1 /** 2 * \file ecp.h 3 * 4 * \brief This file provides an API for Elliptic Curves over GF(P) (ECP). 5 * 6 * The use of ECP in cryptography and TLS is defined in 7 * <em>Standards for Efficient Cryptography Group (SECG): SEC1 8 * Elliptic Curve Cryptography</em> and 9 * <em>RFC-4492: Elliptic Curve Cryptography (ECC) Cipher Suites 10 * for Transport Layer Security (TLS)</em>. 11 * 12 * <em>RFC-2409: The Internet Key Exchange (IKE)</em> defines ECP 13 * group types. 14 * 15 */ 16 17 /* 18 * Copyright The Mbed TLS Contributors 19 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 20 * 21 * This file is provided under the Apache License 2.0, or the 22 * GNU General Public License v2.0 or later. 23 * 24 * ********** 25 * Apache License 2.0: 26 * 27 * Licensed under the Apache License, Version 2.0 (the "License"); you may 28 * not use this file except in compliance with the License. 29 * You may obtain a copy of the License at 30 * 31 * http://www.apache.org/licenses/LICENSE-2.0 32 * 33 * Unless required by applicable law or agreed to in writing, software 34 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 35 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 36 * See the License for the specific language governing permissions and 37 * limitations under the License. 38 * 39 * ********** 40 * 41 * ********** 42 * GNU General Public License v2.0 or later: 43 * 44 * This program is free software; you can redistribute it and/or modify 45 * it under the terms of the GNU General Public License as published by 46 * the Free Software Foundation; either version 2 of the License, or 47 * (at your option) any later version. 48 * 49 * This program is distributed in the hope that it will be useful, 50 * but WITHOUT ANY WARRANTY; without even the implied warranty of 51 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 52 * GNU General Public License for more details. 53 * 54 * You should have received a copy of the GNU General Public License along 55 * with this program; if not, write to the Free Software Foundation, Inc., 56 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 57 * 58 * ********** 59 */ 60 61 #ifndef MBEDTLS_ECP_H 62 #define MBEDTLS_ECP_H 63 64 #if !defined(MBEDTLS_CONFIG_FILE) 65 #include "config.h" 66 #else 67 #include MBEDTLS_CONFIG_FILE 68 #endif 69 70 #include "bignum.h" 71 72 /* 73 * ECP error codes 74 */ 75 #define MBEDTLS_ERR_ECP_BAD_INPUT_DATA -0x4F80 /**< Bad input parameters to function. */ 76 #define MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL -0x4F00 /**< The buffer is too small to write to. */ 77 #define MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE -0x4E80 /**< The requested feature is not available, for example, the requested curve is not supported. */ 78 #define MBEDTLS_ERR_ECP_VERIFY_FAILED -0x4E00 /**< The signature is not valid. */ 79 #define MBEDTLS_ERR_ECP_ALLOC_FAILED -0x4D80 /**< Memory allocation failed. */ 80 #define MBEDTLS_ERR_ECP_RANDOM_FAILED -0x4D00 /**< Generation of random value, such as ephemeral key, failed. */ 81 #define MBEDTLS_ERR_ECP_INVALID_KEY -0x4C80 /**< Invalid private or public key. */ 82 #define MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH -0x4C00 /**< The buffer contains a valid signature followed by more data. */ 83 84 /* MBEDTLS_ERR_ECP_HW_ACCEL_FAILED is deprecated and should not be used. */ 85 #define MBEDTLS_ERR_ECP_HW_ACCEL_FAILED -0x4B80 /**< The ECP hardware accelerator failed. */ 86 87 #define MBEDTLS_ERR_ECP_IN_PROGRESS -0x4B00 /**< Operation in progress, call again with the same parameters to continue. */ 88 89 #ifdef __cplusplus 90 extern "C" { 91 #endif 92 93 /** 94 * Domain-parameter identifiers: curve, subgroup, and generator. 95 * 96 * \note Only curves over prime fields are supported. 97 * 98 * \warning This library does not support validation of arbitrary domain 99 * parameters. Therefore, only standardized domain parameters from trusted 100 * sources should be used. See mbedtls_ecp_group_load(). 101 */ 102 typedef enum 103 { 104 MBEDTLS_ECP_DP_NONE = 0, /*!< Curve not defined. */ 105 MBEDTLS_ECP_DP_SECP192R1, /*!< Domain parameters for the 192-bit curve defined by FIPS 186-4 and SEC1. */ 106 MBEDTLS_ECP_DP_SECP224R1, /*!< Domain parameters for the 224-bit curve defined by FIPS 186-4 and SEC1. */ 107 MBEDTLS_ECP_DP_SECP256R1, /*!< Domain parameters for the 256-bit curve defined by FIPS 186-4 and SEC1. */ 108 MBEDTLS_ECP_DP_SECP384R1, /*!< Domain parameters for the 384-bit curve defined by FIPS 186-4 and SEC1. */ 109 MBEDTLS_ECP_DP_SECP521R1, /*!< Domain parameters for the 521-bit curve defined by FIPS 186-4 and SEC1. */ 110 MBEDTLS_ECP_DP_BP256R1, /*!< Domain parameters for 256-bit Brainpool curve. */ 111 MBEDTLS_ECP_DP_BP384R1, /*!< Domain parameters for 384-bit Brainpool curve. */ 112 MBEDTLS_ECP_DP_BP512R1, /*!< Domain parameters for 512-bit Brainpool curve. */ 113 MBEDTLS_ECP_DP_CURVE25519, /*!< Domain parameters for Curve25519. */ 114 MBEDTLS_ECP_DP_SECP192K1, /*!< Domain parameters for 192-bit "Koblitz" curve. */ 115 MBEDTLS_ECP_DP_SECP224K1, /*!< Domain parameters for 224-bit "Koblitz" curve. */ 116 MBEDTLS_ECP_DP_SECP256K1, /*!< Domain parameters for 256-bit "Koblitz" curve. */ 117 MBEDTLS_ECP_DP_CURVE448, /*!< Domain parameters for Curve448. */ 118 } mbedtls_ecp_group_id; 119 120 /** 121 * The number of supported curves, plus one for #MBEDTLS_ECP_DP_NONE. 122 * 123 * \note Montgomery curves are currently excluded. 124 */ 125 #define MBEDTLS_ECP_DP_MAX 12 126 127 /** 128 * Curve information, for use by other modules. 129 */ 130 typedef struct mbedtls_ecp_curve_info 131 { 132 mbedtls_ecp_group_id grp_id; /*!< An internal identifier. */ 133 uint16_t tls_id; /*!< The TLS NamedCurve identifier. */ 134 uint16_t bit_size; /*!< The curve size in bits. */ 135 const char *name; /*!< A human-friendly name. */ 136 } mbedtls_ecp_curve_info; 137 138 /** 139 * \brief The ECP point structure, in Jacobian coordinates. 140 * 141 * \note All functions expect and return points satisfying 142 * the following condition: <code>Z == 0</code> or 143 * <code>Z == 1</code>. Other values of \p Z are 144 * used only by internal functions. 145 * The point is zero, or "at infinity", if <code>Z == 0</code>. 146 * Otherwise, \p X and \p Y are its standard (affine) 147 * coordinates. 148 */ 149 typedef struct mbedtls_ecp_point 150 { 151 mbedtls_mpi X; /*!< The X coordinate of the ECP point. */ 152 mbedtls_mpi Y; /*!< The Y coordinate of the ECP point. */ 153 mbedtls_mpi Z; /*!< The Z coordinate of the ECP point. */ 154 } 155 mbedtls_ecp_point; 156 157 #if !defined(MBEDTLS_ECP_ALT) 158 /* 159 * default mbed TLS elliptic curve arithmetic implementation 160 * 161 * (in case MBEDTLS_ECP_ALT is defined then the developer has to provide an 162 * alternative implementation for the whole module and it will replace this 163 * one.) 164 */ 165 166 /** 167 * \brief The ECP group structure. 168 * 169 * We consider two types of curve equations: 170 * <ul><li>Short Weierstrass: <code>y^2 = x^3 + A x + B mod P</code> 171 * (SEC1 + RFC-4492)</li> 172 * <li>Montgomery: <code>y^2 = x^3 + A x^2 + x mod P</code> (Curve25519, 173 * Curve448)</li></ul> 174 * In both cases, the generator (\p G) for a prime-order subgroup is fixed. 175 * 176 * For Short Weierstrass, this subgroup is the whole curve, and its 177 * cardinality is denoted by \p N. Our code requires that \p N is an 178 * odd prime as mbedtls_ecp_mul() requires an odd number, and 179 * mbedtls_ecdsa_sign() requires that it is prime for blinding purposes. 180 * 181 * For Montgomery curves, we do not store \p A, but <code>(A + 2) / 4</code>, 182 * which is the quantity used in the formulas. Additionally, \p nbits is 183 * not the size of \p N but the required size for private keys. 184 * 185 * If \p modp is NULL, reduction modulo \p P is done using a generic algorithm. 186 * Otherwise, \p modp must point to a function that takes an \p mbedtls_mpi in the 187 * range of <code>0..2^(2*pbits)-1</code>, and transforms it in-place to an integer 188 * which is congruent mod \p P to the given MPI, and is close enough to \p pbits 189 * in size, so that it may be efficiently brought in the 0..P-1 range by a few 190 * additions or subtractions. Therefore, it is only an approximative modular 191 * reduction. It must return 0 on success and non-zero on failure. 192 * 193 * \note Alternative implementations must keep the group IDs distinct. If 194 * two group structures have the same ID, then they must be 195 * identical. 196 * 197 */ 198 typedef struct mbedtls_ecp_group 199 { 200 mbedtls_ecp_group_id id; /*!< An internal group identifier. */ 201 mbedtls_mpi P; /*!< The prime modulus of the base field. */ 202 mbedtls_mpi A; /*!< For Short Weierstrass: \p A in the equation. For 203 Montgomery curves: <code>(A + 2) / 4</code>. */ 204 mbedtls_mpi B; /*!< For Short Weierstrass: \p B in the equation. 205 For Montgomery curves: unused. */ 206 mbedtls_ecp_point G; /*!< The generator of the subgroup used. */ 207 mbedtls_mpi N; /*!< The order of \p G. */ 208 size_t pbits; /*!< The number of bits in \p P.*/ 209 size_t nbits; /*!< For Short Weierstrass: The number of bits in \p P. 210 For Montgomery curves: the number of bits in the 211 private keys. */ 212 unsigned int h; /*!< \internal 1 if the constants are static. */ 213 int (*modp)(mbedtls_mpi *); /*!< The function for fast pseudo-reduction 214 mod \p P (see above).*/ 215 int (*t_pre)(mbedtls_ecp_point *, void *); /*!< Unused. */ 216 int (*t_post)(mbedtls_ecp_point *, void *); /*!< Unused. */ 217 void *t_data; /*!< Unused. */ 218 mbedtls_ecp_point *T; /*!< Pre-computed points for ecp_mul_comb(). */ 219 size_t T_size; /*!< The number of pre-computed points. */ 220 } 221 mbedtls_ecp_group; 222 223 /** 224 * \name SECTION: Module settings 225 * 226 * The configuration options you can set for this module are in this section. 227 * Either change them in config.h, or define them using the compiler command line. 228 * \{ 229 */ 230 231 #if !defined(MBEDTLS_ECP_MAX_BITS) 232 /** 233 * The maximum size of the groups, that is, of \c N and \c P. 234 */ 235 #define MBEDTLS_ECP_MAX_BITS 521 /**< The maximum size of groups, in bits. */ 236 #endif 237 238 #define MBEDTLS_ECP_MAX_BYTES ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 ) 239 #define MBEDTLS_ECP_MAX_PT_LEN ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 ) 240 241 #if !defined(MBEDTLS_ECP_WINDOW_SIZE) 242 /* 243 * Maximum "window" size used for point multiplication. 244 * Default: 6. 245 * Minimum value: 2. Maximum value: 7. 246 * 247 * Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) ) 248 * points used for point multiplication. This value is directly tied to EC 249 * peak memory usage, so decreasing it by one should roughly cut memory usage 250 * by two (if large curves are in use). 251 * 252 * Reduction in size may reduce speed, but larger curves are impacted first. 253 * Sample performances (in ECDHE handshakes/s, with FIXED_POINT_OPTIM = 1): 254 * w-size: 6 5 4 3 2 255 * 521 145 141 135 120 97 256 * 384 214 209 198 177 146 257 * 256 320 320 303 262 226 258 * 224 475 475 453 398 342 259 * 192 640 640 633 587 476 260 */ 261 #define MBEDTLS_ECP_WINDOW_SIZE 6 /**< The maximum window size used. */ 262 #endif /* MBEDTLS_ECP_WINDOW_SIZE */ 263 264 #if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM) 265 /* 266 * Trade memory for speed on fixed-point multiplication. 267 * 268 * This speeds up repeated multiplication of the generator (that is, the 269 * multiplication in ECDSA signatures, and half of the multiplications in 270 * ECDSA verification and ECDHE) by a factor roughly 3 to 4. 271 * 272 * The cost is increasing EC peak memory usage by a factor roughly 2. 273 * 274 * Change this value to 0 to reduce peak memory usage. 275 */ 276 #define MBEDTLS_ECP_FIXED_POINT_OPTIM 1 /**< Enable fixed-point speed-up. */ 277 #endif /* MBEDTLS_ECP_FIXED_POINT_OPTIM */ 278 279 /* \} name SECTION: Module settings */ 280 281 #else /* MBEDTLS_ECP_ALT */ 282 #include "ecp_alt.h" 283 #endif /* MBEDTLS_ECP_ALT */ 284 285 #if defined(MBEDTLS_ECP_RESTARTABLE) 286 287 /** 288 * \brief Internal restart context for multiplication 289 * 290 * \note Opaque struct 291 */ 292 typedef struct mbedtls_ecp_restart_mul mbedtls_ecp_restart_mul_ctx; 293 294 /** 295 * \brief Internal restart context for ecp_muladd() 296 * 297 * \note Opaque struct 298 */ 299 typedef struct mbedtls_ecp_restart_muladd mbedtls_ecp_restart_muladd_ctx; 300 301 /** 302 * \brief General context for resuming ECC operations 303 */ 304 typedef struct 305 { 306 unsigned ops_done; /*!< current ops count */ 307 unsigned depth; /*!< call depth (0 = top-level) */ 308 mbedtls_ecp_restart_mul_ctx *rsm; /*!< ecp_mul_comb() sub-context */ 309 mbedtls_ecp_restart_muladd_ctx *ma; /*!< ecp_muladd() sub-context */ 310 } mbedtls_ecp_restart_ctx; 311 312 /* 313 * Operation counts for restartable functions 314 */ 315 #define MBEDTLS_ECP_OPS_CHK 3 /*!< basic ops count for ecp_check_pubkey() */ 316 #define MBEDTLS_ECP_OPS_DBL 8 /*!< basic ops count for ecp_double_jac() */ 317 #define MBEDTLS_ECP_OPS_ADD 11 /*!< basic ops count for see ecp_add_mixed() */ 318 #define MBEDTLS_ECP_OPS_INV 120 /*!< empirical equivalent for mpi_mod_inv() */ 319 320 /** 321 * \brief Internal; for restartable functions in other modules. 322 * Check and update basic ops budget. 323 * 324 * \param grp Group structure 325 * \param rs_ctx Restart context 326 * \param ops Number of basic ops to do 327 * 328 * \return \c 0 if doing \p ops basic ops is still allowed, 329 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS otherwise. 330 */ 331 int mbedtls_ecp_check_budget( const mbedtls_ecp_group *grp, 332 mbedtls_ecp_restart_ctx *rs_ctx, 333 unsigned ops ); 334 335 /* Utility macro for checking and updating ops budget */ 336 #define MBEDTLS_ECP_BUDGET( ops ) \ 337 MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, rs_ctx, \ 338 (unsigned) (ops) ) ); 339 340 #else /* MBEDTLS_ECP_RESTARTABLE */ 341 342 #define MBEDTLS_ECP_BUDGET( ops ) /* no-op; for compatibility */ 343 344 /* We want to declare restartable versions of existing functions anyway */ 345 typedef void mbedtls_ecp_restart_ctx; 346 347 #endif /* MBEDTLS_ECP_RESTARTABLE */ 348 349 /** 350 * \brief The ECP key-pair structure. 351 * 352 * A generic key-pair that may be used for ECDSA and fixed ECDH, for example. 353 * 354 * \note Members are deliberately in the same order as in the 355 * ::mbedtls_ecdsa_context structure. 356 */ 357 typedef struct mbedtls_ecp_keypair 358 { 359 mbedtls_ecp_group grp; /*!< Elliptic curve and base point */ 360 mbedtls_mpi d; /*!< our secret value */ 361 mbedtls_ecp_point Q; /*!< our public value */ 362 } 363 mbedtls_ecp_keypair; 364 365 /* 366 * Point formats, from RFC 4492's enum ECPointFormat 367 */ 368 #define MBEDTLS_ECP_PF_UNCOMPRESSED 0 /**< Uncompressed point format. */ 369 #define MBEDTLS_ECP_PF_COMPRESSED 1 /**< Compressed point format. */ 370 371 /* 372 * Some other constants from RFC 4492 373 */ 374 #define MBEDTLS_ECP_TLS_NAMED_CURVE 3 /**< The named_curve of ECCurveType. */ 375 376 #if defined(MBEDTLS_ECP_RESTARTABLE) 377 /** 378 * \brief Set the maximum number of basic operations done in a row. 379 * 380 * If more operations are needed to complete a computation, 381 * #MBEDTLS_ERR_ECP_IN_PROGRESS will be returned by the 382 * function performing the computation. It is then the 383 * caller's responsibility to either call again with the same 384 * parameters until it returns 0 or an error code; or to free 385 * the restart context if the operation is to be aborted. 386 * 387 * It is strictly required that all input parameters and the 388 * restart context be the same on successive calls for the 389 * same operation, but output parameters need not be the 390 * same; they must not be used until the function finally 391 * returns 0. 392 * 393 * This only applies to functions whose documentation 394 * mentions they may return #MBEDTLS_ERR_ECP_IN_PROGRESS (or 395 * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS for functions in the 396 * SSL module). For functions that accept a "restart context" 397 * argument, passing NULL disables restart and makes the 398 * function equivalent to the function with the same name 399 * with \c _restartable removed. For functions in the ECDH 400 * module, restart is disabled unless the function accepts 401 * an "ECDH context" argument and 402 * mbedtls_ecdh_enable_restart() was previously called on 403 * that context. For function in the SSL module, restart is 404 * only enabled for specific sides and key exchanges 405 * (currently only for clients and ECDHE-ECDSA). 406 * 407 * \param max_ops Maximum number of basic operations done in a row. 408 * Default: 0 (unlimited). 409 * Lower (non-zero) values mean ECC functions will block for 410 * a lesser maximum amount of time. 411 * 412 * \note A "basic operation" is defined as a rough equivalent of a 413 * multiplication in GF(p) for the NIST P-256 curve. 414 * As an indication, with default settings, a scalar 415 * multiplication (full run of \c mbedtls_ecp_mul()) is: 416 * - about 3300 basic operations for P-256 417 * - about 9400 basic operations for P-384 418 * 419 * \note Very low values are not always respected: sometimes 420 * functions need to block for a minimum number of 421 * operations, and will do so even if max_ops is set to a 422 * lower value. That minimum depends on the curve size, and 423 * can be made lower by decreasing the value of 424 * \c MBEDTLS_ECP_WINDOW_SIZE. As an indication, here is the 425 * lowest effective value for various curves and values of 426 * that parameter (w for short): 427 * w=6 w=5 w=4 w=3 w=2 428 * P-256 208 208 160 136 124 429 * P-384 682 416 320 272 248 430 * P-521 1364 832 640 544 496 431 * 432 * \note This setting is currently ignored by Curve25519. 433 */ 434 void mbedtls_ecp_set_max_ops( unsigned max_ops ); 435 436 /** 437 * \brief Check if restart is enabled (max_ops != 0) 438 * 439 * \return \c 0 if \c max_ops == 0 (restart disabled) 440 * \return \c 1 otherwise (restart enabled) 441 */ 442 int mbedtls_ecp_restart_is_enabled( void ); 443 #endif /* MBEDTLS_ECP_RESTARTABLE */ 444 445 /** 446 * \brief This function retrieves the information defined in 447 * mbedtls_ecp_curve_info() for all supported curves in order 448 * of preference. 449 * 450 * \return A statically allocated array. The last entry is 0. 451 */ 452 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_list( void ); 453 454 /** 455 * \brief This function retrieves the list of internal group 456 * identifiers of all supported curves in the order of 457 * preference. 458 * 459 * \return A statically allocated array, 460 * terminated with MBEDTLS_ECP_DP_NONE. 461 */ 462 const mbedtls_ecp_group_id *mbedtls_ecp_grp_id_list( void ); 463 464 /** 465 * \brief This function retrieves curve information from an internal 466 * group identifier. 467 * 468 * \param grp_id An \c MBEDTLS_ECP_DP_XXX value. 469 * 470 * \return The associated curve information on success. 471 * \return NULL on failure. 472 */ 473 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_grp_id( mbedtls_ecp_group_id grp_id ); 474 475 /** 476 * \brief This function retrieves curve information from a TLS 477 * NamedCurve value. 478 * 479 * \param tls_id An \c MBEDTLS_ECP_DP_XXX value. 480 * 481 * \return The associated curve information on success. 482 * \return NULL on failure. 483 */ 484 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_tls_id( uint16_t tls_id ); 485 486 /** 487 * \brief This function retrieves curve information from a 488 * human-readable name. 489 * 490 * \param name The human-readable name. 491 * 492 * \return The associated curve information on success. 493 * \return NULL on failure. 494 */ 495 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_name( const char *name ); 496 497 /** 498 * \brief This function initializes a point as zero. 499 * 500 * \param pt The point to initialize. 501 */ 502 void mbedtls_ecp_point_init( mbedtls_ecp_point *pt ); 503 504 /** 505 * \brief This function initializes an ECP group context 506 * without loading any domain parameters. 507 * 508 * \note After this function is called, domain parameters 509 * for various ECP groups can be loaded through the 510 * mbedtls_ecp_group_load() or mbedtls_ecp_tls_read_group() 511 * functions. 512 */ 513 void mbedtls_ecp_group_init( mbedtls_ecp_group *grp ); 514 515 /** 516 * \brief This function initializes a key pair as an invalid one. 517 * 518 * \param key The key pair to initialize. 519 */ 520 void mbedtls_ecp_keypair_init( mbedtls_ecp_keypair *key ); 521 522 /** 523 * \brief This function frees the components of a point. 524 * 525 * \param pt The point to free. 526 */ 527 void mbedtls_ecp_point_free( mbedtls_ecp_point *pt ); 528 529 /** 530 * \brief This function frees the components of an ECP group. 531 * 532 * \param grp The group to free. This may be \c NULL, in which 533 * case this function returns immediately. If it is not 534 * \c NULL, it must point to an initialized ECP group. 535 */ 536 void mbedtls_ecp_group_free( mbedtls_ecp_group *grp ); 537 538 /** 539 * \brief This function frees the components of a key pair. 540 * 541 * \param key The key pair to free. This may be \c NULL, in which 542 * case this function returns immediately. If it is not 543 * \c NULL, it must point to an initialized ECP key pair. 544 */ 545 void mbedtls_ecp_keypair_free( mbedtls_ecp_keypair *key ); 546 547 #if defined(MBEDTLS_ECP_RESTARTABLE) 548 /** 549 * \brief Initialize a restart context. 550 * 551 * \param ctx The restart context to initialize. This must 552 * not be \c NULL. 553 */ 554 void mbedtls_ecp_restart_init( mbedtls_ecp_restart_ctx *ctx ); 555 556 /** 557 * \brief Free the components of a restart context. 558 * 559 * \param ctx The restart context to free. This may be \c NULL, in which 560 * case this function returns immediately. If it is not 561 * \c NULL, it must point to an initialized restart context. 562 */ 563 void mbedtls_ecp_restart_free( mbedtls_ecp_restart_ctx *ctx ); 564 #endif /* MBEDTLS_ECP_RESTARTABLE */ 565 566 /** 567 * \brief This function copies the contents of point \p Q into 568 * point \p P. 569 * 570 * \param P The destination point. This must be initialized. 571 * \param Q The source point. This must be initialized. 572 * 573 * \return \c 0 on success. 574 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 575 * \return Another negative error code for other kinds of failure. 576 */ 577 int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q ); 578 579 /** 580 * \brief This function copies the contents of group \p src into 581 * group \p dst. 582 * 583 * \param dst The destination group. This must be initialized. 584 * \param src The source group. This must be initialized. 585 * 586 * \return \c 0 on success. 587 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 588 * \return Another negative error code on other kinds of failure. 589 */ 590 int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, 591 const mbedtls_ecp_group *src ); 592 593 /** 594 * \brief This function sets a point to the point at infinity. 595 * 596 * \param pt The point to set. This must be initialized. 597 * 598 * \return \c 0 on success. 599 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 600 * \return Another negative error code on other kinds of failure. 601 */ 602 int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt ); 603 604 /** 605 * \brief This function checks if a point is the point at infinity. 606 * 607 * \param pt The point to test. This must be initialized. 608 * 609 * \return \c 1 if the point is zero. 610 * \return \c 0 if the point is non-zero. 611 * \return A negative error code on failure. 612 */ 613 int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt ); 614 615 /** 616 * \brief This function compares two points. 617 * 618 * \note This assumes that the points are normalized. Otherwise, 619 * they may compare as "not equal" even if they are. 620 * 621 * \param P The first point to compare. This must be initialized. 622 * \param Q The second point to compare. This must be initialized. 623 * 624 * \return \c 0 if the points are equal. 625 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the points are not equal. 626 */ 627 int mbedtls_ecp_point_cmp( const mbedtls_ecp_point *P, 628 const mbedtls_ecp_point *Q ); 629 630 /** 631 * \brief This function imports a non-zero point from two ASCII 632 * strings. 633 * 634 * \param P The destination point. This must be initialized. 635 * \param radix The numeric base of the input. 636 * \param x The first affine coordinate, as a null-terminated string. 637 * \param y The second affine coordinate, as a null-terminated string. 638 * 639 * \return \c 0 on success. 640 * \return An \c MBEDTLS_ERR_MPI_XXX error code on failure. 641 */ 642 int mbedtls_ecp_point_read_string( mbedtls_ecp_point *P, int radix, 643 const char *x, const char *y ); 644 645 /** 646 * \brief This function exports a point into unsigned binary data. 647 * 648 * \param grp The group to which the point should belong. 649 * This must be initialized and have group parameters 650 * set, for example through mbedtls_ecp_group_load(). 651 * \param P The point to export. This must be initialized. 652 * \param format The point format. This must be either 653 * #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED. 654 * \param olen The address at which to store the length of 655 * the output in Bytes. This must not be \c NULL. 656 * \param buf The output buffer. This must be a writable buffer 657 * of length \p buflen Bytes. 658 * \param buflen The length of the output buffer \p buf in Bytes. 659 * 660 * \return \c 0 on success. 661 * \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output buffer 662 * is too small to hold the point. 663 * \return Another negative error code on other kinds of failure. 664 */ 665 int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *P, 666 int format, size_t *olen, 667 unsigned char *buf, size_t buflen ); 668 669 /** 670 * \brief This function imports a point from unsigned binary data. 671 * 672 * \note This function does not check that the point actually 673 * belongs to the given group, see mbedtls_ecp_check_pubkey() 674 * for that. 675 * 676 * \param grp The group to which the point should belong. 677 * This must be initialized and have group parameters 678 * set, for example through mbedtls_ecp_group_load(). 679 * \param P The destination context to import the point to. 680 * This must be initialized. 681 * \param buf The input buffer. This must be a readable buffer 682 * of length \p ilen Bytes. 683 * \param ilen The length of the input buffer \p buf in Bytes. 684 * 685 * \return \c 0 on success. 686 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid. 687 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 688 * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the point format 689 * is not implemented. 690 */ 691 int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp, 692 mbedtls_ecp_point *P, 693 const unsigned char *buf, size_t ilen ); 694 695 /** 696 * \brief This function imports a point from a TLS ECPoint record. 697 * 698 * \note On function return, \p *buf is updated to point immediately 699 * after the ECPoint record. 700 * 701 * \param grp The ECP group to use. 702 * This must be initialized and have group parameters 703 * set, for example through mbedtls_ecp_group_load(). 704 * \param pt The destination point. 705 * \param buf The address of the pointer to the start of the input buffer. 706 * \param len The length of the buffer. 707 * 708 * \return \c 0 on success. 709 * \return An \c MBEDTLS_ERR_MPI_XXX error code on initialization 710 * failure. 711 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. 712 */ 713 int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, 714 mbedtls_ecp_point *pt, 715 const unsigned char **buf, size_t len ); 716 717 /** 718 * \brief This function exports a point as a TLS ECPoint record 719 * defined in RFC 4492, Section 5.4. 720 * 721 * \param grp The ECP group to use. 722 * This must be initialized and have group parameters 723 * set, for example through mbedtls_ecp_group_load(). 724 * \param pt The point to be exported. This must be initialized. 725 * \param format The point format to use. This must be either 726 * #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED. 727 * \param olen The address at which to store the length in Bytes 728 * of the data written. 729 * \param buf The target buffer. This must be a writable buffer of 730 * length \p blen Bytes. 731 * \param blen The length of the target buffer \p buf in Bytes. 732 * 733 * \return \c 0 on success. 734 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid. 735 * \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the target buffer 736 * is too small to hold the exported point. 737 * \return Another negative error code on other kinds of failure. 738 */ 739 int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp, 740 const mbedtls_ecp_point *pt, 741 int format, size_t *olen, 742 unsigned char *buf, size_t blen ); 743 744 /** 745 * \brief This function sets up an ECP group context 746 * from a standardized set of domain parameters. 747 * 748 * \note The index should be a value of the NamedCurve enum, 749 * as defined in <em>RFC-4492: Elliptic Curve Cryptography 750 * (ECC) Cipher Suites for Transport Layer Security (TLS)</em>, 751 * usually in the form of an \c MBEDTLS_ECP_DP_XXX macro. 752 * 753 * \param grp The group context to setup. This must be initialized. 754 * \param id The identifier of the domain parameter set to load. 755 * 756 * \return \c 0 on success. 757 * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if \p id doesn't 758 * correspond to a known group. 759 * \return Another negative error code on other kinds of failure. 760 */ 761 int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id id ); 762 763 /** 764 * \brief This function sets up an ECP group context from a TLS 765 * ECParameters record as defined in RFC 4492, Section 5.4. 766 * 767 * \note The read pointer \p buf is updated to point right after 768 * the ECParameters record on exit. 769 * 770 * \param grp The group context to setup. This must be initialized. 771 * \param buf The address of the pointer to the start of the input buffer. 772 * \param len The length of the input buffer \c *buf in Bytes. 773 * 774 * \return \c 0 on success. 775 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. 776 * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not 777 * recognized. 778 * \return Another negative error code on other kinds of failure. 779 */ 780 int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp, 781 const unsigned char **buf, size_t len ); 782 783 /** 784 * \brief This function extracts an elliptic curve group ID from a 785 * TLS ECParameters record as defined in RFC 4492, Section 5.4. 786 * 787 * \note The read pointer \p buf is updated to point right after 788 * the ECParameters record on exit. 789 * 790 * \param grp The address at which to store the group id. 791 * This must not be \c NULL. 792 * \param buf The address of the pointer to the start of the input buffer. 793 * \param len The length of the input buffer \c *buf in Bytes. 794 * 795 * \return \c 0 on success. 796 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. 797 * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not 798 * recognized. 799 * \return Another negative error code on other kinds of failure. 800 */ 801 int mbedtls_ecp_tls_read_group_id( mbedtls_ecp_group_id *grp, 802 const unsigned char **buf, 803 size_t len ); 804 /** 805 * \brief This function exports an elliptic curve as a TLS 806 * ECParameters record as defined in RFC 4492, Section 5.4. 807 * 808 * \param grp The ECP group to be exported. 809 * This must be initialized and have group parameters 810 * set, for example through mbedtls_ecp_group_load(). 811 * \param olen The address at which to store the number of Bytes written. 812 * This must not be \c NULL. 813 * \param buf The buffer to write to. This must be a writable buffer 814 * of length \p blen Bytes. 815 * \param blen The length of the output buffer \p buf in Bytes. 816 * 817 * \return \c 0 on success. 818 * \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output 819 * buffer is too small to hold the exported group. 820 * \return Another negative error code on other kinds of failure. 821 */ 822 int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, 823 size_t *olen, 824 unsigned char *buf, size_t blen ); 825 826 /** 827 * \brief This function performs a scalar multiplication of a point 828 * by an integer: \p R = \p m * \p P. 829 * 830 * It is not thread-safe to use same group in multiple threads. 831 * 832 * \note To prevent timing attacks, this function 833 * executes the exact same sequence of base-field 834 * operations for any valid \p m. It avoids any if-branch or 835 * array index depending on the value of \p m. 836 * 837 * \note If \p f_rng is not NULL, it is used to randomize 838 * intermediate results to prevent potential timing attacks 839 * targeting these results. We recommend always providing 840 * a non-NULL \p f_rng. The overhead is negligible. 841 * Note: unless #MBEDTLS_ECP_NO_INTERNAL_RNG is defined, when 842 * \p f_rng is NULL, an internal RNG (seeded from the value 843 * of \p m) will be used instead. 844 * 845 * \param grp The ECP group to use. 846 * This must be initialized and have group parameters 847 * set, for example through mbedtls_ecp_group_load(). 848 * \param R The point in which to store the result of the calculation. 849 * This must be initialized. 850 * \param m The integer by which to multiply. This must be initialized. 851 * \param P The point to multiply. This must be initialized. 852 * \param f_rng The RNG function. This may be \c NULL if randomization 853 * of intermediate results isn't desired (discouraged). 854 * \param p_rng The RNG context to be passed to \p p_rng. 855 * 856 * \return \c 0 on success. 857 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private 858 * key, or \p P is not a valid public key. 859 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 860 * \return Another negative error code on other kinds of failure. 861 */ 862 int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 863 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 864 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); 865 866 /** 867 * \brief This function performs multiplication of a point by 868 * an integer: \p R = \p m * \p P in a restartable way. 869 * 870 * \see mbedtls_ecp_mul() 871 * 872 * \note This function does the same as \c mbedtls_ecp_mul(), but 873 * it can return early and restart according to the limit set 874 * with \c mbedtls_ecp_set_max_ops() to reduce blocking. 875 * 876 * \param grp The ECP group to use. 877 * This must be initialized and have group parameters 878 * set, for example through mbedtls_ecp_group_load(). 879 * \param R The point in which to store the result of the calculation. 880 * This must be initialized. 881 * \param m The integer by which to multiply. This must be initialized. 882 * \param P The point to multiply. This must be initialized. 883 * \param f_rng The RNG function. This may be \c NULL if randomization 884 * of intermediate results isn't desired (discouraged). 885 * \param p_rng The RNG context to be passed to \p p_rng. 886 * \param rs_ctx The restart context (NULL disables restart). 887 * 888 * \return \c 0 on success. 889 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private 890 * key, or \p P is not a valid public key. 891 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 892 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of 893 * operations was reached: see \c mbedtls_ecp_set_max_ops(). 894 * \return Another negative error code on other kinds of failure. 895 */ 896 int mbedtls_ecp_mul_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 897 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 898 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, 899 mbedtls_ecp_restart_ctx *rs_ctx ); 900 901 /** 902 * \brief This function performs multiplication and addition of two 903 * points by integers: \p R = \p m * \p P + \p n * \p Q 904 * 905 * It is not thread-safe to use same group in multiple threads. 906 * 907 * \note In contrast to mbedtls_ecp_mul(), this function does not 908 * guarantee a constant execution flow and timing. 909 * 910 * \param grp The ECP group to use. 911 * This must be initialized and have group parameters 912 * set, for example through mbedtls_ecp_group_load(). 913 * \param R The point in which to store the result of the calculation. 914 * This must be initialized. 915 * \param m The integer by which to multiply \p P. 916 * This must be initialized. 917 * \param P The point to multiply by \p m. This must be initialized. 918 * \param n The integer by which to multiply \p Q. 919 * This must be initialized. 920 * \param Q The point to be multiplied by \p n. 921 * This must be initialized. 922 * 923 * \return \c 0 on success. 924 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m or \p n are not 925 * valid private keys, or \p P or \p Q are not valid public 926 * keys. 927 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 928 * \return Another negative error code on other kinds of failure. 929 */ 930 int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 931 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 932 const mbedtls_mpi *n, const mbedtls_ecp_point *Q ); 933 934 /** 935 * \brief This function performs multiplication and addition of two 936 * points by integers: \p R = \p m * \p P + \p n * \p Q in a 937 * restartable way. 938 * 939 * \see \c mbedtls_ecp_muladd() 940 * 941 * \note This function works the same as \c mbedtls_ecp_muladd(), 942 * but it can return early and restart according to the limit 943 * set with \c mbedtls_ecp_set_max_ops() to reduce blocking. 944 * 945 * \param grp The ECP group to use. 946 * This must be initialized and have group parameters 947 * set, for example through mbedtls_ecp_group_load(). 948 * \param R The point in which to store the result of the calculation. 949 * This must be initialized. 950 * \param m The integer by which to multiply \p P. 951 * This must be initialized. 952 * \param P The point to multiply by \p m. This must be initialized. 953 * \param n The integer by which to multiply \p Q. 954 * This must be initialized. 955 * \param Q The point to be multiplied by \p n. 956 * This must be initialized. 957 * \param rs_ctx The restart context (NULL disables restart). 958 * 959 * \return \c 0 on success. 960 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m or \p n are not 961 * valid private keys, or \p P or \p Q are not valid public 962 * keys. 963 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 964 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of 965 * operations was reached: see \c mbedtls_ecp_set_max_ops(). 966 * \return Another negative error code on other kinds of failure. 967 */ 968 int mbedtls_ecp_muladd_restartable( 969 mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 970 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 971 const mbedtls_mpi *n, const mbedtls_ecp_point *Q, 972 mbedtls_ecp_restart_ctx *rs_ctx ); 973 974 /** 975 * \brief This function checks that a point is a valid public key 976 * on this curve. 977 * 978 * It only checks that the point is non-zero, has 979 * valid coordinates and lies on the curve. It does not verify 980 * that it is indeed a multiple of \p G. This additional 981 * check is computationally more expensive, is not required 982 * by standards, and should not be necessary if the group 983 * used has a small cofactor. In particular, it is useless for 984 * the NIST groups which all have a cofactor of 1. 985 * 986 * \note This function uses bare components rather than an 987 * ::mbedtls_ecp_keypair structure, to ease use with other 988 * structures, such as ::mbedtls_ecdh_context or 989 * ::mbedtls_ecdsa_context. 990 * 991 * \param grp The ECP group the point should belong to. 992 * This must be initialized and have group parameters 993 * set, for example through mbedtls_ecp_group_load(). 994 * \param pt The point to check. This must be initialized. 995 * 996 * \return \c 0 if the point is a valid public key. 997 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not 998 * a valid public key for the given curve. 999 * \return Another negative error code on other kinds of failure. 1000 */ 1001 int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, 1002 const mbedtls_ecp_point *pt ); 1003 1004 /** 1005 * \brief This function checks that an \p mbedtls_mpi is a 1006 * valid private key for this curve. 1007 * 1008 * \note This function uses bare components rather than an 1009 * ::mbedtls_ecp_keypair structure to ease use with other 1010 * structures, such as ::mbedtls_ecdh_context or 1011 * ::mbedtls_ecdsa_context. 1012 * 1013 * \param grp The ECP group the private key should belong to. 1014 * This must be initialized and have group parameters 1015 * set, for example through mbedtls_ecp_group_load(). 1016 * \param d The integer to check. This must be initialized. 1017 * 1018 * \return \c 0 if the point is a valid private key. 1019 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not a valid 1020 * private key for the given curve. 1021 * \return Another negative error code on other kinds of failure. 1022 */ 1023 int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp, 1024 const mbedtls_mpi *d ); 1025 1026 /** 1027 * \brief This function generates a private key. 1028 * 1029 * \param grp The ECP group to generate a private key for. 1030 * This must be initialized and have group parameters 1031 * set, for example through mbedtls_ecp_group_load(). 1032 * \param d The destination MPI (secret part). This must be initialized. 1033 * \param f_rng The RNG function. This must not be \c NULL. 1034 * \param p_rng The RNG parameter to be passed to \p f_rng. This may be 1035 * \c NULL if \p f_rng doesn't need a context argument. 1036 * 1037 * \return \c 0 on success. 1038 * \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code 1039 * on failure. 1040 */ 1041 int mbedtls_ecp_gen_privkey( const mbedtls_ecp_group *grp, 1042 mbedtls_mpi *d, 1043 int (*f_rng)(void *, unsigned char *, size_t), 1044 void *p_rng ); 1045 1046 /** 1047 * \brief This function generates a keypair with a configurable base 1048 * point. 1049 * 1050 * \note This function uses bare components rather than an 1051 * ::mbedtls_ecp_keypair structure to ease use with other 1052 * structures, such as ::mbedtls_ecdh_context or 1053 * ::mbedtls_ecdsa_context. 1054 * 1055 * \param grp The ECP group to generate a key pair for. 1056 * This must be initialized and have group parameters 1057 * set, for example through mbedtls_ecp_group_load(). 1058 * \param G The base point to use. This must be initialized 1059 * and belong to \p grp. It replaces the default base 1060 * point \c grp->G used by mbedtls_ecp_gen_keypair(). 1061 * \param d The destination MPI (secret part). 1062 * This must be initialized. 1063 * \param Q The destination point (public part). 1064 * This must be initialized. 1065 * \param f_rng The RNG function. This must not be \c NULL. 1066 * \param p_rng The RNG context to be passed to \p f_rng. This may 1067 * be \c NULL if \p f_rng doesn't need a context argument. 1068 * 1069 * \return \c 0 on success. 1070 * \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code 1071 * on failure. 1072 */ 1073 int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp, 1074 const mbedtls_ecp_point *G, 1075 mbedtls_mpi *d, mbedtls_ecp_point *Q, 1076 int (*f_rng)(void *, unsigned char *, size_t), 1077 void *p_rng ); 1078 1079 /** 1080 * \brief This function generates an ECP keypair. 1081 * 1082 * \note This function uses bare components rather than an 1083 * ::mbedtls_ecp_keypair structure to ease use with other 1084 * structures, such as ::mbedtls_ecdh_context or 1085 * ::mbedtls_ecdsa_context. 1086 * 1087 * \param grp The ECP group to generate a key pair for. 1088 * This must be initialized and have group parameters 1089 * set, for example through mbedtls_ecp_group_load(). 1090 * \param d The destination MPI (secret part). 1091 * This must be initialized. 1092 * \param Q The destination point (public part). 1093 * This must be initialized. 1094 * \param f_rng The RNG function. This must not be \c NULL. 1095 * \param p_rng The RNG context to be passed to \p f_rng. This may 1096 * be \c NULL if \p f_rng doesn't need a context argument. 1097 * 1098 * \return \c 0 on success. 1099 * \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code 1100 * on failure. 1101 */ 1102 int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp, mbedtls_mpi *d, 1103 mbedtls_ecp_point *Q, 1104 int (*f_rng)(void *, unsigned char *, size_t), 1105 void *p_rng ); 1106 1107 /** 1108 * \brief This function generates an ECP key. 1109 * 1110 * \param grp_id The ECP group identifier. 1111 * \param key The destination key. This must be initialized. 1112 * \param f_rng The RNG function to use. This must not be \c NULL. 1113 * \param p_rng The RNG context to be passed to \p f_rng. This may 1114 * be \c NULL if \p f_rng doesn't need a context argument. 1115 * 1116 * \return \c 0 on success. 1117 * \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code 1118 * on failure. 1119 */ 1120 int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, 1121 int (*f_rng)(void *, unsigned char *, size_t), 1122 void *p_rng ); 1123 1124 /** 1125 * \brief This function checks that the keypair objects 1126 * \p pub and \p prv have the same group and the 1127 * same public point, and that the private key in 1128 * \p prv is consistent with the public key. 1129 * 1130 * \param pub The keypair structure holding the public key. This 1131 * must be initialized. If it contains a private key, that 1132 * part is ignored. 1133 * \param prv The keypair structure holding the full keypair. 1134 * This must be initialized. 1135 * 1136 * \return \c 0 on success, meaning that the keys are valid and match. 1137 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the keys are invalid or do not match. 1138 * \return An \c MBEDTLS_ERR_ECP_XXX or an \c MBEDTLS_ERR_MPI_XXX 1139 * error code on calculation failure. 1140 */ 1141 int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair *pub, 1142 const mbedtls_ecp_keypair *prv ); 1143 1144 #if defined(MBEDTLS_SELF_TEST) 1145 1146 /** 1147 * \brief The ECP checkup routine. 1148 * 1149 * \return \c 0 on success. 1150 * \return \c 1 on failure. 1151 */ 1152 int mbedtls_ecp_self_test( int verbose ); 1153 1154 #endif /* MBEDTLS_SELF_TEST */ 1155 1156 #ifdef __cplusplus 1157 } 1158 #endif 1159 1160 #endif /* ecp.h */ 1161