1 /** 2 * \file ecp.h 3 * 4 * \brief Elliptic curves over GF(p) 5 * 6 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 7 * SPDX-License-Identifier: Apache-2.0 8 * 9 * Licensed under the Apache License, Version 2.0 (the "License"); you may 10 * not use this file except in compliance with the License. 11 * You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 17 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 * 21 * This file is part of mbed TLS (https://tls.mbed.org) 22 */ 23 #ifndef MBEDTLS_ECP_H 24 #define MBEDTLS_ECP_H 25 26 #include "bignum.h" 27 28 #define MBEDTLS_ECP_DP_SECP192R1_ENABLED 29 #define MBEDTLS_ECP_DP_SECP224R1_ENABLED 30 #define MBEDTLS_ECP_DP_SECP256R1_ENABLED 31 #define MBEDTLS_ECP_DP_SECP384R1_ENABLED 32 #define MBEDTLS_ECP_DP_SECP521R1_ENABLED 33 #define MBEDTLS_ECP_DP_SECP192K1_ENABLED 34 #define MBEDTLS_ECP_DP_SECP224K1_ENABLED 35 #define MBEDTLS_ECP_DP_SECP256K1_ENABLED 36 37 /* 38 * ECP error codes 39 */ 40 #define MBEDTLS_ERR_ECP_BAD_INPUT_DATA -0x4F80 /**< Bad input parameters to function. */ 41 #define MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL -0x4F00 /**< The buffer is too small to write to. */ 42 #define MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE -0x4E80 /**< Requested curve not available. */ 43 #define MBEDTLS_ERR_ECP_VERIFY_FAILED -0x4E00 /**< The signature is not valid. */ 44 #define MBEDTLS_ERR_ECP_ALLOC_FAILED -0x4D80 /**< Memory allocation failed. */ 45 #define MBEDTLS_ERR_ECP_RANDOM_FAILED -0x4D00 /**< Generation of random value, such as (ephemeral) key, failed. */ 46 #define MBEDTLS_ERR_ECP_INVALID_KEY -0x4C80 /**< Invalid private or public key. */ 47 #define MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH -0x4C00 /**< Signature is valid but shorter than the user-supplied length. */ 48 49 #ifdef __cplusplus 50 extern "C" { 51 #endif 52 53 typedef struct ECDSA_KEY { 54 unsigned char d[132]; 55 unsigned char x[132]; 56 unsigned char y[132]; 57 unsigned int d_len; 58 unsigned int x_len; 59 unsigned int y_len; 60 unsigned int curve; 61 unsigned int key_len; /* bit */ 62 } mbed_ecc_key_t; 63 64 /** 65 * Domain parameters (curve, subgroup and generator) identifiers. 66 * 67 * Only curves over prime fields are supported. 68 * 69 * \warning This library does not support validation of arbitrary domain 70 * parameters. Therefore, only well-known domain parameters from trusted 71 * sources should be used. See mbedtls_ecp_group_load(). 72 */ 73 typedef enum 74 { 75 MBEDTLS_ECP_DP_NONE = 0, 76 MBEDTLS_ECP_DP_SECP192R1, /*!< 192-bits NIST curve */ 77 MBEDTLS_ECP_DP_SECP224R1, /*!< 224-bits NIST curve */ 78 MBEDTLS_ECP_DP_SECP256R1, /*!< 256-bits NIST curve */ 79 MBEDTLS_ECP_DP_SECP384R1, /*!< 384-bits NIST curve */ 80 MBEDTLS_ECP_DP_SECP521R1, /*!< 521-bits NIST curve */ 81 MBEDTLS_ECP_DP_BP256R1, /*!< 256-bits Brainpool curve */ 82 MBEDTLS_ECP_DP_BP384R1, /*!< 384-bits Brainpool curve */ 83 MBEDTLS_ECP_DP_BP512R1, /*!< 512-bits Brainpool curve */ 84 MBEDTLS_ECP_DP_CURVE25519, /*!< Curve25519 */ 85 MBEDTLS_ECP_DP_SECP192K1, /*!< 192-bits "Koblitz" curve */ 86 MBEDTLS_ECP_DP_SECP224K1, /*!< 224-bits "Koblitz" curve */ 87 MBEDTLS_ECP_DP_SECP256K1 /*!< 256-bits "Koblitz" curve */ 88 } mbedtls_ecp_group_id; 89 90 /** 91 * Number of supported curves (plus one for NONE). 92 * 93 * (Montgomery curves excluded for now.) 94 */ 95 #define MBEDTLS_ECP_DP_MAX 12 96 97 /** 98 * Curve information for use by other modules 99 */ 100 typedef struct 101 { 102 mbedtls_ecp_group_id grp_id; /*!< Internal identifier */ 103 uint16_t tls_id; /*!< TLS NamedCurve identifier */ 104 uint16_t bit_size; /*!< Curve size in bits */ 105 const char *name; /*!< Human-friendly name */ 106 } mbedtls_ecp_curve_info; 107 108 /** 109 * \brief ECP point structure (jacobian coordinates) 110 * 111 * \note All functions expect and return points satisfying 112 * the following condition: Z == 0 or Z == 1. (Other 113 * values of Z are used by internal functions only.) 114 * The point is zero, or "at infinity", if Z == 0. 115 * Otherwise, X and Y are its standard (affine) coordinates. 116 */ 117 typedef struct 118 { 119 mbedtls_mpi X; /*!< the point's X coordinate */ 120 mbedtls_mpi Y; /*!< the point's Y coordinate */ 121 mbedtls_mpi Z; /*!< the point's Z coordinate */ 122 } 123 mbedtls_ecp_point; 124 125 /** 126 * \brief ECP group structure 127 * 128 * We consider two types of curves equations: 129 * 1. Short Weierstrass y^2 = x^3 + A x + B mod P (SEC1 + RFC 4492) 130 * 2. Montgomery, y^2 = x^3 + A x^2 + x mod P (Curve25519 + draft) 131 * In both cases, a generator G for a prime-order subgroup is fixed. In the 132 * short weierstrass, this subgroup is actually the whole curve, and its 133 * cardinal is denoted by N. 134 * 135 * In the case of Short Weierstrass curves, our code requires that N is an odd 136 * prime. (Use odd in mbedtls_ecp_mul() and prime in mbedtls_ecdsa_sign() for blinding.) 137 * 138 * In the case of Montgomery curves, we don't store A but (A + 2) / 4 which is 139 * the quantity actually used in the formulas. Also, nbits is not the size of N 140 * but the required size for private keys. 141 * 142 * If modp is NULL, reduction modulo P is done using a generic algorithm. 143 * Otherwise, it must point to a function that takes an mbedtls_mpi in the range 144 * 0..2^(2*pbits)-1 and transforms it in-place in an integer of little more 145 * than pbits, so that the integer may be efficiently brought in the 0..P-1 146 * range by a few additions or substractions. It must return 0 on success and 147 * non-zero on failure. 148 */ 149 typedef struct 150 { 151 mbedtls_ecp_group_id id; /*!< internal group identifier */ 152 mbedtls_mpi P; /*!< prime modulus of the base field */ 153 mbedtls_mpi A; /*!< 1. A in the equation, or 2. (A + 2) / 4 */ 154 mbedtls_mpi B; /*!< 1. B in the equation, or 2. unused */ 155 mbedtls_ecp_point G; /*!< generator of the (sub)group used */ 156 mbedtls_mpi N; /*!< 1. the order of G, or 2. unused */ 157 size_t pbits; /*!< number of bits in P */ 158 size_t nbits; /*!< number of bits in 1. P, or 2. private keys */ 159 unsigned int h; /*!< internal: 1 if the constants are static */ 160 int (*modp)(mbedtls_mpi *); /*!< function for fast reduction mod P */ 161 int (*t_pre)(mbedtls_ecp_point *, void *); /*!< unused */ 162 int (*t_post)(mbedtls_ecp_point *, void *); /*!< unused */ 163 void *t_data; /*!< unused */ 164 mbedtls_ecp_point *T; /*!< pre-computed points for ecp_mul_comb() */ 165 size_t T_size; /*!< number for pre-computed points */ 166 } 167 mbedtls_ecp_group; 168 169 /** 170 * \brief ECP key pair structure 171 * 172 * A generic key pair that could be used for ECDSA, fixed ECDH, etc. 173 * 174 * \note Members purposefully in the same order as struc mbedtls_ecdsa_context. 175 */ 176 typedef struct 177 { 178 mbedtls_ecp_group grp; /*!< Elliptic curve and base point */ 179 mbedtls_mpi d; /*!< our secret value */ 180 mbedtls_ecp_point Q; /*!< our public value */ 181 } 182 mbedtls_ecp_keypair; 183 184 /** 185 * \name SECTION: Module settings 186 * 187 * The configuration options you can set for this module are in this section. 188 * Either change them in config.h or define them on the compiler command line. 189 * \{ 190 */ 191 192 #if !defined(MBEDTLS_ECP_MAX_BITS) 193 /** 194 * Maximum size of the groups (that is, of N and P) 195 */ 196 #define MBEDTLS_ECP_MAX_BITS 521 /**< Maximum bit size of groups */ 197 #endif 198 199 #define MBEDTLS_ECP_MAX_BYTES ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 ) 200 #define MBEDTLS_ECP_MAX_PT_LEN ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 ) 201 202 #if !defined(MBEDTLS_ECP_WINDOW_SIZE) 203 /* 204 * Maximum "window" size used for point multiplication. 205 * Default: 6. 206 * Minimum value: 2. Maximum value: 7. 207 * 208 * Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) ) 209 * points used for point multiplication. This value is directly tied to EC 210 * peak memory usage, so decreasing it by one should roughly cut memory usage 211 * by two (if large curves are in use). 212 * 213 * Reduction in size may reduce speed, but larger curves are impacted first. 214 * Sample performances (in ECDHE handshakes/s, with FIXED_POINT_OPTIM = 1): 215 * w-size: 6 5 4 3 2 216 * 521 145 141 135 120 97 217 * 384 214 209 198 177 146 218 * 256 320 320 303 262 226 219 220 * 224 475 475 453 398 342 221 * 192 640 640 633 587 476 222 */ 223 #define MBEDTLS_ECP_WINDOW_SIZE 6 /**< Maximum window size used */ 224 #endif /* MBEDTLS_ECP_WINDOW_SIZE */ 225 226 #if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM) 227 /* 228 * Trade memory for speed on fixed-point multiplication. 229 * 230 * This speeds up repeated multiplication of the generator (that is, the 231 * multiplication in ECDSA signatures, and half of the multiplications in 232 * ECDSA verification and ECDHE) by a factor roughly 3 to 4. 233 * 234 * The cost is increasing EC peak memory usage by a factor roughly 2. 235 * 236 * Change this value to 0 to reduce peak memory usage. 237 */ 238 #define MBEDTLS_ECP_FIXED_POINT_OPTIM 1 /**< Enable fixed-point speed-up */ 239 #endif /* MBEDTLS_ECP_FIXED_POINT_OPTIM */ 240 241 /* \} name SECTION: Module settings */ 242 243 /* 244 * Point formats, from RFC 4492's enum ECPointFormat 245 */ 246 #define MBEDTLS_ECP_PF_UNCOMPRESSED 0 /**< Uncompressed point format */ 247 #define MBEDTLS_ECP_PF_COMPRESSED 1 /**< Compressed point format */ 248 249 /* 250 * Some other constants from RFC 4492 251 */ 252 #define MBEDTLS_ECP_TLS_NAMED_CURVE 3 /**< ECCurveType's named_curve */ 253 254 /** 255 * \brief Get the list of supported curves in order of preferrence 256 * (full information) 257 * 258 * \return A statically allocated array, the last entry is 0. 259 */ 260 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_list( void ); 261 262 /** 263 * \brief Get the list of supported curves in order of preferrence 264 * (grp_id only) 265 * 266 * \return A statically allocated array, 267 * terminated with MBEDTLS_ECP_DP_NONE. 268 */ 269 const mbedtls_ecp_group_id *mbedtls_ecp_grp_id_list( void ); 270 271 /** 272 * \brief Get curve information from an internal group identifier 273 * 274 * \param grp_id A MBEDTLS_ECP_DP_XXX value 275 * 276 * \return The associated curve information or NULL 277 */ 278 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_grp_id( mbedtls_ecp_group_id grp_id ); 279 280 /** 281 * \brief Get curve information from a TLS NamedCurve value 282 * 283 * \param tls_id A MBEDTLS_ECP_DP_XXX value 284 * 285 * \return The associated curve information or NULL 286 */ 287 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_tls_id( uint16_t tls_id ); 288 289 /** 290 * \brief Get curve information from a human-readable name 291 * 292 * \param name The name 293 * 294 * \return The associated curve information or NULL 295 */ 296 const mbedtls_ecp_curve_info *mbedtls_ecp_curve_info_from_name( const char *name ); 297 298 /** 299 * \brief Initialize a point (as zero) 300 */ 301 void mbedtls_ecp_point_init( mbedtls_ecp_point *pt ); 302 303 /** 304 * \brief Initialize a group (to something meaningless) 305 */ 306 void mbedtls_ecp_group_init( mbedtls_ecp_group *grp ); 307 308 /** 309 * \brief Initialize a key pair (as an invalid one) 310 */ 311 void mbedtls_ecp_keypair_init( mbedtls_ecp_keypair *key ); 312 313 /** 314 * \brief Free the components of a point 315 */ 316 void mbedtls_ecp_point_free( mbedtls_ecp_point *pt ); 317 318 /** 319 * \brief Free the components of an ECP group 320 */ 321 void mbedtls_ecp_group_free( mbedtls_ecp_group *grp ); 322 323 /** 324 * \brief Free the components of a key pair 325 */ 326 void mbedtls_ecp_keypair_free( mbedtls_ecp_keypair *key ); 327 328 /** 329 * \brief Copy the contents of point Q into P 330 * 331 * \param P Destination point 332 * \param Q Source point 333 * 334 * \return 0 if successful, 335 * MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed 336 */ 337 int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q ); 338 339 /** 340 * \brief Copy the contents of a group object 341 * 342 * \param dst Destination group 343 * \param src Source group 344 * 345 * \return 0 if successful, 346 * MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed 347 */ 348 int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, const mbedtls_ecp_group *src ); 349 350 /** 351 * \brief Set a point to zero 352 * 353 * \param pt Destination point 354 * 355 * \return 0 if successful, 356 * MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed 357 */ 358 int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt ); 359 360 /** 361 * \brief Tell if a point is zero 362 * 363 * \param pt Point to test 364 * 365 * \return 1 if point is zero, 0 otherwise 366 */ 367 int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt ); 368 369 /** 370 * \brief Compare two points 371 * 372 * \note This assumes the points are normalized. Otherwise, 373 * they may compare as "not equal" even if they are. 374 * 375 * \param P First point to compare 376 * \param Q Second point to compare 377 * 378 * \return 0 if the points are equal, 379 * MBEDTLS_ERR_ECP_BAD_INPUT_DATA otherwise 380 */ 381 int mbedtls_ecp_point_cmp( const mbedtls_ecp_point *P, 382 const mbedtls_ecp_point *Q ); 383 384 /** 385 * \brief Import a non-zero point from two ASCII strings 386 * 387 * \param P Destination point 388 * \param radix Input numeric base 389 * \param x First affine coordinate as a null-terminated string 390 * \param y Second affine coordinate as a null-terminated string 391 * 392 * \return 0 if successful, or a MBEDTLS_ERR_MPI_XXX error code 393 */ 394 int mbedtls_ecp_point_read_string( mbedtls_ecp_point *P, int radix, 395 const char *x, const char *y ); 396 397 /** 398 * \brief Export a point into unsigned binary data 399 * 400 * \param grp Group to which the point should belong 401 * \param P Point to export 402 * \param format Point format, should be a MBEDTLS_ECP_PF_XXX macro 403 * \param olen Length of the actual output 404 * \param buf Output buffer 405 * \param buflen Length of the output buffer 406 * 407 * \return 0 if successful, 408 * or MBEDTLS_ERR_ECP_BAD_INPUT_DATA 409 * or MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL 410 */ 411 int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *P, 412 int format, size_t *olen, 413 unsigned char *buf, size_t buflen ); 414 415 /** 416 * \brief Import a point from unsigned binary data 417 * 418 * \param grp Group to which the point should belong 419 * \param P Point to import 420 * \param buf Input buffer 421 * \param ilen Actual length of input 422 * 423 * \return 0 if successful, 424 * MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid, 425 * MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed, 426 * MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the point format 427 * is not implemented. 428 * 429 * \note This function does NOT check that the point actually 430 * belongs to the given group, see mbedtls_ecp_check_pubkey() for 431 * that. 432 */ 433 int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp, mbedtls_ecp_point *P, 434 const unsigned char *buf, size_t ilen ); 435 436 /** 437 * \brief Import a point from a TLS ECPoint record 438 * 439 * \param grp ECP group used 440 * \param pt Destination point 441 * \param buf $(Start of input buffer) 442 * \param len Buffer length 443 * 444 * \note buf is updated to point right after the ECPoint on exit 445 * 446 * \return 0 if successful, 447 * MBEDTLS_ERR_MPI_XXX if initialization failed 448 * MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid 449 */ 450 int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt, 451 const unsigned char **buf, size_t len ); 452 453 /** 454 * \brief Export a point as a TLS ECPoint record 455 * 456 * \param grp ECP group used 457 * \param pt Point to export 458 * \param format Export format 459 * \param olen length of data written 460 * \param buf Buffer to write to 461 * \param blen Buffer length 462 * 463 * \return 0 if successful, 464 * or MBEDTLS_ERR_ECP_BAD_INPUT_DATA 465 * or MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL 466 */ 467 int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt, 468 int format, size_t *olen, 469 unsigned char *buf, size_t blen ); 470 471 /** 472 * \brief Set a group using well-known domain parameters 473 * 474 * \param grp Destination group 475 * \param index Index in the list of well-known domain parameters 476 * 477 * \return 0 if successful, 478 * MBEDTLS_ERR_MPI_XXX if initialization failed 479 * MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE for unkownn groups 480 * 481 * \note Index should be a value of RFC 4492's enum NamedCurve, 482 * usually in the form of a MBEDTLS_ECP_DP_XXX macro. 483 */ 484 int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id index ); 485 486 /** 487 * \brief Set a group from a TLS ECParameters record 488 * 489 * \param grp Destination group 490 * \param buf &(Start of input buffer) 491 * \param len Buffer length 492 * 493 * \note buf is updated to point right after ECParameters on exit 494 * 495 * \return 0 if successful, 496 * MBEDTLS_ERR_MPI_XXX if initialization failed 497 * MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid 498 */ 499 int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp, const unsigned char **buf, size_t len ); 500 501 /** 502 * \brief Write the TLS ECParameters record for a group 503 * 504 * \param grp ECP group used 505 * \param olen Number of bytes actually written 506 * \param buf Buffer to write to 507 * \param blen Buffer length 508 * 509 * \return 0 if successful, 510 * or MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL 511 */ 512 int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, size_t *olen, 513 unsigned char *buf, size_t blen ); 514 515 /** 516 * \brief Multiplication by an integer: R = m * P 517 * (Not thread-safe to use same group in multiple threads) 518 * 519 * \note In order to prevent timing attacks, this function 520 * executes the exact same sequence of (base field) 521 * operations for any valid m. It avoids any if-branch or 522 * array index depending on the value of m. 523 * 524 * \note If f_rng is not NULL, it is used to randomize intermediate 525 * results in order to prevent potential timing attacks 526 * targeting these results. It is recommended to always 527 * provide a non-NULL f_rng (the overhead is negligible). 528 * 529 * \param grp ECP group 530 * \param R Destination point 531 * \param m Integer by which to multiply 532 * \param P Point to multiply 533 * \param f_rng RNG function (see notes) 534 * \param p_rng RNG parameter 535 * 536 * \return 0 if successful, 537 * MBEDTLS_ERR_ECP_INVALID_KEY if m is not a valid privkey 538 * or P is not a valid pubkey, 539 * MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed 540 */ 541 int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 542 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 543 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); 544 545 /** 546 * \brief Multiplication and addition of two points by integers: 547 * R = m * P + n * Q 548 * (Not thread-safe to use same group in multiple threads) 549 * 550 * \note In contrast to mbedtls_ecp_mul(), this function does not guarantee 551 * a constant execution flow and timing. 552 * 553 * \param grp ECP group 554 * \param R Destination point 555 * \param m Integer by which to multiply P 556 * \param P Point to multiply by m 557 * \param n Integer by which to multiply Q 558 * \param Q Point to be multiplied by n 559 * 560 * \return 0 if successful, 561 * MBEDTLS_ERR_ECP_INVALID_KEY if m or n is not a valid privkey 562 * or P or Q is not a valid pubkey, 563 * MBEDTLS_ERR_MPI_ALLOC_FAILED if memory allocation failed 564 */ 565 int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R, 566 const mbedtls_mpi *m, const mbedtls_ecp_point *P, 567 const mbedtls_mpi *n, const mbedtls_ecp_point *Q ); 568 569 /** 570 * \brief Check that a point is a valid public key on this curve 571 * 572 * \param grp Curve/group the point should belong to 573 * \param pt Point to check 574 * 575 * \return 0 if point is a valid public key, 576 * MBEDTLS_ERR_ECP_INVALID_KEY otherwise. 577 * 578 * \note This function only checks the point is non-zero, has valid 579 * coordinates and lies on the curve, but not that it is 580 * indeed a multiple of G. This is additional check is more 581 * expensive, isn't required by standards, and shouldn't be 582 * necessary if the group used has a small cofactor. In 583 * particular, it is useless for the NIST groups which all 584 * have a cofactor of 1. 585 * 586 * \note Uses bare components rather than an mbedtls_ecp_keypair structure 587 * in order to ease use with other structures such as 588 * mbedtls_ecdh_context of mbedtls_ecdsa_context. 589 */ 590 int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt ); 591 592 /** 593 * \brief Check that an mbedtls_mpi is a valid private key for this curve 594 * 595 * \param grp Group used 596 * \param d Integer to check 597 * 598 * \return 0 if point is a valid private key, 599 * MBEDTLS_ERR_ECP_INVALID_KEY otherwise. 600 * 601 * \note Uses bare components rather than an mbedtls_ecp_keypair structure 602 * in order to ease use with other structures such as 603 * mbedtls_ecdh_context of mbedtls_ecdsa_context. 604 */ 605 int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp, const mbedtls_mpi *d ); 606 607 /** 608 * \brief Generate a keypair with configurable base point 609 * 610 * \param grp ECP group 611 * \param G Chosen base point 612 * \param d Destination MPI (secret part) 613 * \param Q Destination point (public part) 614 * \param f_rng RNG function 615 * \param p_rng RNG parameter 616 * 617 * \return 0 if successful, 618 * or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code 619 * 620 * \note Uses bare components rather than an mbedtls_ecp_keypair structure 621 * in order to ease use with other structures such as 622 * mbedtls_ecdh_context of mbedtls_ecdsa_context. 623 */ 624 int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp, 625 const mbedtls_ecp_point *G, 626 mbedtls_mpi *d, mbedtls_ecp_point *Q, 627 int (*f_rng)(void *, unsigned char *, size_t), 628 void *p_rng ); 629 630 /** 631 * \brief Generate a keypair 632 * 633 * \param grp ECP group 634 * \param d Destination MPI (secret part) 635 * \param Q Destination point (public part) 636 * \param f_rng RNG function 637 * \param p_rng RNG parameter 638 * 639 * \return 0 if successful, 640 * or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code 641 * 642 * \note Uses bare components rather than an mbedtls_ecp_keypair structure 643 * in order to ease use with other structures such as 644 * mbedtls_ecdh_context of mbedtls_ecdsa_context. 645 */ 646 int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp_point *Q, 647 int (*f_rng)(void *, unsigned char *, size_t), 648 void *p_rng ); 649 650 /** 651 * \brief Generate a keypair 652 * 653 * \param grp_id ECP group identifier 654 * \param key Destination keypair 655 * \param f_rng RNG function 656 * \param p_rng RNG parameter 657 * 658 * \return 0 if successful, 659 * or a MBEDTLS_ERR_ECP_XXX or MBEDTLS_MPI_XXX error code 660 */ 661 int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key, 662 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); 663 664 /** 665 * \brief Check a public-private key pair 666 * 667 * \param pub Keypair structure holding a public key 668 * \param prv Keypair structure holding a private (plus public) key 669 * 670 * \return 0 if successful (keys are valid and match), or 671 * MBEDTLS_ERR_ECP_BAD_INPUT_DATA, or 672 * a MBEDTLS_ERR_ECP_XXX or MBEDTLS_ERR_MPI_XXX code. 673 */ 674 int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv ); 675 676 #if defined(MBEDTLS_SELF_TEST) 677 /** 678 * \brief Checkup routine 679 * 680 * \return 0 if successful, or 1 if a test failed 681 */ 682 int mbedtls_ecp_self_test( int verbose ); 683 #endif 684 685 #ifdef __cplusplus 686 } 687 #endif 688 689 #endif /* ecp.h */ 690