/** * Low-level modular bignum functions * * This interface should only be used by the higher-level modular bignum * module (bignum_mod.c) and the ECP module (ecp.c, ecp_curves.c). All other * modules should use the high-level modular bignum interface (bignum_mod.h) * or the legacy bignum interface (bignum.h). * * This is a low-level interface to operations on integers modulo which * has no protection against passing invalid arguments such as arrays of * the wrong size. The functions in bignum_mod.h provide a higher-level * interface that includes protections against accidental misuse, at the * expense of code size and sometimes more cumbersome memory management. */ /* * Copyright The Mbed TLS Contributors * 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. */ #ifndef MBEDTLS_BIGNUM_MOD_RAW_H #define MBEDTLS_BIGNUM_MOD_RAW_H #include "common.h" #if defined(MBEDTLS_BIGNUM_C) #include "mbedtls/bignum.h" #endif #include "bignum_mod.h" /** * \brief Perform a safe conditional copy of an MPI which doesn't reveal * whether the assignment was done or not. * * The size to copy is determined by \p N. * * \param[out] X The address of the destination MPI. * This must be initialized. Must have enough limbs to * store the full value of \p A. * \param[in] A The address of the source MPI. This must be initialized. * \param[in] N The address of the modulus related to \p X and \p A. * \param assign The condition deciding whether to perform the * assignment or not. Must be either 0 or 1: * * \c 1: Perform the assignment `X = A`. * * \c 0: Keep the original value of \p X. * * \note This function avoids leaking any information about whether * the assignment was done or not. * * \warning If \p assign is neither 0 nor 1, the result of this function * is indeterminate, and the resulting value in \p X might be * neither its original value nor the value in \p A. */ void mbedtls_mpi_mod_raw_cond_assign( mbedtls_mpi_uint *X, const mbedtls_mpi_uint *A, const mbedtls_mpi_mod_modulus *N, unsigned char assign ); /** * \brief Perform a safe conditional swap of two MPIs which doesn't reveal * whether the swap was done or not. * * The size to swap is determined by \p N. * * \param[in,out] X The address of the first MPI. This must be initialized. * \param[in,out] Y The address of the second MPI. This must be initialized. * \param[in] N The address of the modulus related to \p X and \p Y. * \param swap The condition deciding whether to perform * the swap or not. Must be either 0 or 1: * * \c 1: Swap the values of \p X and \p Y. * * \c 0: Keep the original values of \p X and \p Y. * * \note This function avoids leaking any information about whether * the swap was done or not. * * \warning If \p swap is neither 0 nor 1, the result of this function * is indeterminate, and both \p X and \p Y might end up with * values different to either of the original ones. */ void mbedtls_mpi_mod_raw_cond_swap( mbedtls_mpi_uint *X, mbedtls_mpi_uint *Y, const mbedtls_mpi_mod_modulus *N, unsigned char swap ); /** Import X from unsigned binary data. * * The MPI needs to have enough limbs to store the full value (including any * most significant zero bytes in the input). * * \param[out] X The address of the MPI. The size is determined by \p m. * (In particular, it must have at least as many limbs as * the modulus \p m.) * \param[in] m The address of the modulus related to \p X. * \param[in] input The input buffer to import from. * \param input_length The length in bytes of \p input. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if \p X isn't * large enough to hold the value in \p input. * \return #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if the external representation * of \p m is invalid or \p X is not less than \p m. */ int mbedtls_mpi_mod_raw_read( mbedtls_mpi_uint *X, const mbedtls_mpi_mod_modulus *m, const unsigned char *input, size_t input_length ); /** Export A into unsigned binary data. * * \param[in] A The address of the MPI. The size is determined by \p m. * (In particular, it must have at least as many limbs as * the modulus \p m.) * \param[in] m The address of the modulus related to \p A. * \param[out] output The output buffer to export to. * \param output_length The length in bytes of \p output. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if \p output isn't * large enough to hold the value of \p A. * \return #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if the external representation * of \p m is invalid. */ int mbedtls_mpi_mod_raw_write( const mbedtls_mpi_uint *A, const mbedtls_mpi_mod_modulus *m, unsigned char *output, size_t output_length ); /* BEGIN MERGE SLOT 1 */ /* END MERGE SLOT 1 */ /* BEGIN MERGE SLOT 2 */ /** \brief Subtract two MPIs, returning the residue modulo the specified * modulus. * * The size of the operation is determined by \p N. \p A and \p B must have * the same number of limbs as \p N. * * \p X may be aliased to \p A or \p B, or even both, but may not overlap * either otherwise. * * \param[out] X The address of the result MPI. * This must be initialized. Must have enough limbs to * store the full value of the result. * \param[in] A The address of the first MPI. This must be initialized. * \param[in] B The address of the second MPI. This must be initialized. * \param[in] N The address of the modulus. Used to perform a modulo * operation on the result of the subtraction. */ void mbedtls_mpi_mod_raw_sub( mbedtls_mpi_uint *X, const mbedtls_mpi_uint *A, const mbedtls_mpi_uint *B, const mbedtls_mpi_mod_modulus *N ); /* END MERGE SLOT 2 */ /* BEGIN MERGE SLOT 3 */ /* END MERGE SLOT 3 */ /* BEGIN MERGE SLOT 4 */ /* END MERGE SLOT 4 */ /* BEGIN MERGE SLOT 5 */ /** * \brief Perform a known-size modular addition. * * Calculate `A + B modulo N`. * * The number of limbs in each operand, and the result, is given by the * modulus \p N. * * \p X may be aliased to \p A or \p B, or even both, but may not overlap * either otherwise. * * \param[out] X The result of the modular addition. * \param[in] A Little-endian presentation of the left operand. This * must be smaller than \p N. * \param[in] B Little-endian presentation of the right operand. This * must be smaller than \p N. * \param[in] N The address of the modulus. */ void mbedtls_mpi_mod_raw_add( mbedtls_mpi_uint *X, const mbedtls_mpi_uint *A, const mbedtls_mpi_uint *B, const mbedtls_mpi_mod_modulus *N ); /* END MERGE SLOT 5 */ /* BEGIN MERGE SLOT 6 */ /* END MERGE SLOT 6 */ /* BEGIN MERGE SLOT 7 */ /** Convert an MPI into Montgomery form. * * \param X The address of the MPI. * Must have the same number of limbs as \p m. * \param m The address of the modulus, which gives the size of * the base `R` = 2^(biL*m->limbs). * * \return \c 0 if successful. */ int mbedtls_mpi_mod_raw_to_mont_rep( mbedtls_mpi_uint *X, const mbedtls_mpi_mod_modulus *m ); /** Convert an MPI back from Montgomery representation. * * \param X The address of the MPI. * Must have the same number of limbs as \p m. * \param m The address of the modulus, which gives the size of * the base `R`= 2^(biL*m->limbs). * * \return \c 0 if successful. */ int mbedtls_mpi_mod_raw_from_mont_rep( mbedtls_mpi_uint *X, const mbedtls_mpi_mod_modulus *m ); /* END MERGE SLOT 7 */ /* BEGIN MERGE SLOT 8 */ /* END MERGE SLOT 8 */ /* BEGIN MERGE SLOT 9 */ /* END MERGE SLOT 9 */ /* BEGIN MERGE SLOT 10 */ /* END MERGE SLOT 10 */ #endif /* MBEDTLS_BIGNUM_MOD_RAW_H */