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 /* Determine the minimum safe value of MBEDTLS_ECP_MAX_BITS. */ 158 #if !defined(MBEDTLS_ECP_C) 159 #define MBEDTLS_ECP_MAX_BITS_MIN 0 160 /* Note: the curves must be listed in DECREASING size! */ 161 #elif defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) 162 #define MBEDTLS_ECP_MAX_BITS_MIN 521 163 #elif defined(MBEDTLS_ECP_DP_BP512R1_ENABLED) 164 #define MBEDTLS_ECP_MAX_BITS_MIN 512 165 #elif defined(MBEDTLS_ECP_DP_CURVE448_ENABLED) 166 #define MBEDTLS_ECP_MAX_BITS_MIN 448 167 #elif defined(MBEDTLS_ECP_DP_BP384R1_ENABLED) 168 #define MBEDTLS_ECP_MAX_BITS_MIN 384 169 #elif defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED) 170 #define MBEDTLS_ECP_MAX_BITS_MIN 384 171 #elif defined(MBEDTLS_ECP_DP_BP256R1_ENABLED) 172 #define MBEDTLS_ECP_MAX_BITS_MIN 256 173 #elif defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED) 174 #define MBEDTLS_ECP_MAX_BITS_MIN 256 175 #elif defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED) 176 #define MBEDTLS_ECP_MAX_BITS_MIN 256 177 #elif defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) 178 #define MBEDTLS_ECP_MAX_BITS_MIN 255 179 #elif defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED) 180 #define MBEDTLS_ECP_MAX_BITS_MIN 225 // n is slightly above 2^224 181 #elif defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED) 182 #define MBEDTLS_ECP_MAX_BITS_MIN 224 183 #elif defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED) 184 #define MBEDTLS_ECP_MAX_BITS_MIN 192 185 #elif defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED) 186 #define MBEDTLS_ECP_MAX_BITS_MIN 192 187 #else 188 #error "MBEDTLS_ECP_C enabled, but no curve?" 189 #endif 190 191 #if !defined(MBEDTLS_ECP_ALT) 192 /* 193 * default mbed TLS elliptic curve arithmetic implementation 194 * 195 * (in case MBEDTLS_ECP_ALT is defined then the developer has to provide an 196 * alternative implementation for the whole module and it will replace this 197 * one.) 198 */ 199 200 /** 201 * \brief The ECP group structure. 202 * 203 * We consider two types of curve equations: 204 * <ul><li>Short Weierstrass: <code>y^2 = x^3 + A x + B mod P</code> 205 * (SEC1 + RFC-4492)</li> 206 * <li>Montgomery: <code>y^2 = x^3 + A x^2 + x mod P</code> (Curve25519, 207 * Curve448)</li></ul> 208 * In both cases, the generator (\p G) for a prime-order subgroup is fixed. 209 * 210 * For Short Weierstrass, this subgroup is the whole curve, and its 211 * cardinality is denoted by \p N. Our code requires that \p N is an 212 * odd prime as mbedtls_ecp_mul() requires an odd number, and 213 * mbedtls_ecdsa_sign() requires that it is prime for blinding purposes. 214 * 215 * For Montgomery curves, we do not store \p A, but <code>(A + 2) / 4</code>, 216 * which is the quantity used in the formulas. Additionally, \p nbits is 217 * not the size of \p N but the required size for private keys. 218 * 219 * If \p modp is NULL, reduction modulo \p P is done using a generic algorithm. 220 * Otherwise, \p modp must point to a function that takes an \p mbedtls_mpi in the 221 * range of <code>0..2^(2*pbits)-1</code>, and transforms it in-place to an integer 222 * which is congruent mod \p P to the given MPI, and is close enough to \p pbits 223 * in size, so that it may be efficiently brought in the 0..P-1 range by a few 224 * additions or subtractions. Therefore, it is only an approximative modular 225 * reduction. It must return 0 on success and non-zero on failure. 226 * 227 * \note Alternative implementations must keep the group IDs distinct. If 228 * two group structures have the same ID, then they must be 229 * identical. 230 * 231 */ 232 typedef struct mbedtls_ecp_group 233 { 234 mbedtls_ecp_group_id id; /*!< An internal group identifier. */ 235 mbedtls_mpi P; /*!< The prime modulus of the base field. */ 236 mbedtls_mpi A; /*!< For Short Weierstrass: \p A in the equation. For 237 Montgomery curves: <code>(A + 2) / 4</code>. */ 238 mbedtls_mpi B; /*!< For Short Weierstrass: \p B in the equation. 239 For Montgomery curves: unused. */ 240 mbedtls_ecp_point G; /*!< The generator of the subgroup used. */ 241 mbedtls_mpi N; /*!< The order of \p G. */ 242 size_t pbits; /*!< The number of bits in \p P.*/ 243 size_t nbits; /*!< For Short Weierstrass: The number of bits in \p P. 244 For Montgomery curves: the number of bits in the 245 private keys. */ 246 unsigned int h; /*!< \internal 1 if the constants are static. */ 247 int (*modp)(mbedtls_mpi *); /*!< The function for fast pseudo-reduction 248 mod \p P (see above).*/ 249 int (*t_pre)(mbedtls_ecp_point *, void *); /*!< Unused. */ 250 int (*t_post)(mbedtls_ecp_point *, void *); /*!< Unused. */ 251 void *t_data; /*!< Unused. */ 252 mbedtls_ecp_point *T; /*!< Pre-computed points for ecp_mul_comb(). */ 253 size_t T_size; /*!< The number of pre-computed points. */ 254 } 255 mbedtls_ecp_group; 256 257 /** 258 * \name SECTION: Module settings 259 * 260 * The configuration options you can set for this module are in this section. 261 * Either change them in config.h, or define them using the compiler command line. 262 * \{ 263 */ 264 265 #if defined(MBEDTLS_ECP_MAX_BITS) 266 267 #if MBEDTLS_ECP_MAX_BITS < MBEDTLS_ECP_MAX_BITS_MIN 268 #error "MBEDTLS_ECP_MAX_BITS is smaller than the largest supported curve" 269 #endif 270 271 #else 272 /** 273 * The maximum size of the groups, that is, of \c N and \c P. 274 */ 275 #define MBEDTLS_ECP_MAX_BITS 521 /**< The maximum size of groups, in bits. */ 276 #endif 277 278 #define MBEDTLS_ECP_MAX_BYTES ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 ) 279 #define MBEDTLS_ECP_MAX_PT_LEN ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 ) 280 281 #if !defined(MBEDTLS_ECP_WINDOW_SIZE) 282 /* 283 * Maximum "window" size used for point multiplication. 284 * Default: 6. 285 * Minimum value: 2. Maximum value: 7. 286 * 287 * Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) ) 288 * points used for point multiplication. This value is directly tied to EC 289 * peak memory usage, so decreasing it by one should roughly cut memory usage 290 * by two (if large curves are in use). 291 * 292 * Reduction in size may reduce speed, but larger curves are impacted first. 293 * Sample performances (in ECDHE handshakes/s, with FIXED_POINT_OPTIM = 1): 294 * w-size: 6 5 4 3 2 295 * 521 145 141 135 120 97 296 * 384 214 209 198 177 146 297 * 256 320 320 303 262 226 298 * 224 475 475 453 398 342 299 * 192 640 640 633 587 476 300 */ 301 #define MBEDTLS_ECP_WINDOW_SIZE 6 /**< The maximum window size used. */ 302 #endif /* MBEDTLS_ECP_WINDOW_SIZE */ 303 304 #if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM) 305 /* 306 * Trade memory for speed on fixed-point multiplication. 307 * 308 * This speeds up repeated multiplication of the generator (that is, the 309 * multiplication in ECDSA signatures, and half of the multiplications in 310 * ECDSA verification and ECDHE) by a factor roughly 3 to 4. 311 * 312 * The cost is increasing EC peak memory usage by a factor roughly 2. 313 * 314 * Change this value to 0 to reduce peak memory usage. 315 */ 316 #define MBEDTLS_ECP_FIXED_POINT_OPTIM 1 /**< Enable fixed-point speed-up. */ 317 #endif /* MBEDTLS_ECP_FIXED_POINT_OPTIM */ 318 319 /* \} name SECTION: Module settings */ 320 321 #else /* MBEDTLS_ECP_ALT */ 322 #include "ecp_alt.h" 323 #endif /* MBEDTLS_ECP_ALT */ 324 325 #if defined(MBEDTLS_ECP_RESTARTABLE) 326 327 /** 328 * \brief Internal restart context for multiplication 329 * 330 * \note Opaque struct 331 */ 332 typedef struct mbedtls_ecp_restart_mul mbedtls_ecp_restart_mul_ctx; 333 334 /** 335 * \brief Internal restart context for ecp_muladd() 336 * 337 * \note Opaque struct 338 */ 339 typedef struct mbedtls_ecp_restart_muladd mbedtls_ecp_restart_muladd_ctx; 340 341 /** 342 * \brief General context for resuming ECC operations 343 */ 344 typedef struct 345 { 346 unsigned ops_done; /*!< current ops count */ 347 unsigned depth; /*!< call depth (0 = top-level) */ 348 mbedtls_ecp_restart_mul_ctx *rsm; /*!< ecp_mul_comb() sub-context */ 349 mbedtls_ecp_restart_muladd_ctx *ma; /*!< ecp_muladd() sub-context */ 350 } mbedtls_ecp_restart_ctx; 351 352 /* 353 * Operation counts for restartable functions 354 */ 355 #define MBEDTLS_ECP_OPS_CHK 3 /*!< basic ops count for ecp_check_pubkey() */ 356 #define MBEDTLS_ECP_OPS_DBL 8 /*!< basic ops count for ecp_double_jac() */ 357 #define MBEDTLS_ECP_OPS_ADD 11 /*!< basic ops count for see ecp_add_mixed() */ 358 #define MBEDTLS_ECP_OPS_INV 120 /*!< empirical equivalent for mpi_mod_inv() */ 359 360 /** 361 * \brief Internal; for restartable functions in other modules. 362 * Check and update basic ops budget. 363 * 364 * \param grp Group structure 365 * \param rs_ctx Restart context 366 * \param ops Number of basic ops to do 367 * 368 * \return \c 0 if doing \p ops basic ops is still allowed, 369 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS otherwise. 370 */ 371 int mbedtls_ecp_check_budget( const mbedtls_ecp_group *grp, 372 mbedtls_ecp_restart_ctx *rs_ctx, 373 unsigned ops ); 374 375 /* Utility macro for checking and updating ops budget */ 376 #define MBEDTLS_ECP_BUDGET( ops ) \ 377 MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, rs_ctx, \ 378 (unsigned) (ops) ) ); 379 380 #else /* MBEDTLS_ECP_RESTARTABLE */ 381 382 #define MBEDTLS_ECP_BUDGET( ops ) /* no-op; for compatibility */ 383 384 /* We want to declare restartable versions of existing functions anyway */ 385 typedef void mbedtls_ecp_restart_ctx; 386 387 #endif /* MBEDTLS_ECP_RESTARTABLE */ 388 389 /** 390 * \brief The ECP key-pair structure. 391 * 392 * A generic key-pair that may be used for ECDSA and fixed ECDH, for example. 393 * 394 * \note Members are deliberately in the same order as in the 395 * ::mbedtls_ecdsa_context structure. 396 */ 397 typedef struct mbedtls_ecp_keypair 398 { 399 mbedtls_ecp_group grp; /*!< Elliptic curve and base point */ 400 mbedtls_mpi d; /*!< our secret value */ 401 mbedtls_ecp_point Q; /*!< our public value */ 402 } 403 mbedtls_ecp_keypair; 404 405 /* 406 * Point formats, from RFC 4492's enum ECPointFormat 407 */ 408 #define MBEDTLS_ECP_PF_UNCOMPRESSED 0 /**< Uncompressed point format. */ 409 #define MBEDTLS_ECP_PF_COMPRESSED 1 /**< Compressed point format. */ 410 411 /* 412 * Some other constants from RFC 4492 413 */ 414 #define MBEDTLS_ECP_TLS_NAMED_CURVE 3 /**< The named_curve of ECCurveType. */ 415 416 #if defined(MBEDTLS_ECP_RESTARTABLE) 417 /** 418 * \brief Set the maximum number of basic operations done in a row. 419 * 420 * If more operations are needed to complete a computation, 421 * #MBEDTLS_ERR_ECP_IN_PROGRESS will be returned by the 422 * function performing the computation. It is then the 423 * caller's responsibility to either call again with the same 424 * parameters until it returns 0 or an error code; or to free 425 * the restart context if the operation is to be aborted. 426 * 427 * It is strictly required that all input parameters and the 428 * restart context be the same on successive calls for the 429 * same operation, but output parameters need not be the 430 * same; they must not be used until the function finally 431 * returns 0. 432 * 433 * This only applies to functions whose documentation 434 * mentions they may return #MBEDTLS_ERR_ECP_IN_PROGRESS (or 435 * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS for functions in the 436 * SSL module). For functions that accept a "restart context" 437 * argument, passing NULL disables restart and makes the 438 * function equivalent to the function with the same name 439 * with \c _restartable removed. For functions in the ECDH 440 * module, restart is disabled unless the function accepts 441 * an "ECDH context" argument and 442 * mbedtls_ecdh_enable_restart() was previously called on 443 * that context. For function in the SSL module, restart is 444 * only enabled for specific sides and key exchanges 445 * (currently only for clients and ECDHE-ECDSA). 446 * 447 * \param max_ops Maximum number of basic operations done in a row. 448 * Default: 0 (unlimited). 449 * Lower (non-zero) values mean ECC functions will block for 450 * a lesser maximum amount of time. 451 * 452 * \note A "basic operation" is defined as a rough equivalent of a 453 * multiplication in GF(p) for the NIST P-256 curve. 454 * As an indication, with default settings, a scalar 455 * multiplication (full run of \c mbedtls_ecp_mul()) is: 456 * - about 3300 basic operations for P-256 457 * - about 9400 basic operations for P-384 458 * 459 * \note Very low values are not always respected: sometimes 460 * functions need to block for a minimum number of 461 * operations, and will do so even if max_ops is set to a 462 * lower value. That minimum depends on the curve size, and 463 * can be made lower by decreasing the value of 464 * \c MBEDTLS_ECP_WINDOW_SIZE. As an indication, here is the 465 * lowest effective value for various curves and values of 466 * that parameter (w for short): 467 * w=6 w=5 w=4 w=3 w=2 468 * P-256 208 208 160 136 124 469 * P-384 682 416 320 272 248 470 * P-521 1364 832 640 544 496 471 * 472 * \note This setting is currently ignored by Curve25519. 473 */ 474 void mbedtls_ecp_set_max_ops( unsigned max_ops ); 475 476 /** 477 * \brief Check if restart is enabled (max_ops != 0) 478 * 479 * \return \c 0 if \c max_ops == 0 (restart disabled) 480 * \return \c 1 otherwise (restart enabled) 481 */ 482 int mbedtls_ecp_restart_is_enabled( void ); 483 #endif /* MBEDTLS_ECP_RESTARTABLE */ 484 485 /** 486 * \brief This function retrieves the information defined in 487 * mbedtls_ecp_curve_info() for all supported curves in order 488 * of preference. 489 * 490 * \return A statically allocated array. The last entry is 0. 491 */ 492 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_list( void ); 493 494 /** 495 * \brief This function retrieves the list of internal group 496 * identifiers of all supported curves in the order of 497 * preference. 498 * 499 * \return A statically allocated array, 500 * terminated with MBEDTLS_ECP_DP_NONE. 501 */ 502 const mbedtls_ecp_group_id *mbedtls_ecp_grp_id_list( void ); 503 504 /** 505 * \brief This function retrieves curve information from an internal 506 * group identifier. 507 * 508 * \param grp_id An \c MBEDTLS_ECP_DP_XXX value. 509 * 510 * \return The associated curve information on success. 511 * \return NULL on failure. 512 */ 513 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_grp_id( mbedtls_ecp_group_id grp_id ); 514 515 /** 516 * \brief This function retrieves curve information from a TLS 517 * NamedCurve value. 518 * 519 * \param tls_id An \c MBEDTLS_ECP_DP_XXX value. 520 * 521 * \return The associated curve information on success. 522 * \return NULL on failure. 523 */ 524 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_tls_id( uint16_t tls_id ); 525 526 /** 527 * \brief This function retrieves curve information from a 528 * human-readable name. 529 * 530 * \param name The human-readable name. 531 * 532 * \return The associated curve information on success. 533 * \return NULL on failure. 534 */ 535 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_name( const char *name ); 536 537 /** 538 * \brief This function initializes a point as zero. 539 * 540 * \param pt The point to initialize. 541 */ 542 void mbedtls_ecp_point_init( mbedtls_ecp_point *pt ); 543 544 /** 545 * \brief This function initializes an ECP group context 546 * without loading any domain parameters. 547 * 548 * \note After this function is called, domain parameters 549 * for various ECP groups can be loaded through the 550 * mbedtls_ecp_group_load() or mbedtls_ecp_tls_read_group() 551 * functions. 552 */ 553 void mbedtls_ecp_group_init( mbedtls_ecp_group *grp ); 554 555 /** 556 * \brief This function initializes a key pair as an invalid one. 557 * 558 * \param key The key pair to initialize. 559 */ 560 void mbedtls_ecp_keypair_init( mbedtls_ecp_keypair *key ); 561 562 /** 563 * \brief This function frees the components of a point. 564 * 565 * \param pt The point to free. 566 */ 567 void mbedtls_ecp_point_free( mbedtls_ecp_point *pt ); 568 569 /** 570 * \brief This function frees the components of an ECP group. 571 * 572 * \param grp The group to free. This may be \c NULL, in which 573 * case this function returns immediately. If it is not 574 * \c NULL, it must point to an initialized ECP group. 575 */ 576 void mbedtls_ecp_group_free( mbedtls_ecp_group *grp ); 577 578 /** 579 * \brief This function frees the components of a key pair. 580 * 581 * \param key The key pair to free. This may be \c NULL, in which 582 * case this function returns immediately. If it is not 583 * \c NULL, it must point to an initialized ECP key pair. 584 */ 585 void mbedtls_ecp_keypair_free( mbedtls_ecp_keypair *key ); 586 587 #if defined(MBEDTLS_ECP_RESTARTABLE) 588 /** 589 * \brief Initialize a restart context. 590 * 591 * \param ctx The restart context to initialize. This must 592 * not be \c NULL. 593 */ 594 void mbedtls_ecp_restart_init( mbedtls_ecp_restart_ctx *ctx ); 595 596 /** 597 * \brief Free the components of a restart context. 598 * 599 * \param ctx The restart context to free. This may be \c NULL, in which 600 * case this function returns immediately. If it is not 601 * \c NULL, it must point to an initialized restart context. 602 */ 603 void mbedtls_ecp_restart_free( mbedtls_ecp_restart_ctx *ctx ); 604 #endif /* MBEDTLS_ECP_RESTARTABLE */ 605 606 /** 607 * \brief This function copies the contents of point \p Q into 608 * point \p P. 609 * 610 * \param P The destination point. This must be initialized. 611 * \param Q The source point. This must be initialized. 612 * 613 * \return \c 0 on success. 614 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 615 * \return Another negative error code for other kinds of failure. 616 */ 617 int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q ); 618 619 /** 620 * \brief This function copies the contents of group \p src into 621 * group \p dst. 622 * 623 * \param dst The destination group. This must be initialized. 624 * \param src The source group. This must be initialized. 625 * 626 * \return \c 0 on success. 627 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 628 * \return Another negative error code on other kinds of failure. 629 */ 630 int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, 631 const mbedtls_ecp_group *src ); 632 633 /** 634 * \brief This function sets a point to the point at infinity. 635 * 636 * \param pt The point to set. This must be initialized. 637 * 638 * \return \c 0 on success. 639 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 640 * \return Another negative error code on other kinds of failure. 641 */ 642 int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt ); 643 644 /** 645 * \brief This function checks if a point is the point at infinity. 646 * 647 * \param pt The point to test. This must be initialized. 648 * 649 * \return \c 1 if the point is zero. 650 * \return \c 0 if the point is non-zero. 651 * \return A negative error code on failure. 652 */ 653 int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt ); 654 655 /** 656 * \brief This function compares two points. 657 * 658 * \note This assumes that the points are normalized. Otherwise, 659 * they may compare as "not equal" even if they are. 660 * 661 * \param P The first point to compare. This must be initialized. 662 * \param Q The second point to compare. This must be initialized. 663 * 664 * \return \c 0 if the points are equal. 665 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the points are not equal. 666 */ 667 int mbedtls_ecp_point_cmp( const mbedtls_ecp_point *P, 668 const mbedtls_ecp_point *Q ); 669 670 /** 671 * \brief This function imports a non-zero point from two ASCII 672 * strings. 673 * 674 * \param P The destination point. This must be initialized. 675 * \param radix The numeric base of the input. 676 * \param x The first affine coordinate, as a null-terminated string. 677 * \param y The second affine coordinate, as a null-terminated string. 678 * 679 * \return \c 0 on success. 680 * \return An \c MBEDTLS_ERR_MPI_XXX error code on failure. 681 */ 682 int mbedtls_ecp_point_read_string( mbedtls_ecp_point *P, int radix, 683 const char *x, const char *y ); 684 685 /** 686 * \brief This function exports a point into unsigned binary data. 687 * 688 * \param grp The group to which the point should belong. 689 * This must be initialized and have group parameters 690 * set, for example through mbedtls_ecp_group_load(). 691 * \param P The point to export. This must be initialized. 692 * \param format The point format. This must be either 693 * #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED. 694 * \param olen The address at which to store the length of 695 * the output in Bytes. This must not be \c NULL. 696 * \param buf The output buffer. This must be a writable buffer 697 * of length \p buflen Bytes. 698 * \param buflen The length of the output buffer \p buf in Bytes. 699 * 700 * \return \c 0 on success. 701 * \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output buffer 702 * is too small to hold the point. 703 * \return Another negative error code on other kinds of failure. 704 */ 705 int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *P, 706 int format, size_t *olen, 707 unsigned char *buf, size_t buflen ); 708 709 /** 710 * \brief This function imports a point from unsigned binary data. 711 * 712 * \note This function does not check that the point actually 713 * belongs to the given group, see mbedtls_ecp_check_pubkey() 714 * for that. 715 * 716 * \param grp The group to which the point should belong. 717 * This must be initialized and have group parameters 718 * set, for example through mbedtls_ecp_group_load(). 719 * \param P The destination context to import the point to. 720 * This must be initialized. 721 * \param buf The input buffer. This must be a readable buffer 722 * of length \p ilen Bytes. 723 * \param ilen The length of the input buffer \p buf in Bytes. 724 * 725 * \return \c 0 on success. 726 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid. 727 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 728 * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the point format 729 * is not implemented. 730 */ 731 int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp, 732 mbedtls_ecp_point *P, 733 const unsigned char *buf, size_t ilen ); 734 735 /** 736 * \brief This function imports a point from a TLS ECPoint record. 737 * 738 * \note On function return, \p *buf is updated to point immediately 739 * after the ECPoint record. 740 * 741 * \param grp The ECP group to use. 742 * This must be initialized and have group parameters 743 * set, for example through mbedtls_ecp_group_load(). 744 * \param pt The destination point. 745 * \param buf The address of the pointer to the start of the input buffer. 746 * \param len The length of the buffer. 747 * 748 * \return \c 0 on success. 749 * \return An \c MBEDTLS_ERR_MPI_XXX error code on initialization 750 * failure. 751 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. 752 */ 753 int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, 754 mbedtls_ecp_point *pt, 755 const unsigned char **buf, size_t len ); 756 757 /** 758 * \brief This function exports a point as a TLS ECPoint record 759 * defined in RFC 4492, Section 5.4. 760 * 761 * \param grp The ECP group to use. 762 * This must be initialized and have group parameters 763 * set, for example through mbedtls_ecp_group_load(). 764 * \param pt The point to be exported. This must be initialized. 765 * \param format The point format to use. This must be either 766 * #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED. 767 * \param olen The address at which to store the length in Bytes 768 * of the data written. 769 * \param buf The target buffer. This must be a writable buffer of 770 * length \p blen Bytes. 771 * \param blen The length of the target buffer \p buf in Bytes. 772 * 773 * \return \c 0 on success. 774 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid. 775 * \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the target buffer 776 * is too small to hold the exported point. 777 * \return Another negative error code on other kinds of failure. 778 */ 779 int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp, 780 const mbedtls_ecp_point *pt, 781 int format, size_t *olen, 782 unsigned char *buf, size_t blen ); 783 784 /** 785 * \brief This function sets up an ECP group context 786 * from a standardized set of domain parameters. 787 * 788 * \note The index should be a value of the NamedCurve enum, 789 * as defined in <em>RFC-4492: Elliptic Curve Cryptography 790 * (ECC) Cipher Suites for Transport Layer Security (TLS)</em>, 791 * usually in the form of an \c MBEDTLS_ECP_DP_XXX macro. 792 * 793 * \param grp The group context to setup. This must be initialized. 794 * \param id The identifier of the domain parameter set to load. 795 * 796 * \return \c 0 on success. 797 * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if \p id doesn't 798 * correspond to a known group. 799 * \return Another negative error code on other kinds of failure. 800 */ 801 int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id id ); 802 803 /** 804 * \brief This function sets up an ECP group context from a TLS 805 * ECParameters record as defined in RFC 4492, Section 5.4. 806 * 807 * \note The read pointer \p buf is updated to point right after 808 * the ECParameters record on exit. 809 * 810 * \param grp The group context to setup. This must be initialized. 811 * \param buf The address of the pointer to the start of the input buffer. 812 * \param len The length of the input buffer \c *buf in Bytes. 813 * 814 * \return \c 0 on success. 815 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. 816 * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not 817 * recognized. 818 * \return Another negative error code on other kinds of failure. 819 */ 820 int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp, 821 const unsigned char **buf, size_t len ); 822 823 /** 824 * \brief This function extracts an elliptic curve group ID from a 825 * TLS ECParameters record as defined in RFC 4492, Section 5.4. 826 * 827 * \note The read pointer \p buf is updated to point right after 828 * the ECParameters record on exit. 829 * 830 * \param grp The address at which to store the group id. 831 * This must not be \c NULL. 832 * \param buf The address of the pointer to the start of the input buffer. 833 * \param len The length of the input buffer \c *buf in Bytes. 834 * 835 * \return \c 0 on success. 836 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid. 837 * \return #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not 838 * recognized. 839 * \return Another negative error code on other kinds of failure. 840 */ 841 int mbedtls_ecp_tls_read_group_id( mbedtls_ecp_group_id *grp, 842 const unsigned char **buf, 843 size_t len ); 844 /** 845 * \brief This function exports an elliptic curve as a TLS 846 * ECParameters record as defined in RFC 4492, Section 5.4. 847 * 848 * \param grp The ECP group to be exported. 849 * This must be initialized and have group parameters 850 * set, for example through mbedtls_ecp_group_load(). 851 * \param olen The address at which to store the number of Bytes written. 852 * This must not be \c NULL. 853 * \param buf The buffer to write to. This must be a writable buffer 854 * of length \p blen Bytes. 855 * \param blen The length of the output buffer \p buf in Bytes. 856 * 857 * \return \c 0 on success. 858 * \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output 859 * buffer is too small to hold the exported group. 860 * \return Another negative error code on other kinds of failure. 861 */ 862 int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, 863 size_t *olen, 864 unsigned char *buf, size_t blen ); 865 866 /** 867 * \brief This function performs a scalar multiplication of a point 868 * by an integer: \p R = \p m * \p P. 869 * 870 * It is not thread-safe to use same group in multiple threads. 871 * 872 * \note To prevent timing attacks, this function 873 * executes the exact same sequence of base-field 874 * operations for any valid \p m. It avoids any if-branch or 875 * array index depending on the value of \p m. 876 * 877 * \note If \p f_rng is not NULL, it is used to randomize 878 * intermediate results to prevent potential timing attacks 879 * targeting these results. We recommend always providing 880 * a non-NULL \p f_rng. The overhead is negligible. 881 * Note: unless #MBEDTLS_ECP_NO_INTERNAL_RNG is defined, when 882 * \p f_rng is NULL, an internal RNG (seeded from the value 883 * of \p m) will be used instead. 884 * 885 * \param grp The ECP group to use. 886 * This must be initialized and have group parameters 887 * set, for example through mbedtls_ecp_group_load(). 888 * \param R The point in which to store the result of the calculation. 889 * This must be initialized. 890 * \param m The integer by which to multiply. This must be initialized. 891 * \param P The point to multiply. This must be initialized. 892 * \param f_rng The RNG function. This may be \c NULL if randomization 893 * of intermediate results isn't desired (discouraged). 894 * \param p_rng The RNG context to be passed to \p p_rng. 895 * 896 * \return \c 0 on success. 897 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private 898 * key, or \p P is not a valid public key. 899 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 900 * \return Another negative error code on other kinds of failure. 901 */ 902 int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 903 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 904 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); 905 906 /** 907 * \brief This function performs multiplication of a point by 908 * an integer: \p R = \p m * \p P in a restartable way. 909 * 910 * \see mbedtls_ecp_mul() 911 * 912 * \note This function does the same as \c mbedtls_ecp_mul(), but 913 * it can return early and restart according to the limit set 914 * with \c mbedtls_ecp_set_max_ops() to reduce blocking. 915 * 916 * \param grp The ECP group to use. 917 * This must be initialized and have group parameters 918 * set, for example through mbedtls_ecp_group_load(). 919 * \param R The point in which to store the result of the calculation. 920 * This must be initialized. 921 * \param m The integer by which to multiply. This must be initialized. 922 * \param P The point to multiply. This must be initialized. 923 * \param f_rng The RNG function. This may be \c NULL if randomization 924 * of intermediate results isn't desired (discouraged). 925 * \param p_rng The RNG context to be passed to \p p_rng. 926 * \param rs_ctx The restart context (NULL disables restart). 927 * 928 * \return \c 0 on success. 929 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private 930 * key, or \p P is not a valid public key. 931 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 932 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of 933 * operations was reached: see \c mbedtls_ecp_set_max_ops(). 934 * \return Another negative error code on other kinds of failure. 935 */ 936 int mbedtls_ecp_mul_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 937 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 938 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, 939 mbedtls_ecp_restart_ctx *rs_ctx ); 940 941 /** 942 * \brief This function performs multiplication and addition of two 943 * points by integers: \p R = \p m * \p P + \p n * \p Q 944 * 945 * It is not thread-safe to use same group in multiple threads. 946 * 947 * \note In contrast to mbedtls_ecp_mul(), this function does not 948 * guarantee a constant execution flow and timing. 949 * 950 * \param grp The ECP group to use. 951 * This must be initialized and have group parameters 952 * set, for example through mbedtls_ecp_group_load(). 953 * \param R The point in which to store the result of the calculation. 954 * This must be initialized. 955 * \param m The integer by which to multiply \p P. 956 * This must be initialized. 957 * \param P The point to multiply by \p m. This must be initialized. 958 * \param n The integer by which to multiply \p Q. 959 * This must be initialized. 960 * \param Q The point to be multiplied by \p n. 961 * This must be initialized. 962 * 963 * \return \c 0 on success. 964 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m or \p n are not 965 * valid private keys, or \p P or \p Q are not valid public 966 * keys. 967 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 968 * \return Another negative error code on other kinds of failure. 969 */ 970 int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 971 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 972 const mbedtls_mpi *n, const mbedtls_ecp_point *Q ); 973 974 /** 975 * \brief This function performs multiplication and addition of two 976 * points by integers: \p R = \p m * \p P + \p n * \p Q in a 977 * restartable way. 978 * 979 * \see \c mbedtls_ecp_muladd() 980 * 981 * \note This function works the same as \c mbedtls_ecp_muladd(), 982 * but it can return early and restart according to the limit 983 * set with \c mbedtls_ecp_set_max_ops() to reduce blocking. 984 * 985 * \param grp The ECP group to use. 986 * This must be initialized and have group parameters 987 * set, for example through mbedtls_ecp_group_load(). 988 * \param R The point in which to store the result of the calculation. 989 * This must be initialized. 990 * \param m The integer by which to multiply \p P. 991 * This must be initialized. 992 * \param P The point to multiply by \p m. This must be initialized. 993 * \param n The integer by which to multiply \p Q. 994 * This must be initialized. 995 * \param Q The point to be multiplied by \p n. 996 * This must be initialized. 997 * \param rs_ctx The restart context (NULL disables restart). 998 * 999 * \return \c 0 on success. 1000 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m or \p n are not 1001 * valid private keys, or \p P or \p Q are not valid public 1002 * keys. 1003 * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure. 1004 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of 1005 * operations was reached: see \c mbedtls_ecp_set_max_ops(). 1006 * \return Another negative error code on other kinds of failure. 1007 */ 1008 int mbedtls_ecp_muladd_restartable( 1009 mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 1010 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 1011 const mbedtls_mpi *n, const mbedtls_ecp_point *Q, 1012 mbedtls_ecp_restart_ctx *rs_ctx ); 1013 1014 /** 1015 * \brief This function checks that a point is a valid public key 1016 * on this curve. 1017 * 1018 * It only checks that the point is non-zero, has 1019 * valid coordinates and lies on the curve. It does not verify 1020 * that it is indeed a multiple of \p G. This additional 1021 * check is computationally more expensive, is not required 1022 * by standards, and should not be necessary if the group 1023 * used has a small cofactor. In particular, it is useless for 1024 * the NIST groups which all have a cofactor of 1. 1025 * 1026 * \note This function uses bare components rather than an 1027 * ::mbedtls_ecp_keypair structure, to ease use with other 1028 * structures, such as ::mbedtls_ecdh_context or 1029 * ::mbedtls_ecdsa_context. 1030 * 1031 * \param grp The ECP group the point should belong to. 1032 * This must be initialized and have group parameters 1033 * set, for example through mbedtls_ecp_group_load(). 1034 * \param pt The point to check. This must be initialized. 1035 * 1036 * \return \c 0 if the point is a valid public key. 1037 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not 1038 * a valid public key for the given curve. 1039 * \return Another negative error code on other kinds of failure. 1040 */ 1041 int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, 1042 const mbedtls_ecp_point *pt ); 1043 1044 /** 1045 * \brief This function checks that an \p mbedtls_mpi is a 1046 * valid private key for this curve. 1047 * 1048 * \note This function uses bare components rather than an 1049 * ::mbedtls_ecp_keypair structure to ease use with other 1050 * structures, such as ::mbedtls_ecdh_context or 1051 * ::mbedtls_ecdsa_context. 1052 * 1053 * \param grp The ECP group the private key should belong to. 1054 * This must be initialized and have group parameters 1055 * set, for example through mbedtls_ecp_group_load(). 1056 * \param d The integer to check. This must be initialized. 1057 * 1058 * \return \c 0 if the point is a valid private key. 1059 * \return #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not a valid 1060 * private key for the given curve. 1061 * \return Another negative error code on other kinds of failure. 1062 */ 1063 int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp, 1064 const mbedtls_mpi *d ); 1065 1066 /** 1067 * \brief This function generates a private key. 1068 * 1069 * \param grp The ECP group to generate a private key for. 1070 * This must be initialized and have group parameters 1071 * set, for example through mbedtls_ecp_group_load(). 1072 * \param d The destination MPI (secret part). This must be initialized. 1073 * \param f_rng The RNG function. This must not be \c NULL. 1074 * \param p_rng The RNG parameter to be passed to \p f_rng. This may be 1075 * \c NULL if \p f_rng doesn't need a context argument. 1076 * 1077 * \return \c 0 on success. 1078 * \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code 1079 * on failure. 1080 */ 1081 int mbedtls_ecp_gen_privkey( const mbedtls_ecp_group *grp, 1082 mbedtls_mpi *d, 1083 int (*f_rng)(void *, unsigned char *, size_t), 1084 void *p_rng ); 1085 1086 /** 1087 * \brief This function generates a keypair with a configurable base 1088 * point. 1089 * 1090 * \note This function uses bare components rather than an 1091 * ::mbedtls_ecp_keypair structure to ease use with other 1092 * structures, such as ::mbedtls_ecdh_context or 1093 * ::mbedtls_ecdsa_context. 1094 * 1095 * \param grp The ECP group to generate a key pair for. 1096 * This must be initialized and have group parameters 1097 * set, for example through mbedtls_ecp_group_load(). 1098 * \param G The base point to use. This must be initialized 1099 * and belong to \p grp. It replaces the default base 1100 * point \c grp->G used by mbedtls_ecp_gen_keypair(). 1101 * \param d The destination MPI (secret part). 1102 * This must be initialized. 1103 * \param Q The destination point (public part). 1104 * This must be initialized. 1105 * \param f_rng The RNG function. This must not be \c NULL. 1106 * \param p_rng The RNG context to be passed to \p f_rng. This may 1107 * be \c NULL if \p f_rng doesn't need a context argument. 1108 * 1109 * \return \c 0 on success. 1110 * \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code 1111 * on failure. 1112 */ 1113 int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp, 1114 const mbedtls_ecp_point *G, 1115 mbedtls_mpi *d, mbedtls_ecp_point *Q, 1116 int (*f_rng)(void *, unsigned char *, size_t), 1117 void *p_rng ); 1118 1119 /** 1120 * \brief This function generates an ECP keypair. 1121 * 1122 * \note This function uses bare components rather than an 1123 * ::mbedtls_ecp_keypair structure to ease use with other 1124 * structures, such as ::mbedtls_ecdh_context or 1125 * ::mbedtls_ecdsa_context. 1126 * 1127 * \param grp The ECP group to generate a key pair for. 1128 * This must be initialized and have group parameters 1129 * set, for example through mbedtls_ecp_group_load(). 1130 * \param d The destination MPI (secret part). 1131 * This must be initialized. 1132 * \param Q The destination point (public part). 1133 * This must be initialized. 1134 * \param f_rng The RNG function. This must not be \c NULL. 1135 * \param p_rng The RNG context to be passed to \p f_rng. This may 1136 * be \c NULL if \p f_rng doesn't need a context argument. 1137 * 1138 * \return \c 0 on success. 1139 * \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code 1140 * on failure. 1141 */ 1142 int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp, mbedtls_mpi *d, 1143 mbedtls_ecp_point *Q, 1144 int (*f_rng)(void *, unsigned char *, size_t), 1145 void *p_rng ); 1146 1147 /** 1148 * \brief This function generates an ECP key. 1149 * 1150 * \param grp_id The ECP group identifier. 1151 * \param key The destination key. This must be initialized. 1152 * \param f_rng The RNG function to use. This must not be \c NULL. 1153 * \param p_rng The RNG context to be passed to \p f_rng. This may 1154 * be \c NULL if \p f_rng doesn't need a context argument. 1155 * 1156 * \return \c 0 on success. 1157 * \return An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code 1158 * on failure. 1159 */ 1160 int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, 1161 int (*f_rng)(void *, unsigned char *, size_t), 1162 void *p_rng ); 1163 1164 /** 1165 * \brief This function checks that the keypair objects 1166 * \p pub and \p prv have the same group and the 1167 * same public point, and that the private key in 1168 * \p prv is consistent with the public key. 1169 * 1170 * \param pub The keypair structure holding the public key. This 1171 * must be initialized. If it contains a private key, that 1172 * part is ignored. 1173 * \param prv The keypair structure holding the full keypair. 1174 * This must be initialized. 1175 * 1176 * \return \c 0 on success, meaning that the keys are valid and match. 1177 * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the keys are invalid or do not match. 1178 * \return An \c MBEDTLS_ERR_ECP_XXX or an \c MBEDTLS_ERR_MPI_XXX 1179 * error code on calculation failure. 1180 */ 1181 int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair *pub, 1182 const mbedtls_ecp_keypair *prv ); 1183 1184 #if defined(MBEDTLS_SELF_TEST) 1185 1186 /** 1187 * \brief The ECP checkup routine. 1188 * 1189 * \return \c 0 on success. 1190 * \return \c 1 on failure. 1191 */ 1192 int mbedtls_ecp_self_test( int verbose ); 1193 1194 #endif /* MBEDTLS_SELF_TEST */ 1195 1196 #ifdef __cplusplus 1197 } 1198 #endif 1199 1200 #endif /* ecp.h */ 1201