GROUP|s returned by this function will always compare as unequal via 301 // |EC_GROUP_cmp| (even to themselves). |EC_GROUP_get_curve_name| will always 302 // return |NID_undef|. 303 // 304 // Avoid using arbitrary curves and use |EC_GROUP_new_by_curve_name| instead. 305 OPENSSL_EXPORT EC_GROUP *EC_GROUP_new_curve_GFp(const BIGNUM *p, 306 const BIGNUM *a, 307 const BIGNUM *b, BN_CTX *ctx); 308 309 // EC_GROUP_set_generator sets the generator for |group| to |generator|, which 310 // must have the given order and cofactor. It may only be used with |EC_GROUP| 311 // objects returned by |EC_GROUP_new_curve_GFp| and may only be used once on 312 // each group. |generator| must have been created using |group|. 313 OPENSSL_EXPORT int EC_GROUP_set_generator(EC_GROUP *group, 314 const EC_POINT *generator, 315 const BIGNUM *order, 316 const BIGNUM *cofactor); 317 318 // EC_GROUP_get_order sets |*order| to the order of |group|, if it's not 319 // NULL. It returns one on success and zero otherwise. |ctx| is ignored. Use 320 // |EC_GROUP_get0_order| instead. 321 OPENSSL_EXPORT int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, 322 BN_CTX *ctx); 323 324 // EC_GROUP_set_asn1_flag does nothing. 325 OPENSSL_EXPORT void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag); 326 327 #define OPENSSL_EC_NAMED_CURVE 0 328 #define OPENSSL_EC_EXPLICIT_CURVE 1 329 330 typedef struct ec_method_st EC_METHOD; 331 332 // EC_GROUP_method_of returns a dummy non-NULL pointer. 333 OPENSSL_EXPORT const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group); 334 335 // EC_METHOD_get_field_type returns NID_X9_62_prime_field. 336 OPENSSL_EXPORT int EC_METHOD_get_field_type(const EC_METHOD *meth); 337 338 // EC_GROUP_set_point_conversion_form aborts the process if |form| is not 339 // |POINT_CONVERSION_UNCOMPRESSED| and otherwise does nothing. 340 OPENSSL_EXPORT void EC_GROUP_set_point_conversion_form( 341 EC_GROUP *group, point_conversion_form_t form); 342 343 // EC_builtin_curve describes a supported elliptic curve. 344 typedef struct { 345 int nid; 346 const char *comment; 347 } EC_builtin_curve; 348 349 // EC_get_builtin_curves writes at most |max_num_curves| elements to 350 // |out_curves| and returns the total number that it would have written, had 351 // |max_num_curves| been large enough. 352 // 353 // The |EC_builtin_curve| items describe the supported elliptic curves. 354 OPENSSL_EXPORT size_t EC_get_builtin_curves(EC_builtin_curve *out_curves, 355 size_t max_num_curves); 356 357 // EC_POINT_clear_free calls |EC_POINT_free|. 358 OPENSSL_EXPORT void EC_POINT_clear_free(EC_POINT *point); 359 360 361 #if defined(__cplusplus) 362 } // extern C 363 #endif 364 365 // Old code expects to get EC_KEY from ec.h. 366 #include <openssl/ec_key.h> 367 368 #if defined(__cplusplus) 369 extern "C++" { 370 371 BSSL_NAMESPACE_BEGIN 372 373 BORINGSSL_MAKE_DELETER(EC_POINT, EC_POINT_free) 374 BORINGSSL_MAKE_DELETER(EC_GROUP, EC_GROUP_free) 375 376 BSSL_NAMESPACE_END 377 378 } // extern C++ 379 380 #endif 381 382 #define EC_R_BUFFER_TOO_SMALL 100 383 #define EC_R_COORDINATES_OUT_OF_RANGE 101 384 #define EC_R_D2I_ECPKPARAMETERS_FAILURE 102 385 #define EC_R_EC_GROUP_NEW_BY_NAME_FAILURE 103 386 #define EC_R_GROUP2PKPARAMETERS_FAILURE 104 387 #define EC_R_I2D_ECPKPARAMETERS_FAILURE 105 388 #define EC_R_INCOMPATIBLE_OBJECTS 106 389 #define EC_R_INVALID_COMPRESSED_POINT 107 390 #define EC_R_INVALID_COMPRESSION_BIT 108 391 #define EC_R_INVALID_ENCODING 109 392 #define EC_R_INVALID_FIELD 110 393 #define EC_R_INVALID_FORM 111 394 #define EC_R_INVALID_GROUP_ORDER 112 395 #define EC_R_INVALID_PRIVATE_KEY 113 396 #define EC_R_MISSING_PARAMETERS 114 397 #define EC_R_MISSING_PRIVATE_KEY 115 398 #define EC_R_NON_NAMED_CURVE 116 399 #define EC_R_NOT_INITIALIZED 117 400 #define EC_R_PKPARAMETERS2GROUP_FAILURE 118 401 #define EC_R_POINT_AT_INFINITY 119 402 #define EC_R_POINT_IS_NOT_ON_CURVE 120 403 #define EC_R_SLOT_FULL 121 404 #define EC_R_UNDEFINED_GENERATOR 122 405 #define EC_R_UNKNOWN_GROUP 123 406 #define EC_R_UNKNOWN_ORDER 124 407 #define EC_R_WRONG_ORDER 125 408 #define EC_R_BIGNUM_OUT_OF_RANGE 126 409 #define EC_R_WRONG_CURVE_PARAMETERS 127 410 #define EC_R_DECODE_ERROR 128 411 #define EC_R_ENCODE_ERROR 129 412 #define EC_R_GROUP_MISMATCH 130 413 #define EC_R_INVALID_COFACTOR 131 414 #define EC_R_PUBLIC_KEY_VALIDATION_FAILED 132 415 #define EC_R_INVALID_SCALAR 133 416 417 #endif // OPENSSL_HEADER_EC_H 418