File indexing completed on 2024-05-12 04:45:15

0001 /*
0002 Copyright (C) 1999-2007 The Botan Project. All rights reserved.
0003 
0004 Redistribution and use in source and binary forms, for any use, with or without
0005 modification, is permitted provided that the following conditions are met:
0006 
0007 1. Redistributions of source code must retain the above copyright notice, this
0008 list of conditions, and the following disclaimer.
0009 
0010 2. Redistributions in binary form must reproduce the above copyright notice,
0011 this list of conditions, and the following disclaimer in the documentation
0012 and/or other materials provided with the distribution.
0013 
0014 THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) "AS IS" AND ANY EXPRESS OR IMPLIED
0015 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
0016 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.
0017 
0018 IN NO EVENT SHALL THE AUTHOR(S) OR CONTRIBUTOR(S) BE LIABLE FOR ANY DIRECT,
0019 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
0020 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
0021 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
0022 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
0023 OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
0024 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0025 */
0026 // LICENSEHEADER_END
0027 namespace QCA { // WRAPNS_LINE
0028 /*************************************************
0029  * MP Shift Algorithms Source File                *
0030  * (C) 1999-2007 The Botan Project                *
0031  *************************************************/
0032 
0033 } // WRAPNS_LINE
0034 #include <botan/mp_core.h>
0035 namespace QCA { // WRAPNS_LINE
0036 } // WRAPNS_LINE
0037 #include <botan/mem_ops.h>
0038 namespace QCA { // WRAPNS_LINE
0039 
0040 namespace Botan {
0041 
0042 extern "C" {
0043 
0044 /*************************************************
0045  * Single Operand Left Shift                      *
0046  *************************************************/
0047 void bigint_shl1(word x[], u32bit x_size, u32bit word_shift, u32bit bit_shift)
0048 {
0049     if (word_shift) {
0050         for (u32bit j = 1; j != x_size + 1; ++j)
0051             x[(x_size - j) + word_shift] = x[x_size - j];
0052         clear_mem(x, word_shift);
0053     }
0054 
0055     if (bit_shift) {
0056         word carry = 0;
0057         for (u32bit j = word_shift; j != x_size + word_shift + 1; ++j) {
0058             word temp = x[j];
0059             x[j]      = (temp << bit_shift) | carry;
0060             carry     = (temp >> (MP_WORD_BITS - bit_shift));
0061         }
0062     }
0063 }
0064 
0065 /*************************************************
0066  * Single Operand Right Shift                     *
0067  *************************************************/
0068 void bigint_shr1(word x[], u32bit x_size, u32bit word_shift, u32bit bit_shift)
0069 {
0070     if (x_size < word_shift) {
0071         clear_mem(x, x_size);
0072         return;
0073     }
0074 
0075     if (word_shift) {
0076         for (u32bit j = 0; j != x_size - word_shift; ++j)
0077             x[j] = x[j + word_shift];
0078         for (u32bit j = x_size - word_shift; j != x_size; ++j)
0079             x[j] = 0;
0080     }
0081 
0082     if (bit_shift) {
0083         word carry = 0;
0084         for (u32bit j = x_size - word_shift; j > 0; --j) {
0085             word temp = x[j - 1];
0086             x[j - 1]  = (temp >> bit_shift) | carry;
0087             carry     = (temp << (MP_WORD_BITS - bit_shift));
0088         }
0089     }
0090 }
0091 
0092 /*************************************************
0093  * Two Operand Left Shift                         *
0094  *************************************************/
0095 void bigint_shl2(word y[], const word x[], u32bit x_size, u32bit word_shift, u32bit bit_shift)
0096 {
0097     for (u32bit j = 0; j != x_size; ++j)
0098         y[j + word_shift] = x[j];
0099     if (bit_shift) {
0100         word carry = 0;
0101         for (u32bit j = word_shift; j != x_size + word_shift + 1; ++j) {
0102             word temp = y[j];
0103             y[j]      = (temp << bit_shift) | carry;
0104             carry     = (temp >> (MP_WORD_BITS - bit_shift));
0105         }
0106     }
0107 }
0108 
0109 /*************************************************
0110  * Two Operand Right Shift                        *
0111  *************************************************/
0112 void bigint_shr2(word y[], const word x[], u32bit x_size, u32bit word_shift, u32bit bit_shift)
0113 {
0114     if (x_size < word_shift)
0115         return;
0116 
0117     for (u32bit j = 0; j != x_size - word_shift; ++j)
0118         y[j] = x[j + word_shift];
0119     if (bit_shift) {
0120         word carry = 0;
0121         for (u32bit j = x_size - word_shift; j > 0; --j) {
0122             word temp = y[j - 1];
0123             y[j - 1]  = (temp >> bit_shift) | carry;
0124             carry     = (temp << (MP_WORD_BITS - bit_shift));
0125         }
0126     }
0127 }
0128 }
0129 
0130 }
0131 } // WRAPNS_LINE