takashi kadono / Mbed OS Nucleo446_SSD1331

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Dependencies:   ssd1331

mbed-os/features/mbedtls/src/rsa_internal.c@3:f3764f852aa8, 2018-10-11 (annotated)

Committer:
kadonotakashi
Date:
Thu Oct 11 02:27:46 2018 +0000
Revision:
3:f3764f852aa8
Parent:
0:8fdf9a60065b 
Nucreo 446 + SSD1331 test version;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kadonotakashi 0:8fdf9a60065b 1 /*
kadonotakashi 0:8fdf9a60065b 2 * Helper functions for the RSA module
kadonotakashi 0:8fdf9a60065b 3 *
kadonotakashi 0:8fdf9a60065b 4 * Copyright (C) 2006-2017, ARM Limited, All Rights Reserved
kadonotakashi 0:8fdf9a60065b 5 * SPDX-License-Identifier: Apache-2.0
kadonotakashi 0:8fdf9a60065b 6 *
kadonotakashi 0:8fdf9a60065b 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
kadonotakashi 0:8fdf9a60065b 8 * not use this file except in compliance with the License.
kadonotakashi 0:8fdf9a60065b 9 * You may obtain a copy of the License at
kadonotakashi 0:8fdf9a60065b 10 *
kadonotakashi 0:8fdf9a60065b 11 * http://www.apache.org/licenses/LICENSE-2.0
kadonotakashi 0:8fdf9a60065b 12 *
kadonotakashi 0:8fdf9a60065b 13 * Unless required by applicable law or agreed to in writing, software
kadonotakashi 0:8fdf9a60065b 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
kadonotakashi 0:8fdf9a60065b 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kadonotakashi 0:8fdf9a60065b 16 * See the License for the specific language governing permissions and
kadonotakashi 0:8fdf9a60065b 17 * limitations under the License.
kadonotakashi 0:8fdf9a60065b 18 *
kadonotakashi 0:8fdf9a60065b 19 * This file is part of mbed TLS (https://tls.mbed.org)
kadonotakashi 0:8fdf9a60065b 20 *
kadonotakashi 0:8fdf9a60065b 21 */
kadonotakashi 0:8fdf9a60065b 22
kadonotakashi 0:8fdf9a60065b 23 #if !defined(MBEDTLS_CONFIG_FILE)
kadonotakashi 0:8fdf9a60065b 24 #include "mbedtls/config.h"
kadonotakashi 0:8fdf9a60065b 25 #else
kadonotakashi 0:8fdf9a60065b 26 #include MBEDTLS_CONFIG_FILE
kadonotakashi 0:8fdf9a60065b 27 #endif
kadonotakashi 0:8fdf9a60065b 28
kadonotakashi 0:8fdf9a60065b 29 #if defined(MBEDTLS_RSA_C)
kadonotakashi 0:8fdf9a60065b 30
kadonotakashi 0:8fdf9a60065b 31 #include "mbedtls/rsa.h"
kadonotakashi 0:8fdf9a60065b 32 #include "mbedtls/bignum.h"
kadonotakashi 0:8fdf9a60065b 33 #include "mbedtls/rsa_internal.h"
kadonotakashi 0:8fdf9a60065b 34
kadonotakashi 0:8fdf9a60065b 35 /*
kadonotakashi 0:8fdf9a60065b 36 * Compute RSA prime factors from public and private exponents
kadonotakashi 0:8fdf9a60065b 37 *
kadonotakashi 0:8fdf9a60065b 38 * Summary of algorithm:
kadonotakashi 0:8fdf9a60065b 39 * Setting F := lcm(P-1,Q-1), the idea is as follows:
kadonotakashi 0:8fdf9a60065b 40 *
kadonotakashi 0:8fdf9a60065b 41 * (a) For any 1 <= X < N with gcd(X,N)=1, we have X^F = 1 modulo N, so X^(F/2)
kadonotakashi 0:8fdf9a60065b 42 * is a square root of 1 in Z/NZ. Since Z/NZ ~= Z/PZ x Z/QZ by CRT and the
kadonotakashi 0:8fdf9a60065b 43 * square roots of 1 in Z/PZ and Z/QZ are +1 and -1, this leaves the four
kadonotakashi 0:8fdf9a60065b 44 * possibilities X^(F/2) = (+-1, +-1). If it happens that X^(F/2) = (-1,+1)
kadonotakashi 0:8fdf9a60065b 45 * or (+1,-1), then gcd(X^(F/2) + 1, N) will be equal to one of the prime
kadonotakashi 0:8fdf9a60065b 46 * factors of N.
kadonotakashi 0:8fdf9a60065b 47 *
kadonotakashi 0:8fdf9a60065b 48 * (b) If we don't know F/2 but (F/2) * K for some odd (!) K, then the same
kadonotakashi 0:8fdf9a60065b 49 * construction still applies since (-)^K is the identity on the set of
kadonotakashi 0:8fdf9a60065b 50 * roots of 1 in Z/NZ.
kadonotakashi 0:8fdf9a60065b 51 *
kadonotakashi 0:8fdf9a60065b 52 * The public and private key primitives (-)^E and (-)^D are mutually inverse
kadonotakashi 0:8fdf9a60065b 53 * bijections on Z/NZ if and only if (-)^(DE) is the identity on Z/NZ, i.e.
kadonotakashi 0:8fdf9a60065b 54 * if and only if DE - 1 is a multiple of F, say DE - 1 = F * L.
kadonotakashi 0:8fdf9a60065b 55 * Splitting L = 2^t * K with K odd, we have
kadonotakashi 0:8fdf9a60065b 56 *
kadonotakashi 0:8fdf9a60065b 57 * DE - 1 = FL = (F/2) * (2^(t+1)) * K,
kadonotakashi 0:8fdf9a60065b 58 *
kadonotakashi 0:8fdf9a60065b 59 * so (F / 2) * K is among the numbers
kadonotakashi 0:8fdf9a60065b 60 *
kadonotakashi 0:8fdf9a60065b 61 * (DE - 1) >> 1, (DE - 1) >> 2, ..., (DE - 1) >> ord
kadonotakashi 0:8fdf9a60065b 62 *
kadonotakashi 0:8fdf9a60065b 63 * where ord is the order of 2 in (DE - 1).
kadonotakashi 0:8fdf9a60065b 64 * We can therefore iterate through these numbers apply the construction
kadonotakashi 0:8fdf9a60065b 65 * of (a) and (b) above to attempt to factor N.
kadonotakashi 0:8fdf9a60065b 66 *
kadonotakashi 0:8fdf9a60065b 67 */
kadonotakashi 0:8fdf9a60065b 68 int mbedtls_rsa_deduce_primes( mbedtls_mpi const *N,
kadonotakashi 0:8fdf9a60065b 69 mbedtls_mpi const *E, mbedtls_mpi const *D,
kadonotakashi 0:8fdf9a60065b 70 mbedtls_mpi *P, mbedtls_mpi *Q )
kadonotakashi 0:8fdf9a60065b 71 {
kadonotakashi 0:8fdf9a60065b 72 int ret = 0;
kadonotakashi 0:8fdf9a60065b 73
kadonotakashi 0:8fdf9a60065b 74 uint16_t attempt; /* Number of current attempt */
kadonotakashi 0:8fdf9a60065b 75 uint16_t iter; /* Number of squares computed in the current attempt */
kadonotakashi 0:8fdf9a60065b 76
kadonotakashi 0:8fdf9a60065b 77 uint16_t order; /* Order of 2 in DE - 1 */
kadonotakashi 0:8fdf9a60065b 78
kadonotakashi 0:8fdf9a60065b 79 mbedtls_mpi T; /* Holds largest odd divisor of DE - 1 */
kadonotakashi 0:8fdf9a60065b 80 mbedtls_mpi K; /* Temporary holding the current candidate */
kadonotakashi 0:8fdf9a60065b 81
kadonotakashi 0:8fdf9a60065b 82 const unsigned char primes[] = { 2,
kadonotakashi 0:8fdf9a60065b 83 3, 5, 7, 11, 13, 17, 19, 23,
kadonotakashi 0:8fdf9a60065b 84 29, 31, 37, 41, 43, 47, 53, 59,
kadonotakashi 0:8fdf9a60065b 85 61, 67, 71, 73, 79, 83, 89, 97,
kadonotakashi 0:8fdf9a60065b 86 101, 103, 107, 109, 113, 127, 131, 137,
kadonotakashi 0:8fdf9a60065b 87 139, 149, 151, 157, 163, 167, 173, 179,
kadonotakashi 0:8fdf9a60065b 88 181, 191, 193, 197, 199, 211, 223, 227,
kadonotakashi 0:8fdf9a60065b 89 229, 233, 239, 241, 251
kadonotakashi 0:8fdf9a60065b 90 };
kadonotakashi 0:8fdf9a60065b 91
kadonotakashi 0:8fdf9a60065b 92 const size_t num_primes = sizeof( primes ) / sizeof( *primes );
kadonotakashi 0:8fdf9a60065b 93
kadonotakashi 0:8fdf9a60065b 94 if( P == NULL || Q == NULL || P->p != NULL || Q->p != NULL )
kadonotakashi 0:8fdf9a60065b 95 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
kadonotakashi 0:8fdf9a60065b 96
kadonotakashi 0:8fdf9a60065b 97 if( mbedtls_mpi_cmp_int( N, 0 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 98 mbedtls_mpi_cmp_int( D, 1 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 99 mbedtls_mpi_cmp_mpi( D, N ) >= 0 ||
kadonotakashi 0:8fdf9a60065b 100 mbedtls_mpi_cmp_int( E, 1 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 101 mbedtls_mpi_cmp_mpi( E, N ) >= 0 )
kadonotakashi 0:8fdf9a60065b 102 {
kadonotakashi 0:8fdf9a60065b 103 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
kadonotakashi 0:8fdf9a60065b 104 }
kadonotakashi 0:8fdf9a60065b 105
kadonotakashi 0:8fdf9a60065b 106 /*
kadonotakashi 0:8fdf9a60065b 107 * Initializations and temporary changes
kadonotakashi 0:8fdf9a60065b 108 */
kadonotakashi 0:8fdf9a60065b 109
kadonotakashi 0:8fdf9a60065b 110 mbedtls_mpi_init( &K );
kadonotakashi 0:8fdf9a60065b 111 mbedtls_mpi_init( &T );
kadonotakashi 0:8fdf9a60065b 112
kadonotakashi 0:8fdf9a60065b 113 /* T := DE - 1 */
kadonotakashi 0:8fdf9a60065b 114 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, D, E ) );
kadonotakashi 0:8fdf9a60065b 115 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &T, &T, 1 ) );
kadonotakashi 0:8fdf9a60065b 116
kadonotakashi 0:8fdf9a60065b 117 if( ( order = (uint16_t) mbedtls_mpi_lsb( &T ) ) == 0 )
kadonotakashi 0:8fdf9a60065b 118 {
kadonotakashi 0:8fdf9a60065b 119 ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
kadonotakashi 0:8fdf9a60065b 120 goto cleanup;
kadonotakashi 0:8fdf9a60065b 121 }
kadonotakashi 0:8fdf9a60065b 122
kadonotakashi 0:8fdf9a60065b 123 /* After this operation, T holds the largest odd divisor of DE - 1. */
kadonotakashi 0:8fdf9a60065b 124 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &T, order ) );
kadonotakashi 0:8fdf9a60065b 125
kadonotakashi 0:8fdf9a60065b 126 /*
kadonotakashi 0:8fdf9a60065b 127 * Actual work
kadonotakashi 0:8fdf9a60065b 128 */
kadonotakashi 0:8fdf9a60065b 129
kadonotakashi 0:8fdf9a60065b 130 /* Skip trying 2 if N == 1 mod 8 */
kadonotakashi 0:8fdf9a60065b 131 attempt = 0;
kadonotakashi 0:8fdf9a60065b 132 if( N->p[0] % 8 == 1 )
kadonotakashi 0:8fdf9a60065b 133 attempt = 1;
kadonotakashi 0:8fdf9a60065b 134
kadonotakashi 0:8fdf9a60065b 135 for( ; attempt < num_primes; ++attempt )
kadonotakashi 0:8fdf9a60065b 136 {
kadonotakashi 0:8fdf9a60065b 137 mbedtls_mpi_lset( &K, primes[attempt] );
kadonotakashi 0:8fdf9a60065b 138
kadonotakashi 0:8fdf9a60065b 139 /* Check if gcd(K,N) = 1 */
kadonotakashi 0:8fdf9a60065b 140 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( P, &K, N ) );
kadonotakashi 0:8fdf9a60065b 141 if( mbedtls_mpi_cmp_int( P, 1 ) != 0 )
kadonotakashi 0:8fdf9a60065b 142 continue;
kadonotakashi 0:8fdf9a60065b 143
kadonotakashi 0:8fdf9a60065b 144 /* Go through K^T + 1, K^(2T) + 1, K^(4T) + 1, ...
kadonotakashi 0:8fdf9a60065b 145 * and check whether they have nontrivial GCD with N. */
kadonotakashi 0:8fdf9a60065b 146 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &K, &K, &T, N,
kadonotakashi 0:8fdf9a60065b 147 Q /* temporarily use Q for storing Montgomery
kadonotakashi 0:8fdf9a60065b 148 * multiplication helper values */ ) );
kadonotakashi 0:8fdf9a60065b 149
kadonotakashi 0:8fdf9a60065b 150 for( iter = 1; iter <= order; ++iter )
kadonotakashi 0:8fdf9a60065b 151 {
kadonotakashi 0:8fdf9a60065b 152 /* If we reach 1 prematurely, there's no point
kadonotakashi 0:8fdf9a60065b 153 * in continuing to square K */
kadonotakashi 0:8fdf9a60065b 154 if( mbedtls_mpi_cmp_int( &K, 1 ) == 0 )
kadonotakashi 0:8fdf9a60065b 155 break;
kadonotakashi 0:8fdf9a60065b 156
kadonotakashi 0:8fdf9a60065b 157 MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &K, &K, 1 ) );
kadonotakashi 0:8fdf9a60065b 158 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( P, &K, N ) );
kadonotakashi 0:8fdf9a60065b 159
kadonotakashi 0:8fdf9a60065b 160 if( mbedtls_mpi_cmp_int( P, 1 ) == 1 &&
kadonotakashi 0:8fdf9a60065b 161 mbedtls_mpi_cmp_mpi( P, N ) == -1 )
kadonotakashi 0:8fdf9a60065b 162 {
kadonotakashi 0:8fdf9a60065b 163 /*
kadonotakashi 0:8fdf9a60065b 164 * Have found a nontrivial divisor P of N.
kadonotakashi 0:8fdf9a60065b 165 * Set Q := N / P.
kadonotakashi 0:8fdf9a60065b 166 */
kadonotakashi 0:8fdf9a60065b 167
kadonotakashi 0:8fdf9a60065b 168 MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( Q, NULL, N, P ) );
kadonotakashi 0:8fdf9a60065b 169 goto cleanup;
kadonotakashi 0:8fdf9a60065b 170 }
kadonotakashi 0:8fdf9a60065b 171
kadonotakashi 0:8fdf9a60065b 172 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
kadonotakashi 0:8fdf9a60065b 173 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, &K, &K ) );
kadonotakashi 0:8fdf9a60065b 174 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, N ) );
kadonotakashi 0:8fdf9a60065b 175 }
kadonotakashi 0:8fdf9a60065b 176
kadonotakashi 0:8fdf9a60065b 177 /*
kadonotakashi 0:8fdf9a60065b 178 * If we get here, then either we prematurely aborted the loop because
kadonotakashi 0:8fdf9a60065b 179 * we reached 1, or K holds primes[attempt]^(DE - 1) mod N, which must
kadonotakashi 0:8fdf9a60065b 180 * be 1 if D,E,N were consistent.
kadonotakashi 0:8fdf9a60065b 181 * Check if that's the case and abort if not, to avoid very long,
kadonotakashi 0:8fdf9a60065b 182 * yet eventually failing, computations if N,D,E were not sane.
kadonotakashi 0:8fdf9a60065b 183 */
kadonotakashi 0:8fdf9a60065b 184 if( mbedtls_mpi_cmp_int( &K, 1 ) != 0 )
kadonotakashi 0:8fdf9a60065b 185 {
kadonotakashi 0:8fdf9a60065b 186 break;
kadonotakashi 0:8fdf9a60065b 187 }
kadonotakashi 0:8fdf9a60065b 188 }
kadonotakashi 0:8fdf9a60065b 189
kadonotakashi 0:8fdf9a60065b 190 ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
kadonotakashi 0:8fdf9a60065b 191
kadonotakashi 0:8fdf9a60065b 192 cleanup:
kadonotakashi 0:8fdf9a60065b 193
kadonotakashi 0:8fdf9a60065b 194 mbedtls_mpi_free( &K );
kadonotakashi 0:8fdf9a60065b 195 mbedtls_mpi_free( &T );
kadonotakashi 0:8fdf9a60065b 196 return( ret );
kadonotakashi 0:8fdf9a60065b 197 }
kadonotakashi 0:8fdf9a60065b 198
kadonotakashi 0:8fdf9a60065b 199 /*
kadonotakashi 0:8fdf9a60065b 200 * Given P, Q and the public exponent E, deduce D.
kadonotakashi 0:8fdf9a60065b 201 * This is essentially a modular inversion.
kadonotakashi 0:8fdf9a60065b 202 */
kadonotakashi 0:8fdf9a60065b 203 int mbedtls_rsa_deduce_private_exponent( mbedtls_mpi const *P,
kadonotakashi 0:8fdf9a60065b 204 mbedtls_mpi const *Q,
kadonotakashi 0:8fdf9a60065b 205 mbedtls_mpi const *E,
kadonotakashi 0:8fdf9a60065b 206 mbedtls_mpi *D )
kadonotakashi 0:8fdf9a60065b 207 {
kadonotakashi 0:8fdf9a60065b 208 int ret = 0;
kadonotakashi 0:8fdf9a60065b 209 mbedtls_mpi K, L;
kadonotakashi 0:8fdf9a60065b 210
kadonotakashi 0:8fdf9a60065b 211 if( D == NULL || mbedtls_mpi_cmp_int( D, 0 ) != 0 )
kadonotakashi 0:8fdf9a60065b 212 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
kadonotakashi 0:8fdf9a60065b 213
kadonotakashi 0:8fdf9a60065b 214 if( mbedtls_mpi_cmp_int( P, 1 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 215 mbedtls_mpi_cmp_int( Q, 1 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 216 mbedtls_mpi_cmp_int( E, 0 ) == 0 )
kadonotakashi 0:8fdf9a60065b 217 {
kadonotakashi 0:8fdf9a60065b 218 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
kadonotakashi 0:8fdf9a60065b 219 }
kadonotakashi 0:8fdf9a60065b 220
kadonotakashi 0:8fdf9a60065b 221 mbedtls_mpi_init( &K );
kadonotakashi 0:8fdf9a60065b 222 mbedtls_mpi_init( &L );
kadonotakashi 0:8fdf9a60065b 223
kadonotakashi 0:8fdf9a60065b 224 /* Temporarily put K := P-1 and L := Q-1 */
kadonotakashi 0:8fdf9a60065b 225 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
kadonotakashi 0:8fdf9a60065b 226 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, Q, 1 ) );
kadonotakashi 0:8fdf9a60065b 227
kadonotakashi 0:8fdf9a60065b 228 /* Temporarily put D := gcd(P-1, Q-1) */
kadonotakashi 0:8fdf9a60065b 229 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( D, &K, &L ) );
kadonotakashi 0:8fdf9a60065b 230
kadonotakashi 0:8fdf9a60065b 231 /* K := LCM(P-1, Q-1) */
kadonotakashi 0:8fdf9a60065b 232 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, &K, &L ) );
kadonotakashi 0:8fdf9a60065b 233 MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &K, NULL, &K, D ) );
kadonotakashi 0:8fdf9a60065b 234
kadonotakashi 0:8fdf9a60065b 235 /* Compute modular inverse of E in LCM(P-1, Q-1) */
kadonotakashi 0:8fdf9a60065b 236 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( D, E, &K ) );
kadonotakashi 0:8fdf9a60065b 237
kadonotakashi 0:8fdf9a60065b 238 cleanup:
kadonotakashi 0:8fdf9a60065b 239
kadonotakashi 0:8fdf9a60065b 240 mbedtls_mpi_free( &K );
kadonotakashi 0:8fdf9a60065b 241 mbedtls_mpi_free( &L );
kadonotakashi 0:8fdf9a60065b 242
kadonotakashi 0:8fdf9a60065b 243 return( ret );
kadonotakashi 0:8fdf9a60065b 244 }
kadonotakashi 0:8fdf9a60065b 245
kadonotakashi 0:8fdf9a60065b 246 /*
kadonotakashi 0:8fdf9a60065b 247 * Check that RSA CRT parameters are in accordance with core parameters.
kadonotakashi 0:8fdf9a60065b 248 */
kadonotakashi 0:8fdf9a60065b 249 int mbedtls_rsa_validate_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
kadonotakashi 0:8fdf9a60065b 250 const mbedtls_mpi *D, const mbedtls_mpi *DP,
kadonotakashi 0:8fdf9a60065b 251 const mbedtls_mpi *DQ, const mbedtls_mpi *QP )
kadonotakashi 0:8fdf9a60065b 252 {
kadonotakashi 0:8fdf9a60065b 253 int ret = 0;
kadonotakashi 0:8fdf9a60065b 254
kadonotakashi 0:8fdf9a60065b 255 mbedtls_mpi K, L;
kadonotakashi 0:8fdf9a60065b 256 mbedtls_mpi_init( &K );
kadonotakashi 0:8fdf9a60065b 257 mbedtls_mpi_init( &L );
kadonotakashi 0:8fdf9a60065b 258
kadonotakashi 0:8fdf9a60065b 259 /* Check that DP - D == 0 mod P - 1 */
kadonotakashi 0:8fdf9a60065b 260 if( DP != NULL )
kadonotakashi 0:8fdf9a60065b 261 {
kadonotakashi 0:8fdf9a60065b 262 if( P == NULL )
kadonotakashi 0:8fdf9a60065b 263 {
kadonotakashi 0:8fdf9a60065b 264 ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
kadonotakashi 0:8fdf9a60065b 265 goto cleanup;
kadonotakashi 0:8fdf9a60065b 266 }
kadonotakashi 0:8fdf9a60065b 267
kadonotakashi 0:8fdf9a60065b 268 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
kadonotakashi 0:8fdf9a60065b 269 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &L, DP, D ) );
kadonotakashi 0:8fdf9a60065b 270 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &L, &L, &K ) );
kadonotakashi 0:8fdf9a60065b 271
kadonotakashi 0:8fdf9a60065b 272 if( mbedtls_mpi_cmp_int( &L, 0 ) != 0 )
kadonotakashi 0:8fdf9a60065b 273 {
kadonotakashi 0:8fdf9a60065b 274 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 275 goto cleanup;
kadonotakashi 0:8fdf9a60065b 276 }
kadonotakashi 0:8fdf9a60065b 277 }
kadonotakashi 0:8fdf9a60065b 278
kadonotakashi 0:8fdf9a60065b 279 /* Check that DQ - D == 0 mod Q - 1 */
kadonotakashi 0:8fdf9a60065b 280 if( DQ != NULL )
kadonotakashi 0:8fdf9a60065b 281 {
kadonotakashi 0:8fdf9a60065b 282 if( Q == NULL )
kadonotakashi 0:8fdf9a60065b 283 {
kadonotakashi 0:8fdf9a60065b 284 ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
kadonotakashi 0:8fdf9a60065b 285 goto cleanup;
kadonotakashi 0:8fdf9a60065b 286 }
kadonotakashi 0:8fdf9a60065b 287
kadonotakashi 0:8fdf9a60065b 288 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, Q, 1 ) );
kadonotakashi 0:8fdf9a60065b 289 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &L, DQ, D ) );
kadonotakashi 0:8fdf9a60065b 290 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &L, &L, &K ) );
kadonotakashi 0:8fdf9a60065b 291
kadonotakashi 0:8fdf9a60065b 292 if( mbedtls_mpi_cmp_int( &L, 0 ) != 0 )
kadonotakashi 0:8fdf9a60065b 293 {
kadonotakashi 0:8fdf9a60065b 294 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 295 goto cleanup;
kadonotakashi 0:8fdf9a60065b 296 }
kadonotakashi 0:8fdf9a60065b 297 }
kadonotakashi 0:8fdf9a60065b 298
kadonotakashi 0:8fdf9a60065b 299 /* Check that QP * Q - 1 == 0 mod P */
kadonotakashi 0:8fdf9a60065b 300 if( QP != NULL )
kadonotakashi 0:8fdf9a60065b 301 {
kadonotakashi 0:8fdf9a60065b 302 if( P == NULL || Q == NULL )
kadonotakashi 0:8fdf9a60065b 303 {
kadonotakashi 0:8fdf9a60065b 304 ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
kadonotakashi 0:8fdf9a60065b 305 goto cleanup;
kadonotakashi 0:8fdf9a60065b 306 }
kadonotakashi 0:8fdf9a60065b 307
kadonotakashi 0:8fdf9a60065b 308 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, QP, Q ) );
kadonotakashi 0:8fdf9a60065b 309 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
kadonotakashi 0:8fdf9a60065b 310 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, P ) );
kadonotakashi 0:8fdf9a60065b 311 if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
kadonotakashi 0:8fdf9a60065b 312 {
kadonotakashi 0:8fdf9a60065b 313 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 314 goto cleanup;
kadonotakashi 0:8fdf9a60065b 315 }
kadonotakashi 0:8fdf9a60065b 316 }
kadonotakashi 0:8fdf9a60065b 317
kadonotakashi 0:8fdf9a60065b 318 cleanup:
kadonotakashi 0:8fdf9a60065b 319
kadonotakashi 0:8fdf9a60065b 320 /* Wrap MPI error codes by RSA check failure error code */
kadonotakashi 0:8fdf9a60065b 321 if( ret != 0 &&
kadonotakashi 0:8fdf9a60065b 322 ret != MBEDTLS_ERR_RSA_KEY_CHECK_FAILED &&
kadonotakashi 0:8fdf9a60065b 323 ret != MBEDTLS_ERR_RSA_BAD_INPUT_DATA )
kadonotakashi 0:8fdf9a60065b 324 {
kadonotakashi 0:8fdf9a60065b 325 ret += MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 326 }
kadonotakashi 0:8fdf9a60065b 327
kadonotakashi 0:8fdf9a60065b 328 mbedtls_mpi_free( &K );
kadonotakashi 0:8fdf9a60065b 329 mbedtls_mpi_free( &L );
kadonotakashi 0:8fdf9a60065b 330
kadonotakashi 0:8fdf9a60065b 331 return( ret );
kadonotakashi 0:8fdf9a60065b 332 }
kadonotakashi 0:8fdf9a60065b 333
kadonotakashi 0:8fdf9a60065b 334 /*
kadonotakashi 0:8fdf9a60065b 335 * Check that core RSA parameters are sane.
kadonotakashi 0:8fdf9a60065b 336 */
kadonotakashi 0:8fdf9a60065b 337 int mbedtls_rsa_validate_params( const mbedtls_mpi *N, const mbedtls_mpi *P,
kadonotakashi 0:8fdf9a60065b 338 const mbedtls_mpi *Q, const mbedtls_mpi *D,
kadonotakashi 0:8fdf9a60065b 339 const mbedtls_mpi *E,
kadonotakashi 0:8fdf9a60065b 340 int (*f_rng)(void *, unsigned char *, size_t),
kadonotakashi 0:8fdf9a60065b 341 void *p_rng )
kadonotakashi 0:8fdf9a60065b 342 {
kadonotakashi 0:8fdf9a60065b 343 int ret = 0;
kadonotakashi 0:8fdf9a60065b 344 mbedtls_mpi K, L;
kadonotakashi 0:8fdf9a60065b 345
kadonotakashi 0:8fdf9a60065b 346 mbedtls_mpi_init( &K );
kadonotakashi 0:8fdf9a60065b 347 mbedtls_mpi_init( &L );
kadonotakashi 0:8fdf9a60065b 348
kadonotakashi 0:8fdf9a60065b 349 /*
kadonotakashi 0:8fdf9a60065b 350 * Step 1: If PRNG provided, check that P and Q are prime
kadonotakashi 0:8fdf9a60065b 351 */
kadonotakashi 0:8fdf9a60065b 352
kadonotakashi 0:8fdf9a60065b 353 #if defined(MBEDTLS_GENPRIME)
kadonotakashi 0:8fdf9a60065b 354 if( f_rng != NULL && P != NULL &&
kadonotakashi 0:8fdf9a60065b 355 ( ret = mbedtls_mpi_is_prime( P, f_rng, p_rng ) ) != 0 )
kadonotakashi 0:8fdf9a60065b 356 {
kadonotakashi 0:8fdf9a60065b 357 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 358 goto cleanup;
kadonotakashi 0:8fdf9a60065b 359 }
kadonotakashi 0:8fdf9a60065b 360
kadonotakashi 0:8fdf9a60065b 361 if( f_rng != NULL && Q != NULL &&
kadonotakashi 0:8fdf9a60065b 362 ( ret = mbedtls_mpi_is_prime( Q, f_rng, p_rng ) ) != 0 )
kadonotakashi 0:8fdf9a60065b 363 {
kadonotakashi 0:8fdf9a60065b 364 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 365 goto cleanup;
kadonotakashi 0:8fdf9a60065b 366 }
kadonotakashi 0:8fdf9a60065b 367 #else
kadonotakashi 0:8fdf9a60065b 368 ((void) f_rng);
kadonotakashi 0:8fdf9a60065b 369 ((void) p_rng);
kadonotakashi 0:8fdf9a60065b 370 #endif /* MBEDTLS_GENPRIME */
kadonotakashi 0:8fdf9a60065b 371
kadonotakashi 0:8fdf9a60065b 372 /*
kadonotakashi 0:8fdf9a60065b 373 * Step 2: Check that 1 < N = P * Q
kadonotakashi 0:8fdf9a60065b 374 */
kadonotakashi 0:8fdf9a60065b 375
kadonotakashi 0:8fdf9a60065b 376 if( P != NULL && Q != NULL && N != NULL )
kadonotakashi 0:8fdf9a60065b 377 {
kadonotakashi 0:8fdf9a60065b 378 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, P, Q ) );
kadonotakashi 0:8fdf9a60065b 379 if( mbedtls_mpi_cmp_int( N, 1 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 380 mbedtls_mpi_cmp_mpi( &K, N ) != 0 )
kadonotakashi 0:8fdf9a60065b 381 {
kadonotakashi 0:8fdf9a60065b 382 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 383 goto cleanup;
kadonotakashi 0:8fdf9a60065b 384 }
kadonotakashi 0:8fdf9a60065b 385 }
kadonotakashi 0:8fdf9a60065b 386
kadonotakashi 0:8fdf9a60065b 387 /*
kadonotakashi 0:8fdf9a60065b 388 * Step 3: Check and 1 < D, E < N if present.
kadonotakashi 0:8fdf9a60065b 389 */
kadonotakashi 0:8fdf9a60065b 390
kadonotakashi 0:8fdf9a60065b 391 if( N != NULL && D != NULL && E != NULL )
kadonotakashi 0:8fdf9a60065b 392 {
kadonotakashi 0:8fdf9a60065b 393 if ( mbedtls_mpi_cmp_int( D, 1 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 394 mbedtls_mpi_cmp_int( E, 1 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 395 mbedtls_mpi_cmp_mpi( D, N ) >= 0 ||
kadonotakashi 0:8fdf9a60065b 396 mbedtls_mpi_cmp_mpi( E, N ) >= 0 )
kadonotakashi 0:8fdf9a60065b 397 {
kadonotakashi 0:8fdf9a60065b 398 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 399 goto cleanup;
kadonotakashi 0:8fdf9a60065b 400 }
kadonotakashi 0:8fdf9a60065b 401 }
kadonotakashi 0:8fdf9a60065b 402
kadonotakashi 0:8fdf9a60065b 403 /*
kadonotakashi 0:8fdf9a60065b 404 * Step 4: Check that D, E are inverse modulo P-1 and Q-1
kadonotakashi 0:8fdf9a60065b 405 */
kadonotakashi 0:8fdf9a60065b 406
kadonotakashi 0:8fdf9a60065b 407 if( P != NULL && Q != NULL && D != NULL && E != NULL )
kadonotakashi 0:8fdf9a60065b 408 {
kadonotakashi 0:8fdf9a60065b 409 if( mbedtls_mpi_cmp_int( P, 1 ) <= 0 ||
kadonotakashi 0:8fdf9a60065b 410 mbedtls_mpi_cmp_int( Q, 1 ) <= 0 )
kadonotakashi 0:8fdf9a60065b 411 {
kadonotakashi 0:8fdf9a60065b 412 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 413 goto cleanup;
kadonotakashi 0:8fdf9a60065b 414 }
kadonotakashi 0:8fdf9a60065b 415
kadonotakashi 0:8fdf9a60065b 416 /* Compute DE-1 mod P-1 */
kadonotakashi 0:8fdf9a60065b 417 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, D, E ) );
kadonotakashi 0:8fdf9a60065b 418 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
kadonotakashi 0:8fdf9a60065b 419 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, P, 1 ) );
kadonotakashi 0:8fdf9a60065b 420 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, &L ) );
kadonotakashi 0:8fdf9a60065b 421 if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
kadonotakashi 0:8fdf9a60065b 422 {
kadonotakashi 0:8fdf9a60065b 423 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 424 goto cleanup;
kadonotakashi 0:8fdf9a60065b 425 }
kadonotakashi 0:8fdf9a60065b 426
kadonotakashi 0:8fdf9a60065b 427 /* Compute DE-1 mod Q-1 */
kadonotakashi 0:8fdf9a60065b 428 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, D, E ) );
kadonotakashi 0:8fdf9a60065b 429 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
kadonotakashi 0:8fdf9a60065b 430 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, Q, 1 ) );
kadonotakashi 0:8fdf9a60065b 431 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, &L ) );
kadonotakashi 0:8fdf9a60065b 432 if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
kadonotakashi 0:8fdf9a60065b 433 {
kadonotakashi 0:8fdf9a60065b 434 ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 435 goto cleanup;
kadonotakashi 0:8fdf9a60065b 436 }
kadonotakashi 0:8fdf9a60065b 437 }
kadonotakashi 0:8fdf9a60065b 438
kadonotakashi 0:8fdf9a60065b 439 cleanup:
kadonotakashi 0:8fdf9a60065b 440
kadonotakashi 0:8fdf9a60065b 441 mbedtls_mpi_free( &K );
kadonotakashi 0:8fdf9a60065b 442 mbedtls_mpi_free( &L );
kadonotakashi 0:8fdf9a60065b 443
kadonotakashi 0:8fdf9a60065b 444 /* Wrap MPI error codes by RSA check failure error code */
kadonotakashi 0:8fdf9a60065b 445 if( ret != 0 && ret != MBEDTLS_ERR_RSA_KEY_CHECK_FAILED )
kadonotakashi 0:8fdf9a60065b 446 {
kadonotakashi 0:8fdf9a60065b 447 ret += MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
kadonotakashi 0:8fdf9a60065b 448 }
kadonotakashi 0:8fdf9a60065b 449
kadonotakashi 0:8fdf9a60065b 450 return( ret );
kadonotakashi 0:8fdf9a60065b 451 }
kadonotakashi 0:8fdf9a60065b 452
kadonotakashi 0:8fdf9a60065b 453 int mbedtls_rsa_deduce_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
kadonotakashi 0:8fdf9a60065b 454 const mbedtls_mpi *D, mbedtls_mpi *DP,
kadonotakashi 0:8fdf9a60065b 455 mbedtls_mpi *DQ, mbedtls_mpi *QP )
kadonotakashi 0:8fdf9a60065b 456 {
kadonotakashi 0:8fdf9a60065b 457 int ret = 0;
kadonotakashi 0:8fdf9a60065b 458 mbedtls_mpi K;
kadonotakashi 0:8fdf9a60065b 459 mbedtls_mpi_init( &K );
kadonotakashi 0:8fdf9a60065b 460
kadonotakashi 0:8fdf9a60065b 461 /* DP = D mod P-1 */
kadonotakashi 0:8fdf9a60065b 462 if( DP != NULL )
kadonotakashi 0:8fdf9a60065b 463 {
kadonotakashi 0:8fdf9a60065b 464 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
kadonotakashi 0:8fdf9a60065b 465 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( DP, D, &K ) );
kadonotakashi 0:8fdf9a60065b 466 }
kadonotakashi 0:8fdf9a60065b 467
kadonotakashi 0:8fdf9a60065b 468 /* DQ = D mod Q-1 */
kadonotakashi 0:8fdf9a60065b 469 if( DQ != NULL )
kadonotakashi 0:8fdf9a60065b 470 {
kadonotakashi 0:8fdf9a60065b 471 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, Q, 1 ) );
kadonotakashi 0:8fdf9a60065b 472 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( DQ, D, &K ) );
kadonotakashi 0:8fdf9a60065b 473 }
kadonotakashi 0:8fdf9a60065b 474
kadonotakashi 0:8fdf9a60065b 475 /* QP = Q^{-1} mod P */
kadonotakashi 0:8fdf9a60065b 476 if( QP != NULL )
kadonotakashi 0:8fdf9a60065b 477 {
kadonotakashi 0:8fdf9a60065b 478 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( QP, Q, P ) );
kadonotakashi 0:8fdf9a60065b 479 }
kadonotakashi 0:8fdf9a60065b 480
kadonotakashi 0:8fdf9a60065b 481 cleanup:
kadonotakashi 0:8fdf9a60065b 482 mbedtls_mpi_free( &K );
kadonotakashi 0:8fdf9a60065b 483
kadonotakashi 0:8fdf9a60065b 484 return( ret );
kadonotakashi 0:8fdf9a60065b 485 }
kadonotakashi 0:8fdf9a60065b 486
kadonotakashi 0:8fdf9a60065b 487 #endif /* MBEDTLS_RSA_C */