1/*
2Copyright (C) 1999-2007 The Botan Project. All rights reserved.
3
4Redistribution and use in source and binary forms, for any use, with or without
5modification, is permitted provided that the following conditions are met:
6
71. Redistributions of source code must retain the above copyright notice, this
8list of conditions, and the following disclaimer.
9
102. Redistributions in binary form must reproduce the above copyright notice,
11this list of conditions, and the following disclaimer in the documentation
12and/or other materials provided with the distribution.
13
14THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) "AS IS" AND ANY EXPRESS OR IMPLIED
15WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
16MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.
17
18IN NO EVENT SHALL THE AUTHOR(S) OR CONTRIBUTOR(S) BE LIABLE FOR ANY DIRECT,
19INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
20BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
22LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
23OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25*/
26// LICENSEHEADER_END
27namespace QCA { // WRAPNS_LINE
28/*************************************************
29 * MP Shift Algorithms Source File *
30 * (C) 1999-2007 The Botan Project *
31 *************************************************/
32
33} // WRAPNS_LINE
34#include <botan/mp_core.h>
35namespace QCA { // WRAPNS_LINE
36} // WRAPNS_LINE
37#include <botan/mem_ops.h>
38namespace QCA { // WRAPNS_LINE
39
40namespace Botan {
41
42extern "C" {
43
44/*************************************************
45 * Single Operand Left Shift *
46 *************************************************/
47void bigint_shl1(word x[], u32bit x_size, u32bit word_shift, u32bit bit_shift)
48{
49 if (word_shift) {
50 for (u32bit j = 1; j != x_size + 1; ++j)
51 x[(x_size - j) + word_shift] = x[x_size - j];
52 clear_mem(ptr: x, n: word_shift);
53 }
54
55 if (bit_shift) {
56 word carry = 0;
57 for (u32bit j = word_shift; j != x_size + word_shift + 1; ++j) {
58 word temp = x[j];
59 x[j] = (temp << bit_shift) | carry;
60 carry = (temp >> (MP_WORD_BITS - bit_shift));
61 }
62 }
63}
64
65/*************************************************
66 * Single Operand Right Shift *
67 *************************************************/
68void bigint_shr1(word x[], u32bit x_size, u32bit word_shift, u32bit bit_shift)
69{
70 if (x_size < word_shift) {
71 clear_mem(ptr: x, n: x_size);
72 return;
73 }
74
75 if (word_shift) {
76 for (u32bit j = 0; j != x_size - word_shift; ++j)
77 x[j] = x[j + word_shift];
78 for (u32bit j = x_size - word_shift; j != x_size; ++j)
79 x[j] = 0;
80 }
81
82 if (bit_shift) {
83 word carry = 0;
84 for (u32bit j = x_size - word_shift; j > 0; --j) {
85 word temp = x[j - 1];
86 x[j - 1] = (temp >> bit_shift) | carry;
87 carry = (temp << (MP_WORD_BITS - bit_shift));
88 }
89 }
90}
91
92/*************************************************
93 * Two Operand Left Shift *
94 *************************************************/
95void bigint_shl2(word y[], const word x[], u32bit x_size, u32bit word_shift, u32bit bit_shift)
96{
97 for (u32bit j = 0; j != x_size; ++j)
98 y[j + word_shift] = x[j];
99 if (bit_shift) {
100 word carry = 0;
101 for (u32bit j = word_shift; j != x_size + word_shift + 1; ++j) {
102 word temp = y[j];
103 y[j] = (temp << bit_shift) | carry;
104 carry = (temp >> (MP_WORD_BITS - bit_shift));
105 }
106 }
107}
108
109/*************************************************
110 * Two Operand Right Shift *
111 *************************************************/
112void bigint_shr2(word y[], const word x[], u32bit x_size, u32bit word_shift, u32bit bit_shift)
113{
114 if (x_size < word_shift)
115 return;
116
117 for (u32bit j = 0; j != x_size - word_shift; ++j)
118 y[j] = x[j + word_shift];
119 if (bit_shift) {
120 word carry = 0;
121 for (u32bit j = x_size - word_shift; j > 0; --j) {
122 word temp = y[j - 1];
123 y[j - 1] = (temp >> bit_shift) | carry;
124 carry = (temp << (MP_WORD_BITS - bit_shift));
125 }
126 }
127}
128}
129
130}
131} // WRAPNS_LINE
132

source code of qca/src/botantools/botan/mp_shift.cpp