+++ /dev/null
-/*
- * Multi-precision integer library
- *
- * Copyright (C) 2006-2010, Brainspark B.V.
- *
- * This file is part of PolarSSL (http://www.polarssl.org)
- * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
- *
- * All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-/*
- * This MPI implementation is based on:
- *
- * http://www.cacr.math.uwaterloo.ca/hac/about/chap14.pdf
- * http://www.stillhq.com/extracted/gnupg-api/mpi/
- * http://math.libtomcrypt.com/files/tommath.pdf
- */
-
-#include "bignum.h"
-#include "bn_mul.h"
-
-#include <string.h>
-#include <stdlib.h>
-#include <stdarg.h>
-
-#define ciL ((int) sizeof(t_int)) /* chars in limb */
-#define biL (ciL << 3) /* bits in limb */
-#define biH (ciL << 2) /* half limb size */
-
-/*
- * Convert between bits/chars and number of limbs
- */
-#define BITS_TO_LIMBS(i) (((i) + biL - 1) / biL)
-#define CHARS_TO_LIMBS(i) (((i) + ciL - 1) / ciL)
-
-/*
- * Initialize one or more mpi
- */
-void mpi_init( mpi *X, ... )
-{
- va_list args;
-
- va_start( args, X );
-
- while( X != NULL )
- {
- X->s = 1;
- X->n = 0;
- X->p = NULL;
-
- X = va_arg( args, mpi* );
- }
-
- va_end( args );
-}
-
-/*
- * Unallocate one or more mpi
- */
-void mpi_free( mpi *X, ... )
-{
- va_list args;
-
- va_start( args, X );
-
- while( X != NULL )
- {
- if( X->p != NULL )
- {
- memset( X->p, 0, X->n * ciL );
- free( X->p );
- }
-
- X->s = 1;
- X->n = 0;
- X->p = NULL;
-
- X = va_arg( args, mpi* );
- }
-
- va_end( args );
-}
-
-/*
- * Enlarge to the specified number of limbs
- */
-int mpi_grow( mpi *X, int nblimbs )
-{
- t_int *p;
-
- if( X->n < nblimbs )
- {
- if( ( p = (t_int *) malloc( nblimbs * ciL ) ) == NULL )
- return( 1 );
-
- memset( p, 0, nblimbs * ciL );
-
- if( X->p != NULL )
- {
- memcpy( p, X->p, X->n * ciL );
- memset( X->p, 0, X->n * ciL );
- free( X->p );
- }
-
- X->n = nblimbs;
- X->p = p;
- }
-
- return( 0 );
-}
-
-/*
- * Copy the contents of Y into X
- */
-int mpi_copy( mpi *X, const mpi *Y )
-{
- int ret, i;
-
- if( X == Y )
- return( 0 );
-
- for( i = Y->n - 1; i > 0; i-- )
- if( Y->p[i] != 0 )
- break;
- i++;
-
- X->s = Y->s;
-
- MPI_CHK( mpi_grow( X, i ) );
-
- memset( X->p, 0, X->n * ciL );
- memcpy( X->p, Y->p, i * ciL );
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Swap the contents of X and Y
- */
-void mpi_swap( mpi *X, mpi *Y )
-{
- mpi T;
-
- memcpy( &T, X, sizeof( mpi ) );
- memcpy( X, Y, sizeof( mpi ) );
- memcpy( Y, &T, sizeof( mpi ) );
-}
-
-/*
- * Set value from integer
- */
-int mpi_lset( mpi *X, int z )
-{
- int ret;
-
- MPI_CHK( mpi_grow( X, 1 ) );
- memset( X->p, 0, X->n * ciL );
-
- X->p[0] = ( z < 0 ) ? -z : z;
- X->s = ( z < 0 ) ? -1 : 1;
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Return the number of least significant bits
- */
-int mpi_lsb( const mpi *X )
-{
- int i, j, count = 0;
-
- for( i = 0; i < X->n; i++ )
- for( j = 0; j < (int) biL; j++, count++ )
- if( ( ( X->p[i] >> j ) & 1 ) != 0 )
- return( count );
-
- return( 0 );
-}
-
-/*
- * Return the number of most significant bits
- */
-int mpi_msb( const mpi *X )
-{
- int i, j;
-
- for( i = X->n - 1; i > 0; i-- )
- if( X->p[i] != 0 )
- break;
-
- for( j = biL - 1; j >= 0; j-- )
- if( ( ( X->p[i] >> j ) & 1 ) != 0 )
- break;
-
- return( ( i * biL ) + j + 1 );
-}
-
-/*
- * Return the total size in bytes
- */
-int mpi_size( const mpi *X )
-{
- return( ( mpi_msb( X ) + 7 ) >> 3 );
-}
-
-/*
- * Convert an ASCII character to digit value
- */
-static int mpi_get_digit( t_int *d, int radix, char c )
-{
- *d = 255;
-
- if( c >= 0x30 && c <= 0x39 ) *d = c - 0x30;
- if( c >= 0x41 && c <= 0x46 ) *d = c - 0x37;
- if( c >= 0x61 && c <= 0x66 ) *d = c - 0x57;
-
- if( *d >= (t_int) radix )
- return( POLARSSL_ERR_MPI_INVALID_CHARACTER );
-
- return( 0 );
-}
-
-/*
- * Import from an ASCII string
- */
-int mpi_read_string( mpi *X, int radix, const char *s )
-{
- int ret, i, j, n, slen;
- t_int d;
- mpi T;
-
- if( radix < 2 || radix > 16 )
- return( POLARSSL_ERR_MPI_BAD_INPUT_DATA );
-
- mpi_init( &T, NULL );
-
- slen = strlen( s );
-
- if( radix == 16 )
- {
- n = BITS_TO_LIMBS( slen << 2 );
-
- MPI_CHK( mpi_grow( X, n ) );
- MPI_CHK( mpi_lset( X, 0 ) );
-
- for( i = slen - 1, j = 0; i >= 0; i--, j++ )
- {
- if( i == 0 && s[i] == '-' )
- {
- X->s = -1;
- break;
- }
-
- MPI_CHK( mpi_get_digit( &d, radix, s[i] ) );
- X->p[j / (2 * ciL)] |= d << ( (j % (2 * ciL)) << 2 );
- }
- }
- else
- {
- MPI_CHK( mpi_lset( X, 0 ) );
-
- for( i = 0; i < slen; i++ )
- {
- if( i == 0 && s[i] == '-' )
- {
- X->s = -1;
- continue;
- }
-
- MPI_CHK( mpi_get_digit( &d, radix, s[i] ) );
- MPI_CHK( mpi_mul_int( &T, X, radix ) );
-
- if( X->s == 1 )
- {
- MPI_CHK( mpi_add_int( X, &T, d ) );
- }
- else
- {
- MPI_CHK( mpi_sub_int( X, &T, d ) );
- }
- }
- }
-
-cleanup:
-
- mpi_free( &T, NULL );
-
- return( ret );
-}
-
-/*
- * Helper to write the digits high-order first
- */
-static int mpi_write_hlp( mpi *X, int radix, char **p )
-{
- int ret;
- t_int r;
-
- if( radix < 2 || radix > 16 )
- return( POLARSSL_ERR_MPI_BAD_INPUT_DATA );
-
- MPI_CHK( mpi_mod_int( &r, X, radix ) );
- MPI_CHK( mpi_div_int( X, NULL, X, radix ) );
-
- if( mpi_cmp_int( X, 0 ) != 0 )
- MPI_CHK( mpi_write_hlp( X, radix, p ) );
-
- if( r < 10 )
- *(*p)++ = (char)( r + 0x30 );
- else
- *(*p)++ = (char)( r + 0x37 );
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Export into an ASCII string
- */
-int mpi_write_string( const mpi *X, int radix, char *s, int *slen )
-{
- int ret = 0, n;
- char *p;
- mpi T;
-
- if( radix < 2 || radix > 16 )
- return( POLARSSL_ERR_MPI_BAD_INPUT_DATA );
-
- n = mpi_msb( X );
- if( radix >= 4 ) n >>= 1;
- if( radix >= 16 ) n >>= 1;
- n += 3;
-
- if( *slen < n )
- {
- *slen = n;
- return( POLARSSL_ERR_MPI_BUFFER_TOO_SMALL );
- }
-
- p = s;
- mpi_init( &T, NULL );
-
- if( X->s == -1 )
- *p++ = '-';
-
- if( radix == 16 )
- {
- int c, i, j, k;
-
- for( i = X->n - 1, k = 0; i >= 0; i-- )
- {
- for( j = ciL - 1; j >= 0; j-- )
- {
- c = ( X->p[i] >> (j << 3) ) & 0xFF;
-
- if( c == 0 && k == 0 && (i + j) != 0 )
- continue;
-
- p += sprintf( p, "%02X", c );
- k = 1;
- }
- }
- }
- else
- {
- MPI_CHK( mpi_copy( &T, X ) );
-
- if( T.s == -1 )
- T.s = 1;
-
- MPI_CHK( mpi_write_hlp( &T, radix, &p ) );
- }
-
- *p++ = '\0';
- *slen = p - s;
-
-cleanup:
-
- mpi_free( &T, NULL );
-
- return( ret );
-}
-
-/*
- * Read X from an opened file
- */
-int mpi_read_file( mpi *X, int radix, FILE *fin )
-{
- t_int d;
- int slen;
- char *p;
- char s[1024];
-
- memset( s, 0, sizeof( s ) );
- if( fgets( s, sizeof( s ) - 1, fin ) == NULL )
- return( POLARSSL_ERR_MPI_FILE_IO_ERROR );
-
- slen = strlen( s );
- if( s[slen - 1] == '\n' ) { slen--; s[slen] = '\0'; }
- if( s[slen - 1] == '\r' ) { slen--; s[slen] = '\0'; }
-
- p = s + slen;
- while( --p >= s )
- if( mpi_get_digit( &d, radix, *p ) != 0 )
- break;
-
- return( mpi_read_string( X, radix, p + 1 ) );
-}
-
-/*
- * Write X into an opened file (or stdout if fout == NULL)
- */
-int mpi_write_file( const char *p, const mpi *X, int radix, FILE *fout )
-{
- int n, ret;
- size_t slen;
- size_t plen;
- char s[2048];
-
- n = sizeof( s );
- memset( s, 0, n );
- n -= 2;
-
- MPI_CHK( mpi_write_string( X, radix, s, (int *) &n ) );
-
- if( p == NULL ) p = "";
-
- plen = strlen( p );
- slen = strlen( s );
- s[slen++] = '\r';
- s[slen++] = '\n';
-
- if( fout != NULL )
- {
- if( fwrite( p, 1, plen, fout ) != plen ||
- fwrite( s, 1, slen, fout ) != slen )
- return( POLARSSL_ERR_MPI_FILE_IO_ERROR );
- }
- else
- printf( "%s%s", p, s );
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Import X from unsigned binary data, big endian
- */
-int mpi_read_binary( mpi *X, const unsigned char *buf, int buflen )
-{
- int ret, i, j, n;
-
- for( n = 0; n < buflen; n++ )
- if( buf[n] != 0 )
- break;
-
- MPI_CHK( mpi_grow( X, CHARS_TO_LIMBS( buflen - n ) ) );
- MPI_CHK( mpi_lset( X, 0 ) );
-
- for( i = buflen - 1, j = 0; i >= n; i--, j++ )
- X->p[j / ciL] |= ((t_int) buf[i]) << ((j % ciL) << 3);
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Export X into unsigned binary data, big endian
- */
-int mpi_write_binary( const mpi *X, unsigned char *buf, int buflen )
-{
- int i, j, n;
-
- n = mpi_size( X );
-
- if( buflen < n )
- return( POLARSSL_ERR_MPI_BUFFER_TOO_SMALL );
-
- memset( buf, 0, buflen );
-
- for( i = buflen - 1, j = 0; n > 0; i--, j++, n-- )
- buf[i] = (unsigned char)( X->p[j / ciL] >> ((j % ciL) << 3) );
-
- return( 0 );
-}
-
-/*
- * Left-shift: X <<= count
- */
-int mpi_shift_l( mpi *X, int count )
-{
- int ret, i, v0, t1;
- t_int r0 = 0, r1;
-
- v0 = count / (biL );
- t1 = count & (biL - 1);
-
- i = mpi_msb( X ) + count;
-
- if( X->n * (int) biL < i )
- MPI_CHK( mpi_grow( X, BITS_TO_LIMBS( i ) ) );
-
- ret = 0;
-
- /*
- * shift by count / limb_size
- */
- if( v0 > 0 )
- {
- for( i = X->n - 1; i >= v0; i-- )
- X->p[i] = X->p[i - v0];
-
- for( ; i >= 0; i-- )
- X->p[i] = 0;
- }
-
- /*
- * shift by count % limb_size
- */
- if( t1 > 0 )
- {
- for( i = v0; i < X->n; i++ )
- {
- r1 = X->p[i] >> (biL - t1);
- X->p[i] <<= t1;
- X->p[i] |= r0;
- r0 = r1;
- }
- }
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Right-shift: X >>= count
- */
-int mpi_shift_r( mpi *X, int count )
-{
- int i, v0, v1;
- t_int r0 = 0, r1;
-
- v0 = count / biL;
- v1 = count & (biL - 1);
-
- /*
- * shift by count / limb_size
- */
- if( v0 > 0 )
- {
- for( i = 0; i < X->n - v0; i++ )
- X->p[i] = X->p[i + v0];
-
- for( ; i < X->n; i++ )
- X->p[i] = 0;
- }
-
- /*
- * shift by count % limb_size
- */
- if( v1 > 0 )
- {
- for( i = X->n - 1; i >= 0; i-- )
- {
- r1 = X->p[i] << (biL - v1);
- X->p[i] >>= v1;
- X->p[i] |= r0;
- r0 = r1;
- }
- }
-
- return( 0 );
-}
-
-/*
- * Compare unsigned values
- */
-int mpi_cmp_abs( const mpi *X, const mpi *Y )
-{
- int i, j;
-
- for( i = X->n - 1; i >= 0; i-- )
- if( X->p[i] != 0 )
- break;
-
- for( j = Y->n - 1; j >= 0; j-- )
- if( Y->p[j] != 0 )
- break;
-
- if( i < 0 && j < 0 )
- return( 0 );
-
- if( i > j ) return( 1 );
- if( j > i ) return( -1 );
-
- for( ; i >= 0; i-- )
- {
- if( X->p[i] > Y->p[i] ) return( 1 );
- if( X->p[i] < Y->p[i] ) return( -1 );
- }
-
- return( 0 );
-}
-
-/*
- * Compare signed values
- */
-int mpi_cmp_mpi( const mpi *X, const mpi *Y )
-{
- int i, j;
-
- for( i = X->n - 1; i >= 0; i-- )
- if( X->p[i] != 0 )
- break;
-
- for( j = Y->n - 1; j >= 0; j-- )
- if( Y->p[j] != 0 )
- break;
-
- if( i < 0 && j < 0 )
- return( 0 );
-
- if( i > j ) return( X->s );
- if( j > i ) return( -X->s );
-
- if( X->s > 0 && Y->s < 0 ) return( 1 );
- if( Y->s > 0 && X->s < 0 ) return( -1 );
-
- for( ; i >= 0; i-- )
- {
- if( X->p[i] > Y->p[i] ) return( X->s );
- if( X->p[i] < Y->p[i] ) return( -X->s );
- }
-
- return( 0 );
-}
-
-/*
- * Compare signed values
- */
-int mpi_cmp_int( const mpi *X, int z )
-{
- mpi Y;
- t_int p[1];
-
- *p = ( z < 0 ) ? -z : z;
- Y.s = ( z < 0 ) ? -1 : 1;
- Y.n = 1;
- Y.p = p;
-
- return( mpi_cmp_mpi( X, &Y ) );
-}
-
-/*
- * Unsigned addition: X = |A| + |B| (HAC 14.7)
- */
-int mpi_add_abs( mpi *X, const mpi *A, const mpi *B )
-{
- int ret, i, j;
- t_int *o, *p, c;
-
- if( X == B )
- {
- const mpi *T = A; A = X; B = T;
- }
-
- if( X != A )
- MPI_CHK( mpi_copy( X, A ) );
-
- /*
- * X should always be positive as a result of unsigned additions.
- */
- X->s = 1;
-
- for( j = B->n - 1; j >= 0; j-- )
- if( B->p[j] != 0 )
- break;
-
- MPI_CHK( mpi_grow( X, j + 1 ) );
-
- o = B->p; p = X->p; c = 0;
-
- for( i = 0; i <= j; i++, o++, p++ )
- {
- *p += c; c = ( *p < c );
- *p += *o; c += ( *p < *o );
- }
-
- while( c != 0 )
- {
- if( i >= X->n )
- {
- MPI_CHK( mpi_grow( X, i + 1 ) );
- p = X->p + i;
- }
-
- *p += c; c = ( *p < c ); i++;
- }
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Helper for mpi substraction
- */
-static void mpi_sub_hlp( int n, t_int *s, t_int *d )
-{
- int i;
- t_int c, z;
-
- for( i = c = 0; i < n; i++, s++, d++ )
- {
- z = ( *d < c ); *d -= c;
- c = ( *d < *s ) + z; *d -= *s;
- }
-
- while( c != 0 )
- {
- z = ( *d < c ); *d -= c;
- c = z; i++; d++;
- }
-}
-
-/*
- * Unsigned substraction: X = |A| - |B| (HAC 14.9)
- */
-int mpi_sub_abs( mpi *X, const mpi *A, const mpi *B )
-{
- mpi TB;
- int ret, n;
-
- if( mpi_cmp_abs( A, B ) < 0 )
- return( POLARSSL_ERR_MPI_NEGATIVE_VALUE );
-
- mpi_init( &TB, NULL );
-
- if( X == B )
- {
- MPI_CHK( mpi_copy( &TB, B ) );
- B = &TB;
- }
-
- if( X != A )
- MPI_CHK( mpi_copy( X, A ) );
-
- /*
- * X should always be positive as a result of unsigned substractions.
- */
- X->s = 1;
-
- ret = 0;
-
- for( n = B->n - 1; n >= 0; n-- )
- if( B->p[n] != 0 )
- break;
-
- mpi_sub_hlp( n + 1, B->p, X->p );
-
-cleanup:
-
- mpi_free( &TB, NULL );
-
- return( ret );
-}
-
-/*
- * Signed addition: X = A + B
- */
-int mpi_add_mpi( mpi *X, const mpi *A, const mpi *B )
-{
- int ret, s = A->s;
-
- if( A->s * B->s < 0 )
- {
- if( mpi_cmp_abs( A, B ) >= 0 )
- {
- MPI_CHK( mpi_sub_abs( X, A, B ) );
- X->s = s;
- }
- else
- {
- MPI_CHK( mpi_sub_abs( X, B, A ) );
- X->s = -s;
- }
- }
- else
- {
- MPI_CHK( mpi_add_abs( X, A, B ) );
- X->s = s;
- }
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Signed substraction: X = A - B
- */
-int mpi_sub_mpi( mpi *X, const mpi *A, const mpi *B )
-{
- int ret, s = A->s;
-
- if( A->s * B->s > 0 )
- {
- if( mpi_cmp_abs( A, B ) >= 0 )
- {
- MPI_CHK( mpi_sub_abs( X, A, B ) );
- X->s = s;
- }
- else
- {
- MPI_CHK( mpi_sub_abs( X, B, A ) );
- X->s = -s;
- }
- }
- else
- {
- MPI_CHK( mpi_add_abs( X, A, B ) );
- X->s = s;
- }
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Signed addition: X = A + b
- */
-int mpi_add_int( mpi *X, const mpi *A, int b )
-{
- mpi _B;
- t_int p[1];
-
- p[0] = ( b < 0 ) ? -b : b;
- _B.s = ( b < 0 ) ? -1 : 1;
- _B.n = 1;
- _B.p = p;
-
- return( mpi_add_mpi( X, A, &_B ) );
-}
-
-/*
- * Signed substraction: X = A - b
- */
-int mpi_sub_int( mpi *X, const mpi *A, int b )
-{
- mpi _B;
- t_int p[1];
-
- p[0] = ( b < 0 ) ? -b : b;
- _B.s = ( b < 0 ) ? -1 : 1;
- _B.n = 1;
- _B.p = p;
-
- return( mpi_sub_mpi( X, A, &_B ) );
-}
-
-/*
- * Helper for mpi multiplication
- */
-static void mpi_mul_hlp( int i, t_int *s, t_int *d, t_int b )
-{
- t_int c = 0, t = 0;
-
-#if defined(MULADDC_HUIT)
- for( ; i >= 8; i -= 8 )
- {
- MULADDC_INIT
- MULADDC_HUIT
- MULADDC_STOP
- }
-
- for( ; i > 0; i-- )
- {
- MULADDC_INIT
- MULADDC_CORE
- MULADDC_STOP
- }
-#else
- for( ; i >= 16; i -= 16 )
- {
- MULADDC_INIT
- MULADDC_CORE MULADDC_CORE
- MULADDC_CORE MULADDC_CORE
- MULADDC_CORE MULADDC_CORE
- MULADDC_CORE MULADDC_CORE
-
- MULADDC_CORE MULADDC_CORE
- MULADDC_CORE MULADDC_CORE
- MULADDC_CORE MULADDC_CORE
- MULADDC_CORE MULADDC_CORE
- MULADDC_STOP
- }
-
- for( ; i >= 8; i -= 8 )
- {
- MULADDC_INIT
- MULADDC_CORE MULADDC_CORE
- MULADDC_CORE MULADDC_CORE
-
- MULADDC_CORE MULADDC_CORE
- MULADDC_CORE MULADDC_CORE
- MULADDC_STOP
- }
-
- for( ; i > 0; i-- )
- {
- MULADDC_INIT
- MULADDC_CORE
- MULADDC_STOP
- }
-#endif
-
- t++;
-
- do {
- *d += c; c = ( *d < c ); d++;
- }
- while( c != 0 );
-}
-
-/*
- * Baseline multiplication: X = A * B (HAC 14.12)
- */
-int mpi_mul_mpi( mpi *X, const mpi *A, const mpi *B )
-{
- int ret, i, j;
- mpi TA, TB;
-
- mpi_init( &TA, &TB, NULL );
-
- if( X == A ) { MPI_CHK( mpi_copy( &TA, A ) ); A = &TA; }
- if( X == B ) { MPI_CHK( mpi_copy( &TB, B ) ); B = &TB; }
-
- for( i = A->n - 1; i >= 0; i-- )
- if( A->p[i] != 0 )
- break;
-
- for( j = B->n - 1; j >= 0; j-- )
- if( B->p[j] != 0 )
- break;
-
- MPI_CHK( mpi_grow( X, i + j + 2 ) );
- MPI_CHK( mpi_lset( X, 0 ) );
-
- for( i++; j >= 0; j-- )
- mpi_mul_hlp( i, A->p, X->p + j, B->p[j] );
-
- X->s = A->s * B->s;
-
-cleanup:
-
- mpi_free( &TB, &TA, NULL );
-
- return( ret );
-}
-
-/*
- * Baseline multiplication: X = A * b
- */
-int mpi_mul_int( mpi *X, const mpi *A, t_int b )
-{
- mpi _B;
- t_int p[1];
-
- _B.s = 1;
- _B.n = 1;
- _B.p = p;
- p[0] = b;
-
- return( mpi_mul_mpi( X, A, &_B ) );
-}
-
-/*
- * Division by mpi: A = Q * B + R (HAC 14.20)
- */
-int mpi_div_mpi( mpi *Q, mpi *R, const mpi *A, const mpi *B )
-{
- int ret, i, n, t, k;
- mpi X, Y, Z, T1, T2;
-
- if( mpi_cmp_int( B, 0 ) == 0 )
- return( POLARSSL_ERR_MPI_DIVISION_BY_ZERO );
-
- mpi_init( &X, &Y, &Z, &T1, &T2, NULL );
-
- if( mpi_cmp_abs( A, B ) < 0 )
- {
- if( Q != NULL ) MPI_CHK( mpi_lset( Q, 0 ) );
- if( R != NULL ) MPI_CHK( mpi_copy( R, A ) );
- return( 0 );
- }
-
- MPI_CHK( mpi_copy( &X, A ) );
- MPI_CHK( mpi_copy( &Y, B ) );
- X.s = Y.s = 1;
-
- MPI_CHK( mpi_grow( &Z, A->n + 2 ) );
- MPI_CHK( mpi_lset( &Z, 0 ) );
- MPI_CHK( mpi_grow( &T1, 2 ) );
- MPI_CHK( mpi_grow( &T2, 3 ) );
-
- k = mpi_msb( &Y ) % biL;
- if( k < (int) biL - 1 )
- {
- k = biL - 1 - k;
- MPI_CHK( mpi_shift_l( &X, k ) );
- MPI_CHK( mpi_shift_l( &Y, k ) );
- }
- else k = 0;
-
- n = X.n - 1;
- t = Y.n - 1;
- mpi_shift_l( &Y, biL * (n - t) );
-
- while( mpi_cmp_mpi( &X, &Y ) >= 0 )
- {
- Z.p[n - t]++;
- mpi_sub_mpi( &X, &X, &Y );
- }
- mpi_shift_r( &Y, biL * (n - t) );
-
- for( i = n; i > t ; i-- )
- {
- if( X.p[i] >= Y.p[t] )
- Z.p[i - t - 1] = ~0;
- else
- {
-#if defined(POLARSSL_HAVE_LONGLONG)
- t_dbl r;
-
- r = (t_dbl) X.p[i] << biL;
- r |= (t_dbl) X.p[i - 1];
- r /= Y.p[t];
- if( r > ((t_dbl) 1 << biL) - 1)
- r = ((t_dbl) 1 << biL) - 1;
-
- Z.p[i - t - 1] = (t_int) r;
-#else
- /*
- * __udiv_qrnnd_c, from gmp/longlong.h
- */
- t_int q0, q1, r0, r1;
- t_int d0, d1, d, m;
-
- d = Y.p[t];
- d0 = ( d << biH ) >> biH;
- d1 = ( d >> biH );
-
- q1 = X.p[i] / d1;
- r1 = X.p[i] - d1 * q1;
- r1 <<= biH;
- r1 |= ( X.p[i - 1] >> biH );
-
- m = q1 * d0;
- if( r1 < m )
- {
- q1--, r1 += d;
- while( r1 >= d && r1 < m )
- q1--, r1 += d;
- }
- r1 -= m;
-
- q0 = r1 / d1;
- r0 = r1 - d1 * q0;
- r0 <<= biH;
- r0 |= ( X.p[i - 1] << biH ) >> biH;
-
- m = q0 * d0;
- if( r0 < m )
- {
- q0--, r0 += d;
- while( r0 >= d && r0 < m )
- q0--, r0 += d;
- }
- r0 -= m;
-
- Z.p[i - t - 1] = ( q1 << biH ) | q0;
-#endif
- }
-
- Z.p[i - t - 1]++;
- do
- {
- Z.p[i - t - 1]--;
-
- MPI_CHK( mpi_lset( &T1, 0 ) );
- T1.p[0] = (t < 1) ? 0 : Y.p[t - 1];
- T1.p[1] = Y.p[t];
- MPI_CHK( mpi_mul_int( &T1, &T1, Z.p[i - t - 1] ) );
-
- MPI_CHK( mpi_lset( &T2, 0 ) );
- T2.p[0] = (i < 2) ? 0 : X.p[i - 2];
- T2.p[1] = (i < 1) ? 0 : X.p[i - 1];
- T2.p[2] = X.p[i];
- }
- while( mpi_cmp_mpi( &T1, &T2 ) > 0 );
-
- MPI_CHK( mpi_mul_int( &T1, &Y, Z.p[i - t - 1] ) );
- MPI_CHK( mpi_shift_l( &T1, biL * (i - t - 1) ) );
- MPI_CHK( mpi_sub_mpi( &X, &X, &T1 ) );
-
- if( mpi_cmp_int( &X, 0 ) < 0 )
- {
- MPI_CHK( mpi_copy( &T1, &Y ) );
- MPI_CHK( mpi_shift_l( &T1, biL * (i - t - 1) ) );
- MPI_CHK( mpi_add_mpi( &X, &X, &T1 ) );
- Z.p[i - t - 1]--;
- }
- }
-
- if( Q != NULL )
- {
- mpi_copy( Q, &Z );
- Q->s = A->s * B->s;
- }
-
- if( R != NULL )
- {
- mpi_shift_r( &X, k );
- mpi_copy( R, &X );
-
- R->s = A->s;
- if( mpi_cmp_int( R, 0 ) == 0 )
- R->s = 1;
- }
-
-cleanup:
-
- mpi_free( &X, &Y, &Z, &T1, &T2, NULL );
-
- return( ret );
-}
-
-/*
- * Division by int: A = Q * b + R
- *
- * Returns 0 if successful
- * 1 if memory allocation failed
- * POLARSSL_ERR_MPI_DIVISION_BY_ZERO if b == 0
- */
-int mpi_div_int( mpi *Q, mpi *R, const mpi *A, int b )
-{
- mpi _B;
- t_int p[1];
-
- p[0] = ( b < 0 ) ? -b : b;
- _B.s = ( b < 0 ) ? -1 : 1;
- _B.n = 1;
- _B.p = p;
-
- return( mpi_div_mpi( Q, R, A, &_B ) );
-}
-
-/*
- * Modulo: R = A mod B
- */
-int mpi_mod_mpi( mpi *R, const mpi *A, const mpi *B )
-{
- int ret;
-
- if( mpi_cmp_int( B, 0 ) < 0 )
- return POLARSSL_ERR_MPI_NEGATIVE_VALUE;
-
- MPI_CHK( mpi_div_mpi( NULL, R, A, B ) );
-
- while( mpi_cmp_int( R, 0 ) < 0 )
- MPI_CHK( mpi_add_mpi( R, R, B ) );
-
- while( mpi_cmp_mpi( R, B ) >= 0 )
- MPI_CHK( mpi_sub_mpi( R, R, B ) );
-
-cleanup:
-
- return( ret );
-}
-
-/*
- * Modulo: r = A mod b
- */
-int mpi_mod_int( t_int *r, const mpi *A, int b )
-{
- int i;
- t_int x, y, z;
-
- if( b == 0 )
- return( POLARSSL_ERR_MPI_DIVISION_BY_ZERO );
-
- if( b < 0 )
- return POLARSSL_ERR_MPI_NEGATIVE_VALUE;
-
- /*
- * handle trivial cases
- */
- if( b == 1 )
- {
- *r = 0;
- return( 0 );
- }
-
- if( b == 2 )
- {
- *r = A->p[0] & 1;
- return( 0 );
- }
-
- /*
- * general case
- */
- for( i = A->n - 1, y = 0; i >= 0; i-- )
- {
- x = A->p[i];
- y = ( y << biH ) | ( x >> biH );
- z = y / b;
- y -= z * b;
-
- x <<= biH;
- y = ( y << biH ) | ( x >> biH );
- z = y / b;
- y -= z * b;
- }
-
- /*
- * If A is negative, then the current y represents a negative value.
- * Flipping it to the positive side.
- */
- if( A->s < 0 && y != 0 )
- y = b - y;
-
- *r = y;
-
- return( 0 );
-}
-
-/*
- * Fast Montgomery initialization (thanks to Tom St Denis)
- */
-static void mpi_montg_init( t_int *mm, const mpi *N )
-{
- t_int x, m0 = N->p[0];
-
- x = m0;
- x += ( ( m0 + 2 ) & 4 ) << 1;
- x *= ( 2 - ( m0 * x ) );
-
- if( biL >= 16 ) x *= ( 2 - ( m0 * x ) );
- if( biL >= 32 ) x *= ( 2 - ( m0 * x ) );
- if( biL >= 64 ) x *= ( 2 - ( m0 * x ) );
-
- *mm = ~x + 1;
-}
-
-/*
- * Montgomery multiplication: A = A * B * R^-1 mod N (HAC 14.36)
- */
-static void mpi_montmul( mpi *A, const mpi *B, const mpi *N, t_int mm, const mpi *T )
-{
- int i, n, m;
- t_int u0, u1, *d;
-
- memset( T->p, 0, T->n * ciL );
-
- d = T->p;
- n = N->n;
- m = ( B->n < n ) ? B->n : n;
-
- for( i = 0; i < n; i++ )
- {
- /*
- * T = (T + u0*B + u1*N) / 2^biL
- */
- u0 = A->p[i];
- u1 = ( d[0] + u0 * B->p[0] ) * mm;
-
- mpi_mul_hlp( m, B->p, d, u0 );
- mpi_mul_hlp( n, N->p, d, u1 );
-
- *d++ = u0; d[n + 1] = 0;
- }
-
- memcpy( A->p, d, (n + 1) * ciL );
-
- if( mpi_cmp_abs( A, N ) >= 0 )
- mpi_sub_hlp( n, N->p, A->p );
- else
- /* prevent timing attacks */
- mpi_sub_hlp( n, A->p, T->p );
-}
-
-/*
- * Montgomery reduction: A = A * R^-1 mod N
- */
-static void mpi_montred( mpi *A, const mpi *N, t_int mm, const mpi *T )
-{
- t_int z = 1;
- mpi U;
-
- U.n = U.s = z;
- U.p = &z;
-
- mpi_montmul( A, &U, N, mm, T );
-}
-
-/*
- * Sliding-window exponentiation: X = A^E mod N (HAC 14.85)
- */
-int mpi_exp_mod( mpi *X, const mpi *A, const mpi *E, const mpi *N, mpi *_RR )
-{
- int ret, i, j, wsize, wbits;
- int bufsize, nblimbs, nbits;
- t_int ei, mm, state;
- mpi RR, T, W[64];
-
- if( mpi_cmp_int( N, 0 ) < 0 || ( N->p[0] & 1 ) == 0 )
- return( POLARSSL_ERR_MPI_BAD_INPUT_DATA );
-
- /*
- * Init temps and window size
- */
- mpi_montg_init( &mm, N );
- mpi_init( &RR, &T, NULL );
- memset( W, 0, sizeof( W ) );
-
- i = mpi_msb( E );
-
- wsize = ( i > 671 ) ? 6 : ( i > 239 ) ? 5 :
- ( i > 79 ) ? 4 : ( i > 23 ) ? 3 : 1;
-
- j = N->n + 1;
- MPI_CHK( mpi_grow( X, j ) );
- MPI_CHK( mpi_grow( &W[1], j ) );
- MPI_CHK( mpi_grow( &T, j * 2 ) );
-
- /*
- * If 1st call, pre-compute R^2 mod N
- */
- if( _RR == NULL || _RR->p == NULL )
- {
- MPI_CHK( mpi_lset( &RR, 1 ) );
- MPI_CHK( mpi_shift_l( &RR, N->n * 2 * biL ) );
- MPI_CHK( mpi_mod_mpi( &RR, &RR, N ) );
-
- if( _RR != NULL )
- memcpy( _RR, &RR, sizeof( mpi ) );
- }
- else
- memcpy( &RR, _RR, sizeof( mpi ) );
-
- /*
- * W[1] = A * R^2 * R^-1 mod N = A * R mod N
- */
- if( mpi_cmp_mpi( A, N ) >= 0 )
- mpi_mod_mpi( &W[1], A, N );
- else mpi_copy( &W[1], A );
-
- mpi_montmul( &W[1], &RR, N, mm, &T );
-
- /*
- * X = R^2 * R^-1 mod N = R mod N
- */
- MPI_CHK( mpi_copy( X, &RR ) );
- mpi_montred( X, N, mm, &T );
-
- if( wsize > 1 )
- {
- /*
- * W[1 << (wsize - 1)] = W[1] ^ (wsize - 1)
- */
- j = 1 << (wsize - 1);
-
- MPI_CHK( mpi_grow( &W[j], N->n + 1 ) );
- MPI_CHK( mpi_copy( &W[j], &W[1] ) );
-
- for( i = 0; i < wsize - 1; i++ )
- mpi_montmul( &W[j], &W[j], N, mm, &T );
-
- /*
- * W[i] = W[i - 1] * W[1]
- */
- for( i = j + 1; i < (1 << wsize); i++ )
- {
- MPI_CHK( mpi_grow( &W[i], N->n + 1 ) );
- MPI_CHK( mpi_copy( &W[i], &W[i - 1] ) );
-
- mpi_montmul( &W[i], &W[1], N, mm, &T );
- }
- }
-
- nblimbs = E->n;
- bufsize = 0;
- nbits = 0;
- wbits = 0;
- state = 0;
-
- while( 1 )
- {
- if( bufsize == 0 )
- {
- if( nblimbs-- == 0 )
- break;
-
- bufsize = sizeof( t_int ) << 3;
- }
-
- bufsize--;
-
- ei = (E->p[nblimbs] >> bufsize) & 1;
-
- /*
- * skip leading 0s
- */
- if( ei == 0 && state == 0 )
- continue;
-
- if( ei == 0 && state == 1 )
- {
- /*
- * out of window, square X
- */
- mpi_montmul( X, X, N, mm, &T );
- continue;
- }
-
- /*
- * add ei to current window
- */
- state = 2;
-
- nbits++;
- wbits |= (ei << (wsize - nbits));
-
- if( nbits == wsize )
- {
- /*
- * X = X^wsize R^-1 mod N
- */
- for( i = 0; i < wsize; i++ )
- mpi_montmul( X, X, N, mm, &T );
-
- /*
- * X = X * W[wbits] R^-1 mod N
- */
- mpi_montmul( X, &W[wbits], N, mm, &T );
-
- state--;
- nbits = 0;
- wbits = 0;
- }
- }
-
- /*
- * process the remaining bits
- */
- for( i = 0; i < nbits; i++ )
- {
- mpi_montmul( X, X, N, mm, &T );
-
- wbits <<= 1;
-
- if( (wbits & (1 << wsize)) != 0 )
- mpi_montmul( X, &W[1], N, mm, &T );
- }
-
- /*
- * X = A^E * R * R^-1 mod N = A^E mod N
- */
- mpi_montred( X, N, mm, &T );
-
-cleanup:
-
- for( i = (1 << (wsize - 1)); i < (1 << wsize); i++ )
- mpi_free( &W[i], NULL );
-
- if( _RR != NULL )
- mpi_free( &W[1], &T, NULL );
- else mpi_free( &W[1], &T, &RR, NULL );
-
- return( ret );
-}
-
-/*
- * Greatest common divisor: G = gcd(A, B) (HAC 14.54)
- */
-int mpi_gcd( mpi *G, const mpi *A, const mpi *B )
-{
- int ret, lz, lzt;
- mpi TG, TA, TB;
-
- mpi_init( &TG, &TA, &TB, NULL );
-
- MPI_CHK( mpi_copy( &TA, A ) );
- MPI_CHK( mpi_copy( &TB, B ) );
-
- lz = mpi_lsb( &TA );
- lzt = mpi_lsb( &TB );
-
- if ( lzt < lz )
- lz = lzt;
-
- MPI_CHK( mpi_shift_r( &TA, lz ) );
- MPI_CHK( mpi_shift_r( &TB, lz ) );
-
- TA.s = TB.s = 1;
-
- while( mpi_cmp_int( &TA, 0 ) != 0 )
- {
- MPI_CHK( mpi_shift_r( &TA, mpi_lsb( &TA ) ) );
- MPI_CHK( mpi_shift_r( &TB, mpi_lsb( &TB ) ) );
-
- if( mpi_cmp_mpi( &TA, &TB ) >= 0 )
- {
- MPI_CHK( mpi_sub_abs( &TA, &TA, &TB ) );
- MPI_CHK( mpi_shift_r( &TA, 1 ) );
- }
- else
- {
- MPI_CHK( mpi_sub_abs( &TB, &TB, &TA ) );
- MPI_CHK( mpi_shift_r( &TB, 1 ) );
- }
- }
-
- MPI_CHK( mpi_shift_l( &TB, lz ) );
- MPI_CHK( mpi_copy( G, &TB ) );
-
-cleanup:
-
- mpi_free( &TB, &TA, &TG, NULL );
-
- return( ret );
-}
-
-#if defined(POLARSSL_GENPRIME)
-
-/*
- * Modular inverse: X = A^-1 mod N (HAC 14.61 / 14.64)
- */
-int mpi_inv_mod( mpi *X, const mpi *A, const mpi *N )
-{
- int ret;
- mpi G, TA, TU, U1, U2, TB, TV, V1, V2;
-
- if( mpi_cmp_int( N, 0 ) <= 0 )
- return( POLARSSL_ERR_MPI_BAD_INPUT_DATA );
-
- mpi_init( &TA, &TU, &U1, &U2, &G,
- &TB, &TV, &V1, &V2, NULL );
-
- MPI_CHK( mpi_gcd( &G, A, N ) );
-
- if( mpi_cmp_int( &G, 1 ) != 0 )
- {
- ret = POLARSSL_ERR_MPI_NOT_ACCEPTABLE;
- goto cleanup;
- }
-
- MPI_CHK( mpi_mod_mpi( &TA, A, N ) );
- MPI_CHK( mpi_copy( &TU, &TA ) );
- MPI_CHK( mpi_copy( &TB, N ) );
- MPI_CHK( mpi_copy( &TV, N ) );
-
- MPI_CHK( mpi_lset( &U1, 1 ) );
- MPI_CHK( mpi_lset( &U2, 0 ) );
- MPI_CHK( mpi_lset( &V1, 0 ) );
- MPI_CHK( mpi_lset( &V2, 1 ) );
-
- do
- {
- while( ( TU.p[0] & 1 ) == 0 )
- {
- MPI_CHK( mpi_shift_r( &TU, 1 ) );
-
- if( ( U1.p[0] & 1 ) != 0 || ( U2.p[0] & 1 ) != 0 )
- {
- MPI_CHK( mpi_add_mpi( &U1, &U1, &TB ) );
- MPI_CHK( mpi_sub_mpi( &U2, &U2, &TA ) );
- }
-
- MPI_CHK( mpi_shift_r( &U1, 1 ) );
- MPI_CHK( mpi_shift_r( &U2, 1 ) );
- }
-
- while( ( TV.p[0] & 1 ) == 0 )
- {
- MPI_CHK( mpi_shift_r( &TV, 1 ) );
-
- if( ( V1.p[0] & 1 ) != 0 || ( V2.p[0] & 1 ) != 0 )
- {
- MPI_CHK( mpi_add_mpi( &V1, &V1, &TB ) );
- MPI_CHK( mpi_sub_mpi( &V2, &V2, &TA ) );
- }
-
- MPI_CHK( mpi_shift_r( &V1, 1 ) );
- MPI_CHK( mpi_shift_r( &V2, 1 ) );
- }
-
- if( mpi_cmp_mpi( &TU, &TV ) >= 0 )
- {
- MPI_CHK( mpi_sub_mpi( &TU, &TU, &TV ) );
- MPI_CHK( mpi_sub_mpi( &U1, &U1, &V1 ) );
- MPI_CHK( mpi_sub_mpi( &U2, &U2, &V2 ) );
- }
- else
- {
- MPI_CHK( mpi_sub_mpi( &TV, &TV, &TU ) );
- MPI_CHK( mpi_sub_mpi( &V1, &V1, &U1 ) );
- MPI_CHK( mpi_sub_mpi( &V2, &V2, &U2 ) );
- }
- }
- while( mpi_cmp_int( &TU, 0 ) != 0 );
-
- while( mpi_cmp_int( &V1, 0 ) < 0 )
- MPI_CHK( mpi_add_mpi( &V1, &V1, N ) );
-
- while( mpi_cmp_mpi( &V1, N ) >= 0 )
- MPI_CHK( mpi_sub_mpi( &V1, &V1, N ) );
-
- MPI_CHK( mpi_copy( X, &V1 ) );
-
-cleanup:
-
- mpi_free( &V2, &V1, &TV, &TB, &G,
- &U2, &U1, &TU, &TA, NULL );
-
- return( ret );
-}
-
-static const int small_prime[] =
-{
- 3, 5, 7, 11, 13, 17, 19, 23,
- 29, 31, 37, 41, 43, 47, 53, 59,
- 61, 67, 71, 73, 79, 83, 89, 97,
- 101, 103, 107, 109, 113, 127, 131, 137,
- 139, 149, 151, 157, 163, 167, 173, 179,
- 181, 191, 193, 197, 199, 211, 223, 227,
- 229, 233, 239, 241, 251, 257, 263, 269,
- 271, 277, 281, 283, 293, 307, 311, 313,
- 317, 331, 337, 347, 349, 353, 359, 367,
- 373, 379, 383, 389, 397, 401, 409, 419,
- 421, 431, 433, 439, 443, 449, 457, 461,
- 463, 467, 479, 487, 491, 499, 503, 509,
- 521, 523, 541, 547, 557, 563, 569, 571,
- 577, 587, 593, 599, 601, 607, 613, 617,
- 619, 631, 641, 643, 647, 653, 659, 661,
- 673, 677, 683, 691, 701, 709, 719, 727,
- 733, 739, 743, 751, 757, 761, 769, 773,
- 787, 797, 809, 811, 821, 823, 827, 829,
- 839, 853, 857, 859, 863, 877, 881, 883,
- 887, 907, 911, 919, 929, 937, 941, 947,
- 953, 967, 971, 977, 983, 991, 997, -103
-};
-
-/*
- * Miller-Rabin primality test (HAC 4.24)
- */
-int mpi_is_prime( mpi *X, int (*f_rng)(void *), void *p_rng )
-{
- int ret, i, j, n, s, xs;
- mpi W, R, T, A, RR;
- unsigned char *p;
-
- if( mpi_cmp_int( X, 0 ) == 0 ||
- mpi_cmp_int( X, 1 ) == 0 )
- return( POLARSSL_ERR_MPI_NOT_ACCEPTABLE );
-
- if( mpi_cmp_int( X, 2 ) == 0 )
- return( 0 );
-
- mpi_init( &W, &R, &T, &A, &RR, NULL );
-
- xs = X->s; X->s = 1;
-
- /*
- * test trivial factors first
- */
- if( ( X->p[0] & 1 ) == 0 )
- return( POLARSSL_ERR_MPI_NOT_ACCEPTABLE );
-
- for( i = 0; small_prime[i] > 0; i++ )
- {
- t_int r;
-
- if( mpi_cmp_int( X, small_prime[i] ) <= 0 )
- return( 0 );
-
- MPI_CHK( mpi_mod_int( &r, X, small_prime[i] ) );
-
- if( r == 0 )
- return( POLARSSL_ERR_MPI_NOT_ACCEPTABLE );
- }
-
- /*
- * W = |X| - 1
- * R = W >> lsb( W )
- */
- MPI_CHK( mpi_sub_int( &W, X, 1 ) );
- s = mpi_lsb( &W );
- MPI_CHK( mpi_copy( &R, &W ) );
- MPI_CHK( mpi_shift_r( &R, s ) );
-
- i = mpi_msb( X );
- /*
- * HAC, table 4.4
- */
- n = ( ( i >= 1300 ) ? 2 : ( i >= 850 ) ? 3 :
- ( i >= 650 ) ? 4 : ( i >= 350 ) ? 8 :
- ( i >= 250 ) ? 12 : ( i >= 150 ) ? 18 : 27 );
-
- for( i = 0; i < n; i++ )
- {
- /*
- * pick a random A, 1 < A < |X| - 1
- */
- MPI_CHK( mpi_grow( &A, X->n ) );
-
- p = (unsigned char *) A.p;
- for( j = 0; j < A.n * ciL; j++ )
- *p++ = (unsigned char) f_rng( p_rng );
-
- j = mpi_msb( &A ) - mpi_msb( &W );
- MPI_CHK( mpi_shift_r( &A, j + 1 ) );
- A.p[0] |= 3;
-
- /*
- * A = A^R mod |X|
- */
- MPI_CHK( mpi_exp_mod( &A, &A, &R, X, &RR ) );
-
- if( mpi_cmp_mpi( &A, &W ) == 0 ||
- mpi_cmp_int( &A, 1 ) == 0 )
- continue;
-
- j = 1;
- while( j < s && mpi_cmp_mpi( &A, &W ) != 0 )
- {
- /*
- * A = A * A mod |X|
- */
- MPI_CHK( mpi_mul_mpi( &T, &A, &A ) );
- MPI_CHK( mpi_mod_mpi( &A, &T, X ) );
-
- if( mpi_cmp_int( &A, 1 ) == 0 )
- break;
-
- j++;
- }
-
- /*
- * not prime if A != |X| - 1 or A == 1
- */
- if( mpi_cmp_mpi( &A, &W ) != 0 ||
- mpi_cmp_int( &A, 1 ) == 0 )
- {
- ret = POLARSSL_ERR_MPI_NOT_ACCEPTABLE;
- break;
- }
- }
-
-cleanup:
-
- X->s = xs;
-
- mpi_free( &RR, &A, &T, &R, &W, NULL );
-
- return( ret );
-}
-
-/*
- * Prime number generation
- */
-int mpi_gen_prime( mpi *X, int nbits, int dh_flag,
- int (*f_rng)(void *), void *p_rng )
-{
- int ret, k, n;
- unsigned char *p;
- mpi Y;
-
- if( nbits < 3 )
- return( POLARSSL_ERR_MPI_BAD_INPUT_DATA );
-
- mpi_init( &Y, NULL );
-
- n = BITS_TO_LIMBS( nbits );
-
- MPI_CHK( mpi_grow( X, n ) );
- MPI_CHK( mpi_lset( X, 0 ) );
-
- p = (unsigned char *) X->p;
- for( k = 0; k < X->n * ciL; k++ )
- *p++ = (unsigned char) f_rng( p_rng );
-
- k = mpi_msb( X );
- if( k < nbits ) MPI_CHK( mpi_shift_l( X, nbits - k ) );
- if( k > nbits ) MPI_CHK( mpi_shift_r( X, k - nbits ) );
-
- X->p[0] |= 3;
-
- if( dh_flag == 0 )
- {
- while( ( ret = mpi_is_prime( X, f_rng, p_rng ) ) != 0 )
- {
- if( ret != POLARSSL_ERR_MPI_NOT_ACCEPTABLE )
- goto cleanup;
-
- MPI_CHK( mpi_add_int( X, X, 2 ) );
- }
- }
- else
- {
- MPI_CHK( mpi_sub_int( &Y, X, 1 ) );
- MPI_CHK( mpi_shift_r( &Y, 1 ) );
-
- while( 1 )
- {
- if( ( ret = mpi_is_prime( X, f_rng, p_rng ) ) == 0 )
- {
- if( ( ret = mpi_is_prime( &Y, f_rng, p_rng ) ) == 0 )
- break;
-
- if( ret != POLARSSL_ERR_MPI_NOT_ACCEPTABLE )
- goto cleanup;
- }
-
- if( ret != POLARSSL_ERR_MPI_NOT_ACCEPTABLE )
- goto cleanup;
-
- MPI_CHK( mpi_add_int( &Y, X, 1 ) );
- MPI_CHK( mpi_add_int( X, X, 2 ) );
- MPI_CHK( mpi_shift_r( &Y, 1 ) );
- }
- }
-
-cleanup:
-
- mpi_free( &Y, NULL );
-
- return( ret );
-}
-
-#endif
HCoop / hcoop / debian / exim4.git / blobdiff