/** * \file bignum_helpers.c * * \brief This file contains the prototypes of helper functions for * bignum-related testing. */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ #define MBEDTLS_ALLOW_PRIVATE_ACCESS #include <test/bignum_helpers.h> #if defined(MBEDTLS_BIGNUM_C) #include <stdlib.h> #include <string.h> #include <mbedtls/bignum.h> #include <bignum_core.h> #include <bignum_mod.h> #include <bignum_mod_raw.h> #include <test/helpers.h> #include <test/macros.h> int mbedtls_test_read_mpi_core(mbedtls_mpi_uint **pX, size_t *plimbs, const char *input) { /* Sanity check */ if (*pX != NULL) { return MBEDTLS_ERR_MPI_BAD_INPUT_DATA; } size_t hex_len = strlen(input); size_t byte_len = (hex_len + 1) / 2; *plimbs = CHARS_TO_LIMBS(byte_len); /* A core bignum is not allowed to be empty. Forbid it as test data, * this way static analyzers have a chance of knowing we don't expect * the bignum functions to support empty inputs. */ if (*plimbs == 0) { return MBEDTLS_ERR_MPI_BAD_INPUT_DATA; } *pX = mbedtls_calloc(*plimbs, sizeof(**pX)); if (*pX == NULL) { return MBEDTLS_ERR_MPI_ALLOC_FAILED; } unsigned char *byte_start = (unsigned char *) *pX; if (byte_len % sizeof(mbedtls_mpi_uint) != 0) { byte_start += sizeof(mbedtls_mpi_uint) - byte_len % sizeof(mbedtls_mpi_uint); } if ((hex_len & 1) != 0) { /* mbedtls_test_unhexify wants an even number of hex digits */ TEST_ASSERT(mbedtls_test_ascii2uc(*input, byte_start) == 0); ++byte_start; ++input; --byte_len; } TEST_ASSERT(mbedtls_test_unhexify(byte_start, byte_len, input, &byte_len) == 0); mbedtls_mpi_core_bigendian_to_host(*pX, *plimbs); return 0; exit: mbedtls_free(*pX); return MBEDTLS_ERR_MPI_BAD_INPUT_DATA; } #if defined(MBEDTLS_ECP_WITH_MPI_UINT) int mbedtls_test_read_mpi_modulus(mbedtls_mpi_mod_modulus *N, const char *s, mbedtls_mpi_mod_rep_selector int_rep) { mbedtls_mpi_uint *p = NULL; size_t limbs = 0; if (N->limbs != 0) { return MBEDTLS_ERR_MPI_BAD_INPUT_DATA; } int ret = mbedtls_test_read_mpi_core(&p, &limbs, s); if (ret != 0) { return ret; } switch (int_rep) { case MBEDTLS_MPI_MOD_REP_MONTGOMERY: ret = mbedtls_mpi_mod_modulus_setup(N, p, limbs); break; case MBEDTLS_MPI_MOD_REP_OPT_RED: ret = mbedtls_mpi_mod_optred_modulus_setup(N, p, limbs, NULL); break; default: ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA; break; } if (ret != 0) { mbedtls_free(p); } return ret; } void mbedtls_test_mpi_mod_modulus_free_with_limbs(mbedtls_mpi_mod_modulus *N) { mbedtls_free((mbedtls_mpi_uint *) N->p); mbedtls_mpi_mod_modulus_free(N); } #endif /* MBEDTLS_ECP_WITH_MPI_UINT */ int mbedtls_test_read_mpi(mbedtls_mpi *X, const char *s) { int negative = 0; /* Always set the sign bit to -1 if the input has a minus sign, even for 0. * This creates an invalid representation, which mbedtls_mpi_read_string() * avoids but we want to be able to create that in test data. */ if (s[0] == '-') { ++s; negative = 1; } /* mbedtls_mpi_read_string() currently retains leading zeros. * It always allocates at least one limb for the value 0. */ if (s[0] == 0) { mbedtls_mpi_free(X); return 0; } int ret = mbedtls_mpi_read_string(X, 16, s); if (ret != 0) { return ret; } if (negative) { if (mbedtls_mpi_cmp_int(X, 0) == 0) { mbedtls_test_increment_case_uses_negative_0(); } X->s = -1; } return 0; } #endif /* MBEDTLS_BIGNUM_C */