| /* |
| * Copyright (c) 2018, The OpenThread Authors. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of the copyright holder nor the |
| * names of its contributors may be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| * |
| * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #if defined(MBEDTLS_ECP_ALT) |
| |
| /* |
| * default mbed TLS elliptic curve arithmetic implementation |
| * |
| * (in case MBEDTLS_ECP_ALT is defined then the developer has to provide an |
| * alternative implementation for the whole module and it will replace this |
| * one.) |
| */ |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /** |
| * \brief ECP group structure |
| * |
| * We consider two types of curves equations: |
| * 1. Short Weierstrass y^2 = x^3 + A x + B mod P (SEC1 + RFC 4492) |
| * 2. Montgomery, y^2 = x^3 + A x^2 + x mod P (Curve25519 + draft) |
| * In both cases, a generator G for a prime-order subgroup is fixed. In the |
| * short weierstrass, this subgroup is actually the whole curve, and its |
| * cardinal is denoted by N. |
| * |
| * In the case of Short Weierstrass curves, our code requires that N is an odd |
| * prime. (Use odd in mbedtls_ecp_mul() and prime in mbedtls_ecdsa_sign() for blinding.) |
| * |
| * In the case of Montgomery curves, we don't store A but (A + 2) / 4 which is |
| * the quantity actually used in the formulas. Also, nbits is not the size of N |
| * but the required size for private keys. |
| * |
| * If modp is NULL, reduction modulo P is done using a generic algorithm. |
| * Otherwise, it must point to a function that takes an mbedtls_mpi in the range |
| * 0..2^(2*pbits)-1 and transforms it in-place in an integer of little more |
| * than pbits, so that the integer may be efficiently brought in the 0..P-1 |
| * range by a few additions or substractions. It must return 0 on success and |
| * non-zero on failure. |
| */ |
| typedef struct |
| { |
| mbedtls_ecp_group_id id; /*!< internal group identifier */ |
| mbedtls_mpi P; /*!< prime modulus of the base field */ |
| mbedtls_mpi A; /*!< 1. A in the equation, or 2. (A + 2) / 4 */ |
| mbedtls_mpi B; /*!< 1. B in the equation, or 2. unused */ |
| mbedtls_ecp_point G; /*!< generator of the (sub)group used */ |
| mbedtls_mpi N; /*!< 1. the order of G, or 2. unused */ |
| size_t pbits; /*!< number of bits in P */ |
| size_t nbits; /*!< number of bits in 1. P, or 2. private keys */ |
| unsigned int h; /*!< internal: 1 if the constants are static */ |
| int (*modp)(mbedtls_mpi *); /*!< function for fast reduction mod P */ |
| int (*t_pre)(mbedtls_ecp_point *, void *); /*!< unused */ |
| int (*t_post)(mbedtls_ecp_point *, void *); /*!< unused */ |
| void *t_data; /*!< unused */ |
| mbedtls_ecp_point *T; /*!< pre-computed points for ecp_mul_comb() */ |
| size_t T_size; /*!< number for pre-computed points */ |
| } |
| mbedtls_ecp_group; |
| |
| /** |
| * \name SECTION: Module settings |
| * |
| * The configuration options you can set for this module are in this section. |
| * Either change them in config.h or define them on the compiler command line. |
| * \{ |
| */ |
| |
| #if !defined(MBEDTLS_ECP_MAX_BITS) |
| /** |
| * Maximum size of the groups (that is, of N and P) |
| */ |
| #define MBEDTLS_ECP_MAX_BITS 521 /**< Maximum bit size of groups */ |
| #endif |
| |
| #define MBEDTLS_ECP_MAX_BYTES ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 ) |
| #define MBEDTLS_ECP_MAX_PT_LEN ( 2 * MBEDTLS_ECP_MAX_BYTES + 1 ) |
| |
| #if !defined(MBEDTLS_ECP_WINDOW_SIZE) |
| /* |
| * Maximum "window" size used for point multiplication. |
| * Default: 6. |
| * Minimum value: 2. Maximum value: 7. |
| * |
| * Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) ) |
| * points used for point multiplication. This value is directly tied to EC |
| * peak memory usage, so decreasing it by one should roughly cut memory usage |
| * by two (if large curves are in use). |
| * |
| * Reduction in size may reduce speed, but larger curves are impacted first. |
| * Sample performances (in ECDHE handshakes/s, with FIXED_POINT_OPTIM = 1): |
| * w-size: 6 5 4 3 2 |
| * 521 145 141 135 120 97 |
| * 384 214 209 198 177 146 |
| * 256 320 320 303 262 226 |
| |
| * 224 475 475 453 398 342 |
| * 192 640 640 633 587 476 |
| */ |
| #define MBEDTLS_ECP_WINDOW_SIZE 6 /**< Maximum window size used */ |
| #endif /* MBEDTLS_ECP_WINDOW_SIZE */ |
| |
| #if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM) |
| /* |
| * Trade memory for speed on fixed-point multiplication. |
| * |
| * This speeds up repeated multiplication of the generator (that is, the |
| * multiplication in ECDSA signatures, and half of the multiplications in |
| * ECDSA verification and ECDHE) by a factor roughly 3 to 4. |
| * |
| * The cost is increasing EC peak memory usage by a factor roughly 2. |
| * |
| * Change this value to 0 to reduce peak memory usage. |
| */ |
| #define MBEDTLS_ECP_FIXED_POINT_OPTIM 1 /**< Enable fixed-point speed-up */ |
| #endif /* MBEDTLS_ECP_FIXED_POINT_OPTIM */ |
| |
| /* \} name SECTION: Module settings */ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif // MBEDTLS_ECP_ALT |
