Rahul Dahiya / Mbed OS STM32F7 Ethernet

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mbed-os/features/mbedtls/src/bignum.c@0:fb8047b156bb, 2020-01-15 (annotated)

Committer:
rahul_dahiya
Date:
Wed Jan 15 15:57:15 2020 +0530
Revision:
0:fb8047b156bb
STM32F7 LWIP

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rahul_dahiya 0:fb8047b156bb 1 /*
rahul_dahiya 0:fb8047b156bb 2 * Multi-precision integer library
rahul_dahiya 0:fb8047b156bb 3 *
rahul_dahiya 0:fb8047b156bb 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
rahul_dahiya 0:fb8047b156bb 5 * SPDX-License-Identifier: Apache-2.0
rahul_dahiya 0:fb8047b156bb 6 *
rahul_dahiya 0:fb8047b156bb 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
rahul_dahiya 0:fb8047b156bb 8 * not use this file except in compliance with the License.
rahul_dahiya 0:fb8047b156bb 9 * You may obtain a copy of the License at
rahul_dahiya 0:fb8047b156bb 10 *
rahul_dahiya 0:fb8047b156bb 11 * http://www.apache.org/licenses/LICENSE-2.0
rahul_dahiya 0:fb8047b156bb 12 *
rahul_dahiya 0:fb8047b156bb 13 * Unless required by applicable law or agreed to in writing, software
rahul_dahiya 0:fb8047b156bb 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
rahul_dahiya 0:fb8047b156bb 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
rahul_dahiya 0:fb8047b156bb 16 * See the License for the specific language governing permissions and
rahul_dahiya 0:fb8047b156bb 17 * limitations under the License.
rahul_dahiya 0:fb8047b156bb 18 *
rahul_dahiya 0:fb8047b156bb 19 * This file is part of mbed TLS (https://tls.mbed.org)
rahul_dahiya 0:fb8047b156bb 20 */
rahul_dahiya 0:fb8047b156bb 21
rahul_dahiya 0:fb8047b156bb 22 /*
rahul_dahiya 0:fb8047b156bb 23 * The following sources were referenced in the design of this Multi-precision
rahul_dahiya 0:fb8047b156bb 24 * Integer library:
rahul_dahiya 0:fb8047b156bb 25 *
rahul_dahiya 0:fb8047b156bb 26 * [1] Handbook of Applied Cryptography - 1997
rahul_dahiya 0:fb8047b156bb 27 * Menezes, van Oorschot and Vanstone
rahul_dahiya 0:fb8047b156bb 28 *
rahul_dahiya 0:fb8047b156bb 29 * [2] Multi-Precision Math
rahul_dahiya 0:fb8047b156bb 30 * Tom St Denis
rahul_dahiya 0:fb8047b156bb 31 * https://github.com/libtom/libtommath/blob/develop/tommath.pdf
rahul_dahiya 0:fb8047b156bb 32 *
rahul_dahiya 0:fb8047b156bb 33 * [3] GNU Multi-Precision Arithmetic Library
rahul_dahiya 0:fb8047b156bb 34 * https://gmplib.org/manual/index.html
rahul_dahiya 0:fb8047b156bb 35 *
rahul_dahiya 0:fb8047b156bb 36 */
rahul_dahiya 0:fb8047b156bb 37
rahul_dahiya 0:fb8047b156bb 38 #if !defined(MBEDTLS_CONFIG_FILE)
rahul_dahiya 0:fb8047b156bb 39 #include "mbedtls/config.h"
rahul_dahiya 0:fb8047b156bb 40 #else
rahul_dahiya 0:fb8047b156bb 41 #include MBEDTLS_CONFIG_FILE
rahul_dahiya 0:fb8047b156bb 42 #endif
rahul_dahiya 0:fb8047b156bb 43
rahul_dahiya 0:fb8047b156bb 44 #if defined(MBEDTLS_BIGNUM_C)
rahul_dahiya 0:fb8047b156bb 45
rahul_dahiya 0:fb8047b156bb 46 #include "mbedtls/bignum.h"
rahul_dahiya 0:fb8047b156bb 47 #include "mbedtls/bn_mul.h"
rahul_dahiya 0:fb8047b156bb 48
rahul_dahiya 0:fb8047b156bb 49 #include <string.h>
rahul_dahiya 0:fb8047b156bb 50
rahul_dahiya 0:fb8047b156bb 51 #if defined(MBEDTLS_PLATFORM_C)
rahul_dahiya 0:fb8047b156bb 52 #include "mbedtls/platform.h"
rahul_dahiya 0:fb8047b156bb 53 #else
rahul_dahiya 0:fb8047b156bb 54 #include <stdio.h>
rahul_dahiya 0:fb8047b156bb 55 #include <stdlib.h>
rahul_dahiya 0:fb8047b156bb 56 #define mbedtls_printf printf
rahul_dahiya 0:fb8047b156bb 57 #define mbedtls_calloc calloc
rahul_dahiya 0:fb8047b156bb 58 #define mbedtls_free free
rahul_dahiya 0:fb8047b156bb 59 #endif
rahul_dahiya 0:fb8047b156bb 60
rahul_dahiya 0:fb8047b156bb 61 /* Implementation that should never be optimized out by the compiler */
rahul_dahiya 0:fb8047b156bb 62 static void mbedtls_mpi_zeroize( mbedtls_mpi_uint *v, size_t n ) {
rahul_dahiya 0:fb8047b156bb 63 volatile mbedtls_mpi_uint *p = v; while( n-- ) *p++ = 0;
rahul_dahiya 0:fb8047b156bb 64 }
rahul_dahiya 0:fb8047b156bb 65
rahul_dahiya 0:fb8047b156bb 66 #define ciL (sizeof(mbedtls_mpi_uint)) /* chars in limb */
rahul_dahiya 0:fb8047b156bb 67 #define biL (ciL << 3) /* bits in limb */
rahul_dahiya 0:fb8047b156bb 68 #define biH (ciL << 2) /* half limb size */
rahul_dahiya 0:fb8047b156bb 69
rahul_dahiya 0:fb8047b156bb 70 #define MPI_SIZE_T_MAX ( (size_t) -1 ) /* SIZE_T_MAX is not standard */
rahul_dahiya 0:fb8047b156bb 71
rahul_dahiya 0:fb8047b156bb 72 /*
rahul_dahiya 0:fb8047b156bb 73 * Convert between bits/chars and number of limbs
rahul_dahiya 0:fb8047b156bb 74 * Divide first in order to avoid potential overflows
rahul_dahiya 0:fb8047b156bb 75 */
rahul_dahiya 0:fb8047b156bb 76 #define BITS_TO_LIMBS(i) ( (i) / biL + ( (i) % biL != 0 ) )
rahul_dahiya 0:fb8047b156bb 77 #define CHARS_TO_LIMBS(i) ( (i) / ciL + ( (i) % ciL != 0 ) )
rahul_dahiya 0:fb8047b156bb 78
rahul_dahiya 0:fb8047b156bb 79 /*
rahul_dahiya 0:fb8047b156bb 80 * Initialize one MPI
rahul_dahiya 0:fb8047b156bb 81 */
rahul_dahiya 0:fb8047b156bb 82 void mbedtls_mpi_init( mbedtls_mpi *X )
rahul_dahiya 0:fb8047b156bb 83 {
rahul_dahiya 0:fb8047b156bb 84 if( X == NULL )
rahul_dahiya 0:fb8047b156bb 85 return;
rahul_dahiya 0:fb8047b156bb 86
rahul_dahiya 0:fb8047b156bb 87 X->s = 1;
rahul_dahiya 0:fb8047b156bb 88 X->n = 0;
rahul_dahiya 0:fb8047b156bb 89 X->p = NULL;
rahul_dahiya 0:fb8047b156bb 90 }
rahul_dahiya 0:fb8047b156bb 91
rahul_dahiya 0:fb8047b156bb 92 /*
rahul_dahiya 0:fb8047b156bb 93 * Unallocate one MPI
rahul_dahiya 0:fb8047b156bb 94 */
rahul_dahiya 0:fb8047b156bb 95 void mbedtls_mpi_free( mbedtls_mpi *X )
rahul_dahiya 0:fb8047b156bb 96 {
rahul_dahiya 0:fb8047b156bb 97 if( X == NULL )
rahul_dahiya 0:fb8047b156bb 98 return;
rahul_dahiya 0:fb8047b156bb 99
rahul_dahiya 0:fb8047b156bb 100 if( X->p != NULL )
rahul_dahiya 0:fb8047b156bb 101 {
rahul_dahiya 0:fb8047b156bb 102 mbedtls_mpi_zeroize( X->p, X->n );
rahul_dahiya 0:fb8047b156bb 103 mbedtls_free( X->p );
rahul_dahiya 0:fb8047b156bb 104 }
rahul_dahiya 0:fb8047b156bb 105
rahul_dahiya 0:fb8047b156bb 106 X->s = 1;
rahul_dahiya 0:fb8047b156bb 107 X->n = 0;
rahul_dahiya 0:fb8047b156bb 108 X->p = NULL;
rahul_dahiya 0:fb8047b156bb 109 }
rahul_dahiya 0:fb8047b156bb 110
rahul_dahiya 0:fb8047b156bb 111 /*
rahul_dahiya 0:fb8047b156bb 112 * Enlarge to the specified number of limbs
rahul_dahiya 0:fb8047b156bb 113 */
rahul_dahiya 0:fb8047b156bb 114 int mbedtls_mpi_grow( mbedtls_mpi *X, size_t nblimbs )
rahul_dahiya 0:fb8047b156bb 115 {
rahul_dahiya 0:fb8047b156bb 116 mbedtls_mpi_uint *p;
rahul_dahiya 0:fb8047b156bb 117
rahul_dahiya 0:fb8047b156bb 118 if( nblimbs > MBEDTLS_MPI_MAX_LIMBS )
rahul_dahiya 0:fb8047b156bb 119 return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
rahul_dahiya 0:fb8047b156bb 120
rahul_dahiya 0:fb8047b156bb 121 if( X->n < nblimbs )
rahul_dahiya 0:fb8047b156bb 122 {
rahul_dahiya 0:fb8047b156bb 123 if( ( p = (mbedtls_mpi_uint*)mbedtls_calloc( nblimbs, ciL ) ) == NULL )
rahul_dahiya 0:fb8047b156bb 124 return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
rahul_dahiya 0:fb8047b156bb 125
rahul_dahiya 0:fb8047b156bb 126 if( X->p != NULL )
rahul_dahiya 0:fb8047b156bb 127 {
rahul_dahiya 0:fb8047b156bb 128 memcpy( p, X->p, X->n * ciL );
rahul_dahiya 0:fb8047b156bb 129 mbedtls_mpi_zeroize( X->p, X->n );
rahul_dahiya 0:fb8047b156bb 130 mbedtls_free( X->p );
rahul_dahiya 0:fb8047b156bb 131 }
rahul_dahiya 0:fb8047b156bb 132
rahul_dahiya 0:fb8047b156bb 133 X->n = nblimbs;
rahul_dahiya 0:fb8047b156bb 134 X->p = p;
rahul_dahiya 0:fb8047b156bb 135 }
rahul_dahiya 0:fb8047b156bb 136
rahul_dahiya 0:fb8047b156bb 137 return( 0 );
rahul_dahiya 0:fb8047b156bb 138 }
rahul_dahiya 0:fb8047b156bb 139
rahul_dahiya 0:fb8047b156bb 140 /*
rahul_dahiya 0:fb8047b156bb 141 * Resize down as much as possible,
rahul_dahiya 0:fb8047b156bb 142 * while keeping at least the specified number of limbs
rahul_dahiya 0:fb8047b156bb 143 */
rahul_dahiya 0:fb8047b156bb 144 int mbedtls_mpi_shrink( mbedtls_mpi *X, size_t nblimbs )
rahul_dahiya 0:fb8047b156bb 145 {
rahul_dahiya 0:fb8047b156bb 146 mbedtls_mpi_uint *p;
rahul_dahiya 0:fb8047b156bb 147 size_t i;
rahul_dahiya 0:fb8047b156bb 148
rahul_dahiya 0:fb8047b156bb 149 /* Actually resize up in this case */
rahul_dahiya 0:fb8047b156bb 150 if( X->n <= nblimbs )
rahul_dahiya 0:fb8047b156bb 151 return( mbedtls_mpi_grow( X, nblimbs ) );
rahul_dahiya 0:fb8047b156bb 152
rahul_dahiya 0:fb8047b156bb 153 for( i = X->n - 1; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 154 if( X->p[i] != 0 )
rahul_dahiya 0:fb8047b156bb 155 break;
rahul_dahiya 0:fb8047b156bb 156 i++;
rahul_dahiya 0:fb8047b156bb 157
rahul_dahiya 0:fb8047b156bb 158 if( i < nblimbs )
rahul_dahiya 0:fb8047b156bb 159 i = nblimbs;
rahul_dahiya 0:fb8047b156bb 160
rahul_dahiya 0:fb8047b156bb 161 if( ( p = (mbedtls_mpi_uint*)mbedtls_calloc( i, ciL ) ) == NULL )
rahul_dahiya 0:fb8047b156bb 162 return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
rahul_dahiya 0:fb8047b156bb 163
rahul_dahiya 0:fb8047b156bb 164 if( X->p != NULL )
rahul_dahiya 0:fb8047b156bb 165 {
rahul_dahiya 0:fb8047b156bb 166 memcpy( p, X->p, i * ciL );
rahul_dahiya 0:fb8047b156bb 167 mbedtls_mpi_zeroize( X->p, X->n );
rahul_dahiya 0:fb8047b156bb 168 mbedtls_free( X->p );
rahul_dahiya 0:fb8047b156bb 169 }
rahul_dahiya 0:fb8047b156bb 170
rahul_dahiya 0:fb8047b156bb 171 X->n = i;
rahul_dahiya 0:fb8047b156bb 172 X->p = p;
rahul_dahiya 0:fb8047b156bb 173
rahul_dahiya 0:fb8047b156bb 174 return( 0 );
rahul_dahiya 0:fb8047b156bb 175 }
rahul_dahiya 0:fb8047b156bb 176
rahul_dahiya 0:fb8047b156bb 177 /*
rahul_dahiya 0:fb8047b156bb 178 * Copy the contents of Y into X
rahul_dahiya 0:fb8047b156bb 179 */
rahul_dahiya 0:fb8047b156bb 180 int mbedtls_mpi_copy( mbedtls_mpi *X, const mbedtls_mpi *Y )
rahul_dahiya 0:fb8047b156bb 181 {
rahul_dahiya 0:fb8047b156bb 182 int ret;
rahul_dahiya 0:fb8047b156bb 183 size_t i;
rahul_dahiya 0:fb8047b156bb 184
rahul_dahiya 0:fb8047b156bb 185 if( X == Y )
rahul_dahiya 0:fb8047b156bb 186 return( 0 );
rahul_dahiya 0:fb8047b156bb 187
rahul_dahiya 0:fb8047b156bb 188 if( Y->p == NULL )
rahul_dahiya 0:fb8047b156bb 189 {
rahul_dahiya 0:fb8047b156bb 190 mbedtls_mpi_free( X );
rahul_dahiya 0:fb8047b156bb 191 return( 0 );
rahul_dahiya 0:fb8047b156bb 192 }
rahul_dahiya 0:fb8047b156bb 193
rahul_dahiya 0:fb8047b156bb 194 for( i = Y->n - 1; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 195 if( Y->p[i] != 0 )
rahul_dahiya 0:fb8047b156bb 196 break;
rahul_dahiya 0:fb8047b156bb 197 i++;
rahul_dahiya 0:fb8047b156bb 198
rahul_dahiya 0:fb8047b156bb 199 X->s = Y->s;
rahul_dahiya 0:fb8047b156bb 200
rahul_dahiya 0:fb8047b156bb 201 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, i ) );
rahul_dahiya 0:fb8047b156bb 202
rahul_dahiya 0:fb8047b156bb 203 memset( X->p, 0, X->n * ciL );
rahul_dahiya 0:fb8047b156bb 204 memcpy( X->p, Y->p, i * ciL );
rahul_dahiya 0:fb8047b156bb 205
rahul_dahiya 0:fb8047b156bb 206 cleanup:
rahul_dahiya 0:fb8047b156bb 207
rahul_dahiya 0:fb8047b156bb 208 return( ret );
rahul_dahiya 0:fb8047b156bb 209 }
rahul_dahiya 0:fb8047b156bb 210
rahul_dahiya 0:fb8047b156bb 211 /*
rahul_dahiya 0:fb8047b156bb 212 * Swap the contents of X and Y
rahul_dahiya 0:fb8047b156bb 213 */
rahul_dahiya 0:fb8047b156bb 214 void mbedtls_mpi_swap( mbedtls_mpi *X, mbedtls_mpi *Y )
rahul_dahiya 0:fb8047b156bb 215 {
rahul_dahiya 0:fb8047b156bb 216 mbedtls_mpi T;
rahul_dahiya 0:fb8047b156bb 217
rahul_dahiya 0:fb8047b156bb 218 memcpy( &T, X, sizeof( mbedtls_mpi ) );
rahul_dahiya 0:fb8047b156bb 219 memcpy( X, Y, sizeof( mbedtls_mpi ) );
rahul_dahiya 0:fb8047b156bb 220 memcpy( Y, &T, sizeof( mbedtls_mpi ) );
rahul_dahiya 0:fb8047b156bb 221 }
rahul_dahiya 0:fb8047b156bb 222
rahul_dahiya 0:fb8047b156bb 223 /*
rahul_dahiya 0:fb8047b156bb 224 * Conditionally assign X = Y, without leaking information
rahul_dahiya 0:fb8047b156bb 225 * about whether the assignment was made or not.
rahul_dahiya 0:fb8047b156bb 226 * (Leaking information about the respective sizes of X and Y is ok however.)
rahul_dahiya 0:fb8047b156bb 227 */
rahul_dahiya 0:fb8047b156bb 228 int mbedtls_mpi_safe_cond_assign( mbedtls_mpi *X, const mbedtls_mpi *Y, unsigned char assign )
rahul_dahiya 0:fb8047b156bb 229 {
rahul_dahiya 0:fb8047b156bb 230 int ret = 0;
rahul_dahiya 0:fb8047b156bb 231 size_t i;
rahul_dahiya 0:fb8047b156bb 232
rahul_dahiya 0:fb8047b156bb 233 /* make sure assign is 0 or 1 in a time-constant manner */
rahul_dahiya 0:fb8047b156bb 234 assign = (assign | (unsigned char)-assign) >> 7;
rahul_dahiya 0:fb8047b156bb 235
rahul_dahiya 0:fb8047b156bb 236 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, Y->n ) );
rahul_dahiya 0:fb8047b156bb 237
rahul_dahiya 0:fb8047b156bb 238 X->s = X->s * ( 1 - assign ) + Y->s * assign;
rahul_dahiya 0:fb8047b156bb 239
rahul_dahiya 0:fb8047b156bb 240 for( i = 0; i < Y->n; i++ )
rahul_dahiya 0:fb8047b156bb 241 X->p[i] = X->p[i] * ( 1 - assign ) + Y->p[i] * assign;
rahul_dahiya 0:fb8047b156bb 242
rahul_dahiya 0:fb8047b156bb 243 for( ; i < X->n; i++ )
rahul_dahiya 0:fb8047b156bb 244 X->p[i] *= ( 1 - assign );
rahul_dahiya 0:fb8047b156bb 245
rahul_dahiya 0:fb8047b156bb 246 cleanup:
rahul_dahiya 0:fb8047b156bb 247 return( ret );
rahul_dahiya 0:fb8047b156bb 248 }
rahul_dahiya 0:fb8047b156bb 249
rahul_dahiya 0:fb8047b156bb 250 /*
rahul_dahiya 0:fb8047b156bb 251 * Conditionally swap X and Y, without leaking information
rahul_dahiya 0:fb8047b156bb 252 * about whether the swap was made or not.
rahul_dahiya 0:fb8047b156bb 253 * Here it is not ok to simply swap the pointers, which whould lead to
rahul_dahiya 0:fb8047b156bb 254 * different memory access patterns when X and Y are used afterwards.
rahul_dahiya 0:fb8047b156bb 255 */
rahul_dahiya 0:fb8047b156bb 256 int mbedtls_mpi_safe_cond_swap( mbedtls_mpi *X, mbedtls_mpi *Y, unsigned char swap )
rahul_dahiya 0:fb8047b156bb 257 {
rahul_dahiya 0:fb8047b156bb 258 int ret, s;
rahul_dahiya 0:fb8047b156bb 259 size_t i;
rahul_dahiya 0:fb8047b156bb 260 mbedtls_mpi_uint tmp;
rahul_dahiya 0:fb8047b156bb 261
rahul_dahiya 0:fb8047b156bb 262 if( X == Y )
rahul_dahiya 0:fb8047b156bb 263 return( 0 );
rahul_dahiya 0:fb8047b156bb 264
rahul_dahiya 0:fb8047b156bb 265 /* make sure swap is 0 or 1 in a time-constant manner */
rahul_dahiya 0:fb8047b156bb 266 swap = (swap | (unsigned char)-swap) >> 7;
rahul_dahiya 0:fb8047b156bb 267
rahul_dahiya 0:fb8047b156bb 268 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, Y->n ) );
rahul_dahiya 0:fb8047b156bb 269 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( Y, X->n ) );
rahul_dahiya 0:fb8047b156bb 270
rahul_dahiya 0:fb8047b156bb 271 s = X->s;
rahul_dahiya 0:fb8047b156bb 272 X->s = X->s * ( 1 - swap ) + Y->s * swap;
rahul_dahiya 0:fb8047b156bb 273 Y->s = Y->s * ( 1 - swap ) + s * swap;
rahul_dahiya 0:fb8047b156bb 274
rahul_dahiya 0:fb8047b156bb 275
rahul_dahiya 0:fb8047b156bb 276 for( i = 0; i < X->n; i++ )
rahul_dahiya 0:fb8047b156bb 277 {
rahul_dahiya 0:fb8047b156bb 278 tmp = X->p[i];
rahul_dahiya 0:fb8047b156bb 279 X->p[i] = X->p[i] * ( 1 - swap ) + Y->p[i] * swap;
rahul_dahiya 0:fb8047b156bb 280 Y->p[i] = Y->p[i] * ( 1 - swap ) + tmp * swap;
rahul_dahiya 0:fb8047b156bb 281 }
rahul_dahiya 0:fb8047b156bb 282
rahul_dahiya 0:fb8047b156bb 283 cleanup:
rahul_dahiya 0:fb8047b156bb 284 return( ret );
rahul_dahiya 0:fb8047b156bb 285 }
rahul_dahiya 0:fb8047b156bb 286
rahul_dahiya 0:fb8047b156bb 287 /*
rahul_dahiya 0:fb8047b156bb 288 * Set value from integer
rahul_dahiya 0:fb8047b156bb 289 */
rahul_dahiya 0:fb8047b156bb 290 int mbedtls_mpi_lset( mbedtls_mpi *X, mbedtls_mpi_sint z )
rahul_dahiya 0:fb8047b156bb 291 {
rahul_dahiya 0:fb8047b156bb 292 int ret;
rahul_dahiya 0:fb8047b156bb 293
rahul_dahiya 0:fb8047b156bb 294 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, 1 ) );
rahul_dahiya 0:fb8047b156bb 295 memset( X->p, 0, X->n * ciL );
rahul_dahiya 0:fb8047b156bb 296
rahul_dahiya 0:fb8047b156bb 297 X->p[0] = ( z < 0 ) ? -z : z;
rahul_dahiya 0:fb8047b156bb 298 X->s = ( z < 0 ) ? -1 : 1;
rahul_dahiya 0:fb8047b156bb 299
rahul_dahiya 0:fb8047b156bb 300 cleanup:
rahul_dahiya 0:fb8047b156bb 301
rahul_dahiya 0:fb8047b156bb 302 return( ret );
rahul_dahiya 0:fb8047b156bb 303 }
rahul_dahiya 0:fb8047b156bb 304
rahul_dahiya 0:fb8047b156bb 305 /*
rahul_dahiya 0:fb8047b156bb 306 * Get a specific bit
rahul_dahiya 0:fb8047b156bb 307 */
rahul_dahiya 0:fb8047b156bb 308 int mbedtls_mpi_get_bit( const mbedtls_mpi *X, size_t pos )
rahul_dahiya 0:fb8047b156bb 309 {
rahul_dahiya 0:fb8047b156bb 310 if( X->n * biL <= pos )
rahul_dahiya 0:fb8047b156bb 311 return( 0 );
rahul_dahiya 0:fb8047b156bb 312
rahul_dahiya 0:fb8047b156bb 313 return( ( X->p[pos / biL] >> ( pos % biL ) ) & 0x01 );
rahul_dahiya 0:fb8047b156bb 314 }
rahul_dahiya 0:fb8047b156bb 315
rahul_dahiya 0:fb8047b156bb 316 /*
rahul_dahiya 0:fb8047b156bb 317 * Set a bit to a specific value of 0 or 1
rahul_dahiya 0:fb8047b156bb 318 */
rahul_dahiya 0:fb8047b156bb 319 int mbedtls_mpi_set_bit( mbedtls_mpi *X, size_t pos, unsigned char val )
rahul_dahiya 0:fb8047b156bb 320 {
rahul_dahiya 0:fb8047b156bb 321 int ret = 0;
rahul_dahiya 0:fb8047b156bb 322 size_t off = pos / biL;
rahul_dahiya 0:fb8047b156bb 323 size_t idx = pos % biL;
rahul_dahiya 0:fb8047b156bb 324
rahul_dahiya 0:fb8047b156bb 325 if( val != 0 && val != 1 )
rahul_dahiya 0:fb8047b156bb 326 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 327
rahul_dahiya 0:fb8047b156bb 328 if( X->n * biL <= pos )
rahul_dahiya 0:fb8047b156bb 329 {
rahul_dahiya 0:fb8047b156bb 330 if( val == 0 )
rahul_dahiya 0:fb8047b156bb 331 return( 0 );
rahul_dahiya 0:fb8047b156bb 332
rahul_dahiya 0:fb8047b156bb 333 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, off + 1 ) );
rahul_dahiya 0:fb8047b156bb 334 }
rahul_dahiya 0:fb8047b156bb 335
rahul_dahiya 0:fb8047b156bb 336 X->p[off] &= ~( (mbedtls_mpi_uint) 0x01 << idx );
rahul_dahiya 0:fb8047b156bb 337 X->p[off] |= (mbedtls_mpi_uint) val << idx;
rahul_dahiya 0:fb8047b156bb 338
rahul_dahiya 0:fb8047b156bb 339 cleanup:
rahul_dahiya 0:fb8047b156bb 340
rahul_dahiya 0:fb8047b156bb 341 return( ret );
rahul_dahiya 0:fb8047b156bb 342 }
rahul_dahiya 0:fb8047b156bb 343
rahul_dahiya 0:fb8047b156bb 344 /*
rahul_dahiya 0:fb8047b156bb 345 * Return the number of less significant zero-bits
rahul_dahiya 0:fb8047b156bb 346 */
rahul_dahiya 0:fb8047b156bb 347 size_t mbedtls_mpi_lsb( const mbedtls_mpi *X )
rahul_dahiya 0:fb8047b156bb 348 {
rahul_dahiya 0:fb8047b156bb 349 size_t i, j, count = 0;
rahul_dahiya 0:fb8047b156bb 350
rahul_dahiya 0:fb8047b156bb 351 for( i = 0; i < X->n; i++ )
rahul_dahiya 0:fb8047b156bb 352 for( j = 0; j < biL; j++, count++ )
rahul_dahiya 0:fb8047b156bb 353 if( ( ( X->p[i] >> j ) & 1 ) != 0 )
rahul_dahiya 0:fb8047b156bb 354 return( count );
rahul_dahiya 0:fb8047b156bb 355
rahul_dahiya 0:fb8047b156bb 356 return( 0 );
rahul_dahiya 0:fb8047b156bb 357 }
rahul_dahiya 0:fb8047b156bb 358
rahul_dahiya 0:fb8047b156bb 359 /*
rahul_dahiya 0:fb8047b156bb 360 * Count leading zero bits in a given integer
rahul_dahiya 0:fb8047b156bb 361 */
rahul_dahiya 0:fb8047b156bb 362 static size_t mbedtls_clz( const mbedtls_mpi_uint x )
rahul_dahiya 0:fb8047b156bb 363 {
rahul_dahiya 0:fb8047b156bb 364 size_t j;
rahul_dahiya 0:fb8047b156bb 365 mbedtls_mpi_uint mask = (mbedtls_mpi_uint) 1 << (biL - 1);
rahul_dahiya 0:fb8047b156bb 366
rahul_dahiya 0:fb8047b156bb 367 for( j = 0; j < biL; j++ )
rahul_dahiya 0:fb8047b156bb 368 {
rahul_dahiya 0:fb8047b156bb 369 if( x & mask ) break;
rahul_dahiya 0:fb8047b156bb 370
rahul_dahiya 0:fb8047b156bb 371 mask >>= 1;
rahul_dahiya 0:fb8047b156bb 372 }
rahul_dahiya 0:fb8047b156bb 373
rahul_dahiya 0:fb8047b156bb 374 return j;
rahul_dahiya 0:fb8047b156bb 375 }
rahul_dahiya 0:fb8047b156bb 376
rahul_dahiya 0:fb8047b156bb 377 /*
rahul_dahiya 0:fb8047b156bb 378 * Return the number of bits
rahul_dahiya 0:fb8047b156bb 379 */
rahul_dahiya 0:fb8047b156bb 380 size_t mbedtls_mpi_bitlen( const mbedtls_mpi *X )
rahul_dahiya 0:fb8047b156bb 381 {
rahul_dahiya 0:fb8047b156bb 382 size_t i, j;
rahul_dahiya 0:fb8047b156bb 383
rahul_dahiya 0:fb8047b156bb 384 if( X->n == 0 )
rahul_dahiya 0:fb8047b156bb 385 return( 0 );
rahul_dahiya 0:fb8047b156bb 386
rahul_dahiya 0:fb8047b156bb 387 for( i = X->n - 1; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 388 if( X->p[i] != 0 )
rahul_dahiya 0:fb8047b156bb 389 break;
rahul_dahiya 0:fb8047b156bb 390
rahul_dahiya 0:fb8047b156bb 391 j = biL - mbedtls_clz( X->p[i] );
rahul_dahiya 0:fb8047b156bb 392
rahul_dahiya 0:fb8047b156bb 393 return( ( i * biL ) + j );
rahul_dahiya 0:fb8047b156bb 394 }
rahul_dahiya 0:fb8047b156bb 395
rahul_dahiya 0:fb8047b156bb 396 /*
rahul_dahiya 0:fb8047b156bb 397 * Return the total size in bytes
rahul_dahiya 0:fb8047b156bb 398 */
rahul_dahiya 0:fb8047b156bb 399 size_t mbedtls_mpi_size( const mbedtls_mpi *X )
rahul_dahiya 0:fb8047b156bb 400 {
rahul_dahiya 0:fb8047b156bb 401 return( ( mbedtls_mpi_bitlen( X ) + 7 ) >> 3 );
rahul_dahiya 0:fb8047b156bb 402 }
rahul_dahiya 0:fb8047b156bb 403
rahul_dahiya 0:fb8047b156bb 404 /*
rahul_dahiya 0:fb8047b156bb 405 * Convert an ASCII character to digit value
rahul_dahiya 0:fb8047b156bb 406 */
rahul_dahiya 0:fb8047b156bb 407 static int mpi_get_digit( mbedtls_mpi_uint *d, int radix, char c )
rahul_dahiya 0:fb8047b156bb 408 {
rahul_dahiya 0:fb8047b156bb 409 *d = 255;
rahul_dahiya 0:fb8047b156bb 410
rahul_dahiya 0:fb8047b156bb 411 if( c >= 0x30 && c <= 0x39 ) *d = c - 0x30;
rahul_dahiya 0:fb8047b156bb 412 if( c >= 0x41 && c <= 0x46 ) *d = c - 0x37;
rahul_dahiya 0:fb8047b156bb 413 if( c >= 0x61 && c <= 0x66 ) *d = c - 0x57;
rahul_dahiya 0:fb8047b156bb 414
rahul_dahiya 0:fb8047b156bb 415 if( *d >= (mbedtls_mpi_uint) radix )
rahul_dahiya 0:fb8047b156bb 416 return( MBEDTLS_ERR_MPI_INVALID_CHARACTER );
rahul_dahiya 0:fb8047b156bb 417
rahul_dahiya 0:fb8047b156bb 418 return( 0 );
rahul_dahiya 0:fb8047b156bb 419 }
rahul_dahiya 0:fb8047b156bb 420
rahul_dahiya 0:fb8047b156bb 421 /*
rahul_dahiya 0:fb8047b156bb 422 * Import from an ASCII string
rahul_dahiya 0:fb8047b156bb 423 */
rahul_dahiya 0:fb8047b156bb 424 int mbedtls_mpi_read_string( mbedtls_mpi *X, int radix, const char *s )
rahul_dahiya 0:fb8047b156bb 425 {
rahul_dahiya 0:fb8047b156bb 426 int ret;
rahul_dahiya 0:fb8047b156bb 427 size_t i, j, slen, n;
rahul_dahiya 0:fb8047b156bb 428 mbedtls_mpi_uint d;
rahul_dahiya 0:fb8047b156bb 429 mbedtls_mpi T;
rahul_dahiya 0:fb8047b156bb 430
rahul_dahiya 0:fb8047b156bb 431 if( radix < 2 || radix > 16 )
rahul_dahiya 0:fb8047b156bb 432 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 433
rahul_dahiya 0:fb8047b156bb 434 mbedtls_mpi_init( &T );
rahul_dahiya 0:fb8047b156bb 435
rahul_dahiya 0:fb8047b156bb 436 slen = strlen( s );
rahul_dahiya 0:fb8047b156bb 437
rahul_dahiya 0:fb8047b156bb 438 if( radix == 16 )
rahul_dahiya 0:fb8047b156bb 439 {
rahul_dahiya 0:fb8047b156bb 440 if( slen > MPI_SIZE_T_MAX >> 2 )
rahul_dahiya 0:fb8047b156bb 441 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 442
rahul_dahiya 0:fb8047b156bb 443 n = BITS_TO_LIMBS( slen << 2 );
rahul_dahiya 0:fb8047b156bb 444
rahul_dahiya 0:fb8047b156bb 445 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, n ) );
rahul_dahiya 0:fb8047b156bb 446 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( X, 0 ) );
rahul_dahiya 0:fb8047b156bb 447
rahul_dahiya 0:fb8047b156bb 448 for( i = slen, j = 0; i > 0; i--, j++ )
rahul_dahiya 0:fb8047b156bb 449 {
rahul_dahiya 0:fb8047b156bb 450 if( i == 1 && s[i - 1] == '-' )
rahul_dahiya 0:fb8047b156bb 451 {
rahul_dahiya 0:fb8047b156bb 452 X->s = -1;
rahul_dahiya 0:fb8047b156bb 453 break;
rahul_dahiya 0:fb8047b156bb 454 }
rahul_dahiya 0:fb8047b156bb 455
rahul_dahiya 0:fb8047b156bb 456 MBEDTLS_MPI_CHK( mpi_get_digit( &d, radix, s[i - 1] ) );
rahul_dahiya 0:fb8047b156bb 457 X->p[j / ( 2 * ciL )] |= d << ( ( j % ( 2 * ciL ) ) << 2 );
rahul_dahiya 0:fb8047b156bb 458 }
rahul_dahiya 0:fb8047b156bb 459 }
rahul_dahiya 0:fb8047b156bb 460 else
rahul_dahiya 0:fb8047b156bb 461 {
rahul_dahiya 0:fb8047b156bb 462 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( X, 0 ) );
rahul_dahiya 0:fb8047b156bb 463
rahul_dahiya 0:fb8047b156bb 464 for( i = 0; i < slen; i++ )
rahul_dahiya 0:fb8047b156bb 465 {
rahul_dahiya 0:fb8047b156bb 466 if( i == 0 && s[i] == '-' )
rahul_dahiya 0:fb8047b156bb 467 {
rahul_dahiya 0:fb8047b156bb 468 X->s = -1;
rahul_dahiya 0:fb8047b156bb 469 continue;
rahul_dahiya 0:fb8047b156bb 470 }
rahul_dahiya 0:fb8047b156bb 471
rahul_dahiya 0:fb8047b156bb 472 MBEDTLS_MPI_CHK( mpi_get_digit( &d, radix, s[i] ) );
rahul_dahiya 0:fb8047b156bb 473 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_int( &T, X, radix ) );
rahul_dahiya 0:fb8047b156bb 474
rahul_dahiya 0:fb8047b156bb 475 if( X->s == 1 )
rahul_dahiya 0:fb8047b156bb 476 {
rahul_dahiya 0:fb8047b156bb 477 MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( X, &T, d ) );
rahul_dahiya 0:fb8047b156bb 478 }
rahul_dahiya 0:fb8047b156bb 479 else
rahul_dahiya 0:fb8047b156bb 480 {
rahul_dahiya 0:fb8047b156bb 481 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( X, &T, d ) );
rahul_dahiya 0:fb8047b156bb 482 }
rahul_dahiya 0:fb8047b156bb 483 }
rahul_dahiya 0:fb8047b156bb 484 }
rahul_dahiya 0:fb8047b156bb 485
rahul_dahiya 0:fb8047b156bb 486 cleanup:
rahul_dahiya 0:fb8047b156bb 487
rahul_dahiya 0:fb8047b156bb 488 mbedtls_mpi_free( &T );
rahul_dahiya 0:fb8047b156bb 489
rahul_dahiya 0:fb8047b156bb 490 return( ret );
rahul_dahiya 0:fb8047b156bb 491 }
rahul_dahiya 0:fb8047b156bb 492
rahul_dahiya 0:fb8047b156bb 493 /*
rahul_dahiya 0:fb8047b156bb 494 * Helper to write the digits high-order first
rahul_dahiya 0:fb8047b156bb 495 */
rahul_dahiya 0:fb8047b156bb 496 static int mpi_write_hlp( mbedtls_mpi *X, int radix, char **p )
rahul_dahiya 0:fb8047b156bb 497 {
rahul_dahiya 0:fb8047b156bb 498 int ret;
rahul_dahiya 0:fb8047b156bb 499 mbedtls_mpi_uint r;
rahul_dahiya 0:fb8047b156bb 500
rahul_dahiya 0:fb8047b156bb 501 if( radix < 2 || radix > 16 )
rahul_dahiya 0:fb8047b156bb 502 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 503
rahul_dahiya 0:fb8047b156bb 504 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_int( &r, X, radix ) );
rahul_dahiya 0:fb8047b156bb 505 MBEDTLS_MPI_CHK( mbedtls_mpi_div_int( X, NULL, X, radix ) );
rahul_dahiya 0:fb8047b156bb 506
rahul_dahiya 0:fb8047b156bb 507 if( mbedtls_mpi_cmp_int( X, 0 ) != 0 )
rahul_dahiya 0:fb8047b156bb 508 MBEDTLS_MPI_CHK( mpi_write_hlp( X, radix, p ) );
rahul_dahiya 0:fb8047b156bb 509
rahul_dahiya 0:fb8047b156bb 510 if( r < 10 )
rahul_dahiya 0:fb8047b156bb 511 *(*p)++ = (char)( r + 0x30 );
rahul_dahiya 0:fb8047b156bb 512 else
rahul_dahiya 0:fb8047b156bb 513 *(*p)++ = (char)( r + 0x37 );
rahul_dahiya 0:fb8047b156bb 514
rahul_dahiya 0:fb8047b156bb 515 cleanup:
rahul_dahiya 0:fb8047b156bb 516
rahul_dahiya 0:fb8047b156bb 517 return( ret );
rahul_dahiya 0:fb8047b156bb 518 }
rahul_dahiya 0:fb8047b156bb 519
rahul_dahiya 0:fb8047b156bb 520 /*
rahul_dahiya 0:fb8047b156bb 521 * Export into an ASCII string
rahul_dahiya 0:fb8047b156bb 522 */
rahul_dahiya 0:fb8047b156bb 523 int mbedtls_mpi_write_string( const mbedtls_mpi *X, int radix,
rahul_dahiya 0:fb8047b156bb 524 char *buf, size_t buflen, size_t *olen )
rahul_dahiya 0:fb8047b156bb 525 {
rahul_dahiya 0:fb8047b156bb 526 int ret = 0;
rahul_dahiya 0:fb8047b156bb 527 size_t n;
rahul_dahiya 0:fb8047b156bb 528 char *p;
rahul_dahiya 0:fb8047b156bb 529 mbedtls_mpi T;
rahul_dahiya 0:fb8047b156bb 530
rahul_dahiya 0:fb8047b156bb 531 if( radix < 2 || radix > 16 )
rahul_dahiya 0:fb8047b156bb 532 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 533
rahul_dahiya 0:fb8047b156bb 534 n = mbedtls_mpi_bitlen( X );
rahul_dahiya 0:fb8047b156bb 535 if( radix >= 4 ) n >>= 1;
rahul_dahiya 0:fb8047b156bb 536 if( radix >= 16 ) n >>= 1;
rahul_dahiya 0:fb8047b156bb 537 /*
rahul_dahiya 0:fb8047b156bb 538 * Round up the buffer length to an even value to ensure that there is
rahul_dahiya 0:fb8047b156bb 539 * enough room for hexadecimal values that can be represented in an odd
rahul_dahiya 0:fb8047b156bb 540 * number of digits.
rahul_dahiya 0:fb8047b156bb 541 */
rahul_dahiya 0:fb8047b156bb 542 n += 3 + ( ( n + 1 ) & 1 );
rahul_dahiya 0:fb8047b156bb 543
rahul_dahiya 0:fb8047b156bb 544 if( buflen < n )
rahul_dahiya 0:fb8047b156bb 545 {
rahul_dahiya 0:fb8047b156bb 546 *olen = n;
rahul_dahiya 0:fb8047b156bb 547 return( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL );
rahul_dahiya 0:fb8047b156bb 548 }
rahul_dahiya 0:fb8047b156bb 549
rahul_dahiya 0:fb8047b156bb 550 p = buf;
rahul_dahiya 0:fb8047b156bb 551 mbedtls_mpi_init( &T );
rahul_dahiya 0:fb8047b156bb 552
rahul_dahiya 0:fb8047b156bb 553 if( X->s == -1 )
rahul_dahiya 0:fb8047b156bb 554 *p++ = '-';
rahul_dahiya 0:fb8047b156bb 555
rahul_dahiya 0:fb8047b156bb 556 if( radix == 16 )
rahul_dahiya 0:fb8047b156bb 557 {
rahul_dahiya 0:fb8047b156bb 558 int c;
rahul_dahiya 0:fb8047b156bb 559 size_t i, j, k;
rahul_dahiya 0:fb8047b156bb 560
rahul_dahiya 0:fb8047b156bb 561 for( i = X->n, k = 0; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 562 {
rahul_dahiya 0:fb8047b156bb 563 for( j = ciL; j > 0; j-- )
rahul_dahiya 0:fb8047b156bb 564 {
rahul_dahiya 0:fb8047b156bb 565 c = ( X->p[i - 1] >> ( ( j - 1 ) << 3) ) & 0xFF;
rahul_dahiya 0:fb8047b156bb 566
rahul_dahiya 0:fb8047b156bb 567 if( c == 0 && k == 0 && ( i + j ) != 2 )
rahul_dahiya 0:fb8047b156bb 568 continue;
rahul_dahiya 0:fb8047b156bb 569
rahul_dahiya 0:fb8047b156bb 570 *(p++) = "0123456789ABCDEF" [c / 16];
rahul_dahiya 0:fb8047b156bb 571 *(p++) = "0123456789ABCDEF" [c % 16];
rahul_dahiya 0:fb8047b156bb 572 k = 1;
rahul_dahiya 0:fb8047b156bb 573 }
rahul_dahiya 0:fb8047b156bb 574 }
rahul_dahiya 0:fb8047b156bb 575 }
rahul_dahiya 0:fb8047b156bb 576 else
rahul_dahiya 0:fb8047b156bb 577 {
rahul_dahiya 0:fb8047b156bb 578 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &T, X ) );
rahul_dahiya 0:fb8047b156bb 579
rahul_dahiya 0:fb8047b156bb 580 if( T.s == -1 )
rahul_dahiya 0:fb8047b156bb 581 T.s = 1;
rahul_dahiya 0:fb8047b156bb 582
rahul_dahiya 0:fb8047b156bb 583 MBEDTLS_MPI_CHK( mpi_write_hlp( &T, radix, &p ) );
rahul_dahiya 0:fb8047b156bb 584 }
rahul_dahiya 0:fb8047b156bb 585
rahul_dahiya 0:fb8047b156bb 586 *p++ = '\0';
rahul_dahiya 0:fb8047b156bb 587 *olen = p - buf;
rahul_dahiya 0:fb8047b156bb 588
rahul_dahiya 0:fb8047b156bb 589 cleanup:
rahul_dahiya 0:fb8047b156bb 590
rahul_dahiya 0:fb8047b156bb 591 mbedtls_mpi_free( &T );
rahul_dahiya 0:fb8047b156bb 592
rahul_dahiya 0:fb8047b156bb 593 return( ret );
rahul_dahiya 0:fb8047b156bb 594 }
rahul_dahiya 0:fb8047b156bb 595
rahul_dahiya 0:fb8047b156bb 596 #if defined(MBEDTLS_FS_IO)
rahul_dahiya 0:fb8047b156bb 597 /*
rahul_dahiya 0:fb8047b156bb 598 * Read X from an opened file
rahul_dahiya 0:fb8047b156bb 599 */
rahul_dahiya 0:fb8047b156bb 600 int mbedtls_mpi_read_file( mbedtls_mpi *X, int radix, FILE *fin )
rahul_dahiya 0:fb8047b156bb 601 {
rahul_dahiya 0:fb8047b156bb 602 mbedtls_mpi_uint d;
rahul_dahiya 0:fb8047b156bb 603 size_t slen;
rahul_dahiya 0:fb8047b156bb 604 char *p;
rahul_dahiya 0:fb8047b156bb 605 /*
rahul_dahiya 0:fb8047b156bb 606 * Buffer should have space for (short) label and decimal formatted MPI,
rahul_dahiya 0:fb8047b156bb 607 * newline characters and '\0'
rahul_dahiya 0:fb8047b156bb 608 */
rahul_dahiya 0:fb8047b156bb 609 char s[ MBEDTLS_MPI_RW_BUFFER_SIZE ];
rahul_dahiya 0:fb8047b156bb 610
rahul_dahiya 0:fb8047b156bb 611 memset( s, 0, sizeof( s ) );
rahul_dahiya 0:fb8047b156bb 612 if( fgets( s, sizeof( s ) - 1, fin ) == NULL )
rahul_dahiya 0:fb8047b156bb 613 return( MBEDTLS_ERR_MPI_FILE_IO_ERROR );
rahul_dahiya 0:fb8047b156bb 614
rahul_dahiya 0:fb8047b156bb 615 slen = strlen( s );
rahul_dahiya 0:fb8047b156bb 616 if( slen == sizeof( s ) - 2 )
rahul_dahiya 0:fb8047b156bb 617 return( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL );
rahul_dahiya 0:fb8047b156bb 618
rahul_dahiya 0:fb8047b156bb 619 if( slen > 0 && s[slen - 1] == '\n' ) { slen--; s[slen] = '\0'; }
rahul_dahiya 0:fb8047b156bb 620 if( slen > 0 && s[slen - 1] == '\r' ) { slen--; s[slen] = '\0'; }
rahul_dahiya 0:fb8047b156bb 621
rahul_dahiya 0:fb8047b156bb 622 p = s + slen;
rahul_dahiya 0:fb8047b156bb 623 while( p-- > s )
rahul_dahiya 0:fb8047b156bb 624 if( mpi_get_digit( &d, radix, *p ) != 0 )
rahul_dahiya 0:fb8047b156bb 625 break;
rahul_dahiya 0:fb8047b156bb 626
rahul_dahiya 0:fb8047b156bb 627 return( mbedtls_mpi_read_string( X, radix, p + 1 ) );
rahul_dahiya 0:fb8047b156bb 628 }
rahul_dahiya 0:fb8047b156bb 629
rahul_dahiya 0:fb8047b156bb 630 /*
rahul_dahiya 0:fb8047b156bb 631 * Write X into an opened file (or stdout if fout == NULL)
rahul_dahiya 0:fb8047b156bb 632 */
rahul_dahiya 0:fb8047b156bb 633 int mbedtls_mpi_write_file( const char *p, const mbedtls_mpi *X, int radix, FILE *fout )
rahul_dahiya 0:fb8047b156bb 634 {
rahul_dahiya 0:fb8047b156bb 635 int ret;
rahul_dahiya 0:fb8047b156bb 636 size_t n, slen, plen;
rahul_dahiya 0:fb8047b156bb 637 /*
rahul_dahiya 0:fb8047b156bb 638 * Buffer should have space for (short) label and decimal formatted MPI,
rahul_dahiya 0:fb8047b156bb 639 * newline characters and '\0'
rahul_dahiya 0:fb8047b156bb 640 */
rahul_dahiya 0:fb8047b156bb 641 char s[ MBEDTLS_MPI_RW_BUFFER_SIZE ];
rahul_dahiya 0:fb8047b156bb 642
rahul_dahiya 0:fb8047b156bb 643 memset( s, 0, sizeof( s ) );
rahul_dahiya 0:fb8047b156bb 644
rahul_dahiya 0:fb8047b156bb 645 MBEDTLS_MPI_CHK( mbedtls_mpi_write_string( X, radix, s, sizeof( s ) - 2, &n ) );
rahul_dahiya 0:fb8047b156bb 646
rahul_dahiya 0:fb8047b156bb 647 if( p == NULL ) p = "";
rahul_dahiya 0:fb8047b156bb 648
rahul_dahiya 0:fb8047b156bb 649 plen = strlen( p );
rahul_dahiya 0:fb8047b156bb 650 slen = strlen( s );
rahul_dahiya 0:fb8047b156bb 651 s[slen++] = '\r';
rahul_dahiya 0:fb8047b156bb 652 s[slen++] = '\n';
rahul_dahiya 0:fb8047b156bb 653
rahul_dahiya 0:fb8047b156bb 654 if( fout != NULL )
rahul_dahiya 0:fb8047b156bb 655 {
rahul_dahiya 0:fb8047b156bb 656 if( fwrite( p, 1, plen, fout ) != plen ||
rahul_dahiya 0:fb8047b156bb 657 fwrite( s, 1, slen, fout ) != slen )
rahul_dahiya 0:fb8047b156bb 658 return( MBEDTLS_ERR_MPI_FILE_IO_ERROR );
rahul_dahiya 0:fb8047b156bb 659 }
rahul_dahiya 0:fb8047b156bb 660 else
rahul_dahiya 0:fb8047b156bb 661 mbedtls_printf( "%s%s", p, s );
rahul_dahiya 0:fb8047b156bb 662
rahul_dahiya 0:fb8047b156bb 663 cleanup:
rahul_dahiya 0:fb8047b156bb 664
rahul_dahiya 0:fb8047b156bb 665 return( ret );
rahul_dahiya 0:fb8047b156bb 666 }
rahul_dahiya 0:fb8047b156bb 667 #endif /* MBEDTLS_FS_IO */
rahul_dahiya 0:fb8047b156bb 668
rahul_dahiya 0:fb8047b156bb 669 /*
rahul_dahiya 0:fb8047b156bb 670 * Import X from unsigned binary data, big endian
rahul_dahiya 0:fb8047b156bb 671 */
rahul_dahiya 0:fb8047b156bb 672 int mbedtls_mpi_read_binary( mbedtls_mpi *X, const unsigned char *buf, size_t buflen )
rahul_dahiya 0:fb8047b156bb 673 {
rahul_dahiya 0:fb8047b156bb 674 int ret;
rahul_dahiya 0:fb8047b156bb 675 size_t i, j, n;
rahul_dahiya 0:fb8047b156bb 676
rahul_dahiya 0:fb8047b156bb 677 for( n = 0; n < buflen; n++ )
rahul_dahiya 0:fb8047b156bb 678 if( buf[n] != 0 )
rahul_dahiya 0:fb8047b156bb 679 break;
rahul_dahiya 0:fb8047b156bb 680
rahul_dahiya 0:fb8047b156bb 681 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, CHARS_TO_LIMBS( buflen - n ) ) );
rahul_dahiya 0:fb8047b156bb 682 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( X, 0 ) );
rahul_dahiya 0:fb8047b156bb 683
rahul_dahiya 0:fb8047b156bb 684 for( i = buflen, j = 0; i > n; i--, j++ )
rahul_dahiya 0:fb8047b156bb 685 X->p[j / ciL] |= ((mbedtls_mpi_uint) buf[i - 1]) << ((j % ciL) << 3);
rahul_dahiya 0:fb8047b156bb 686
rahul_dahiya 0:fb8047b156bb 687 cleanup:
rahul_dahiya 0:fb8047b156bb 688
rahul_dahiya 0:fb8047b156bb 689 return( ret );
rahul_dahiya 0:fb8047b156bb 690 }
rahul_dahiya 0:fb8047b156bb 691
rahul_dahiya 0:fb8047b156bb 692 /*
rahul_dahiya 0:fb8047b156bb 693 * Export X into unsigned binary data, big endian
rahul_dahiya 0:fb8047b156bb 694 */
rahul_dahiya 0:fb8047b156bb 695 int mbedtls_mpi_write_binary( const mbedtls_mpi *X, unsigned char *buf, size_t buflen )
rahul_dahiya 0:fb8047b156bb 696 {
rahul_dahiya 0:fb8047b156bb 697 size_t i, j, n;
rahul_dahiya 0:fb8047b156bb 698
rahul_dahiya 0:fb8047b156bb 699 n = mbedtls_mpi_size( X );
rahul_dahiya 0:fb8047b156bb 700
rahul_dahiya 0:fb8047b156bb 701 if( buflen < n )
rahul_dahiya 0:fb8047b156bb 702 return( MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL );
rahul_dahiya 0:fb8047b156bb 703
rahul_dahiya 0:fb8047b156bb 704 memset( buf, 0, buflen );
rahul_dahiya 0:fb8047b156bb 705
rahul_dahiya 0:fb8047b156bb 706 for( i = buflen - 1, j = 0; n > 0; i--, j++, n-- )
rahul_dahiya 0:fb8047b156bb 707 buf[i] = (unsigned char)( X->p[j / ciL] >> ((j % ciL) << 3) );
rahul_dahiya 0:fb8047b156bb 708
rahul_dahiya 0:fb8047b156bb 709 return( 0 );
rahul_dahiya 0:fb8047b156bb 710 }
rahul_dahiya 0:fb8047b156bb 711
rahul_dahiya 0:fb8047b156bb 712 /*
rahul_dahiya 0:fb8047b156bb 713 * Left-shift: X <<= count
rahul_dahiya 0:fb8047b156bb 714 */
rahul_dahiya 0:fb8047b156bb 715 int mbedtls_mpi_shift_l( mbedtls_mpi *X, size_t count )
rahul_dahiya 0:fb8047b156bb 716 {
rahul_dahiya 0:fb8047b156bb 717 int ret;
rahul_dahiya 0:fb8047b156bb 718 size_t i, v0, t1;
rahul_dahiya 0:fb8047b156bb 719 mbedtls_mpi_uint r0 = 0, r1;
rahul_dahiya 0:fb8047b156bb 720
rahul_dahiya 0:fb8047b156bb 721 v0 = count / (biL );
rahul_dahiya 0:fb8047b156bb 722 t1 = count & (biL - 1);
rahul_dahiya 0:fb8047b156bb 723
rahul_dahiya 0:fb8047b156bb 724 i = mbedtls_mpi_bitlen( X ) + count;
rahul_dahiya 0:fb8047b156bb 725
rahul_dahiya 0:fb8047b156bb 726 if( X->n * biL < i )
rahul_dahiya 0:fb8047b156bb 727 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, BITS_TO_LIMBS( i ) ) );
rahul_dahiya 0:fb8047b156bb 728
rahul_dahiya 0:fb8047b156bb 729 ret = 0;
rahul_dahiya 0:fb8047b156bb 730
rahul_dahiya 0:fb8047b156bb 731 /*
rahul_dahiya 0:fb8047b156bb 732 * shift by count / limb_size
rahul_dahiya 0:fb8047b156bb 733 */
rahul_dahiya 0:fb8047b156bb 734 if( v0 > 0 )
rahul_dahiya 0:fb8047b156bb 735 {
rahul_dahiya 0:fb8047b156bb 736 for( i = X->n; i > v0; i-- )
rahul_dahiya 0:fb8047b156bb 737 X->p[i - 1] = X->p[i - v0 - 1];
rahul_dahiya 0:fb8047b156bb 738
rahul_dahiya 0:fb8047b156bb 739 for( ; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 740 X->p[i - 1] = 0;
rahul_dahiya 0:fb8047b156bb 741 }
rahul_dahiya 0:fb8047b156bb 742
rahul_dahiya 0:fb8047b156bb 743 /*
rahul_dahiya 0:fb8047b156bb 744 * shift by count % limb_size
rahul_dahiya 0:fb8047b156bb 745 */
rahul_dahiya 0:fb8047b156bb 746 if( t1 > 0 )
rahul_dahiya 0:fb8047b156bb 747 {
rahul_dahiya 0:fb8047b156bb 748 for( i = v0; i < X->n; i++ )
rahul_dahiya 0:fb8047b156bb 749 {
rahul_dahiya 0:fb8047b156bb 750 r1 = X->p[i] >> (biL - t1);
rahul_dahiya 0:fb8047b156bb 751 X->p[i] <<= t1;
rahul_dahiya 0:fb8047b156bb 752 X->p[i] |= r0;
rahul_dahiya 0:fb8047b156bb 753 r0 = r1;
rahul_dahiya 0:fb8047b156bb 754 }
rahul_dahiya 0:fb8047b156bb 755 }
rahul_dahiya 0:fb8047b156bb 756
rahul_dahiya 0:fb8047b156bb 757 cleanup:
rahul_dahiya 0:fb8047b156bb 758
rahul_dahiya 0:fb8047b156bb 759 return( ret );
rahul_dahiya 0:fb8047b156bb 760 }
rahul_dahiya 0:fb8047b156bb 761
rahul_dahiya 0:fb8047b156bb 762 /*
rahul_dahiya 0:fb8047b156bb 763 * Right-shift: X >>= count
rahul_dahiya 0:fb8047b156bb 764 */
rahul_dahiya 0:fb8047b156bb 765 int mbedtls_mpi_shift_r( mbedtls_mpi *X, size_t count )
rahul_dahiya 0:fb8047b156bb 766 {
rahul_dahiya 0:fb8047b156bb 767 size_t i, v0, v1;
rahul_dahiya 0:fb8047b156bb 768 mbedtls_mpi_uint r0 = 0, r1;
rahul_dahiya 0:fb8047b156bb 769
rahul_dahiya 0:fb8047b156bb 770 v0 = count / biL;
rahul_dahiya 0:fb8047b156bb 771 v1 = count & (biL - 1);
rahul_dahiya 0:fb8047b156bb 772
rahul_dahiya 0:fb8047b156bb 773 if( v0 > X->n || ( v0 == X->n && v1 > 0 ) )
rahul_dahiya 0:fb8047b156bb 774 return mbedtls_mpi_lset( X, 0 );
rahul_dahiya 0:fb8047b156bb 775
rahul_dahiya 0:fb8047b156bb 776 /*
rahul_dahiya 0:fb8047b156bb 777 * shift by count / limb_size
rahul_dahiya 0:fb8047b156bb 778 */
rahul_dahiya 0:fb8047b156bb 779 if( v0 > 0 )
rahul_dahiya 0:fb8047b156bb 780 {
rahul_dahiya 0:fb8047b156bb 781 for( i = 0; i < X->n - v0; i++ )
rahul_dahiya 0:fb8047b156bb 782 X->p[i] = X->p[i + v0];
rahul_dahiya 0:fb8047b156bb 783
rahul_dahiya 0:fb8047b156bb 784 for( ; i < X->n; i++ )
rahul_dahiya 0:fb8047b156bb 785 X->p[i] = 0;
rahul_dahiya 0:fb8047b156bb 786 }
rahul_dahiya 0:fb8047b156bb 787
rahul_dahiya 0:fb8047b156bb 788 /*
rahul_dahiya 0:fb8047b156bb 789 * shift by count % limb_size
rahul_dahiya 0:fb8047b156bb 790 */
rahul_dahiya 0:fb8047b156bb 791 if( v1 > 0 )
rahul_dahiya 0:fb8047b156bb 792 {
rahul_dahiya 0:fb8047b156bb 793 for( i = X->n; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 794 {
rahul_dahiya 0:fb8047b156bb 795 r1 = X->p[i - 1] << (biL - v1);
rahul_dahiya 0:fb8047b156bb 796 X->p[i - 1] >>= v1;
rahul_dahiya 0:fb8047b156bb 797 X->p[i - 1] |= r0;
rahul_dahiya 0:fb8047b156bb 798 r0 = r1;
rahul_dahiya 0:fb8047b156bb 799 }
rahul_dahiya 0:fb8047b156bb 800 }
rahul_dahiya 0:fb8047b156bb 801
rahul_dahiya 0:fb8047b156bb 802 return( 0 );
rahul_dahiya 0:fb8047b156bb 803 }
rahul_dahiya 0:fb8047b156bb 804
rahul_dahiya 0:fb8047b156bb 805 /*
rahul_dahiya 0:fb8047b156bb 806 * Compare unsigned values
rahul_dahiya 0:fb8047b156bb 807 */
rahul_dahiya 0:fb8047b156bb 808 int mbedtls_mpi_cmp_abs( const mbedtls_mpi *X, const mbedtls_mpi *Y )
rahul_dahiya 0:fb8047b156bb 809 {
rahul_dahiya 0:fb8047b156bb 810 size_t i, j;
rahul_dahiya 0:fb8047b156bb 811
rahul_dahiya 0:fb8047b156bb 812 for( i = X->n; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 813 if( X->p[i - 1] != 0 )
rahul_dahiya 0:fb8047b156bb 814 break;
rahul_dahiya 0:fb8047b156bb 815
rahul_dahiya 0:fb8047b156bb 816 for( j = Y->n; j > 0; j-- )
rahul_dahiya 0:fb8047b156bb 817 if( Y->p[j - 1] != 0 )
rahul_dahiya 0:fb8047b156bb 818 break;
rahul_dahiya 0:fb8047b156bb 819
rahul_dahiya 0:fb8047b156bb 820 if( i == 0 && j == 0 )
rahul_dahiya 0:fb8047b156bb 821 return( 0 );
rahul_dahiya 0:fb8047b156bb 822
rahul_dahiya 0:fb8047b156bb 823 if( i > j ) return( 1 );
rahul_dahiya 0:fb8047b156bb 824 if( j > i ) return( -1 );
rahul_dahiya 0:fb8047b156bb 825
rahul_dahiya 0:fb8047b156bb 826 for( ; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 827 {
rahul_dahiya 0:fb8047b156bb 828 if( X->p[i - 1] > Y->p[i - 1] ) return( 1 );
rahul_dahiya 0:fb8047b156bb 829 if( X->p[i - 1] < Y->p[i - 1] ) return( -1 );
rahul_dahiya 0:fb8047b156bb 830 }
rahul_dahiya 0:fb8047b156bb 831
rahul_dahiya 0:fb8047b156bb 832 return( 0 );
rahul_dahiya 0:fb8047b156bb 833 }
rahul_dahiya 0:fb8047b156bb 834
rahul_dahiya 0:fb8047b156bb 835 /*
rahul_dahiya 0:fb8047b156bb 836 * Compare signed values
rahul_dahiya 0:fb8047b156bb 837 */
rahul_dahiya 0:fb8047b156bb 838 int mbedtls_mpi_cmp_mpi( const mbedtls_mpi *X, const mbedtls_mpi *Y )
rahul_dahiya 0:fb8047b156bb 839 {
rahul_dahiya 0:fb8047b156bb 840 size_t i, j;
rahul_dahiya 0:fb8047b156bb 841
rahul_dahiya 0:fb8047b156bb 842 for( i = X->n; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 843 if( X->p[i - 1] != 0 )
rahul_dahiya 0:fb8047b156bb 844 break;
rahul_dahiya 0:fb8047b156bb 845
rahul_dahiya 0:fb8047b156bb 846 for( j = Y->n; j > 0; j-- )
rahul_dahiya 0:fb8047b156bb 847 if( Y->p[j - 1] != 0 )
rahul_dahiya 0:fb8047b156bb 848 break;
rahul_dahiya 0:fb8047b156bb 849
rahul_dahiya 0:fb8047b156bb 850 if( i == 0 && j == 0 )
rahul_dahiya 0:fb8047b156bb 851 return( 0 );
rahul_dahiya 0:fb8047b156bb 852
rahul_dahiya 0:fb8047b156bb 853 if( i > j ) return( X->s );
rahul_dahiya 0:fb8047b156bb 854 if( j > i ) return( -Y->s );
rahul_dahiya 0:fb8047b156bb 855
rahul_dahiya 0:fb8047b156bb 856 if( X->s > 0 && Y->s < 0 ) return( 1 );
rahul_dahiya 0:fb8047b156bb 857 if( Y->s > 0 && X->s < 0 ) return( -1 );
rahul_dahiya 0:fb8047b156bb 858
rahul_dahiya 0:fb8047b156bb 859 for( ; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 860 {
rahul_dahiya 0:fb8047b156bb 861 if( X->p[i - 1] > Y->p[i - 1] ) return( X->s );
rahul_dahiya 0:fb8047b156bb 862 if( X->p[i - 1] < Y->p[i - 1] ) return( -X->s );
rahul_dahiya 0:fb8047b156bb 863 }
rahul_dahiya 0:fb8047b156bb 864
rahul_dahiya 0:fb8047b156bb 865 return( 0 );
rahul_dahiya 0:fb8047b156bb 866 }
rahul_dahiya 0:fb8047b156bb 867
rahul_dahiya 0:fb8047b156bb 868 /*
rahul_dahiya 0:fb8047b156bb 869 * Compare signed values
rahul_dahiya 0:fb8047b156bb 870 */
rahul_dahiya 0:fb8047b156bb 871 int mbedtls_mpi_cmp_int( const mbedtls_mpi *X, mbedtls_mpi_sint z )
rahul_dahiya 0:fb8047b156bb 872 {
rahul_dahiya 0:fb8047b156bb 873 mbedtls_mpi Y;
rahul_dahiya 0:fb8047b156bb 874 mbedtls_mpi_uint p[1];
rahul_dahiya 0:fb8047b156bb 875
rahul_dahiya 0:fb8047b156bb 876 *p = ( z < 0 ) ? -z : z;
rahul_dahiya 0:fb8047b156bb 877 Y.s = ( z < 0 ) ? -1 : 1;
rahul_dahiya 0:fb8047b156bb 878 Y.n = 1;
rahul_dahiya 0:fb8047b156bb 879 Y.p = p;
rahul_dahiya 0:fb8047b156bb 880
rahul_dahiya 0:fb8047b156bb 881 return( mbedtls_mpi_cmp_mpi( X, &Y ) );
rahul_dahiya 0:fb8047b156bb 882 }
rahul_dahiya 0:fb8047b156bb 883
rahul_dahiya 0:fb8047b156bb 884 /*
rahul_dahiya 0:fb8047b156bb 885 * Unsigned addition: X = |A| + |B| (HAC 14.7)
rahul_dahiya 0:fb8047b156bb 886 */
rahul_dahiya 0:fb8047b156bb 887 int mbedtls_mpi_add_abs( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
rahul_dahiya 0:fb8047b156bb 888 {
rahul_dahiya 0:fb8047b156bb 889 int ret;
rahul_dahiya 0:fb8047b156bb 890 size_t i, j;
rahul_dahiya 0:fb8047b156bb 891 mbedtls_mpi_uint *o, *p, c, tmp;
rahul_dahiya 0:fb8047b156bb 892
rahul_dahiya 0:fb8047b156bb 893 if( X == B )
rahul_dahiya 0:fb8047b156bb 894 {
rahul_dahiya 0:fb8047b156bb 895 const mbedtls_mpi *T = A; A = X; B = T;
rahul_dahiya 0:fb8047b156bb 896 }
rahul_dahiya 0:fb8047b156bb 897
rahul_dahiya 0:fb8047b156bb 898 if( X != A )
rahul_dahiya 0:fb8047b156bb 899 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( X, A ) );
rahul_dahiya 0:fb8047b156bb 900
rahul_dahiya 0:fb8047b156bb 901 /*
rahul_dahiya 0:fb8047b156bb 902 * X should always be positive as a result of unsigned additions.
rahul_dahiya 0:fb8047b156bb 903 */
rahul_dahiya 0:fb8047b156bb 904 X->s = 1;
rahul_dahiya 0:fb8047b156bb 905
rahul_dahiya 0:fb8047b156bb 906 for( j = B->n; j > 0; j-- )
rahul_dahiya 0:fb8047b156bb 907 if( B->p[j - 1] != 0 )
rahul_dahiya 0:fb8047b156bb 908 break;
rahul_dahiya 0:fb8047b156bb 909
rahul_dahiya 0:fb8047b156bb 910 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, j ) );
rahul_dahiya 0:fb8047b156bb 911
rahul_dahiya 0:fb8047b156bb 912 o = B->p; p = X->p; c = 0;
rahul_dahiya 0:fb8047b156bb 913
rahul_dahiya 0:fb8047b156bb 914 /*
rahul_dahiya 0:fb8047b156bb 915 * tmp is used because it might happen that p == o
rahul_dahiya 0:fb8047b156bb 916 */
rahul_dahiya 0:fb8047b156bb 917 for( i = 0; i < j; i++, o++, p++ )
rahul_dahiya 0:fb8047b156bb 918 {
rahul_dahiya 0:fb8047b156bb 919 tmp= *o;
rahul_dahiya 0:fb8047b156bb 920 *p += c; c = ( *p < c );
rahul_dahiya 0:fb8047b156bb 921 *p += tmp; c += ( *p < tmp );
rahul_dahiya 0:fb8047b156bb 922 }
rahul_dahiya 0:fb8047b156bb 923
rahul_dahiya 0:fb8047b156bb 924 while( c != 0 )
rahul_dahiya 0:fb8047b156bb 925 {
rahul_dahiya 0:fb8047b156bb 926 if( i >= X->n )
rahul_dahiya 0:fb8047b156bb 927 {
rahul_dahiya 0:fb8047b156bb 928 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, i + 1 ) );
rahul_dahiya 0:fb8047b156bb 929 p = X->p + i;
rahul_dahiya 0:fb8047b156bb 930 }
rahul_dahiya 0:fb8047b156bb 931
rahul_dahiya 0:fb8047b156bb 932 *p += c; c = ( *p < c ); i++; p++;
rahul_dahiya 0:fb8047b156bb 933 }
rahul_dahiya 0:fb8047b156bb 934
rahul_dahiya 0:fb8047b156bb 935 cleanup:
rahul_dahiya 0:fb8047b156bb 936
rahul_dahiya 0:fb8047b156bb 937 return( ret );
rahul_dahiya 0:fb8047b156bb 938 }
rahul_dahiya 0:fb8047b156bb 939
rahul_dahiya 0:fb8047b156bb 940 /*
rahul_dahiya 0:fb8047b156bb 941 * Helper for mbedtls_mpi subtraction
rahul_dahiya 0:fb8047b156bb 942 */
rahul_dahiya 0:fb8047b156bb 943 static void mpi_sub_hlp( size_t n, mbedtls_mpi_uint *s, mbedtls_mpi_uint *d )
rahul_dahiya 0:fb8047b156bb 944 {
rahul_dahiya 0:fb8047b156bb 945 size_t i;
rahul_dahiya 0:fb8047b156bb 946 mbedtls_mpi_uint c, z;
rahul_dahiya 0:fb8047b156bb 947
rahul_dahiya 0:fb8047b156bb 948 for( i = c = 0; i < n; i++, s++, d++ )
rahul_dahiya 0:fb8047b156bb 949 {
rahul_dahiya 0:fb8047b156bb 950 z = ( *d < c ); *d -= c;
rahul_dahiya 0:fb8047b156bb 951 c = ( *d < *s ) + z; *d -= *s;
rahul_dahiya 0:fb8047b156bb 952 }
rahul_dahiya 0:fb8047b156bb 953
rahul_dahiya 0:fb8047b156bb 954 while( c != 0 )
rahul_dahiya 0:fb8047b156bb 955 {
rahul_dahiya 0:fb8047b156bb 956 z = ( *d < c ); *d -= c;
rahul_dahiya 0:fb8047b156bb 957 c = z; i++; d++;
rahul_dahiya 0:fb8047b156bb 958 }
rahul_dahiya 0:fb8047b156bb 959 }
rahul_dahiya 0:fb8047b156bb 960
rahul_dahiya 0:fb8047b156bb 961 /*
rahul_dahiya 0:fb8047b156bb 962 * Unsigned subtraction: X = |A| - |B| (HAC 14.9)
rahul_dahiya 0:fb8047b156bb 963 */
rahul_dahiya 0:fb8047b156bb 964 int mbedtls_mpi_sub_abs( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
rahul_dahiya 0:fb8047b156bb 965 {
rahul_dahiya 0:fb8047b156bb 966 mbedtls_mpi TB;
rahul_dahiya 0:fb8047b156bb 967 int ret;
rahul_dahiya 0:fb8047b156bb 968 size_t n;
rahul_dahiya 0:fb8047b156bb 969
rahul_dahiya 0:fb8047b156bb 970 if( mbedtls_mpi_cmp_abs( A, B ) < 0 )
rahul_dahiya 0:fb8047b156bb 971 return( MBEDTLS_ERR_MPI_NEGATIVE_VALUE );
rahul_dahiya 0:fb8047b156bb 972
rahul_dahiya 0:fb8047b156bb 973 mbedtls_mpi_init( &TB );
rahul_dahiya 0:fb8047b156bb 974
rahul_dahiya 0:fb8047b156bb 975 if( X == B )
rahul_dahiya 0:fb8047b156bb 976 {
rahul_dahiya 0:fb8047b156bb 977 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TB, B ) );
rahul_dahiya 0:fb8047b156bb 978 B = &TB;
rahul_dahiya 0:fb8047b156bb 979 }
rahul_dahiya 0:fb8047b156bb 980
rahul_dahiya 0:fb8047b156bb 981 if( X != A )
rahul_dahiya 0:fb8047b156bb 982 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( X, A ) );
rahul_dahiya 0:fb8047b156bb 983
rahul_dahiya 0:fb8047b156bb 984 /*
rahul_dahiya 0:fb8047b156bb 985 * X should always be positive as a result of unsigned subtractions.
rahul_dahiya 0:fb8047b156bb 986 */
rahul_dahiya 0:fb8047b156bb 987 X->s = 1;
rahul_dahiya 0:fb8047b156bb 988
rahul_dahiya 0:fb8047b156bb 989 ret = 0;
rahul_dahiya 0:fb8047b156bb 990
rahul_dahiya 0:fb8047b156bb 991 for( n = B->n; n > 0; n-- )
rahul_dahiya 0:fb8047b156bb 992 if( B->p[n - 1] != 0 )
rahul_dahiya 0:fb8047b156bb 993 break;
rahul_dahiya 0:fb8047b156bb 994
rahul_dahiya 0:fb8047b156bb 995 mpi_sub_hlp( n, B->p, X->p );
rahul_dahiya 0:fb8047b156bb 996
rahul_dahiya 0:fb8047b156bb 997 cleanup:
rahul_dahiya 0:fb8047b156bb 998
rahul_dahiya 0:fb8047b156bb 999 mbedtls_mpi_free( &TB );
rahul_dahiya 0:fb8047b156bb 1000
rahul_dahiya 0:fb8047b156bb 1001 return( ret );
rahul_dahiya 0:fb8047b156bb 1002 }
rahul_dahiya 0:fb8047b156bb 1003
rahul_dahiya 0:fb8047b156bb 1004 /*
rahul_dahiya 0:fb8047b156bb 1005 * Signed addition: X = A + B
rahul_dahiya 0:fb8047b156bb 1006 */
rahul_dahiya 0:fb8047b156bb 1007 int mbedtls_mpi_add_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
rahul_dahiya 0:fb8047b156bb 1008 {
rahul_dahiya 0:fb8047b156bb 1009 int ret, s = A->s;
rahul_dahiya 0:fb8047b156bb 1010
rahul_dahiya 0:fb8047b156bb 1011 if( A->s * B->s < 0 )
rahul_dahiya 0:fb8047b156bb 1012 {
rahul_dahiya 0:fb8047b156bb 1013 if( mbedtls_mpi_cmp_abs( A, B ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1014 {
rahul_dahiya 0:fb8047b156bb 1015 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( X, A, B ) );
rahul_dahiya 0:fb8047b156bb 1016 X->s = s;
rahul_dahiya 0:fb8047b156bb 1017 }
rahul_dahiya 0:fb8047b156bb 1018 else
rahul_dahiya 0:fb8047b156bb 1019 {
rahul_dahiya 0:fb8047b156bb 1020 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( X, B, A ) );
rahul_dahiya 0:fb8047b156bb 1021 X->s = -s;
rahul_dahiya 0:fb8047b156bb 1022 }
rahul_dahiya 0:fb8047b156bb 1023 }
rahul_dahiya 0:fb8047b156bb 1024 else
rahul_dahiya 0:fb8047b156bb 1025 {
rahul_dahiya 0:fb8047b156bb 1026 MBEDTLS_MPI_CHK( mbedtls_mpi_add_abs( X, A, B ) );
rahul_dahiya 0:fb8047b156bb 1027 X->s = s;
rahul_dahiya 0:fb8047b156bb 1028 }
rahul_dahiya 0:fb8047b156bb 1029
rahul_dahiya 0:fb8047b156bb 1030 cleanup:
rahul_dahiya 0:fb8047b156bb 1031
rahul_dahiya 0:fb8047b156bb 1032 return( ret );
rahul_dahiya 0:fb8047b156bb 1033 }
rahul_dahiya 0:fb8047b156bb 1034
rahul_dahiya 0:fb8047b156bb 1035 /*
rahul_dahiya 0:fb8047b156bb 1036 * Signed subtraction: X = A - B
rahul_dahiya 0:fb8047b156bb 1037 */
rahul_dahiya 0:fb8047b156bb 1038 int mbedtls_mpi_sub_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
rahul_dahiya 0:fb8047b156bb 1039 {
rahul_dahiya 0:fb8047b156bb 1040 int ret, s = A->s;
rahul_dahiya 0:fb8047b156bb 1041
rahul_dahiya 0:fb8047b156bb 1042 if( A->s * B->s > 0 )
rahul_dahiya 0:fb8047b156bb 1043 {
rahul_dahiya 0:fb8047b156bb 1044 if( mbedtls_mpi_cmp_abs( A, B ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1045 {
rahul_dahiya 0:fb8047b156bb 1046 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( X, A, B ) );
rahul_dahiya 0:fb8047b156bb 1047 X->s = s;
rahul_dahiya 0:fb8047b156bb 1048 }
rahul_dahiya 0:fb8047b156bb 1049 else
rahul_dahiya 0:fb8047b156bb 1050 {
rahul_dahiya 0:fb8047b156bb 1051 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( X, B, A ) );
rahul_dahiya 0:fb8047b156bb 1052 X->s = -s;
rahul_dahiya 0:fb8047b156bb 1053 }
rahul_dahiya 0:fb8047b156bb 1054 }
rahul_dahiya 0:fb8047b156bb 1055 else
rahul_dahiya 0:fb8047b156bb 1056 {
rahul_dahiya 0:fb8047b156bb 1057 MBEDTLS_MPI_CHK( mbedtls_mpi_add_abs( X, A, B ) );
rahul_dahiya 0:fb8047b156bb 1058 X->s = s;
rahul_dahiya 0:fb8047b156bb 1059 }
rahul_dahiya 0:fb8047b156bb 1060
rahul_dahiya 0:fb8047b156bb 1061 cleanup:
rahul_dahiya 0:fb8047b156bb 1062
rahul_dahiya 0:fb8047b156bb 1063 return( ret );
rahul_dahiya 0:fb8047b156bb 1064 }
rahul_dahiya 0:fb8047b156bb 1065
rahul_dahiya 0:fb8047b156bb 1066 /*
rahul_dahiya 0:fb8047b156bb 1067 * Signed addition: X = A + b
rahul_dahiya 0:fb8047b156bb 1068 */
rahul_dahiya 0:fb8047b156bb 1069 int mbedtls_mpi_add_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint b )
rahul_dahiya 0:fb8047b156bb 1070 {
rahul_dahiya 0:fb8047b156bb 1071 mbedtls_mpi _B;
rahul_dahiya 0:fb8047b156bb 1072 mbedtls_mpi_uint p[1];
rahul_dahiya 0:fb8047b156bb 1073
rahul_dahiya 0:fb8047b156bb 1074 p[0] = ( b < 0 ) ? -b : b;
rahul_dahiya 0:fb8047b156bb 1075 _B.s = ( b < 0 ) ? -1 : 1;
rahul_dahiya 0:fb8047b156bb 1076 _B.n = 1;
rahul_dahiya 0:fb8047b156bb 1077 _B.p = p;
rahul_dahiya 0:fb8047b156bb 1078
rahul_dahiya 0:fb8047b156bb 1079 return( mbedtls_mpi_add_mpi( X, A, &_B ) );
rahul_dahiya 0:fb8047b156bb 1080 }
rahul_dahiya 0:fb8047b156bb 1081
rahul_dahiya 0:fb8047b156bb 1082 /*
rahul_dahiya 0:fb8047b156bb 1083 * Signed subtraction: X = A - b
rahul_dahiya 0:fb8047b156bb 1084 */
rahul_dahiya 0:fb8047b156bb 1085 int mbedtls_mpi_sub_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_sint b )
rahul_dahiya 0:fb8047b156bb 1086 {
rahul_dahiya 0:fb8047b156bb 1087 mbedtls_mpi _B;
rahul_dahiya 0:fb8047b156bb 1088 mbedtls_mpi_uint p[1];
rahul_dahiya 0:fb8047b156bb 1089
rahul_dahiya 0:fb8047b156bb 1090 p[0] = ( b < 0 ) ? -b : b;
rahul_dahiya 0:fb8047b156bb 1091 _B.s = ( b < 0 ) ? -1 : 1;
rahul_dahiya 0:fb8047b156bb 1092 _B.n = 1;
rahul_dahiya 0:fb8047b156bb 1093 _B.p = p;
rahul_dahiya 0:fb8047b156bb 1094
rahul_dahiya 0:fb8047b156bb 1095 return( mbedtls_mpi_sub_mpi( X, A, &_B ) );
rahul_dahiya 0:fb8047b156bb 1096 }
rahul_dahiya 0:fb8047b156bb 1097
rahul_dahiya 0:fb8047b156bb 1098 /*
rahul_dahiya 0:fb8047b156bb 1099 * Helper for mbedtls_mpi multiplication
rahul_dahiya 0:fb8047b156bb 1100 */
rahul_dahiya 0:fb8047b156bb 1101 static
rahul_dahiya 0:fb8047b156bb 1102 #if defined(__APPLE__) && defined(__arm__)
rahul_dahiya 0:fb8047b156bb 1103 /*
rahul_dahiya 0:fb8047b156bb 1104 * Apple LLVM version 4.2 (clang-425.0.24) (based on LLVM 3.2svn)
rahul_dahiya 0:fb8047b156bb 1105 * appears to need this to prevent bad ARM code generation at -O3.
rahul_dahiya 0:fb8047b156bb 1106 */
rahul_dahiya 0:fb8047b156bb 1107 __attribute__ ((noinline))
rahul_dahiya 0:fb8047b156bb 1108 #endif
rahul_dahiya 0:fb8047b156bb 1109 void mpi_mul_hlp( size_t i, mbedtls_mpi_uint *s, mbedtls_mpi_uint *d, mbedtls_mpi_uint b )
rahul_dahiya 0:fb8047b156bb 1110 {
rahul_dahiya 0:fb8047b156bb 1111 mbedtls_mpi_uint c = 0, t = 0;
rahul_dahiya 0:fb8047b156bb 1112
rahul_dahiya 0:fb8047b156bb 1113 #if defined(MULADDC_HUIT)
rahul_dahiya 0:fb8047b156bb 1114 for( ; i >= 8; i -= 8 )
rahul_dahiya 0:fb8047b156bb 1115 {
rahul_dahiya 0:fb8047b156bb 1116 MULADDC_INIT
rahul_dahiya 0:fb8047b156bb 1117 MULADDC_HUIT
rahul_dahiya 0:fb8047b156bb 1118 MULADDC_STOP
rahul_dahiya 0:fb8047b156bb 1119 }
rahul_dahiya 0:fb8047b156bb 1120
rahul_dahiya 0:fb8047b156bb 1121 for( ; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 1122 {
rahul_dahiya 0:fb8047b156bb 1123 MULADDC_INIT
rahul_dahiya 0:fb8047b156bb 1124 MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1125 MULADDC_STOP
rahul_dahiya 0:fb8047b156bb 1126 }
rahul_dahiya 0:fb8047b156bb 1127 #else /* MULADDC_HUIT */
rahul_dahiya 0:fb8047b156bb 1128 for( ; i >= 16; i -= 16 )
rahul_dahiya 0:fb8047b156bb 1129 {
rahul_dahiya 0:fb8047b156bb 1130 MULADDC_INIT
rahul_dahiya 0:fb8047b156bb 1131 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1132 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1133 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1134 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1135
rahul_dahiya 0:fb8047b156bb 1136 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1137 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1138 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1139 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1140 MULADDC_STOP
rahul_dahiya 0:fb8047b156bb 1141 }
rahul_dahiya 0:fb8047b156bb 1142
rahul_dahiya 0:fb8047b156bb 1143 for( ; i >= 8; i -= 8 )
rahul_dahiya 0:fb8047b156bb 1144 {
rahul_dahiya 0:fb8047b156bb 1145 MULADDC_INIT
rahul_dahiya 0:fb8047b156bb 1146 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1147 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1148
rahul_dahiya 0:fb8047b156bb 1149 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1150 MULADDC_CORE MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1151 MULADDC_STOP
rahul_dahiya 0:fb8047b156bb 1152 }
rahul_dahiya 0:fb8047b156bb 1153
rahul_dahiya 0:fb8047b156bb 1154 for( ; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 1155 {
rahul_dahiya 0:fb8047b156bb 1156 MULADDC_INIT
rahul_dahiya 0:fb8047b156bb 1157 MULADDC_CORE
rahul_dahiya 0:fb8047b156bb 1158 MULADDC_STOP
rahul_dahiya 0:fb8047b156bb 1159 }
rahul_dahiya 0:fb8047b156bb 1160 #endif /* MULADDC_HUIT */
rahul_dahiya 0:fb8047b156bb 1161
rahul_dahiya 0:fb8047b156bb 1162 t++;
rahul_dahiya 0:fb8047b156bb 1163
rahul_dahiya 0:fb8047b156bb 1164 do {
rahul_dahiya 0:fb8047b156bb 1165 *d += c; c = ( *d < c ); d++;
rahul_dahiya 0:fb8047b156bb 1166 }
rahul_dahiya 0:fb8047b156bb 1167 while( c != 0 );
rahul_dahiya 0:fb8047b156bb 1168 }
rahul_dahiya 0:fb8047b156bb 1169
rahul_dahiya 0:fb8047b156bb 1170 /*
rahul_dahiya 0:fb8047b156bb 1171 * Baseline multiplication: X = A * B (HAC 14.12)
rahul_dahiya 0:fb8047b156bb 1172 */
rahul_dahiya 0:fb8047b156bb 1173 int mbedtls_mpi_mul_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
rahul_dahiya 0:fb8047b156bb 1174 {
rahul_dahiya 0:fb8047b156bb 1175 int ret;
rahul_dahiya 0:fb8047b156bb 1176 size_t i, j;
rahul_dahiya 0:fb8047b156bb 1177 mbedtls_mpi TA, TB;
rahul_dahiya 0:fb8047b156bb 1178
rahul_dahiya 0:fb8047b156bb 1179 mbedtls_mpi_init( &TA ); mbedtls_mpi_init( &TB );
rahul_dahiya 0:fb8047b156bb 1180
rahul_dahiya 0:fb8047b156bb 1181 if( X == A ) { MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TA, A ) ); A = &TA; }
rahul_dahiya 0:fb8047b156bb 1182 if( X == B ) { MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TB, B ) ); B = &TB; }
rahul_dahiya 0:fb8047b156bb 1183
rahul_dahiya 0:fb8047b156bb 1184 for( i = A->n; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 1185 if( A->p[i - 1] != 0 )
rahul_dahiya 0:fb8047b156bb 1186 break;
rahul_dahiya 0:fb8047b156bb 1187
rahul_dahiya 0:fb8047b156bb 1188 for( j = B->n; j > 0; j-- )
rahul_dahiya 0:fb8047b156bb 1189 if( B->p[j - 1] != 0 )
rahul_dahiya 0:fb8047b156bb 1190 break;
rahul_dahiya 0:fb8047b156bb 1191
rahul_dahiya 0:fb8047b156bb 1192 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, i + j ) );
rahul_dahiya 0:fb8047b156bb 1193 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( X, 0 ) );
rahul_dahiya 0:fb8047b156bb 1194
rahul_dahiya 0:fb8047b156bb 1195 for( i++; j > 0; j-- )
rahul_dahiya 0:fb8047b156bb 1196 mpi_mul_hlp( i - 1, A->p, X->p + j - 1, B->p[j - 1] );
rahul_dahiya 0:fb8047b156bb 1197
rahul_dahiya 0:fb8047b156bb 1198 X->s = A->s * B->s;
rahul_dahiya 0:fb8047b156bb 1199
rahul_dahiya 0:fb8047b156bb 1200 cleanup:
rahul_dahiya 0:fb8047b156bb 1201
rahul_dahiya 0:fb8047b156bb 1202 mbedtls_mpi_free( &TB ); mbedtls_mpi_free( &TA );
rahul_dahiya 0:fb8047b156bb 1203
rahul_dahiya 0:fb8047b156bb 1204 return( ret );
rahul_dahiya 0:fb8047b156bb 1205 }
rahul_dahiya 0:fb8047b156bb 1206
rahul_dahiya 0:fb8047b156bb 1207 /*
rahul_dahiya 0:fb8047b156bb 1208 * Baseline multiplication: X = A * b
rahul_dahiya 0:fb8047b156bb 1209 */
rahul_dahiya 0:fb8047b156bb 1210 int mbedtls_mpi_mul_int( mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_uint b )
rahul_dahiya 0:fb8047b156bb 1211 {
rahul_dahiya 0:fb8047b156bb 1212 mbedtls_mpi _B;
rahul_dahiya 0:fb8047b156bb 1213 mbedtls_mpi_uint p[1];
rahul_dahiya 0:fb8047b156bb 1214
rahul_dahiya 0:fb8047b156bb 1215 _B.s = 1;
rahul_dahiya 0:fb8047b156bb 1216 _B.n = 1;
rahul_dahiya 0:fb8047b156bb 1217 _B.p = p;
rahul_dahiya 0:fb8047b156bb 1218 p[0] = b;
rahul_dahiya 0:fb8047b156bb 1219
rahul_dahiya 0:fb8047b156bb 1220 return( mbedtls_mpi_mul_mpi( X, A, &_B ) );
rahul_dahiya 0:fb8047b156bb 1221 }
rahul_dahiya 0:fb8047b156bb 1222
rahul_dahiya 0:fb8047b156bb 1223 /*
rahul_dahiya 0:fb8047b156bb 1224 * Unsigned integer divide - double mbedtls_mpi_uint dividend, u1/u0, and
rahul_dahiya 0:fb8047b156bb 1225 * mbedtls_mpi_uint divisor, d
rahul_dahiya 0:fb8047b156bb 1226 */
rahul_dahiya 0:fb8047b156bb 1227 static mbedtls_mpi_uint mbedtls_int_div_int( mbedtls_mpi_uint u1,
rahul_dahiya 0:fb8047b156bb 1228 mbedtls_mpi_uint u0, mbedtls_mpi_uint d, mbedtls_mpi_uint *r )
rahul_dahiya 0:fb8047b156bb 1229 {
rahul_dahiya 0:fb8047b156bb 1230 #if defined(MBEDTLS_HAVE_UDBL)
rahul_dahiya 0:fb8047b156bb 1231 mbedtls_t_udbl dividend, quotient;
rahul_dahiya 0:fb8047b156bb 1232 #else
rahul_dahiya 0:fb8047b156bb 1233 const mbedtls_mpi_uint radix = (mbedtls_mpi_uint) 1 << biH;
rahul_dahiya 0:fb8047b156bb 1234 const mbedtls_mpi_uint uint_halfword_mask = ( (mbedtls_mpi_uint) 1 << biH ) - 1;
rahul_dahiya 0:fb8047b156bb 1235 mbedtls_mpi_uint d0, d1, q0, q1, rAX, r0, quotient;
rahul_dahiya 0:fb8047b156bb 1236 mbedtls_mpi_uint u0_msw, u0_lsw;
rahul_dahiya 0:fb8047b156bb 1237 size_t s;
rahul_dahiya 0:fb8047b156bb 1238 #endif
rahul_dahiya 0:fb8047b156bb 1239
rahul_dahiya 0:fb8047b156bb 1240 /*
rahul_dahiya 0:fb8047b156bb 1241 * Check for overflow
rahul_dahiya 0:fb8047b156bb 1242 */
rahul_dahiya 0:fb8047b156bb 1243 if( 0 == d || u1 >= d )
rahul_dahiya 0:fb8047b156bb 1244 {
rahul_dahiya 0:fb8047b156bb 1245 if (r != NULL) *r = ~0;
rahul_dahiya 0:fb8047b156bb 1246
rahul_dahiya 0:fb8047b156bb 1247 return ( ~0 );
rahul_dahiya 0:fb8047b156bb 1248 }
rahul_dahiya 0:fb8047b156bb 1249
rahul_dahiya 0:fb8047b156bb 1250 #if defined(MBEDTLS_HAVE_UDBL)
rahul_dahiya 0:fb8047b156bb 1251 dividend = (mbedtls_t_udbl) u1 << biL;
rahul_dahiya 0:fb8047b156bb 1252 dividend |= (mbedtls_t_udbl) u0;
rahul_dahiya 0:fb8047b156bb 1253 quotient = dividend / d;
rahul_dahiya 0:fb8047b156bb 1254 if( quotient > ( (mbedtls_t_udbl) 1 << biL ) - 1 )
rahul_dahiya 0:fb8047b156bb 1255 quotient = ( (mbedtls_t_udbl) 1 << biL ) - 1;
rahul_dahiya 0:fb8047b156bb 1256
rahul_dahiya 0:fb8047b156bb 1257 if( r != NULL )
rahul_dahiya 0:fb8047b156bb 1258 *r = (mbedtls_mpi_uint)( dividend - (quotient * d ) );
rahul_dahiya 0:fb8047b156bb 1259
rahul_dahiya 0:fb8047b156bb 1260 return (mbedtls_mpi_uint) quotient;
rahul_dahiya 0:fb8047b156bb 1261 #else
rahul_dahiya 0:fb8047b156bb 1262
rahul_dahiya 0:fb8047b156bb 1263 /*
rahul_dahiya 0:fb8047b156bb 1264 * Algorithm D, Section 4.3.1 - The Art of Computer Programming
rahul_dahiya 0:fb8047b156bb 1265 * Vol. 2 - Seminumerical Algorithms, Knuth
rahul_dahiya 0:fb8047b156bb 1266 */
rahul_dahiya 0:fb8047b156bb 1267
rahul_dahiya 0:fb8047b156bb 1268 /*
rahul_dahiya 0:fb8047b156bb 1269 * Normalize the divisor, d, and dividend, u0, u1
rahul_dahiya 0:fb8047b156bb 1270 */
rahul_dahiya 0:fb8047b156bb 1271 s = mbedtls_clz( d );
rahul_dahiya 0:fb8047b156bb 1272 d = d << s;
rahul_dahiya 0:fb8047b156bb 1273
rahul_dahiya 0:fb8047b156bb 1274 u1 = u1 << s;
rahul_dahiya 0:fb8047b156bb 1275 u1 |= ( u0 >> ( biL - s ) ) & ( -(mbedtls_mpi_sint)s >> ( biL - 1 ) );
rahul_dahiya 0:fb8047b156bb 1276 u0 = u0 << s;
rahul_dahiya 0:fb8047b156bb 1277
rahul_dahiya 0:fb8047b156bb 1278 d1 = d >> biH;
rahul_dahiya 0:fb8047b156bb 1279 d0 = d & uint_halfword_mask;
rahul_dahiya 0:fb8047b156bb 1280
rahul_dahiya 0:fb8047b156bb 1281 u0_msw = u0 >> biH;
rahul_dahiya 0:fb8047b156bb 1282 u0_lsw = u0 & uint_halfword_mask;
rahul_dahiya 0:fb8047b156bb 1283
rahul_dahiya 0:fb8047b156bb 1284 /*
rahul_dahiya 0:fb8047b156bb 1285 * Find the first quotient and remainder
rahul_dahiya 0:fb8047b156bb 1286 */
rahul_dahiya 0:fb8047b156bb 1287 q1 = u1 / d1;
rahul_dahiya 0:fb8047b156bb 1288 r0 = u1 - d1 * q1;
rahul_dahiya 0:fb8047b156bb 1289
rahul_dahiya 0:fb8047b156bb 1290 while( q1 >= radix || ( q1 * d0 > radix * r0 + u0_msw ) )
rahul_dahiya 0:fb8047b156bb 1291 {
rahul_dahiya 0:fb8047b156bb 1292 q1 -= 1;
rahul_dahiya 0:fb8047b156bb 1293 r0 += d1;
rahul_dahiya 0:fb8047b156bb 1294
rahul_dahiya 0:fb8047b156bb 1295 if ( r0 >= radix ) break;
rahul_dahiya 0:fb8047b156bb 1296 }
rahul_dahiya 0:fb8047b156bb 1297
rahul_dahiya 0:fb8047b156bb 1298 rAX = ( u1 * radix ) + ( u0_msw - q1 * d );
rahul_dahiya 0:fb8047b156bb 1299 q0 = rAX / d1;
rahul_dahiya 0:fb8047b156bb 1300 r0 = rAX - q0 * d1;
rahul_dahiya 0:fb8047b156bb 1301
rahul_dahiya 0:fb8047b156bb 1302 while( q0 >= radix || ( q0 * d0 > radix * r0 + u0_lsw ) )
rahul_dahiya 0:fb8047b156bb 1303 {
rahul_dahiya 0:fb8047b156bb 1304 q0 -= 1;
rahul_dahiya 0:fb8047b156bb 1305 r0 += d1;
rahul_dahiya 0:fb8047b156bb 1306
rahul_dahiya 0:fb8047b156bb 1307 if ( r0 >= radix ) break;
rahul_dahiya 0:fb8047b156bb 1308 }
rahul_dahiya 0:fb8047b156bb 1309
rahul_dahiya 0:fb8047b156bb 1310 if (r != NULL)
rahul_dahiya 0:fb8047b156bb 1311 *r = ( rAX * radix + u0_lsw - q0 * d ) >> s;
rahul_dahiya 0:fb8047b156bb 1312
rahul_dahiya 0:fb8047b156bb 1313 quotient = q1 * radix + q0;
rahul_dahiya 0:fb8047b156bb 1314
rahul_dahiya 0:fb8047b156bb 1315 return quotient;
rahul_dahiya 0:fb8047b156bb 1316 #endif
rahul_dahiya 0:fb8047b156bb 1317 }
rahul_dahiya 0:fb8047b156bb 1318
rahul_dahiya 0:fb8047b156bb 1319 /*
rahul_dahiya 0:fb8047b156bb 1320 * Division by mbedtls_mpi: A = Q * B + R (HAC 14.20)
rahul_dahiya 0:fb8047b156bb 1321 */
rahul_dahiya 0:fb8047b156bb 1322 int mbedtls_mpi_div_mpi( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B )
rahul_dahiya 0:fb8047b156bb 1323 {
rahul_dahiya 0:fb8047b156bb 1324 int ret;
rahul_dahiya 0:fb8047b156bb 1325 size_t i, n, t, k;
rahul_dahiya 0:fb8047b156bb 1326 mbedtls_mpi X, Y, Z, T1, T2;
rahul_dahiya 0:fb8047b156bb 1327
rahul_dahiya 0:fb8047b156bb 1328 if( mbedtls_mpi_cmp_int( B, 0 ) == 0 )
rahul_dahiya 0:fb8047b156bb 1329 return( MBEDTLS_ERR_MPI_DIVISION_BY_ZERO );
rahul_dahiya 0:fb8047b156bb 1330
rahul_dahiya 0:fb8047b156bb 1331 mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &Z );
rahul_dahiya 0:fb8047b156bb 1332 mbedtls_mpi_init( &T1 ); mbedtls_mpi_init( &T2 );
rahul_dahiya 0:fb8047b156bb 1333
rahul_dahiya 0:fb8047b156bb 1334 if( mbedtls_mpi_cmp_abs( A, B ) < 0 )
rahul_dahiya 0:fb8047b156bb 1335 {
rahul_dahiya 0:fb8047b156bb 1336 if( Q != NULL ) MBEDTLS_MPI_CHK( mbedtls_mpi_lset( Q, 0 ) );
rahul_dahiya 0:fb8047b156bb 1337 if( R != NULL ) MBEDTLS_MPI_CHK( mbedtls_mpi_copy( R, A ) );
rahul_dahiya 0:fb8047b156bb 1338 return( 0 );
rahul_dahiya 0:fb8047b156bb 1339 }
rahul_dahiya 0:fb8047b156bb 1340
rahul_dahiya 0:fb8047b156bb 1341 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &X, A ) );
rahul_dahiya 0:fb8047b156bb 1342 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &Y, B ) );
rahul_dahiya 0:fb8047b156bb 1343 X.s = Y.s = 1;
rahul_dahiya 0:fb8047b156bb 1344
rahul_dahiya 0:fb8047b156bb 1345 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( &Z, A->n + 2 ) );
rahul_dahiya 0:fb8047b156bb 1346 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &Z, 0 ) );
rahul_dahiya 0:fb8047b156bb 1347 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( &T1, 2 ) );
rahul_dahiya 0:fb8047b156bb 1348 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( &T2, 3 ) );
rahul_dahiya 0:fb8047b156bb 1349
rahul_dahiya 0:fb8047b156bb 1350 k = mbedtls_mpi_bitlen( &Y ) % biL;
rahul_dahiya 0:fb8047b156bb 1351 if( k < biL - 1 )
rahul_dahiya 0:fb8047b156bb 1352 {
rahul_dahiya 0:fb8047b156bb 1353 k = biL - 1 - k;
rahul_dahiya 0:fb8047b156bb 1354 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &X, k ) );
rahul_dahiya 0:fb8047b156bb 1355 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &Y, k ) );
rahul_dahiya 0:fb8047b156bb 1356 }
rahul_dahiya 0:fb8047b156bb 1357 else k = 0;
rahul_dahiya 0:fb8047b156bb 1358
rahul_dahiya 0:fb8047b156bb 1359 n = X.n - 1;
rahul_dahiya 0:fb8047b156bb 1360 t = Y.n - 1;
rahul_dahiya 0:fb8047b156bb 1361 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &Y, biL * ( n - t ) ) );
rahul_dahiya 0:fb8047b156bb 1362
rahul_dahiya 0:fb8047b156bb 1363 while( mbedtls_mpi_cmp_mpi( &X, &Y ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1364 {
rahul_dahiya 0:fb8047b156bb 1365 Z.p[n - t]++;
rahul_dahiya 0:fb8047b156bb 1366 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &X, &X, &Y ) );
rahul_dahiya 0:fb8047b156bb 1367 }
rahul_dahiya 0:fb8047b156bb 1368 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &Y, biL * ( n - t ) ) );
rahul_dahiya 0:fb8047b156bb 1369
rahul_dahiya 0:fb8047b156bb 1370 for( i = n; i > t ; i-- )
rahul_dahiya 0:fb8047b156bb 1371 {
rahul_dahiya 0:fb8047b156bb 1372 if( X.p[i] >= Y.p[t] )
rahul_dahiya 0:fb8047b156bb 1373 Z.p[i - t - 1] = ~0;
rahul_dahiya 0:fb8047b156bb 1374 else
rahul_dahiya 0:fb8047b156bb 1375 {
rahul_dahiya 0:fb8047b156bb 1376 Z.p[i - t - 1] = mbedtls_int_div_int( X.p[i], X.p[i - 1],
rahul_dahiya 0:fb8047b156bb 1377 Y.p[t], NULL);
rahul_dahiya 0:fb8047b156bb 1378 }
rahul_dahiya 0:fb8047b156bb 1379
rahul_dahiya 0:fb8047b156bb 1380 Z.p[i - t - 1]++;
rahul_dahiya 0:fb8047b156bb 1381 do
rahul_dahiya 0:fb8047b156bb 1382 {
rahul_dahiya 0:fb8047b156bb 1383 Z.p[i - t - 1]--;
rahul_dahiya 0:fb8047b156bb 1384
rahul_dahiya 0:fb8047b156bb 1385 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &T1, 0 ) );
rahul_dahiya 0:fb8047b156bb 1386 T1.p[0] = ( t < 1 ) ? 0 : Y.p[t - 1];
rahul_dahiya 0:fb8047b156bb 1387 T1.p[1] = Y.p[t];
rahul_dahiya 0:fb8047b156bb 1388 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_int( &T1, &T1, Z.p[i - t - 1] ) );
rahul_dahiya 0:fb8047b156bb 1389
rahul_dahiya 0:fb8047b156bb 1390 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &T2, 0 ) );
rahul_dahiya 0:fb8047b156bb 1391 T2.p[0] = ( i < 2 ) ? 0 : X.p[i - 2];
rahul_dahiya 0:fb8047b156bb 1392 T2.p[1] = ( i < 1 ) ? 0 : X.p[i - 1];
rahul_dahiya 0:fb8047b156bb 1393 T2.p[2] = X.p[i];
rahul_dahiya 0:fb8047b156bb 1394 }
rahul_dahiya 0:fb8047b156bb 1395 while( mbedtls_mpi_cmp_mpi( &T1, &T2 ) > 0 );
rahul_dahiya 0:fb8047b156bb 1396
rahul_dahiya 0:fb8047b156bb 1397 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_int( &T1, &Y, Z.p[i - t - 1] ) );
rahul_dahiya 0:fb8047b156bb 1398 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &T1, biL * ( i - t - 1 ) ) );
rahul_dahiya 0:fb8047b156bb 1399 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &X, &X, &T1 ) );
rahul_dahiya 0:fb8047b156bb 1400
rahul_dahiya 0:fb8047b156bb 1401 if( mbedtls_mpi_cmp_int( &X, 0 ) < 0 )
rahul_dahiya 0:fb8047b156bb 1402 {
rahul_dahiya 0:fb8047b156bb 1403 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &T1, &Y ) );
rahul_dahiya 0:fb8047b156bb 1404 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &T1, biL * ( i - t - 1 ) ) );
rahul_dahiya 0:fb8047b156bb 1405 MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &X, &X, &T1 ) );
rahul_dahiya 0:fb8047b156bb 1406 Z.p[i - t - 1]--;
rahul_dahiya 0:fb8047b156bb 1407 }
rahul_dahiya 0:fb8047b156bb 1408 }
rahul_dahiya 0:fb8047b156bb 1409
rahul_dahiya 0:fb8047b156bb 1410 if( Q != NULL )
rahul_dahiya 0:fb8047b156bb 1411 {
rahul_dahiya 0:fb8047b156bb 1412 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( Q, &Z ) );
rahul_dahiya 0:fb8047b156bb 1413 Q->s = A->s * B->s;
rahul_dahiya 0:fb8047b156bb 1414 }
rahul_dahiya 0:fb8047b156bb 1415
rahul_dahiya 0:fb8047b156bb 1416 if( R != NULL )
rahul_dahiya 0:fb8047b156bb 1417 {
rahul_dahiya 0:fb8047b156bb 1418 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &X, k ) );
rahul_dahiya 0:fb8047b156bb 1419 X.s = A->s;
rahul_dahiya 0:fb8047b156bb 1420 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( R, &X ) );
rahul_dahiya 0:fb8047b156bb 1421
rahul_dahiya 0:fb8047b156bb 1422 if( mbedtls_mpi_cmp_int( R, 0 ) == 0 )
rahul_dahiya 0:fb8047b156bb 1423 R->s = 1;
rahul_dahiya 0:fb8047b156bb 1424 }
rahul_dahiya 0:fb8047b156bb 1425
rahul_dahiya 0:fb8047b156bb 1426 cleanup:
rahul_dahiya 0:fb8047b156bb 1427
rahul_dahiya 0:fb8047b156bb 1428 mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z );
rahul_dahiya 0:fb8047b156bb 1429 mbedtls_mpi_free( &T1 ); mbedtls_mpi_free( &T2 );
rahul_dahiya 0:fb8047b156bb 1430
rahul_dahiya 0:fb8047b156bb 1431 return( ret );
rahul_dahiya 0:fb8047b156bb 1432 }
rahul_dahiya 0:fb8047b156bb 1433
rahul_dahiya 0:fb8047b156bb 1434 /*
rahul_dahiya 0:fb8047b156bb 1435 * Division by int: A = Q * b + R
rahul_dahiya 0:fb8047b156bb 1436 */
rahul_dahiya 0:fb8047b156bb 1437 int mbedtls_mpi_div_int( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, mbedtls_mpi_sint b )
rahul_dahiya 0:fb8047b156bb 1438 {
rahul_dahiya 0:fb8047b156bb 1439 mbedtls_mpi _B;
rahul_dahiya 0:fb8047b156bb 1440 mbedtls_mpi_uint p[1];
rahul_dahiya 0:fb8047b156bb 1441
rahul_dahiya 0:fb8047b156bb 1442 p[0] = ( b < 0 ) ? -b : b;
rahul_dahiya 0:fb8047b156bb 1443 _B.s = ( b < 0 ) ? -1 : 1;
rahul_dahiya 0:fb8047b156bb 1444 _B.n = 1;
rahul_dahiya 0:fb8047b156bb 1445 _B.p = p;
rahul_dahiya 0:fb8047b156bb 1446
rahul_dahiya 0:fb8047b156bb 1447 return( mbedtls_mpi_div_mpi( Q, R, A, &_B ) );
rahul_dahiya 0:fb8047b156bb 1448 }
rahul_dahiya 0:fb8047b156bb 1449
rahul_dahiya 0:fb8047b156bb 1450 /*
rahul_dahiya 0:fb8047b156bb 1451 * Modulo: R = A mod B
rahul_dahiya 0:fb8047b156bb 1452 */
rahul_dahiya 0:fb8047b156bb 1453 int mbedtls_mpi_mod_mpi( mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B )
rahul_dahiya 0:fb8047b156bb 1454 {
rahul_dahiya 0:fb8047b156bb 1455 int ret;
rahul_dahiya 0:fb8047b156bb 1456
rahul_dahiya 0:fb8047b156bb 1457 if( mbedtls_mpi_cmp_int( B, 0 ) < 0 )
rahul_dahiya 0:fb8047b156bb 1458 return( MBEDTLS_ERR_MPI_NEGATIVE_VALUE );
rahul_dahiya 0:fb8047b156bb 1459
rahul_dahiya 0:fb8047b156bb 1460 MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( NULL, R, A, B ) );
rahul_dahiya 0:fb8047b156bb 1461
rahul_dahiya 0:fb8047b156bb 1462 while( mbedtls_mpi_cmp_int( R, 0 ) < 0 )
rahul_dahiya 0:fb8047b156bb 1463 MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( R, R, B ) );
rahul_dahiya 0:fb8047b156bb 1464
rahul_dahiya 0:fb8047b156bb 1465 while( mbedtls_mpi_cmp_mpi( R, B ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1466 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( R, R, B ) );
rahul_dahiya 0:fb8047b156bb 1467
rahul_dahiya 0:fb8047b156bb 1468 cleanup:
rahul_dahiya 0:fb8047b156bb 1469
rahul_dahiya 0:fb8047b156bb 1470 return( ret );
rahul_dahiya 0:fb8047b156bb 1471 }
rahul_dahiya 0:fb8047b156bb 1472
rahul_dahiya 0:fb8047b156bb 1473 /*
rahul_dahiya 0:fb8047b156bb 1474 * Modulo: r = A mod b
rahul_dahiya 0:fb8047b156bb 1475 */
rahul_dahiya 0:fb8047b156bb 1476 int mbedtls_mpi_mod_int( mbedtls_mpi_uint *r, const mbedtls_mpi *A, mbedtls_mpi_sint b )
rahul_dahiya 0:fb8047b156bb 1477 {
rahul_dahiya 0:fb8047b156bb 1478 size_t i;
rahul_dahiya 0:fb8047b156bb 1479 mbedtls_mpi_uint x, y, z;
rahul_dahiya 0:fb8047b156bb 1480
rahul_dahiya 0:fb8047b156bb 1481 if( b == 0 )
rahul_dahiya 0:fb8047b156bb 1482 return( MBEDTLS_ERR_MPI_DIVISION_BY_ZERO );
rahul_dahiya 0:fb8047b156bb 1483
rahul_dahiya 0:fb8047b156bb 1484 if( b < 0 )
rahul_dahiya 0:fb8047b156bb 1485 return( MBEDTLS_ERR_MPI_NEGATIVE_VALUE );
rahul_dahiya 0:fb8047b156bb 1486
rahul_dahiya 0:fb8047b156bb 1487 /*
rahul_dahiya 0:fb8047b156bb 1488 * handle trivial cases
rahul_dahiya 0:fb8047b156bb 1489 */
rahul_dahiya 0:fb8047b156bb 1490 if( b == 1 )
rahul_dahiya 0:fb8047b156bb 1491 {
rahul_dahiya 0:fb8047b156bb 1492 *r = 0;
rahul_dahiya 0:fb8047b156bb 1493 return( 0 );
rahul_dahiya 0:fb8047b156bb 1494 }
rahul_dahiya 0:fb8047b156bb 1495
rahul_dahiya 0:fb8047b156bb 1496 if( b == 2 )
rahul_dahiya 0:fb8047b156bb 1497 {
rahul_dahiya 0:fb8047b156bb 1498 *r = A->p[0] & 1;
rahul_dahiya 0:fb8047b156bb 1499 return( 0 );
rahul_dahiya 0:fb8047b156bb 1500 }
rahul_dahiya 0:fb8047b156bb 1501
rahul_dahiya 0:fb8047b156bb 1502 /*
rahul_dahiya 0:fb8047b156bb 1503 * general case
rahul_dahiya 0:fb8047b156bb 1504 */
rahul_dahiya 0:fb8047b156bb 1505 for( i = A->n, y = 0; i > 0; i-- )
rahul_dahiya 0:fb8047b156bb 1506 {
rahul_dahiya 0:fb8047b156bb 1507 x = A->p[i - 1];
rahul_dahiya 0:fb8047b156bb 1508 y = ( y << biH ) | ( x >> biH );
rahul_dahiya 0:fb8047b156bb 1509 z = y / b;
rahul_dahiya 0:fb8047b156bb 1510 y -= z * b;
rahul_dahiya 0:fb8047b156bb 1511
rahul_dahiya 0:fb8047b156bb 1512 x <<= biH;
rahul_dahiya 0:fb8047b156bb 1513 y = ( y << biH ) | ( x >> biH );
rahul_dahiya 0:fb8047b156bb 1514 z = y / b;
rahul_dahiya 0:fb8047b156bb 1515 y -= z * b;
rahul_dahiya 0:fb8047b156bb 1516 }
rahul_dahiya 0:fb8047b156bb 1517
rahul_dahiya 0:fb8047b156bb 1518 /*
rahul_dahiya 0:fb8047b156bb 1519 * If A is negative, then the current y represents a negative value.
rahul_dahiya 0:fb8047b156bb 1520 * Flipping it to the positive side.
rahul_dahiya 0:fb8047b156bb 1521 */
rahul_dahiya 0:fb8047b156bb 1522 if( A->s < 0 && y != 0 )
rahul_dahiya 0:fb8047b156bb 1523 y = b - y;
rahul_dahiya 0:fb8047b156bb 1524
rahul_dahiya 0:fb8047b156bb 1525 *r = y;
rahul_dahiya 0:fb8047b156bb 1526
rahul_dahiya 0:fb8047b156bb 1527 return( 0 );
rahul_dahiya 0:fb8047b156bb 1528 }
rahul_dahiya 0:fb8047b156bb 1529
rahul_dahiya 0:fb8047b156bb 1530 /*
rahul_dahiya 0:fb8047b156bb 1531 * Fast Montgomery initialization (thanks to Tom St Denis)
rahul_dahiya 0:fb8047b156bb 1532 */
rahul_dahiya 0:fb8047b156bb 1533 static void mpi_montg_init( mbedtls_mpi_uint *mm, const mbedtls_mpi *N )
rahul_dahiya 0:fb8047b156bb 1534 {
rahul_dahiya 0:fb8047b156bb 1535 mbedtls_mpi_uint x, m0 = N->p[0];
rahul_dahiya 0:fb8047b156bb 1536 unsigned int i;
rahul_dahiya 0:fb8047b156bb 1537
rahul_dahiya 0:fb8047b156bb 1538 x = m0;
rahul_dahiya 0:fb8047b156bb 1539 x += ( ( m0 + 2 ) & 4 ) << 1;
rahul_dahiya 0:fb8047b156bb 1540
rahul_dahiya 0:fb8047b156bb 1541 for( i = biL; i >= 8; i /= 2 )
rahul_dahiya 0:fb8047b156bb 1542 x *= ( 2 - ( m0 * x ) );
rahul_dahiya 0:fb8047b156bb 1543
rahul_dahiya 0:fb8047b156bb 1544 *mm = ~x + 1;
rahul_dahiya 0:fb8047b156bb 1545 }
rahul_dahiya 0:fb8047b156bb 1546
rahul_dahiya 0:fb8047b156bb 1547 /*
rahul_dahiya 0:fb8047b156bb 1548 * Montgomery multiplication: A = A * B * R^-1 mod N (HAC 14.36)
rahul_dahiya 0:fb8047b156bb 1549 */
rahul_dahiya 0:fb8047b156bb 1550 static int mpi_montmul( mbedtls_mpi *A, const mbedtls_mpi *B, const mbedtls_mpi *N, mbedtls_mpi_uint mm,
rahul_dahiya 0:fb8047b156bb 1551 const mbedtls_mpi *T )
rahul_dahiya 0:fb8047b156bb 1552 {
rahul_dahiya 0:fb8047b156bb 1553 size_t i, n, m;
rahul_dahiya 0:fb8047b156bb 1554 mbedtls_mpi_uint u0, u1, *d;
rahul_dahiya 0:fb8047b156bb 1555
rahul_dahiya 0:fb8047b156bb 1556 if( T->n < N->n + 1 || T->p == NULL )
rahul_dahiya 0:fb8047b156bb 1557 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 1558
rahul_dahiya 0:fb8047b156bb 1559 memset( T->p, 0, T->n * ciL );
rahul_dahiya 0:fb8047b156bb 1560
rahul_dahiya 0:fb8047b156bb 1561 d = T->p;
rahul_dahiya 0:fb8047b156bb 1562 n = N->n;
rahul_dahiya 0:fb8047b156bb 1563 m = ( B->n < n ) ? B->n : n;
rahul_dahiya 0:fb8047b156bb 1564
rahul_dahiya 0:fb8047b156bb 1565 for( i = 0; i < n; i++ )
rahul_dahiya 0:fb8047b156bb 1566 {
rahul_dahiya 0:fb8047b156bb 1567 /*
rahul_dahiya 0:fb8047b156bb 1568 * T = (T + u0*B + u1*N) / 2^biL
rahul_dahiya 0:fb8047b156bb 1569 */
rahul_dahiya 0:fb8047b156bb 1570 u0 = A->p[i];
rahul_dahiya 0:fb8047b156bb 1571 u1 = ( d[0] + u0 * B->p[0] ) * mm;
rahul_dahiya 0:fb8047b156bb 1572
rahul_dahiya 0:fb8047b156bb 1573 mpi_mul_hlp( m, B->p, d, u0 );
rahul_dahiya 0:fb8047b156bb 1574 mpi_mul_hlp( n, N->p, d, u1 );
rahul_dahiya 0:fb8047b156bb 1575
rahul_dahiya 0:fb8047b156bb 1576 *d++ = u0; d[n + 1] = 0;
rahul_dahiya 0:fb8047b156bb 1577 }
rahul_dahiya 0:fb8047b156bb 1578
rahul_dahiya 0:fb8047b156bb 1579 memcpy( A->p, d, ( n + 1 ) * ciL );
rahul_dahiya 0:fb8047b156bb 1580
rahul_dahiya 0:fb8047b156bb 1581 if( mbedtls_mpi_cmp_abs( A, N ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1582 mpi_sub_hlp( n, N->p, A->p );
rahul_dahiya 0:fb8047b156bb 1583 else
rahul_dahiya 0:fb8047b156bb 1584 /* prevent timing attacks */
rahul_dahiya 0:fb8047b156bb 1585 mpi_sub_hlp( n, A->p, T->p );
rahul_dahiya 0:fb8047b156bb 1586
rahul_dahiya 0:fb8047b156bb 1587 return( 0 );
rahul_dahiya 0:fb8047b156bb 1588 }
rahul_dahiya 0:fb8047b156bb 1589
rahul_dahiya 0:fb8047b156bb 1590 /*
rahul_dahiya 0:fb8047b156bb 1591 * Montgomery reduction: A = A * R^-1 mod N
rahul_dahiya 0:fb8047b156bb 1592 */
rahul_dahiya 0:fb8047b156bb 1593 static int mpi_montred( mbedtls_mpi *A, const mbedtls_mpi *N, mbedtls_mpi_uint mm, const mbedtls_mpi *T )
rahul_dahiya 0:fb8047b156bb 1594 {
rahul_dahiya 0:fb8047b156bb 1595 mbedtls_mpi_uint z = 1;
rahul_dahiya 0:fb8047b156bb 1596 mbedtls_mpi U;
rahul_dahiya 0:fb8047b156bb 1597
rahul_dahiya 0:fb8047b156bb 1598 U.n = U.s = (int) z;
rahul_dahiya 0:fb8047b156bb 1599 U.p = &z;
rahul_dahiya 0:fb8047b156bb 1600
rahul_dahiya 0:fb8047b156bb 1601 return( mpi_montmul( A, &U, N, mm, T ) );
rahul_dahiya 0:fb8047b156bb 1602 }
rahul_dahiya 0:fb8047b156bb 1603
rahul_dahiya 0:fb8047b156bb 1604 /*
rahul_dahiya 0:fb8047b156bb 1605 * Sliding-window exponentiation: X = A^E mod N (HAC 14.85)
rahul_dahiya 0:fb8047b156bb 1606 */
rahul_dahiya 0:fb8047b156bb 1607 int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *E, const mbedtls_mpi *N, mbedtls_mpi *_RR )
rahul_dahiya 0:fb8047b156bb 1608 {
rahul_dahiya 0:fb8047b156bb 1609 int ret;
rahul_dahiya 0:fb8047b156bb 1610 size_t wbits, wsize, one = 1;
rahul_dahiya 0:fb8047b156bb 1611 size_t i, j, nblimbs;
rahul_dahiya 0:fb8047b156bb 1612 size_t bufsize, nbits;
rahul_dahiya 0:fb8047b156bb 1613 mbedtls_mpi_uint ei, mm, state;
rahul_dahiya 0:fb8047b156bb 1614 mbedtls_mpi RR, T, W[ 2 << MBEDTLS_MPI_WINDOW_SIZE ], Apos;
rahul_dahiya 0:fb8047b156bb 1615 int neg;
rahul_dahiya 0:fb8047b156bb 1616
rahul_dahiya 0:fb8047b156bb 1617 if( mbedtls_mpi_cmp_int( N, 0 ) < 0 || ( N->p[0] & 1 ) == 0 )
rahul_dahiya 0:fb8047b156bb 1618 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 1619
rahul_dahiya 0:fb8047b156bb 1620 if( mbedtls_mpi_cmp_int( E, 0 ) < 0 )
rahul_dahiya 0:fb8047b156bb 1621 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 1622
rahul_dahiya 0:fb8047b156bb 1623 /*
rahul_dahiya 0:fb8047b156bb 1624 * Init temps and window size
rahul_dahiya 0:fb8047b156bb 1625 */
rahul_dahiya 0:fb8047b156bb 1626 mpi_montg_init( &mm, N );
rahul_dahiya 0:fb8047b156bb 1627 mbedtls_mpi_init( &RR ); mbedtls_mpi_init( &T );
rahul_dahiya 0:fb8047b156bb 1628 mbedtls_mpi_init( &Apos );
rahul_dahiya 0:fb8047b156bb 1629 memset( W, 0, sizeof( W ) );
rahul_dahiya 0:fb8047b156bb 1630
rahul_dahiya 0:fb8047b156bb 1631 i = mbedtls_mpi_bitlen( E );
rahul_dahiya 0:fb8047b156bb 1632
rahul_dahiya 0:fb8047b156bb 1633 wsize = ( i > 671 ) ? 6 : ( i > 239 ) ? 5 :
rahul_dahiya 0:fb8047b156bb 1634 ( i > 79 ) ? 4 : ( i > 23 ) ? 3 : 1;
rahul_dahiya 0:fb8047b156bb 1635
rahul_dahiya 0:fb8047b156bb 1636 if( wsize > MBEDTLS_MPI_WINDOW_SIZE )
rahul_dahiya 0:fb8047b156bb 1637 wsize = MBEDTLS_MPI_WINDOW_SIZE;
rahul_dahiya 0:fb8047b156bb 1638
rahul_dahiya 0:fb8047b156bb 1639 j = N->n + 1;
rahul_dahiya 0:fb8047b156bb 1640 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( X, j ) );
rahul_dahiya 0:fb8047b156bb 1641 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( &W[1], j ) );
rahul_dahiya 0:fb8047b156bb 1642 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( &T, j * 2 ) );
rahul_dahiya 0:fb8047b156bb 1643
rahul_dahiya 0:fb8047b156bb 1644 /*
rahul_dahiya 0:fb8047b156bb 1645 * Compensate for negative A (and correct at the end)
rahul_dahiya 0:fb8047b156bb 1646 */
rahul_dahiya 0:fb8047b156bb 1647 neg = ( A->s == -1 );
rahul_dahiya 0:fb8047b156bb 1648 if( neg )
rahul_dahiya 0:fb8047b156bb 1649 {
rahul_dahiya 0:fb8047b156bb 1650 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &Apos, A ) );
rahul_dahiya 0:fb8047b156bb 1651 Apos.s = 1;
rahul_dahiya 0:fb8047b156bb 1652 A = &Apos;
rahul_dahiya 0:fb8047b156bb 1653 }
rahul_dahiya 0:fb8047b156bb 1654
rahul_dahiya 0:fb8047b156bb 1655 /*
rahul_dahiya 0:fb8047b156bb 1656 * If 1st call, pre-compute R^2 mod N
rahul_dahiya 0:fb8047b156bb 1657 */
rahul_dahiya 0:fb8047b156bb 1658 if( _RR == NULL || _RR->p == NULL )
rahul_dahiya 0:fb8047b156bb 1659 {
rahul_dahiya 0:fb8047b156bb 1660 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &RR, 1 ) );
rahul_dahiya 0:fb8047b156bb 1661 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &RR, N->n * 2 * biL ) );
rahul_dahiya 0:fb8047b156bb 1662 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &RR, &RR, N ) );
rahul_dahiya 0:fb8047b156bb 1663
rahul_dahiya 0:fb8047b156bb 1664 if( _RR != NULL )
rahul_dahiya 0:fb8047b156bb 1665 memcpy( _RR, &RR, sizeof( mbedtls_mpi ) );
rahul_dahiya 0:fb8047b156bb 1666 }
rahul_dahiya 0:fb8047b156bb 1667 else
rahul_dahiya 0:fb8047b156bb 1668 memcpy( &RR, _RR, sizeof( mbedtls_mpi ) );
rahul_dahiya 0:fb8047b156bb 1669
rahul_dahiya 0:fb8047b156bb 1670 /*
rahul_dahiya 0:fb8047b156bb 1671 * W[1] = A * R^2 * R^-1 mod N = A * R mod N
rahul_dahiya 0:fb8047b156bb 1672 */
rahul_dahiya 0:fb8047b156bb 1673 if( mbedtls_mpi_cmp_mpi( A, N ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1674 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &W[1], A, N ) );
rahul_dahiya 0:fb8047b156bb 1675 else
rahul_dahiya 0:fb8047b156bb 1676 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &W[1], A ) );
rahul_dahiya 0:fb8047b156bb 1677
rahul_dahiya 0:fb8047b156bb 1678 MBEDTLS_MPI_CHK( mpi_montmul( &W[1], &RR, N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1679
rahul_dahiya 0:fb8047b156bb 1680 /*
rahul_dahiya 0:fb8047b156bb 1681 * X = R^2 * R^-1 mod N = R mod N
rahul_dahiya 0:fb8047b156bb 1682 */
rahul_dahiya 0:fb8047b156bb 1683 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( X, &RR ) );
rahul_dahiya 0:fb8047b156bb 1684 MBEDTLS_MPI_CHK( mpi_montred( X, N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1685
rahul_dahiya 0:fb8047b156bb 1686 if( wsize > 1 )
rahul_dahiya 0:fb8047b156bb 1687 {
rahul_dahiya 0:fb8047b156bb 1688 /*
rahul_dahiya 0:fb8047b156bb 1689 * W[1 << (wsize - 1)] = W[1] ^ (wsize - 1)
rahul_dahiya 0:fb8047b156bb 1690 */
rahul_dahiya 0:fb8047b156bb 1691 j = one << ( wsize - 1 );
rahul_dahiya 0:fb8047b156bb 1692
rahul_dahiya 0:fb8047b156bb 1693 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( &W[j], N->n + 1 ) );
rahul_dahiya 0:fb8047b156bb 1694 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &W[j], &W[1] ) );
rahul_dahiya 0:fb8047b156bb 1695
rahul_dahiya 0:fb8047b156bb 1696 for( i = 0; i < wsize - 1; i++ )
rahul_dahiya 0:fb8047b156bb 1697 MBEDTLS_MPI_CHK( mpi_montmul( &W[j], &W[j], N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1698
rahul_dahiya 0:fb8047b156bb 1699 /*
rahul_dahiya 0:fb8047b156bb 1700 * W[i] = W[i - 1] * W[1]
rahul_dahiya 0:fb8047b156bb 1701 */
rahul_dahiya 0:fb8047b156bb 1702 for( i = j + 1; i < ( one << wsize ); i++ )
rahul_dahiya 0:fb8047b156bb 1703 {
rahul_dahiya 0:fb8047b156bb 1704 MBEDTLS_MPI_CHK( mbedtls_mpi_grow( &W[i], N->n + 1 ) );
rahul_dahiya 0:fb8047b156bb 1705 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &W[i], &W[i - 1] ) );
rahul_dahiya 0:fb8047b156bb 1706
rahul_dahiya 0:fb8047b156bb 1707 MBEDTLS_MPI_CHK( mpi_montmul( &W[i], &W[1], N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1708 }
rahul_dahiya 0:fb8047b156bb 1709 }
rahul_dahiya 0:fb8047b156bb 1710
rahul_dahiya 0:fb8047b156bb 1711 nblimbs = E->n;
rahul_dahiya 0:fb8047b156bb 1712 bufsize = 0;
rahul_dahiya 0:fb8047b156bb 1713 nbits = 0;
rahul_dahiya 0:fb8047b156bb 1714 wbits = 0;
rahul_dahiya 0:fb8047b156bb 1715 state = 0;
rahul_dahiya 0:fb8047b156bb 1716
rahul_dahiya 0:fb8047b156bb 1717 while( 1 )
rahul_dahiya 0:fb8047b156bb 1718 {
rahul_dahiya 0:fb8047b156bb 1719 if( bufsize == 0 )
rahul_dahiya 0:fb8047b156bb 1720 {
rahul_dahiya 0:fb8047b156bb 1721 if( nblimbs == 0 )
rahul_dahiya 0:fb8047b156bb 1722 break;
rahul_dahiya 0:fb8047b156bb 1723
rahul_dahiya 0:fb8047b156bb 1724 nblimbs--;
rahul_dahiya 0:fb8047b156bb 1725
rahul_dahiya 0:fb8047b156bb 1726 bufsize = sizeof( mbedtls_mpi_uint ) << 3;
rahul_dahiya 0:fb8047b156bb 1727 }
rahul_dahiya 0:fb8047b156bb 1728
rahul_dahiya 0:fb8047b156bb 1729 bufsize--;
rahul_dahiya 0:fb8047b156bb 1730
rahul_dahiya 0:fb8047b156bb 1731 ei = (E->p[nblimbs] >> bufsize) & 1;
rahul_dahiya 0:fb8047b156bb 1732
rahul_dahiya 0:fb8047b156bb 1733 /*
rahul_dahiya 0:fb8047b156bb 1734 * skip leading 0s
rahul_dahiya 0:fb8047b156bb 1735 */
rahul_dahiya 0:fb8047b156bb 1736 if( ei == 0 && state == 0 )
rahul_dahiya 0:fb8047b156bb 1737 continue;
rahul_dahiya 0:fb8047b156bb 1738
rahul_dahiya 0:fb8047b156bb 1739 if( ei == 0 && state == 1 )
rahul_dahiya 0:fb8047b156bb 1740 {
rahul_dahiya 0:fb8047b156bb 1741 /*
rahul_dahiya 0:fb8047b156bb 1742 * out of window, square X
rahul_dahiya 0:fb8047b156bb 1743 */
rahul_dahiya 0:fb8047b156bb 1744 MBEDTLS_MPI_CHK( mpi_montmul( X, X, N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1745 continue;
rahul_dahiya 0:fb8047b156bb 1746 }
rahul_dahiya 0:fb8047b156bb 1747
rahul_dahiya 0:fb8047b156bb 1748 /*
rahul_dahiya 0:fb8047b156bb 1749 * add ei to current window
rahul_dahiya 0:fb8047b156bb 1750 */
rahul_dahiya 0:fb8047b156bb 1751 state = 2;
rahul_dahiya 0:fb8047b156bb 1752
rahul_dahiya 0:fb8047b156bb 1753 nbits++;
rahul_dahiya 0:fb8047b156bb 1754 wbits |= ( ei << ( wsize - nbits ) );
rahul_dahiya 0:fb8047b156bb 1755
rahul_dahiya 0:fb8047b156bb 1756 if( nbits == wsize )
rahul_dahiya 0:fb8047b156bb 1757 {
rahul_dahiya 0:fb8047b156bb 1758 /*
rahul_dahiya 0:fb8047b156bb 1759 * X = X^wsize R^-1 mod N
rahul_dahiya 0:fb8047b156bb 1760 */
rahul_dahiya 0:fb8047b156bb 1761 for( i = 0; i < wsize; i++ )
rahul_dahiya 0:fb8047b156bb 1762 MBEDTLS_MPI_CHK( mpi_montmul( X, X, N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1763
rahul_dahiya 0:fb8047b156bb 1764 /*
rahul_dahiya 0:fb8047b156bb 1765 * X = X * W[wbits] R^-1 mod N
rahul_dahiya 0:fb8047b156bb 1766 */
rahul_dahiya 0:fb8047b156bb 1767 MBEDTLS_MPI_CHK( mpi_montmul( X, &W[wbits], N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1768
rahul_dahiya 0:fb8047b156bb 1769 state--;
rahul_dahiya 0:fb8047b156bb 1770 nbits = 0;
rahul_dahiya 0:fb8047b156bb 1771 wbits = 0;
rahul_dahiya 0:fb8047b156bb 1772 }
rahul_dahiya 0:fb8047b156bb 1773 }
rahul_dahiya 0:fb8047b156bb 1774
rahul_dahiya 0:fb8047b156bb 1775 /*
rahul_dahiya 0:fb8047b156bb 1776 * process the remaining bits
rahul_dahiya 0:fb8047b156bb 1777 */
rahul_dahiya 0:fb8047b156bb 1778 for( i = 0; i < nbits; i++ )
rahul_dahiya 0:fb8047b156bb 1779 {
rahul_dahiya 0:fb8047b156bb 1780 MBEDTLS_MPI_CHK( mpi_montmul( X, X, N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1781
rahul_dahiya 0:fb8047b156bb 1782 wbits <<= 1;
rahul_dahiya 0:fb8047b156bb 1783
rahul_dahiya 0:fb8047b156bb 1784 if( ( wbits & ( one << wsize ) ) != 0 )
rahul_dahiya 0:fb8047b156bb 1785 MBEDTLS_MPI_CHK( mpi_montmul( X, &W[1], N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1786 }
rahul_dahiya 0:fb8047b156bb 1787
rahul_dahiya 0:fb8047b156bb 1788 /*
rahul_dahiya 0:fb8047b156bb 1789 * X = A^E * R * R^-1 mod N = A^E mod N
rahul_dahiya 0:fb8047b156bb 1790 */
rahul_dahiya 0:fb8047b156bb 1791 MBEDTLS_MPI_CHK( mpi_montred( X, N, mm, &T ) );
rahul_dahiya 0:fb8047b156bb 1792
rahul_dahiya 0:fb8047b156bb 1793 if( neg && E->n != 0 && ( E->p[0] & 1 ) != 0 )
rahul_dahiya 0:fb8047b156bb 1794 {
rahul_dahiya 0:fb8047b156bb 1795 X->s = -1;
rahul_dahiya 0:fb8047b156bb 1796 MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( X, N, X ) );
rahul_dahiya 0:fb8047b156bb 1797 }
rahul_dahiya 0:fb8047b156bb 1798
rahul_dahiya 0:fb8047b156bb 1799 cleanup:
rahul_dahiya 0:fb8047b156bb 1800
rahul_dahiya 0:fb8047b156bb 1801 for( i = ( one << ( wsize - 1 ) ); i < ( one << wsize ); i++ )
rahul_dahiya 0:fb8047b156bb 1802 mbedtls_mpi_free( &W[i] );
rahul_dahiya 0:fb8047b156bb 1803
rahul_dahiya 0:fb8047b156bb 1804 mbedtls_mpi_free( &W[1] ); mbedtls_mpi_free( &T ); mbedtls_mpi_free( &Apos );
rahul_dahiya 0:fb8047b156bb 1805
rahul_dahiya 0:fb8047b156bb 1806 if( _RR == NULL || _RR->p == NULL )
rahul_dahiya 0:fb8047b156bb 1807 mbedtls_mpi_free( &RR );
rahul_dahiya 0:fb8047b156bb 1808
rahul_dahiya 0:fb8047b156bb 1809 return( ret );
rahul_dahiya 0:fb8047b156bb 1810 }
rahul_dahiya 0:fb8047b156bb 1811
rahul_dahiya 0:fb8047b156bb 1812 /*
rahul_dahiya 0:fb8047b156bb 1813 * Greatest common divisor: G = gcd(A, B) (HAC 14.54)
rahul_dahiya 0:fb8047b156bb 1814 */
rahul_dahiya 0:fb8047b156bb 1815 int mbedtls_mpi_gcd( mbedtls_mpi *G, const mbedtls_mpi *A, const mbedtls_mpi *B )
rahul_dahiya 0:fb8047b156bb 1816 {
rahul_dahiya 0:fb8047b156bb 1817 int ret;
rahul_dahiya 0:fb8047b156bb 1818 size_t lz, lzt;
rahul_dahiya 0:fb8047b156bb 1819 mbedtls_mpi TG, TA, TB;
rahul_dahiya 0:fb8047b156bb 1820
rahul_dahiya 0:fb8047b156bb 1821 mbedtls_mpi_init( &TG ); mbedtls_mpi_init( &TA ); mbedtls_mpi_init( &TB );
rahul_dahiya 0:fb8047b156bb 1822
rahul_dahiya 0:fb8047b156bb 1823 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TA, A ) );
rahul_dahiya 0:fb8047b156bb 1824 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TB, B ) );
rahul_dahiya 0:fb8047b156bb 1825
rahul_dahiya 0:fb8047b156bb 1826 lz = mbedtls_mpi_lsb( &TA );
rahul_dahiya 0:fb8047b156bb 1827 lzt = mbedtls_mpi_lsb( &TB );
rahul_dahiya 0:fb8047b156bb 1828
rahul_dahiya 0:fb8047b156bb 1829 if( lzt < lz )
rahul_dahiya 0:fb8047b156bb 1830 lz = lzt;
rahul_dahiya 0:fb8047b156bb 1831
rahul_dahiya 0:fb8047b156bb 1832 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &TA, lz ) );
rahul_dahiya 0:fb8047b156bb 1833 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &TB, lz ) );
rahul_dahiya 0:fb8047b156bb 1834
rahul_dahiya 0:fb8047b156bb 1835 TA.s = TB.s = 1;
rahul_dahiya 0:fb8047b156bb 1836
rahul_dahiya 0:fb8047b156bb 1837 while( mbedtls_mpi_cmp_int( &TA, 0 ) != 0 )
rahul_dahiya 0:fb8047b156bb 1838 {
rahul_dahiya 0:fb8047b156bb 1839 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &TA, mbedtls_mpi_lsb( &TA ) ) );
rahul_dahiya 0:fb8047b156bb 1840 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &TB, mbedtls_mpi_lsb( &TB ) ) );
rahul_dahiya 0:fb8047b156bb 1841
rahul_dahiya 0:fb8047b156bb 1842 if( mbedtls_mpi_cmp_mpi( &TA, &TB ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1843 {
rahul_dahiya 0:fb8047b156bb 1844 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( &TA, &TA, &TB ) );
rahul_dahiya 0:fb8047b156bb 1845 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &TA, 1 ) );
rahul_dahiya 0:fb8047b156bb 1846 }
rahul_dahiya 0:fb8047b156bb 1847 else
rahul_dahiya 0:fb8047b156bb 1848 {
rahul_dahiya 0:fb8047b156bb 1849 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( &TB, &TB, &TA ) );
rahul_dahiya 0:fb8047b156bb 1850 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &TB, 1 ) );
rahul_dahiya 0:fb8047b156bb 1851 }
rahul_dahiya 0:fb8047b156bb 1852 }
rahul_dahiya 0:fb8047b156bb 1853
rahul_dahiya 0:fb8047b156bb 1854 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_l( &TB, lz ) );
rahul_dahiya 0:fb8047b156bb 1855 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( G, &TB ) );
rahul_dahiya 0:fb8047b156bb 1856
rahul_dahiya 0:fb8047b156bb 1857 cleanup:
rahul_dahiya 0:fb8047b156bb 1858
rahul_dahiya 0:fb8047b156bb 1859 mbedtls_mpi_free( &TG ); mbedtls_mpi_free( &TA ); mbedtls_mpi_free( &TB );
rahul_dahiya 0:fb8047b156bb 1860
rahul_dahiya 0:fb8047b156bb 1861 return( ret );
rahul_dahiya 0:fb8047b156bb 1862 }
rahul_dahiya 0:fb8047b156bb 1863
rahul_dahiya 0:fb8047b156bb 1864 /*
rahul_dahiya 0:fb8047b156bb 1865 * Fill X with size bytes of random.
rahul_dahiya 0:fb8047b156bb 1866 *
rahul_dahiya 0:fb8047b156bb 1867 * Use a temporary bytes representation to make sure the result is the same
rahul_dahiya 0:fb8047b156bb 1868 * regardless of the platform endianness (useful when f_rng is actually
rahul_dahiya 0:fb8047b156bb 1869 * deterministic, eg for tests).
rahul_dahiya 0:fb8047b156bb 1870 */
rahul_dahiya 0:fb8047b156bb 1871 int mbedtls_mpi_fill_random( mbedtls_mpi *X, size_t size,
rahul_dahiya 0:fb8047b156bb 1872 int (*f_rng)(void *, unsigned char *, size_t),
rahul_dahiya 0:fb8047b156bb 1873 void *p_rng )
rahul_dahiya 0:fb8047b156bb 1874 {
rahul_dahiya 0:fb8047b156bb 1875 int ret;
rahul_dahiya 0:fb8047b156bb 1876 unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
rahul_dahiya 0:fb8047b156bb 1877
rahul_dahiya 0:fb8047b156bb 1878 if( size > MBEDTLS_MPI_MAX_SIZE )
rahul_dahiya 0:fb8047b156bb 1879 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 1880
rahul_dahiya 0:fb8047b156bb 1881 MBEDTLS_MPI_CHK( f_rng( p_rng, buf, size ) );
rahul_dahiya 0:fb8047b156bb 1882 MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( X, buf, size ) );
rahul_dahiya 0:fb8047b156bb 1883
rahul_dahiya 0:fb8047b156bb 1884 cleanup:
rahul_dahiya 0:fb8047b156bb 1885 return( ret );
rahul_dahiya 0:fb8047b156bb 1886 }
rahul_dahiya 0:fb8047b156bb 1887
rahul_dahiya 0:fb8047b156bb 1888 /*
rahul_dahiya 0:fb8047b156bb 1889 * Modular inverse: X = A^-1 mod N (HAC 14.61 / 14.64)
rahul_dahiya 0:fb8047b156bb 1890 */
rahul_dahiya 0:fb8047b156bb 1891 int mbedtls_mpi_inv_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *N )
rahul_dahiya 0:fb8047b156bb 1892 {
rahul_dahiya 0:fb8047b156bb 1893 int ret;
rahul_dahiya 0:fb8047b156bb 1894 mbedtls_mpi G, TA, TU, U1, U2, TB, TV, V1, V2;
rahul_dahiya 0:fb8047b156bb 1895
rahul_dahiya 0:fb8047b156bb 1896 if( mbedtls_mpi_cmp_int( N, 1 ) <= 0 )
rahul_dahiya 0:fb8047b156bb 1897 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 1898
rahul_dahiya 0:fb8047b156bb 1899 mbedtls_mpi_init( &TA ); mbedtls_mpi_init( &TU ); mbedtls_mpi_init( &U1 ); mbedtls_mpi_init( &U2 );
rahul_dahiya 0:fb8047b156bb 1900 mbedtls_mpi_init( &G ); mbedtls_mpi_init( &TB ); mbedtls_mpi_init( &TV );
rahul_dahiya 0:fb8047b156bb 1901 mbedtls_mpi_init( &V1 ); mbedtls_mpi_init( &V2 );
rahul_dahiya 0:fb8047b156bb 1902
rahul_dahiya 0:fb8047b156bb 1903 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, A, N ) );
rahul_dahiya 0:fb8047b156bb 1904
rahul_dahiya 0:fb8047b156bb 1905 if( mbedtls_mpi_cmp_int( &G, 1 ) != 0 )
rahul_dahiya 0:fb8047b156bb 1906 {
rahul_dahiya 0:fb8047b156bb 1907 ret = MBEDTLS_ERR_MPI_NOT_ACCEPTABLE;
rahul_dahiya 0:fb8047b156bb 1908 goto cleanup;
rahul_dahiya 0:fb8047b156bb 1909 }
rahul_dahiya 0:fb8047b156bb 1910
rahul_dahiya 0:fb8047b156bb 1911 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &TA, A, N ) );
rahul_dahiya 0:fb8047b156bb 1912 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TU, &TA ) );
rahul_dahiya 0:fb8047b156bb 1913 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TB, N ) );
rahul_dahiya 0:fb8047b156bb 1914 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &TV, N ) );
rahul_dahiya 0:fb8047b156bb 1915
rahul_dahiya 0:fb8047b156bb 1916 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &U1, 1 ) );
rahul_dahiya 0:fb8047b156bb 1917 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &U2, 0 ) );
rahul_dahiya 0:fb8047b156bb 1918 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &V1, 0 ) );
rahul_dahiya 0:fb8047b156bb 1919 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &V2, 1 ) );
rahul_dahiya 0:fb8047b156bb 1920
rahul_dahiya 0:fb8047b156bb 1921 do
rahul_dahiya 0:fb8047b156bb 1922 {
rahul_dahiya 0:fb8047b156bb 1923 while( ( TU.p[0] & 1 ) == 0 )
rahul_dahiya 0:fb8047b156bb 1924 {
rahul_dahiya 0:fb8047b156bb 1925 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &TU, 1 ) );
rahul_dahiya 0:fb8047b156bb 1926
rahul_dahiya 0:fb8047b156bb 1927 if( ( U1.p[0] & 1 ) != 0 || ( U2.p[0] & 1 ) != 0 )
rahul_dahiya 0:fb8047b156bb 1928 {
rahul_dahiya 0:fb8047b156bb 1929 MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &U1, &U1, &TB ) );
rahul_dahiya 0:fb8047b156bb 1930 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &U2, &U2, &TA ) );
rahul_dahiya 0:fb8047b156bb 1931 }
rahul_dahiya 0:fb8047b156bb 1932
rahul_dahiya 0:fb8047b156bb 1933 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &U1, 1 ) );
rahul_dahiya 0:fb8047b156bb 1934 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &U2, 1 ) );
rahul_dahiya 0:fb8047b156bb 1935 }
rahul_dahiya 0:fb8047b156bb 1936
rahul_dahiya 0:fb8047b156bb 1937 while( ( TV.p[0] & 1 ) == 0 )
rahul_dahiya 0:fb8047b156bb 1938 {
rahul_dahiya 0:fb8047b156bb 1939 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &TV, 1 ) );
rahul_dahiya 0:fb8047b156bb 1940
rahul_dahiya 0:fb8047b156bb 1941 if( ( V1.p[0] & 1 ) != 0 || ( V2.p[0] & 1 ) != 0 )
rahul_dahiya 0:fb8047b156bb 1942 {
rahul_dahiya 0:fb8047b156bb 1943 MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &V1, &V1, &TB ) );
rahul_dahiya 0:fb8047b156bb 1944 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &V2, &V2, &TA ) );
rahul_dahiya 0:fb8047b156bb 1945 }
rahul_dahiya 0:fb8047b156bb 1946
rahul_dahiya 0:fb8047b156bb 1947 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &V1, 1 ) );
rahul_dahiya 0:fb8047b156bb 1948 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &V2, 1 ) );
rahul_dahiya 0:fb8047b156bb 1949 }
rahul_dahiya 0:fb8047b156bb 1950
rahul_dahiya 0:fb8047b156bb 1951 if( mbedtls_mpi_cmp_mpi( &TU, &TV ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1952 {
rahul_dahiya 0:fb8047b156bb 1953 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &TU, &TU, &TV ) );
rahul_dahiya 0:fb8047b156bb 1954 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &U1, &U1, &V1 ) );
rahul_dahiya 0:fb8047b156bb 1955 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &U2, &U2, &V2 ) );
rahul_dahiya 0:fb8047b156bb 1956 }
rahul_dahiya 0:fb8047b156bb 1957 else
rahul_dahiya 0:fb8047b156bb 1958 {
rahul_dahiya 0:fb8047b156bb 1959 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &TV, &TV, &TU ) );
rahul_dahiya 0:fb8047b156bb 1960 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &V1, &V1, &U1 ) );
rahul_dahiya 0:fb8047b156bb 1961 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &V2, &V2, &U2 ) );
rahul_dahiya 0:fb8047b156bb 1962 }
rahul_dahiya 0:fb8047b156bb 1963 }
rahul_dahiya 0:fb8047b156bb 1964 while( mbedtls_mpi_cmp_int( &TU, 0 ) != 0 );
rahul_dahiya 0:fb8047b156bb 1965
rahul_dahiya 0:fb8047b156bb 1966 while( mbedtls_mpi_cmp_int( &V1, 0 ) < 0 )
rahul_dahiya 0:fb8047b156bb 1967 MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &V1, &V1, N ) );
rahul_dahiya 0:fb8047b156bb 1968
rahul_dahiya 0:fb8047b156bb 1969 while( mbedtls_mpi_cmp_mpi( &V1, N ) >= 0 )
rahul_dahiya 0:fb8047b156bb 1970 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &V1, &V1, N ) );
rahul_dahiya 0:fb8047b156bb 1971
rahul_dahiya 0:fb8047b156bb 1972 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( X, &V1 ) );
rahul_dahiya 0:fb8047b156bb 1973
rahul_dahiya 0:fb8047b156bb 1974 cleanup:
rahul_dahiya 0:fb8047b156bb 1975
rahul_dahiya 0:fb8047b156bb 1976 mbedtls_mpi_free( &TA ); mbedtls_mpi_free( &TU ); mbedtls_mpi_free( &U1 ); mbedtls_mpi_free( &U2 );
rahul_dahiya 0:fb8047b156bb 1977 mbedtls_mpi_free( &G ); mbedtls_mpi_free( &TB ); mbedtls_mpi_free( &TV );
rahul_dahiya 0:fb8047b156bb 1978 mbedtls_mpi_free( &V1 ); mbedtls_mpi_free( &V2 );
rahul_dahiya 0:fb8047b156bb 1979
rahul_dahiya 0:fb8047b156bb 1980 return( ret );
rahul_dahiya 0:fb8047b156bb 1981 }
rahul_dahiya 0:fb8047b156bb 1982
rahul_dahiya 0:fb8047b156bb 1983 #if defined(MBEDTLS_GENPRIME)
rahul_dahiya 0:fb8047b156bb 1984
rahul_dahiya 0:fb8047b156bb 1985 static const int small_prime[] =
rahul_dahiya 0:fb8047b156bb 1986 {
rahul_dahiya 0:fb8047b156bb 1987 3, 5, 7, 11, 13, 17, 19, 23,
rahul_dahiya 0:fb8047b156bb 1988 29, 31, 37, 41, 43, 47, 53, 59,
rahul_dahiya 0:fb8047b156bb 1989 61, 67, 71, 73, 79, 83, 89, 97,
rahul_dahiya 0:fb8047b156bb 1990 101, 103, 107, 109, 113, 127, 131, 137,
rahul_dahiya 0:fb8047b156bb 1991 139, 149, 151, 157, 163, 167, 173, 179,
rahul_dahiya 0:fb8047b156bb 1992 181, 191, 193, 197, 199, 211, 223, 227,
rahul_dahiya 0:fb8047b156bb 1993 229, 233, 239, 241, 251, 257, 263, 269,
rahul_dahiya 0:fb8047b156bb 1994 271, 277, 281, 283, 293, 307, 311, 313,
rahul_dahiya 0:fb8047b156bb 1995 317, 331, 337, 347, 349, 353, 359, 367,
rahul_dahiya 0:fb8047b156bb 1996 373, 379, 383, 389, 397, 401, 409, 419,
rahul_dahiya 0:fb8047b156bb 1997 421, 431, 433, 439, 443, 449, 457, 461,
rahul_dahiya 0:fb8047b156bb 1998 463, 467, 479, 487, 491, 499, 503, 509,
rahul_dahiya 0:fb8047b156bb 1999 521, 523, 541, 547, 557, 563, 569, 571,
rahul_dahiya 0:fb8047b156bb 2000 577, 587, 593, 599, 601, 607, 613, 617,
rahul_dahiya 0:fb8047b156bb 2001 619, 631, 641, 643, 647, 653, 659, 661,
rahul_dahiya 0:fb8047b156bb 2002 673, 677, 683, 691, 701, 709, 719, 727,
rahul_dahiya 0:fb8047b156bb 2003 733, 739, 743, 751, 757, 761, 769, 773,
rahul_dahiya 0:fb8047b156bb 2004 787, 797, 809, 811, 821, 823, 827, 829,
rahul_dahiya 0:fb8047b156bb 2005 839, 853, 857, 859, 863, 877, 881, 883,
rahul_dahiya 0:fb8047b156bb 2006 887, 907, 911, 919, 929, 937, 941, 947,
rahul_dahiya 0:fb8047b156bb 2007 953, 967, 971, 977, 983, 991, 997, -103
rahul_dahiya 0:fb8047b156bb 2008 };
rahul_dahiya 0:fb8047b156bb 2009
rahul_dahiya 0:fb8047b156bb 2010 /*
rahul_dahiya 0:fb8047b156bb 2011 * Small divisors test (X must be positive)
rahul_dahiya 0:fb8047b156bb 2012 *
rahul_dahiya 0:fb8047b156bb 2013 * Return values:
rahul_dahiya 0:fb8047b156bb 2014 * 0: no small factor (possible prime, more tests needed)
rahul_dahiya 0:fb8047b156bb 2015 * 1: certain prime
rahul_dahiya 0:fb8047b156bb 2016 * MBEDTLS_ERR_MPI_NOT_ACCEPTABLE: certain non-prime
rahul_dahiya 0:fb8047b156bb 2017 * other negative: error
rahul_dahiya 0:fb8047b156bb 2018 */
rahul_dahiya 0:fb8047b156bb 2019 static int mpi_check_small_factors( const mbedtls_mpi *X )
rahul_dahiya 0:fb8047b156bb 2020 {
rahul_dahiya 0:fb8047b156bb 2021 int ret = 0;
rahul_dahiya 0:fb8047b156bb 2022 size_t i;
rahul_dahiya 0:fb8047b156bb 2023 mbedtls_mpi_uint r;
rahul_dahiya 0:fb8047b156bb 2024
rahul_dahiya 0:fb8047b156bb 2025 if( ( X->p[0] & 1 ) == 0 )
rahul_dahiya 0:fb8047b156bb 2026 return( MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
rahul_dahiya 0:fb8047b156bb 2027
rahul_dahiya 0:fb8047b156bb 2028 for( i = 0; small_prime[i] > 0; i++ )
rahul_dahiya 0:fb8047b156bb 2029 {
rahul_dahiya 0:fb8047b156bb 2030 if( mbedtls_mpi_cmp_int( X, small_prime[i] ) <= 0 )
rahul_dahiya 0:fb8047b156bb 2031 return( 1 );
rahul_dahiya 0:fb8047b156bb 2032
rahul_dahiya 0:fb8047b156bb 2033 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_int( &r, X, small_prime[i] ) );
rahul_dahiya 0:fb8047b156bb 2034
rahul_dahiya 0:fb8047b156bb 2035 if( r == 0 )
rahul_dahiya 0:fb8047b156bb 2036 return( MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
rahul_dahiya 0:fb8047b156bb 2037 }
rahul_dahiya 0:fb8047b156bb 2038
rahul_dahiya 0:fb8047b156bb 2039 cleanup:
rahul_dahiya 0:fb8047b156bb 2040 return( ret );
rahul_dahiya 0:fb8047b156bb 2041 }
rahul_dahiya 0:fb8047b156bb 2042
rahul_dahiya 0:fb8047b156bb 2043 /*
rahul_dahiya 0:fb8047b156bb 2044 * Miller-Rabin pseudo-primality test (HAC 4.24)
rahul_dahiya 0:fb8047b156bb 2045 */
rahul_dahiya 0:fb8047b156bb 2046 static int mpi_miller_rabin( const mbedtls_mpi *X,
rahul_dahiya 0:fb8047b156bb 2047 int (*f_rng)(void *, unsigned char *, size_t),
rahul_dahiya 0:fb8047b156bb 2048 void *p_rng )
rahul_dahiya 0:fb8047b156bb 2049 {
rahul_dahiya 0:fb8047b156bb 2050 int ret, count;
rahul_dahiya 0:fb8047b156bb 2051 size_t i, j, k, n, s;
rahul_dahiya 0:fb8047b156bb 2052 mbedtls_mpi W, R, T, A, RR;
rahul_dahiya 0:fb8047b156bb 2053
rahul_dahiya 0:fb8047b156bb 2054 mbedtls_mpi_init( &W ); mbedtls_mpi_init( &R ); mbedtls_mpi_init( &T ); mbedtls_mpi_init( &A );
rahul_dahiya 0:fb8047b156bb 2055 mbedtls_mpi_init( &RR );
rahul_dahiya 0:fb8047b156bb 2056
rahul_dahiya 0:fb8047b156bb 2057 /*
rahul_dahiya 0:fb8047b156bb 2058 * W = |X| - 1
rahul_dahiya 0:fb8047b156bb 2059 * R = W >> lsb( W )
rahul_dahiya 0:fb8047b156bb 2060 */
rahul_dahiya 0:fb8047b156bb 2061 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &W, X, 1 ) );
rahul_dahiya 0:fb8047b156bb 2062 s = mbedtls_mpi_lsb( &W );
rahul_dahiya 0:fb8047b156bb 2063 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &R, &W ) );
rahul_dahiya 0:fb8047b156bb 2064 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &R, s ) );
rahul_dahiya 0:fb8047b156bb 2065
rahul_dahiya 0:fb8047b156bb 2066 i = mbedtls_mpi_bitlen( X );
rahul_dahiya 0:fb8047b156bb 2067 /*
rahul_dahiya 0:fb8047b156bb 2068 * HAC, table 4.4
rahul_dahiya 0:fb8047b156bb 2069 */
rahul_dahiya 0:fb8047b156bb 2070 n = ( ( i >= 1300 ) ? 2 : ( i >= 850 ) ? 3 :
rahul_dahiya 0:fb8047b156bb 2071 ( i >= 650 ) ? 4 : ( i >= 350 ) ? 8 :
rahul_dahiya 0:fb8047b156bb 2072 ( i >= 250 ) ? 12 : ( i >= 150 ) ? 18 : 27 );
rahul_dahiya 0:fb8047b156bb 2073
rahul_dahiya 0:fb8047b156bb 2074 for( i = 0; i < n; i++ )
rahul_dahiya 0:fb8047b156bb 2075 {
rahul_dahiya 0:fb8047b156bb 2076 /*
rahul_dahiya 0:fb8047b156bb 2077 * pick a random A, 1 < A < |X| - 1
rahul_dahiya 0:fb8047b156bb 2078 */
rahul_dahiya 0:fb8047b156bb 2079 MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &A, X->n * ciL, f_rng, p_rng ) );
rahul_dahiya 0:fb8047b156bb 2080
rahul_dahiya 0:fb8047b156bb 2081 if( mbedtls_mpi_cmp_mpi( &A, &W ) >= 0 )
rahul_dahiya 0:fb8047b156bb 2082 {
rahul_dahiya 0:fb8047b156bb 2083 j = mbedtls_mpi_bitlen( &A ) - mbedtls_mpi_bitlen( &W );
rahul_dahiya 0:fb8047b156bb 2084 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &A, j + 1 ) );
rahul_dahiya 0:fb8047b156bb 2085 }
rahul_dahiya 0:fb8047b156bb 2086 A.p[0] |= 3;
rahul_dahiya 0:fb8047b156bb 2087
rahul_dahiya 0:fb8047b156bb 2088 count = 0;
rahul_dahiya 0:fb8047b156bb 2089 do {
rahul_dahiya 0:fb8047b156bb 2090 MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &A, X->n * ciL, f_rng, p_rng ) );
rahul_dahiya 0:fb8047b156bb 2091
rahul_dahiya 0:fb8047b156bb 2092 j = mbedtls_mpi_bitlen( &A );
rahul_dahiya 0:fb8047b156bb 2093 k = mbedtls_mpi_bitlen( &W );
rahul_dahiya 0:fb8047b156bb 2094 if (j > k) {
rahul_dahiya 0:fb8047b156bb 2095 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &A, j - k ) );
rahul_dahiya 0:fb8047b156bb 2096 }
rahul_dahiya 0:fb8047b156bb 2097
rahul_dahiya 0:fb8047b156bb 2098 if (count++ > 30) {
rahul_dahiya 0:fb8047b156bb 2099 return MBEDTLS_ERR_MPI_NOT_ACCEPTABLE;
rahul_dahiya 0:fb8047b156bb 2100 }
rahul_dahiya 0:fb8047b156bb 2101
rahul_dahiya 0:fb8047b156bb 2102 } while ( mbedtls_mpi_cmp_mpi( &A, &W ) >= 0 ||
rahul_dahiya 0:fb8047b156bb 2103 mbedtls_mpi_cmp_int( &A, 1 ) <= 0 );
rahul_dahiya 0:fb8047b156bb 2104
rahul_dahiya 0:fb8047b156bb 2105 /*
rahul_dahiya 0:fb8047b156bb 2106 * A = A^R mod |X|
rahul_dahiya 0:fb8047b156bb 2107 */
rahul_dahiya 0:fb8047b156bb 2108 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &A, &A, &R, X, &RR ) );
rahul_dahiya 0:fb8047b156bb 2109
rahul_dahiya 0:fb8047b156bb 2110 if( mbedtls_mpi_cmp_mpi( &A, &W ) == 0 ||
rahul_dahiya 0:fb8047b156bb 2111 mbedtls_mpi_cmp_int( &A, 1 ) == 0 )
rahul_dahiya 0:fb8047b156bb 2112 continue;
rahul_dahiya 0:fb8047b156bb 2113
rahul_dahiya 0:fb8047b156bb 2114 j = 1;
rahul_dahiya 0:fb8047b156bb 2115 while( j < s && mbedtls_mpi_cmp_mpi( &A, &W ) != 0 )
rahul_dahiya 0:fb8047b156bb 2116 {
rahul_dahiya 0:fb8047b156bb 2117 /*
rahul_dahiya 0:fb8047b156bb 2118 * A = A * A mod |X|
rahul_dahiya 0:fb8047b156bb 2119 */
rahul_dahiya 0:fb8047b156bb 2120 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &A, &A ) );
rahul_dahiya 0:fb8047b156bb 2121 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &A, &T, X ) );
rahul_dahiya 0:fb8047b156bb 2122
rahul_dahiya 0:fb8047b156bb 2123 if( mbedtls_mpi_cmp_int( &A, 1 ) == 0 )
rahul_dahiya 0:fb8047b156bb 2124 break;
rahul_dahiya 0:fb8047b156bb 2125
rahul_dahiya 0:fb8047b156bb 2126 j++;
rahul_dahiya 0:fb8047b156bb 2127 }
rahul_dahiya 0:fb8047b156bb 2128
rahul_dahiya 0:fb8047b156bb 2129 /*
rahul_dahiya 0:fb8047b156bb 2130 * not prime if A != |X| - 1 or A == 1
rahul_dahiya 0:fb8047b156bb 2131 */
rahul_dahiya 0:fb8047b156bb 2132 if( mbedtls_mpi_cmp_mpi( &A, &W ) != 0 ||
rahul_dahiya 0:fb8047b156bb 2133 mbedtls_mpi_cmp_int( &A, 1 ) == 0 )
rahul_dahiya 0:fb8047b156bb 2134 {
rahul_dahiya 0:fb8047b156bb 2135 ret = MBEDTLS_ERR_MPI_NOT_ACCEPTABLE;
rahul_dahiya 0:fb8047b156bb 2136 break;
rahul_dahiya 0:fb8047b156bb 2137 }
rahul_dahiya 0:fb8047b156bb 2138 }
rahul_dahiya 0:fb8047b156bb 2139
rahul_dahiya 0:fb8047b156bb 2140 cleanup:
rahul_dahiya 0:fb8047b156bb 2141 mbedtls_mpi_free( &W ); mbedtls_mpi_free( &R ); mbedtls_mpi_free( &T ); mbedtls_mpi_free( &A );
rahul_dahiya 0:fb8047b156bb 2142 mbedtls_mpi_free( &RR );
rahul_dahiya 0:fb8047b156bb 2143
rahul_dahiya 0:fb8047b156bb 2144 return( ret );
rahul_dahiya 0:fb8047b156bb 2145 }
rahul_dahiya 0:fb8047b156bb 2146
rahul_dahiya 0:fb8047b156bb 2147 /*
rahul_dahiya 0:fb8047b156bb 2148 * Pseudo-primality test: small factors, then Miller-Rabin
rahul_dahiya 0:fb8047b156bb 2149 */
rahul_dahiya 0:fb8047b156bb 2150 int mbedtls_mpi_is_prime( const mbedtls_mpi *X,
rahul_dahiya 0:fb8047b156bb 2151 int (*f_rng)(void *, unsigned char *, size_t),
rahul_dahiya 0:fb8047b156bb 2152 void *p_rng )
rahul_dahiya 0:fb8047b156bb 2153 {
rahul_dahiya 0:fb8047b156bb 2154 int ret;
rahul_dahiya 0:fb8047b156bb 2155 mbedtls_mpi XX;
rahul_dahiya 0:fb8047b156bb 2156
rahul_dahiya 0:fb8047b156bb 2157 XX.s = 1;
rahul_dahiya 0:fb8047b156bb 2158 XX.n = X->n;
rahul_dahiya 0:fb8047b156bb 2159 XX.p = X->p;
rahul_dahiya 0:fb8047b156bb 2160
rahul_dahiya 0:fb8047b156bb 2161 if( mbedtls_mpi_cmp_int( &XX, 0 ) == 0 ||
rahul_dahiya 0:fb8047b156bb 2162 mbedtls_mpi_cmp_int( &XX, 1 ) == 0 )
rahul_dahiya 0:fb8047b156bb 2163 return( MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
rahul_dahiya 0:fb8047b156bb 2164
rahul_dahiya 0:fb8047b156bb 2165 if( mbedtls_mpi_cmp_int( &XX, 2 ) == 0 )
rahul_dahiya 0:fb8047b156bb 2166 return( 0 );
rahul_dahiya 0:fb8047b156bb 2167
rahul_dahiya 0:fb8047b156bb 2168 if( ( ret = mpi_check_small_factors( &XX ) ) != 0 )
rahul_dahiya 0:fb8047b156bb 2169 {
rahul_dahiya 0:fb8047b156bb 2170 if( ret == 1 )
rahul_dahiya 0:fb8047b156bb 2171 return( 0 );
rahul_dahiya 0:fb8047b156bb 2172
rahul_dahiya 0:fb8047b156bb 2173 return( ret );
rahul_dahiya 0:fb8047b156bb 2174 }
rahul_dahiya 0:fb8047b156bb 2175
rahul_dahiya 0:fb8047b156bb 2176 return( mpi_miller_rabin( &XX, f_rng, p_rng ) );
rahul_dahiya 0:fb8047b156bb 2177 }
rahul_dahiya 0:fb8047b156bb 2178
rahul_dahiya 0:fb8047b156bb 2179 /*
rahul_dahiya 0:fb8047b156bb 2180 * Prime number generation
rahul_dahiya 0:fb8047b156bb 2181 */
rahul_dahiya 0:fb8047b156bb 2182 int mbedtls_mpi_gen_prime( mbedtls_mpi *X, size_t nbits, int dh_flag,
rahul_dahiya 0:fb8047b156bb 2183 int (*f_rng)(void *, unsigned char *, size_t),
rahul_dahiya 0:fb8047b156bb 2184 void *p_rng )
rahul_dahiya 0:fb8047b156bb 2185 {
rahul_dahiya 0:fb8047b156bb 2186 int ret;
rahul_dahiya 0:fb8047b156bb 2187 size_t k, n;
rahul_dahiya 0:fb8047b156bb 2188 mbedtls_mpi_uint r;
rahul_dahiya 0:fb8047b156bb 2189 mbedtls_mpi Y;
rahul_dahiya 0:fb8047b156bb 2190
rahul_dahiya 0:fb8047b156bb 2191 if( nbits < 3 || nbits > MBEDTLS_MPI_MAX_BITS )
rahul_dahiya 0:fb8047b156bb 2192 return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
rahul_dahiya 0:fb8047b156bb 2193
rahul_dahiya 0:fb8047b156bb 2194 mbedtls_mpi_init( &Y );
rahul_dahiya 0:fb8047b156bb 2195
rahul_dahiya 0:fb8047b156bb 2196 n = BITS_TO_LIMBS( nbits );
rahul_dahiya 0:fb8047b156bb 2197
rahul_dahiya 0:fb8047b156bb 2198 MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( X, n * ciL, f_rng, p_rng ) );
rahul_dahiya 0:fb8047b156bb 2199
rahul_dahiya 0:fb8047b156bb 2200 k = mbedtls_mpi_bitlen( X );
rahul_dahiya 0:fb8047b156bb 2201 if( k > nbits ) MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( X, k - nbits + 1 ) );
rahul_dahiya 0:fb8047b156bb 2202
rahul_dahiya 0:fb8047b156bb 2203 mbedtls_mpi_set_bit( X, nbits-1, 1 );
rahul_dahiya 0:fb8047b156bb 2204
rahul_dahiya 0:fb8047b156bb 2205 X->p[0] |= 1;
rahul_dahiya 0:fb8047b156bb 2206
rahul_dahiya 0:fb8047b156bb 2207 if( dh_flag == 0 )
rahul_dahiya 0:fb8047b156bb 2208 {
rahul_dahiya 0:fb8047b156bb 2209 while( ( ret = mbedtls_mpi_is_prime( X, f_rng, p_rng ) ) != 0 )
rahul_dahiya 0:fb8047b156bb 2210 {
rahul_dahiya 0:fb8047b156bb 2211 if( ret != MBEDTLS_ERR_MPI_NOT_ACCEPTABLE )
rahul_dahiya 0:fb8047b156bb 2212 goto cleanup;
rahul_dahiya 0:fb8047b156bb 2213
rahul_dahiya 0:fb8047b156bb 2214 MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( X, X, 2 ) );
rahul_dahiya 0:fb8047b156bb 2215 }
rahul_dahiya 0:fb8047b156bb 2216 }
rahul_dahiya 0:fb8047b156bb 2217 else
rahul_dahiya 0:fb8047b156bb 2218 {
rahul_dahiya 0:fb8047b156bb 2219 /*
rahul_dahiya 0:fb8047b156bb 2220 * An necessary condition for Y and X = 2Y + 1 to be prime
rahul_dahiya 0:fb8047b156bb 2221 * is X = 2 mod 3 (which is equivalent to Y = 2 mod 3).
rahul_dahiya 0:fb8047b156bb 2222 * Make sure it is satisfied, while keeping X = 3 mod 4
rahul_dahiya 0:fb8047b156bb 2223 */
rahul_dahiya 0:fb8047b156bb 2224
rahul_dahiya 0:fb8047b156bb 2225 X->p[0] |= 2;
rahul_dahiya 0:fb8047b156bb 2226
rahul_dahiya 0:fb8047b156bb 2227 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_int( &r, X, 3 ) );
rahul_dahiya 0:fb8047b156bb 2228 if( r == 0 )
rahul_dahiya 0:fb8047b156bb 2229 MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( X, X, 8 ) );
rahul_dahiya 0:fb8047b156bb 2230 else if( r == 1 )
rahul_dahiya 0:fb8047b156bb 2231 MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( X, X, 4 ) );
rahul_dahiya 0:fb8047b156bb 2232
rahul_dahiya 0:fb8047b156bb 2233 /* Set Y = (X-1) / 2, which is X / 2 because X is odd */
rahul_dahiya 0:fb8047b156bb 2234 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &Y, X ) );
rahul_dahiya 0:fb8047b156bb 2235 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &Y, 1 ) );
rahul_dahiya 0:fb8047b156bb 2236
rahul_dahiya 0:fb8047b156bb 2237 while( 1 )
rahul_dahiya 0:fb8047b156bb 2238 {
rahul_dahiya 0:fb8047b156bb 2239 /*
rahul_dahiya 0:fb8047b156bb 2240 * First, check small factors for X and Y
rahul_dahiya 0:fb8047b156bb 2241 * before doing Miller-Rabin on any of them
rahul_dahiya 0:fb8047b156bb 2242 */
rahul_dahiya 0:fb8047b156bb 2243 if( ( ret = mpi_check_small_factors( X ) ) == 0 &&
rahul_dahiya 0:fb8047b156bb 2244 ( ret = mpi_check_small_factors( &Y ) ) == 0 &&
rahul_dahiya 0:fb8047b156bb 2245 ( ret = mpi_miller_rabin( X, f_rng, p_rng ) ) == 0 &&
rahul_dahiya 0:fb8047b156bb 2246 ( ret = mpi_miller_rabin( &Y, f_rng, p_rng ) ) == 0 )
rahul_dahiya 0:fb8047b156bb 2247 {
rahul_dahiya 0:fb8047b156bb 2248 break;
rahul_dahiya 0:fb8047b156bb 2249 }
rahul_dahiya 0:fb8047b156bb 2250
rahul_dahiya 0:fb8047b156bb 2251 if( ret != MBEDTLS_ERR_MPI_NOT_ACCEPTABLE )
rahul_dahiya 0:fb8047b156bb 2252 goto cleanup;
rahul_dahiya 0:fb8047b156bb 2253
rahul_dahiya 0:fb8047b156bb 2254 /*
rahul_dahiya 0:fb8047b156bb 2255 * Next candidates. We want to preserve Y = (X-1) / 2 and
rahul_dahiya 0:fb8047b156bb 2256 * Y = 1 mod 2 and Y = 2 mod 3 (eq X = 3 mod 4 and X = 2 mod 3)
rahul_dahiya 0:fb8047b156bb 2257 * so up Y by 6 and X by 12.
rahul_dahiya 0:fb8047b156bb 2258 */
rahul_dahiya 0:fb8047b156bb 2259 MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( X, X, 12 ) );
rahul_dahiya 0:fb8047b156bb 2260 MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &Y, &Y, 6 ) );
rahul_dahiya 0:fb8047b156bb 2261 }
rahul_dahiya 0:fb8047b156bb 2262 }
rahul_dahiya 0:fb8047b156bb 2263
rahul_dahiya 0:fb8047b156bb 2264 cleanup:
rahul_dahiya 0:fb8047b156bb 2265
rahul_dahiya 0:fb8047b156bb 2266 mbedtls_mpi_free( &Y );
rahul_dahiya 0:fb8047b156bb 2267
rahul_dahiya 0:fb8047b156bb 2268 return( ret );
rahul_dahiya 0:fb8047b156bb 2269 }
rahul_dahiya 0:fb8047b156bb 2270
rahul_dahiya 0:fb8047b156bb 2271 #endif /* MBEDTLS_GENPRIME */
rahul_dahiya 0:fb8047b156bb 2272
rahul_dahiya 0:fb8047b156bb 2273 #if defined(MBEDTLS_SELF_TEST)
rahul_dahiya 0:fb8047b156bb 2274
rahul_dahiya 0:fb8047b156bb 2275 #define GCD_PAIR_COUNT 3
rahul_dahiya 0:fb8047b156bb 2276
rahul_dahiya 0:fb8047b156bb 2277 static const int gcd_pairs[GCD_PAIR_COUNT][3] =
rahul_dahiya 0:fb8047b156bb 2278 {
rahul_dahiya 0:fb8047b156bb 2279 { 693, 609, 21 },
rahul_dahiya 0:fb8047b156bb 2280 { 1764, 868, 28 },
rahul_dahiya 0:fb8047b156bb 2281 { 768454923, 542167814, 1 }
rahul_dahiya 0:fb8047b156bb 2282 };
rahul_dahiya 0:fb8047b156bb 2283
rahul_dahiya 0:fb8047b156bb 2284 /*
rahul_dahiya 0:fb8047b156bb 2285 * Checkup routine
rahul_dahiya 0:fb8047b156bb 2286 */
rahul_dahiya 0:fb8047b156bb 2287 int mbedtls_mpi_self_test( int verbose )
rahul_dahiya 0:fb8047b156bb 2288 {
rahul_dahiya 0:fb8047b156bb 2289 int ret, i;
rahul_dahiya 0:fb8047b156bb 2290 mbedtls_mpi A, E, N, X, Y, U, V;
rahul_dahiya 0:fb8047b156bb 2291
rahul_dahiya 0:fb8047b156bb 2292 mbedtls_mpi_init( &A ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &N ); mbedtls_mpi_init( &X );
rahul_dahiya 0:fb8047b156bb 2293 mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &U ); mbedtls_mpi_init( &V );
rahul_dahiya 0:fb8047b156bb 2294
rahul_dahiya 0:fb8047b156bb 2295 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &A, 16,
rahul_dahiya 0:fb8047b156bb 2296 "EFE021C2645FD1DC586E69184AF4A31E" \
rahul_dahiya 0:fb8047b156bb 2297 "D5F53E93B5F123FA41680867BA110131" \
rahul_dahiya 0:fb8047b156bb 2298 "944FE7952E2517337780CB0DB80E61AA" \
rahul_dahiya 0:fb8047b156bb 2299 "E7C8DDC6C5C6AADEB34EB38A2F40D5E6" ) );
rahul_dahiya 0:fb8047b156bb 2300
rahul_dahiya 0:fb8047b156bb 2301 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &E, 16,
rahul_dahiya 0:fb8047b156bb 2302 "B2E7EFD37075B9F03FF989C7C5051C20" \
rahul_dahiya 0:fb8047b156bb 2303 "34D2A323810251127E7BF8625A4F49A5" \
rahul_dahiya 0:fb8047b156bb 2304 "F3E27F4DA8BD59C47D6DAABA4C8127BD" \
rahul_dahiya 0:fb8047b156bb 2305 "5B5C25763222FEFCCFC38B832366C29E" ) );
rahul_dahiya 0:fb8047b156bb 2306
rahul_dahiya 0:fb8047b156bb 2307 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &N, 16,
rahul_dahiya 0:fb8047b156bb 2308 "0066A198186C18C10B2F5ED9B522752A" \
rahul_dahiya 0:fb8047b156bb 2309 "9830B69916E535C8F047518A889A43A5" \
rahul_dahiya 0:fb8047b156bb 2310 "94B6BED27A168D31D4A52F88925AA8F5" ) );
rahul_dahiya 0:fb8047b156bb 2311
rahul_dahiya 0:fb8047b156bb 2312 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &X, &A, &N ) );
rahul_dahiya 0:fb8047b156bb 2313
rahul_dahiya 0:fb8047b156bb 2314 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &U, 16,
rahul_dahiya 0:fb8047b156bb 2315 "602AB7ECA597A3D6B56FF9829A5E8B85" \
rahul_dahiya 0:fb8047b156bb 2316 "9E857EA95A03512E2BAE7391688D264A" \
rahul_dahiya 0:fb8047b156bb 2317 "A5663B0341DB9CCFD2C4C5F421FEC814" \
rahul_dahiya 0:fb8047b156bb 2318 "8001B72E848A38CAE1C65F78E56ABDEF" \
rahul_dahiya 0:fb8047b156bb 2319 "E12D3C039B8A02D6BE593F0BBBDA56F1" \
rahul_dahiya 0:fb8047b156bb 2320 "ECF677152EF804370C1A305CAF3B5BF1" \
rahul_dahiya 0:fb8047b156bb 2321 "30879B56C61DE584A0F53A2447A51E" ) );
rahul_dahiya 0:fb8047b156bb 2322
rahul_dahiya 0:fb8047b156bb 2323 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2324 mbedtls_printf( " MPI test #1 (mul_mpi): " );
rahul_dahiya 0:fb8047b156bb 2325
rahul_dahiya 0:fb8047b156bb 2326 if( mbedtls_mpi_cmp_mpi( &X, &U ) != 0 )
rahul_dahiya 0:fb8047b156bb 2327 {
rahul_dahiya 0:fb8047b156bb 2328 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2329 mbedtls_printf( "failed\n" );
rahul_dahiya 0:fb8047b156bb 2330
rahul_dahiya 0:fb8047b156bb 2331 ret = 1;
rahul_dahiya 0:fb8047b156bb 2332 goto cleanup;
rahul_dahiya 0:fb8047b156bb 2333 }
rahul_dahiya 0:fb8047b156bb 2334
rahul_dahiya 0:fb8047b156bb 2335 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2336 mbedtls_printf( "passed\n" );
rahul_dahiya 0:fb8047b156bb 2337
rahul_dahiya 0:fb8047b156bb 2338 MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &X, &Y, &A, &N ) );
rahul_dahiya 0:fb8047b156bb 2339
rahul_dahiya 0:fb8047b156bb 2340 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &U, 16,
rahul_dahiya 0:fb8047b156bb 2341 "256567336059E52CAE22925474705F39A94" ) );
rahul_dahiya 0:fb8047b156bb 2342
rahul_dahiya 0:fb8047b156bb 2343 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &V, 16,
rahul_dahiya 0:fb8047b156bb 2344 "6613F26162223DF488E9CD48CC132C7A" \
rahul_dahiya 0:fb8047b156bb 2345 "0AC93C701B001B092E4E5B9F73BCD27B" \
rahul_dahiya 0:fb8047b156bb 2346 "9EE50D0657C77F374E903CDFA4C642" ) );
rahul_dahiya 0:fb8047b156bb 2347
rahul_dahiya 0:fb8047b156bb 2348 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2349 mbedtls_printf( " MPI test #2 (div_mpi): " );
rahul_dahiya 0:fb8047b156bb 2350
rahul_dahiya 0:fb8047b156bb 2351 if( mbedtls_mpi_cmp_mpi( &X, &U ) != 0 ||
rahul_dahiya 0:fb8047b156bb 2352 mbedtls_mpi_cmp_mpi( &Y, &V ) != 0 )
rahul_dahiya 0:fb8047b156bb 2353 {
rahul_dahiya 0:fb8047b156bb 2354 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2355 mbedtls_printf( "failed\n" );
rahul_dahiya 0:fb8047b156bb 2356
rahul_dahiya 0:fb8047b156bb 2357 ret = 1;
rahul_dahiya 0:fb8047b156bb 2358 goto cleanup;
rahul_dahiya 0:fb8047b156bb 2359 }
rahul_dahiya 0:fb8047b156bb 2360
rahul_dahiya 0:fb8047b156bb 2361 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2362 mbedtls_printf( "passed\n" );
rahul_dahiya 0:fb8047b156bb 2363
rahul_dahiya 0:fb8047b156bb 2364 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &X, &A, &E, &N, NULL ) );
rahul_dahiya 0:fb8047b156bb 2365
rahul_dahiya 0:fb8047b156bb 2366 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &U, 16,
rahul_dahiya 0:fb8047b156bb 2367 "36E139AEA55215609D2816998ED020BB" \
rahul_dahiya 0:fb8047b156bb 2368 "BD96C37890F65171D948E9BC7CBAA4D9" \
rahul_dahiya 0:fb8047b156bb 2369 "325D24D6A3C12710F10A09FA08AB87" ) );
rahul_dahiya 0:fb8047b156bb 2370
rahul_dahiya 0:fb8047b156bb 2371 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2372 mbedtls_printf( " MPI test #3 (exp_mod): " );
rahul_dahiya 0:fb8047b156bb 2373
rahul_dahiya 0:fb8047b156bb 2374 if( mbedtls_mpi_cmp_mpi( &X, &U ) != 0 )
rahul_dahiya 0:fb8047b156bb 2375 {
rahul_dahiya 0:fb8047b156bb 2376 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2377 mbedtls_printf( "failed\n" );
rahul_dahiya 0:fb8047b156bb 2378
rahul_dahiya 0:fb8047b156bb 2379 ret = 1;
rahul_dahiya 0:fb8047b156bb 2380 goto cleanup;
rahul_dahiya 0:fb8047b156bb 2381 }
rahul_dahiya 0:fb8047b156bb 2382
rahul_dahiya 0:fb8047b156bb 2383 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2384 mbedtls_printf( "passed\n" );
rahul_dahiya 0:fb8047b156bb 2385
rahul_dahiya 0:fb8047b156bb 2386 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &X, &A, &N ) );
rahul_dahiya 0:fb8047b156bb 2387
rahul_dahiya 0:fb8047b156bb 2388 MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &U, 16,
rahul_dahiya 0:fb8047b156bb 2389 "003A0AAEDD7E784FC07D8F9EC6E3BFD5" \
rahul_dahiya 0:fb8047b156bb 2390 "C3DBA76456363A10869622EAC2DD84EC" \
rahul_dahiya 0:fb8047b156bb 2391 "C5B8A74DAC4D09E03B5E0BE779F2DF61" ) );
rahul_dahiya 0:fb8047b156bb 2392
rahul_dahiya 0:fb8047b156bb 2393 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2394 mbedtls_printf( " MPI test #4 (inv_mod): " );
rahul_dahiya 0:fb8047b156bb 2395
rahul_dahiya 0:fb8047b156bb 2396 if( mbedtls_mpi_cmp_mpi( &X, &U ) != 0 )
rahul_dahiya 0:fb8047b156bb 2397 {
rahul_dahiya 0:fb8047b156bb 2398 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2399 mbedtls_printf( "failed\n" );
rahul_dahiya 0:fb8047b156bb 2400
rahul_dahiya 0:fb8047b156bb 2401 ret = 1;
rahul_dahiya 0:fb8047b156bb 2402 goto cleanup;
rahul_dahiya 0:fb8047b156bb 2403 }
rahul_dahiya 0:fb8047b156bb 2404
rahul_dahiya 0:fb8047b156bb 2405 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2406 mbedtls_printf( "passed\n" );
rahul_dahiya 0:fb8047b156bb 2407
rahul_dahiya 0:fb8047b156bb 2408 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2409 mbedtls_printf( " MPI test #5 (simple gcd): " );
rahul_dahiya 0:fb8047b156bb 2410
rahul_dahiya 0:fb8047b156bb 2411 for( i = 0; i < GCD_PAIR_COUNT; i++ )
rahul_dahiya 0:fb8047b156bb 2412 {
rahul_dahiya 0:fb8047b156bb 2413 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &X, gcd_pairs[i][0] ) );
rahul_dahiya 0:fb8047b156bb 2414 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &Y, gcd_pairs[i][1] ) );
rahul_dahiya 0:fb8047b156bb 2415
rahul_dahiya 0:fb8047b156bb 2416 MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &A, &X, &Y ) );
rahul_dahiya 0:fb8047b156bb 2417
rahul_dahiya 0:fb8047b156bb 2418 if( mbedtls_mpi_cmp_int( &A, gcd_pairs[i][2] ) != 0 )
rahul_dahiya 0:fb8047b156bb 2419 {
rahul_dahiya 0:fb8047b156bb 2420 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2421 mbedtls_printf( "failed at %d\n", i );
rahul_dahiya 0:fb8047b156bb 2422
rahul_dahiya 0:fb8047b156bb 2423 ret = 1;
rahul_dahiya 0:fb8047b156bb 2424 goto cleanup;
rahul_dahiya 0:fb8047b156bb 2425 }
rahul_dahiya 0:fb8047b156bb 2426 }
rahul_dahiya 0:fb8047b156bb 2427
rahul_dahiya 0:fb8047b156bb 2428 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2429 mbedtls_printf( "passed\n" );
rahul_dahiya 0:fb8047b156bb 2430
rahul_dahiya 0:fb8047b156bb 2431 cleanup:
rahul_dahiya 0:fb8047b156bb 2432
rahul_dahiya 0:fb8047b156bb 2433 if( ret != 0 && verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2434 mbedtls_printf( "Unexpected error, return code = %08X\n", ret );
rahul_dahiya 0:fb8047b156bb 2435
rahul_dahiya 0:fb8047b156bb 2436 mbedtls_mpi_free( &A ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &N ); mbedtls_mpi_free( &X );
rahul_dahiya 0:fb8047b156bb 2437 mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &U ); mbedtls_mpi_free( &V );
rahul_dahiya 0:fb8047b156bb 2438
rahul_dahiya 0:fb8047b156bb 2439 if( verbose != 0 )
rahul_dahiya 0:fb8047b156bb 2440 mbedtls_printf( "\n" );
rahul_dahiya 0:fb8047b156bb 2441
rahul_dahiya 0:fb8047b156bb 2442 return( ret );
rahul_dahiya 0:fb8047b156bb 2443 }
rahul_dahiya 0:fb8047b156bb 2444
rahul_dahiya 0:fb8047b156bb 2445 #endif /* MBEDTLS_SELF_TEST */
rahul_dahiya 0:fb8047b156bb 2446
rahul_dahiya 0:fb8047b156bb 2447 #endif /* MBEDTLS_BIGNUM_C */