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https://github.com/Mbed-TLS/mbedtls.git
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Merge pull request #8831 from yanesca/switch_to_new_exp
Use mpi_core_exp_mod in bignum
This commit is contained in:
commit
9cc01ccbf8
6
ChangeLog.d/use_exp_mod_core.txt
Normal file
6
ChangeLog.d/use_exp_mod_core.txt
Normal file
@ -0,0 +1,6 @@
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Changes
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* mbedtls_mpi_exp_mod and code that uses it, notably RSA and DHM operations,
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have changed their speed/memory compromise as part of a proactive security
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improvement. The new default value of MBEDTLS_MPI_WINDOW_SIZE roughly
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preserves the current speed, at the expense of increasing memory
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consumption.
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@ -51,15 +51,15 @@
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#if !defined(MBEDTLS_MPI_WINDOW_SIZE)
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/*
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* Maximum window size used for modular exponentiation. Default: 2
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* Maximum window size used for modular exponentiation. Default: 3
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* Minimum value: 1. Maximum value: 6.
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*
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* Result is an array of ( 2 ** MBEDTLS_MPI_WINDOW_SIZE ) MPIs used
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* for the sliding window calculation. (So 64 by default)
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* for the sliding window calculation. (So 8 by default)
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*
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* Reduction in size, reduces speed.
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*/
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#define MBEDTLS_MPI_WINDOW_SIZE 2 /**< Maximum window size used. */
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#define MBEDTLS_MPI_WINDOW_SIZE 3 /**< Maximum window size used. */
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#endif /* !MBEDTLS_MPI_WINDOW_SIZE */
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#if !defined(MBEDTLS_MPI_MAX_SIZE)
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|
374
library/bignum.c
374
library/bignum.c
@ -37,6 +37,19 @@
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#include "mbedtls/platform.h"
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/*
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* Conditionally select an MPI sign in constant time.
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* (MPI sign is the field s in mbedtls_mpi. It is unsigned short and only 1 and -1 are valid
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* values.)
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*/
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static inline signed short mbedtls_ct_mpi_sign_if(mbedtls_ct_condition_t cond,
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signed short sign1, signed short sign2)
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{
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return (signed short) mbedtls_ct_uint_if(cond, sign1 + 1, sign2 + 1) - 1;
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}
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/*
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* Compare signed values in constant time
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*/
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@ -112,7 +125,7 @@ int mbedtls_mpi_safe_cond_assign(mbedtls_mpi *X,
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{
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mbedtls_ct_condition_t do_assign = mbedtls_ct_bool(assign);
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X->s = (int) mbedtls_ct_uint_if(do_assign, Y->s, X->s);
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X->s = mbedtls_ct_mpi_sign_if(do_assign, Y->s, X->s);
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mbedtls_mpi_core_cond_assign(X->p, Y->p, Y->n, do_assign);
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@ -149,8 +162,8 @@ int mbedtls_mpi_safe_cond_swap(mbedtls_mpi *X,
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MBEDTLS_MPI_CHK(mbedtls_mpi_grow(Y, X->n));
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s = X->s;
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X->s = (int) mbedtls_ct_uint_if(do_swap, Y->s, X->s);
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Y->s = (int) mbedtls_ct_uint_if(do_swap, s, Y->s);
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X->s = mbedtls_ct_mpi_sign_if(do_swap, Y->s, X->s);
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Y->s = mbedtls_ct_mpi_sign_if(do_swap, s, Y->s);
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mbedtls_mpi_core_cond_swap(X->p, Y->p, X->n, do_swap);
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@ -288,8 +301,7 @@ static int mbedtls_mpi_resize_clear(mbedtls_mpi *X, size_t limbs)
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* This function is not constant-time. Leading zeros in Y may be removed.
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*
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* Ensure that X does not shrink. This is not guaranteed by the public API,
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* but some code in the bignum module relies on this property, for example
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* in mbedtls_mpi_exp_mod().
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* but some code in the bignum module might still rely on this property.
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*/
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int mbedtls_mpi_copy(mbedtls_mpi *X, const mbedtls_mpi *Y)
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{
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@ -1598,98 +1610,11 @@ int mbedtls_mpi_mod_int(mbedtls_mpi_uint *r, const mbedtls_mpi *A, mbedtls_mpi_s
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return 0;
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}
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static void mpi_montg_init(mbedtls_mpi_uint *mm, const mbedtls_mpi *N)
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{
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*mm = mbedtls_mpi_core_montmul_init(N->p);
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}
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/** Montgomery multiplication: A = A * B * R^-1 mod N (HAC 14.36)
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*
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* \param[in,out] A One of the numbers to multiply.
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* It must have at least as many limbs as N
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* (A->n >= N->n), and any limbs beyond n are ignored.
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* On successful completion, A contains the result of
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* the multiplication A * B * R^-1 mod N where
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* R = (2^ciL)^n.
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* \param[in] B One of the numbers to multiply.
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* It must be nonzero and must not have more limbs than N
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* (B->n <= N->n).
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* \param[in] N The modulus. \p N must be odd.
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* \param mm The value calculated by `mpi_montg_init(&mm, N)`.
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* This is -N^-1 mod 2^ciL.
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* \param[in,out] T A bignum for temporary storage.
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* It must be at least twice the limb size of N plus 1
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* (T->n >= 2 * N->n + 1).
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* Its initial content is unused and
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* its final content is indeterminate.
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* It does not get reallocated.
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*/
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static void mpi_montmul(mbedtls_mpi *A, const mbedtls_mpi *B,
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const mbedtls_mpi *N, mbedtls_mpi_uint mm,
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mbedtls_mpi *T)
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{
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mbedtls_mpi_core_montmul(A->p, A->p, B->p, B->n, N->p, N->n, mm, T->p);
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}
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/*
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* Montgomery reduction: A = A * R^-1 mod N
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*
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* See mpi_montmul() regarding constraints and guarantees on the parameters.
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*/
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static void mpi_montred(mbedtls_mpi *A, const mbedtls_mpi *N,
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mbedtls_mpi_uint mm, mbedtls_mpi *T)
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{
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mbedtls_mpi_uint z = 1;
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mbedtls_mpi U;
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U.n = 1;
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U.s = 1;
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U.p = &z;
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mpi_montmul(A, &U, N, mm, T);
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}
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/**
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* Select an MPI from a table without leaking the index.
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*
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* This is functionally equivalent to mbedtls_mpi_copy(R, T[idx]) except it
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* reads the entire table in order to avoid leaking the value of idx to an
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* attacker able to observe memory access patterns.
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*
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* \param[out] R Where to write the selected MPI.
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* \param[in] T The table to read from.
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* \param[in] T_size The number of elements in the table.
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* \param[in] idx The index of the element to select;
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* this must satisfy 0 <= idx < T_size.
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*
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* \return \c 0 on success, or a negative error code.
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*/
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static int mpi_select(mbedtls_mpi *R, const mbedtls_mpi *T, size_t T_size, size_t idx)
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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for (size_t i = 0; i < T_size; i++) {
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MBEDTLS_MPI_CHK(mbedtls_mpi_safe_cond_assign(R, &T[i],
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(unsigned char) mbedtls_ct_uint_eq(i, idx)));
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}
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cleanup:
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return ret;
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}
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/*
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* Sliding-window exponentiation: X = A^E mod N (HAC 14.85)
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*/
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int mbedtls_mpi_exp_mod(mbedtls_mpi *X, const mbedtls_mpi *A,
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const mbedtls_mpi *E, const mbedtls_mpi *N,
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mbedtls_mpi *prec_RR)
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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size_t window_bitsize;
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size_t i, j, nblimbs;
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size_t bufsize, nbits;
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size_t exponent_bits_in_window = 0;
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mbedtls_mpi_uint ei, mm, state;
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mbedtls_mpi RR, T, W[(size_t) 1 << MBEDTLS_MPI_WINDOW_SIZE], WW, Apos;
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int neg;
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if (mbedtls_mpi_cmp_int(N, 0) <= 0 || (N->p[0] & 1) == 0) {
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return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
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@ -1705,261 +1630,86 @@ int mbedtls_mpi_exp_mod(mbedtls_mpi *X, const mbedtls_mpi *A,
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}
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/*
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* Init temps and window size
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* Ensure that the exponent that we are passing to the core is not NULL.
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*/
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mpi_montg_init(&mm, N);
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mbedtls_mpi_init(&RR); mbedtls_mpi_init(&T);
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mbedtls_mpi_init(&Apos);
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mbedtls_mpi_init(&WW);
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memset(W, 0, sizeof(W));
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i = mbedtls_mpi_bitlen(E);
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window_bitsize = (i > 671) ? 6 : (i > 239) ? 5 :
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(i > 79) ? 4 : (i > 23) ? 3 : 1;
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#if (MBEDTLS_MPI_WINDOW_SIZE < 6)
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if (window_bitsize > MBEDTLS_MPI_WINDOW_SIZE) {
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window_bitsize = MBEDTLS_MPI_WINDOW_SIZE;
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if (E->n == 0) {
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ret = mbedtls_mpi_lset(X, 1);
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return ret;
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}
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#endif
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const size_t w_table_used_size = (size_t) 1 << window_bitsize;
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/*
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* This function is not constant-trace: its memory accesses depend on the
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* exponent value. To defend against timing attacks, callers (such as RSA
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* and DHM) should use exponent blinding. However this is not enough if the
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* adversary can find the exponent in a single trace, so this function
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* takes extra precautions against adversaries who can observe memory
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* access patterns.
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*
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* This function performs a series of multiplications by table elements and
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* squarings, and we want the prevent the adversary from finding out which
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* table element was used, and from distinguishing between multiplications
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* and squarings. Firstly, when multiplying by an element of the window
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* W[i], we do a constant-trace table lookup to obfuscate i. This leaves
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* squarings as having a different memory access patterns from other
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* multiplications. So secondly, we put the accumulator in the table as
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* well, and also do a constant-trace table lookup to multiply by the
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* accumulator which is W[x_index].
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*
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* This way, all multiplications take the form of a lookup-and-multiply.
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* The number of lookup-and-multiply operations inside each iteration of
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* the main loop still depends on the bits of the exponent, but since the
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* other operations in the loop don't have an easily recognizable memory
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* trace, an adversary is unlikely to be able to observe the exact
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* patterns.
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*
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* An adversary may still be able to recover the exponent if they can
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* observe both memory accesses and branches. However, branch prediction
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* exploitation typically requires many traces of execution over the same
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* data, which is defeated by randomized blinding.
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* Allocate working memory for mbedtls_mpi_core_exp_mod()
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*/
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const size_t x_index = 0;
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mbedtls_mpi_init(&W[x_index]);
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j = N->n + 1;
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/* All W[i] including the accumulator must have at least N->n limbs for
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* the mpi_montmul() and mpi_montred() calls later. Here we ensure that
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* W[1] and the accumulator W[x_index] are large enough. later we'll grow
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* other W[i] to the same length. They must not be shrunk midway through
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* this function!
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*/
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MBEDTLS_MPI_CHK(mbedtls_mpi_grow(&W[x_index], j));
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MBEDTLS_MPI_CHK(mbedtls_mpi_grow(&W[1], j));
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MBEDTLS_MPI_CHK(mbedtls_mpi_grow(&T, j * 2));
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/*
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* Compensate for negative A (and correct at the end)
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*/
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neg = (A->s == -1);
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if (neg) {
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MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&Apos, A));
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Apos.s = 1;
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A = &Apos;
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size_t T_limbs = mbedtls_mpi_core_exp_mod_working_limbs(N->n, E->n);
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mbedtls_mpi_uint *T = (mbedtls_mpi_uint *) mbedtls_calloc(T_limbs, sizeof(mbedtls_mpi_uint));
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if (T == NULL) {
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return MBEDTLS_ERR_MPI_ALLOC_FAILED;
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}
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mbedtls_mpi RR;
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mbedtls_mpi_init(&RR);
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/*
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* If 1st call, pre-compute R^2 mod N
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*/
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if (prec_RR == NULL || prec_RR->p == NULL) {
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MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&RR, 1));
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MBEDTLS_MPI_CHK(mbedtls_mpi_shift_l(&RR, N->n * 2 * biL));
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MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&RR, &RR, N));
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MBEDTLS_MPI_CHK(mbedtls_mpi_core_get_mont_r2_unsafe(&RR, N));
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if (prec_RR != NULL) {
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memcpy(prec_RR, &RR, sizeof(mbedtls_mpi));
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*prec_RR = RR;
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}
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} else {
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memcpy(&RR, prec_RR, sizeof(mbedtls_mpi));
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MBEDTLS_MPI_CHK(mbedtls_mpi_grow(prec_RR, N->n));
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RR = *prec_RR;
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}
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/*
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* W[1] = A * R^2 * R^-1 mod N = A * R mod N
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* To preserve constness we need to make a copy of A. Using X for this to
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* save memory.
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*/
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if (mbedtls_mpi_cmp_mpi(A, N) >= 0) {
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MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&W[1], A, N));
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/* This should be a no-op because W[1] is already that large before
|
||||
* mbedtls_mpi_mod_mpi(), but it's necessary to avoid an overflow
|
||||
* in mpi_montmul() below, so let's make sure. */
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||||
MBEDTLS_MPI_CHK(mbedtls_mpi_grow(&W[1], N->n + 1));
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||||
} else {
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||||
MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&W[1], A));
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||||
}
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||||
|
||||
/* Note that this is safe because W[1] always has at least N->n limbs
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||||
* (it grew above and was preserved by mbedtls_mpi_copy()). */
|
||||
mpi_montmul(&W[1], &RR, N, mm, &T);
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||||
MBEDTLS_MPI_CHK(mbedtls_mpi_copy(X, A));
|
||||
|
||||
/*
|
||||
* W[x_index] = R^2 * R^-1 mod N = R mod N
|
||||
* Compensate for negative A (and correct at the end).
|
||||
*/
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&W[x_index], &RR));
|
||||
mpi_montred(&W[x_index], N, mm, &T);
|
||||
|
||||
|
||||
if (window_bitsize > 1) {
|
||||
/*
|
||||
* W[i] = W[1] ^ i
|
||||
*
|
||||
* The first bit of the sliding window is always 1 and therefore we
|
||||
* only need to store the second half of the table.
|
||||
*
|
||||
* (There are two special elements in the table: W[0] for the
|
||||
* accumulator/result and W[1] for A in Montgomery form. Both of these
|
||||
* are already set at this point.)
|
||||
*/
|
||||
j = w_table_used_size / 2;
|
||||
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_grow(&W[j], N->n + 1));
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&W[j], &W[1]));
|
||||
|
||||
for (i = 0; i < window_bitsize - 1; i++) {
|
||||
mpi_montmul(&W[j], &W[j], N, mm, &T);
|
||||
}
|
||||
|
||||
/*
|
||||
* W[i] = W[i - 1] * W[1]
|
||||
*/
|
||||
for (i = j + 1; i < w_table_used_size; i++) {
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_grow(&W[i], N->n + 1));
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&W[i], &W[i - 1]));
|
||||
|
||||
mpi_montmul(&W[i], &W[1], N, mm, &T);
|
||||
}
|
||||
}
|
||||
|
||||
nblimbs = E->n;
|
||||
bufsize = 0;
|
||||
nbits = 0;
|
||||
state = 0;
|
||||
|
||||
while (1) {
|
||||
if (bufsize == 0) {
|
||||
if (nblimbs == 0) {
|
||||
break;
|
||||
}
|
||||
|
||||
nblimbs--;
|
||||
|
||||
bufsize = sizeof(mbedtls_mpi_uint) << 3;
|
||||
}
|
||||
|
||||
bufsize--;
|
||||
|
||||
ei = (E->p[nblimbs] >> bufsize) & 1;
|
||||
|
||||
/*
|
||||
* skip leading 0s
|
||||
*/
|
||||
if (ei == 0 && state == 0) {
|
||||
continue;
|
||||
}
|
||||
|
||||
if (ei == 0 && state == 1) {
|
||||
/*
|
||||
* out of window, square W[x_index]
|
||||
*/
|
||||
MBEDTLS_MPI_CHK(mpi_select(&WW, W, w_table_used_size, x_index));
|
||||
mpi_montmul(&W[x_index], &WW, N, mm, &T);
|
||||
continue;
|
||||
}
|
||||
|
||||
/*
|
||||
* add ei to current window
|
||||
*/
|
||||
state = 2;
|
||||
|
||||
nbits++;
|
||||
exponent_bits_in_window |= (ei << (window_bitsize - nbits));
|
||||
|
||||
if (nbits == window_bitsize) {
|
||||
/*
|
||||
* W[x_index] = W[x_index]^window_bitsize R^-1 mod N
|
||||
*/
|
||||
for (i = 0; i < window_bitsize; i++) {
|
||||
MBEDTLS_MPI_CHK(mpi_select(&WW, W, w_table_used_size,
|
||||
x_index));
|
||||
mpi_montmul(&W[x_index], &WW, N, mm, &T);
|
||||
}
|
||||
|
||||
/*
|
||||
* W[x_index] = W[x_index] * W[exponent_bits_in_window] R^-1 mod N
|
||||
*/
|
||||
MBEDTLS_MPI_CHK(mpi_select(&WW, W, w_table_used_size,
|
||||
exponent_bits_in_window));
|
||||
mpi_montmul(&W[x_index], &WW, N, mm, &T);
|
||||
|
||||
state--;
|
||||
nbits = 0;
|
||||
exponent_bits_in_window = 0;
|
||||
}
|
||||
}
|
||||
X->s = 1;
|
||||
|
||||
/*
|
||||
* process the remaining bits
|
||||
* Make sure that X is in a form that is safe for consumption by
|
||||
* the core functions.
|
||||
*
|
||||
* - The core functions will not touch the limbs of X above N->n. The
|
||||
* result will be correct if those limbs are 0, which the mod call
|
||||
* ensures.
|
||||
* - Also, X must have at least as many limbs as N for the calls to the
|
||||
* core functions.
|
||||
*/
|
||||
for (i = 0; i < nbits; i++) {
|
||||
MBEDTLS_MPI_CHK(mpi_select(&WW, W, w_table_used_size, x_index));
|
||||
mpi_montmul(&W[x_index], &WW, N, mm, &T);
|
||||
|
||||
exponent_bits_in_window <<= 1;
|
||||
|
||||
if ((exponent_bits_in_window & ((size_t) 1 << window_bitsize)) != 0) {
|
||||
MBEDTLS_MPI_CHK(mpi_select(&WW, W, w_table_used_size, 1));
|
||||
mpi_montmul(&W[x_index], &WW, N, mm, &T);
|
||||
}
|
||||
if (mbedtls_mpi_cmp_mpi(X, N) >= 0) {
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(X, X, N));
|
||||
}
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_grow(X, N->n));
|
||||
|
||||
/*
|
||||
* W[x_index] = A^E * R * R^-1 mod N = A^E mod N
|
||||
* Convert to and from Montgomery around mbedtls_mpi_core_exp_mod().
|
||||
*/
|
||||
mpi_montred(&W[x_index], N, mm, &T);
|
||||
|
||||
if (neg && E->n != 0 && (E->p[0] & 1) != 0) {
|
||||
W[x_index].s = -1;
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&W[x_index], N, &W[x_index]));
|
||||
}
|
||||
mbedtls_mpi_uint mm = mbedtls_mpi_core_montmul_init(N->p);
|
||||
mbedtls_mpi_core_to_mont_rep(X->p, X->p, N->p, N->n, mm, RR.p, T);
|
||||
mbedtls_mpi_core_exp_mod(X->p, X->p, N->p, N->n, E->p, E->n, RR.p, T);
|
||||
mbedtls_mpi_core_from_mont_rep(X->p, X->p, N->p, N->n, mm, T);
|
||||
|
||||
/*
|
||||
* Load the result in the output variable.
|
||||
* Correct for negative A.
|
||||
*/
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_copy(X, &W[x_index]));
|
||||
if (A->s == -1 && (E->p[0] & 1) != 0) {
|
||||
mbedtls_ct_condition_t is_x_non_zero = mbedtls_mpi_core_check_zero_ct(X->p, X->n);
|
||||
X->s = mbedtls_ct_mpi_sign_if(is_x_non_zero, -1, 1);
|
||||
|
||||
MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(X, N, X));
|
||||
}
|
||||
|
||||
cleanup:
|
||||
|
||||
/* The first bit of the sliding window is always 1 and therefore the first
|
||||
* half of the table was unused. */
|
||||
for (i = w_table_used_size/2; i < w_table_used_size; i++) {
|
||||
mbedtls_mpi_free(&W[i]);
|
||||
}
|
||||
|
||||
mbedtls_mpi_free(&W[x_index]);
|
||||
mbedtls_mpi_free(&W[1]);
|
||||
mbedtls_mpi_free(&T);
|
||||
mbedtls_mpi_free(&Apos);
|
||||
mbedtls_mpi_free(&WW);
|
||||
mbedtls_mpi_zeroize_and_free(T, T_limbs);
|
||||
|
||||
if (prec_RR == NULL || prec_RR->p == NULL) {
|
||||
mbedtls_mpi_free(&RR);
|
||||
|
@ -856,16 +856,17 @@ mbedtls_mpi_uint mbedtls_mpi_core_sub_int(mbedtls_mpi_uint *X,
|
||||
return c;
|
||||
}
|
||||
|
||||
mbedtls_mpi_uint mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
|
||||
size_t limbs)
|
||||
mbedtls_ct_condition_t mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
|
||||
size_t limbs)
|
||||
{
|
||||
volatile const mbedtls_mpi_uint *force_read_A = A;
|
||||
mbedtls_mpi_uint bits = 0;
|
||||
|
||||
for (size_t i = 0; i < limbs; i++) {
|
||||
bits |= A[i];
|
||||
bits |= force_read_A[i];
|
||||
}
|
||||
|
||||
return bits;
|
||||
return mbedtls_ct_bool(bits);
|
||||
}
|
||||
|
||||
void mbedtls_mpi_core_to_mont_rep(mbedtls_mpi_uint *X,
|
||||
|
@ -662,11 +662,11 @@ mbedtls_mpi_uint mbedtls_mpi_core_sub_int(mbedtls_mpi_uint *X,
|
||||
* \param[in] A The MPI to test.
|
||||
* \param limbs Number of limbs in \p A.
|
||||
*
|
||||
* \return 0 if `A == 0`
|
||||
* non-0 (may be any value) if `A != 0`.
|
||||
* \return MBEDTLS_CT_FALSE if `A == 0`
|
||||
* MBEDTLS_CT_TRUE if `A != 0`.
|
||||
*/
|
||||
mbedtls_mpi_uint mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
|
||||
size_t limbs);
|
||||
mbedtls_ct_condition_t mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
|
||||
size_t limbs);
|
||||
|
||||
/**
|
||||
* \brief Returns the number of limbs of working memory required for
|
||||
|
@ -965,6 +965,45 @@ exit:
|
||||
}
|
||||
/* END_CASE */
|
||||
|
||||
/* BEGIN_CASE */
|
||||
void mpi_exp_mod_min_RR(char *input_A, char *input_E,
|
||||
char *input_N, char *input_X,
|
||||
int exp_result)
|
||||
{
|
||||
mbedtls_mpi A, E, N, RR, Z, X;
|
||||
int res;
|
||||
mbedtls_mpi_init(&A); mbedtls_mpi_init(&E); mbedtls_mpi_init(&N);
|
||||
mbedtls_mpi_init(&RR); mbedtls_mpi_init(&Z); mbedtls_mpi_init(&X);
|
||||
|
||||
TEST_EQUAL(mbedtls_test_read_mpi(&A, input_A), 0);
|
||||
TEST_EQUAL(mbedtls_test_read_mpi(&E, input_E), 0);
|
||||
TEST_EQUAL(mbedtls_test_read_mpi(&N, input_N), 0);
|
||||
TEST_EQUAL(mbedtls_test_read_mpi(&X, input_X), 0);
|
||||
|
||||
TEST_EQUAL(mbedtls_mpi_core_get_mont_r2_unsafe(&RR, &N), 0);
|
||||
TEST_EQUAL(mbedtls_mpi_shrink(&RR, 0), 0);
|
||||
/* The objective of this test is to check that exp_mod defends
|
||||
* against a smaller RR. */
|
||||
TEST_LE_U(RR.n, N.n - 1);
|
||||
|
||||
res = mbedtls_mpi_exp_mod(&Z, &A, &E, &N, &RR);
|
||||
/* We know that exp_mod internally needs RR to be as large as N.
|
||||
* Validate that it is the case now, otherwise there was probably
|
||||
* a buffer overread. */
|
||||
TEST_EQUAL(RR.n, N.n);
|
||||
|
||||
TEST_EQUAL(res, exp_result);
|
||||
if (res == 0) {
|
||||
TEST_EQUAL(sign_is_valid(&Z), 1);
|
||||
TEST_EQUAL(mbedtls_mpi_cmp_mpi(&Z, &X), 0);
|
||||
}
|
||||
|
||||
exit:
|
||||
mbedtls_mpi_free(&A); mbedtls_mpi_free(&E); mbedtls_mpi_free(&N);
|
||||
mbedtls_mpi_free(&RR); mbedtls_mpi_free(&Z); mbedtls_mpi_free(&X);
|
||||
}
|
||||
/* END_CASE */
|
||||
|
||||
/* BEGIN_CASE */
|
||||
void mpi_exp_mod(char *input_A, char *input_E,
|
||||
char *input_N, char *input_X,
|
||||
|
@ -1362,6 +1362,9 @@ mpi_exp_mod:"04":"00":"09":"1":0
|
||||
Test mbedtls_mpi_exp_mod: 10 ^ 0 (1 limb) mod 9
|
||||
mpi_exp_mod:"0a":"00":"09":"1":0
|
||||
|
||||
Test mbedtls_mpi_exp_mod: -3 ^ 3 mod 27
|
||||
mpi_exp_mod:"-3":"3":"1b":"1b":0
|
||||
|
||||
Test mbedtls_mpi_exp_mod: MAX_SIZE exponent
|
||||
mpi_exp_mod_size:2:MBEDTLS_MPI_MAX_SIZE:10:"":0
|
||||
|
||||
@ -1391,6 +1394,14 @@ Test mbedtls_mpi_exp_mod (Negative base) [#2]
|
||||
depends_on:MPI_MAX_BITS_LARGER_THAN_792
|
||||
mpi_exp_mod:"-9f13012cd92aa72fb86ac8879d2fde4f7fd661aaae43a00971f081cc60ca277059d5c37e89652e2af2585d281d66ef6a9d38a117e9608e9e7574cd142dc55278838a2161dd56db9470d4c1da2d5df15a908ee2eb886aaa890f23be16de59386663a12f1afbb325431a3e835e3fd89b98b96a6f77382f458ef9a37e1f84a03045c8676ab55291a94c2228ea15448ee96b626b998":"40a54d1b9e86789f06d9607fb158672d64867665c73ee9abb545fc7a785634b354c7bae5b962ce8040cf45f2c1f3d3659b2ee5ede17534c8fc2ec85c815e8df1fe7048d12c90ee31b88a68a081f17f0d8ce5f4030521e9400083bcea73a429031d4ca7949c2000d597088e0c39a6014d8bf962b73bb2e8083bd0390a4e00b9b3":"eeaf0ab9adb38dd69c33f80afa8fc5e86072618775ff3c0b9ea2314c9c256576d674df7496ea81d3383b4813d692c6e0e0d5d8e250b98be48e495c1d6089dad15dc7d7b46154d6b6ce8ef4ad69b15d4982559b297bcf1885c529f566660e57ec68edbc3c05726cc02fd4cbf4976eaa9afd5138fe8376435b9fc61d2fc0eb06e3":"21acc7199e1b90f9b4844ffe12c19f00ec548c5d32b21c647d48b6015d8eb9ec9db05b4f3d44db4227a2b5659c1a7cceb9d5fa8fa60376047953ce7397d90aaeb7465e14e820734f84aa52ad0fc66701bcbb991d57715806a11531268e1e83dd48288c72b424a6287e9ce4e5cc4db0dd67614aecc23b0124a5776d36e5c89483":0
|
||||
|
||||
Test mbedtls_mpi_exp_mod (N.n=3, RR.n=1 on 32 bit)
|
||||
depends_on:MBEDTLS_HAVE_INT32
|
||||
mpi_exp_mod_min_RR:"10":"2":"10000000100000001":"100":0
|
||||
|
||||
Test mbedtls_mpi_exp_mod (N.n=3, RR.n=1 on 64 bit)
|
||||
depends_on:MBEDTLS_HAVE_INT64
|
||||
mpi_exp_mod_min_RR:"10":"2":"100000000000000010000000000000001":"100":0
|
||||
|
||||
Base test GCD #1
|
||||
mpi_gcd:"2b5":"261":"15"
|
||||
|
||||
|
Loading…
x
Reference in New Issue
Block a user