1 | //FIXME Not checked on threadsafety yet; after checking please remove this line
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2 | /* crypto/bn/bn_mul.c */
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3 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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4 | * All rights reserved.
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5 | *
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6 | * This package is an SSL implementation written
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7 | * by Eric Young (eay@cryptsoft.com).
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8 | * The implementation was written so as to conform with Netscapes SSL.
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9 | *
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10 | * This library is free for commercial and non-commercial use as long as
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11 | * the following conditions are aheared to. The following conditions
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12 | * apply to all code found in this distribution, be it the RC4, RSA,
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13 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation
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14 | * included with this distribution is covered by the same copyright terms
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15 | * except that the holder is Tim Hudson (tjh@cryptsoft.com).
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16 | *
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17 | * Copyright remains Eric Young's, and as such any Copyright notices in
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18 | * the code are not to be removed.
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19 | * If this package is used in a product, Eric Young should be given attribution
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20 | * as the author of the parts of the library used.
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21 | * This can be in the form of a textual message at program startup or
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22 | * in documentation (online or textual) provided with the package.
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23 | *
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24 | * Redistribution and use in source and binary forms, with or without
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25 | * modification, are permitted provided that the following conditions
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26 | * are met:
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27 | * 1. Redistributions of source code must retain the copyright
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28 | * notice, this list of conditions and the following disclaimer.
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29 | * 2. Redistributions in binary form must reproduce the above copyright
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30 | * notice, this list of conditions and the following disclaimer in the
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31 | * documentation and/or other materials provided with the distribution.
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32 | * 3. All advertising materials mentioning features or use of this software
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33 | * must display the following acknowledgement:
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34 | * "This product includes cryptographic software written by
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35 | * Eric Young (eay@cryptsoft.com)"
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36 | * The word 'cryptographic' can be left out if the rouines from the library
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37 | * being used are not cryptographic related :-).
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38 | * 4. If you include any Windows specific code (or a derivative thereof) from
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39 | * the apps directory (application code) you must include an acknowledgement:
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40 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
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41 | *
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42 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
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43 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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44 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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45 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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46 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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47 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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48 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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49 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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50 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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51 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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52 | * SUCH DAMAGE.
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53 | *
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54 | * The licence and distribution terms for any publically available version or
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55 | * derivative of this code cannot be changed. i.e. this code cannot simply be
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56 | * copied and put under another distribution licence
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57 | * [including the GNU Public Licence.]
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58 | */
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59 |
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60 | #include <stdio.h>
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61 | #include <string.h>
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62 | #include "bn_lcl.h"
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63 | #include "openssl_mods.h"
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64 |
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65 | #ifdef BN_RECURSION
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66 | /* Karatsuba recursive multiplication algorithm
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67 | * (cf. Knuth, The Art of Computer Programming, Vol. 2) */
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68 |
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69 | /* r is 2*n2 words in size,
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70 | * a and b are both n2 words in size.
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71 | * n2 must be a power of 2.
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72 | * We multiply and return the result.
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73 | * t must be 2*n2 words in size
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74 | * We calculate
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75 | * a[0]*b[0]
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76 | * a[0]*b[0]+a[1]*b[1]+(a[0]-a[1])*(b[1]-b[0])
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77 | * a[1]*b[1]
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78 | */
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79 | void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
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80 | BN_ULONG *t)
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81 | {
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82 | int n=n2/2,c1,c2;
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83 | unsigned int neg,zero;
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84 | BN_ULONG ln,lo,*p;
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85 |
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86 | # ifdef BN_COUNT
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87 | printf(" bn_mul_recursive %d * %d\n",n2,n2);
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88 | # endif
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89 | # ifdef BN_MUL_COMBA
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90 | # if 0
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91 | if (n2 == 4)
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92 | {
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93 | bn_mul_comba4(r,a,b);
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94 | return;
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95 | }
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96 | # endif
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97 | if (n2 == 8)
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98 | {
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99 | bn_mul_comba8(r,a,b);
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100 | return;
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101 | }
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102 | # endif /* BN_MUL_COMBA */
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103 | if (n2 < BN_MUL_RECURSIVE_SIZE_NORMAL)
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104 | {
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105 | /* This should not happen */
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106 | bn_mul_normal(r,a,n2,b,n2);
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107 | return;
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108 | }
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109 | /* r=(a[0]-a[1])*(b[1]-b[0]) */
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110 | c1=bn_cmp_words(a,&(a[n]),n);
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111 | c2=bn_cmp_words(&(b[n]),b,n);
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112 | zero=neg=0;
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113 | switch (c1*3+c2)
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114 | {
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115 | case -4:
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116 | bn_sub_words(t, &(a[n]),a, n); /* - */
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117 | bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
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118 | break;
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119 | case -3:
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120 | zero=1;
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121 | break;
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122 | case -2:
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123 | bn_sub_words(t, &(a[n]),a, n); /* - */
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124 | bn_sub_words(&(t[n]),&(b[n]),b, n); /* + */
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125 | neg=1;
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126 | break;
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127 | case -1:
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128 | case 0:
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129 | case 1:
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130 | zero=1;
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131 | break;
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132 | case 2:
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133 | bn_sub_words(t, a, &(a[n]),n); /* + */
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134 | bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
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135 | neg=1;
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136 | break;
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137 | case 3:
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138 | zero=1;
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139 | break;
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140 | case 4:
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141 | bn_sub_words(t, a, &(a[n]),n);
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142 | bn_sub_words(&(t[n]),&(b[n]),b, n);
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143 | break;
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144 | }
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145 |
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146 | # ifdef BN_MUL_COMBA
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147 | if (n == 4)
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148 | {
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149 | if (!zero)
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150 | bn_mul_comba4(&(t[n2]),t,&(t[n]));
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151 | else
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152 | memset(&(t[n2]),0,8*sizeof(BN_ULONG));
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153 |
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154 | bn_mul_comba4(r,a,b);
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155 | bn_mul_comba4(&(r[n2]),&(a[n]),&(b[n]));
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156 | }
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157 | else if (n == 8)
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158 | {
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159 | if (!zero)
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160 | bn_mul_comba8(&(t[n2]),t,&(t[n]));
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161 | else
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162 | memset(&(t[n2]),0,16*sizeof(BN_ULONG));
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163 |
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164 | bn_mul_comba8(r,a,b);
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165 | bn_mul_comba8(&(r[n2]),&(a[n]),&(b[n]));
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166 | }
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167 | else
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168 | # endif /* BN_MUL_COMBA */
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169 | {
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170 | p= &(t[n2*2]);
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171 | if (!zero)
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172 | bn_mul_recursive(&(t[n2]),t,&(t[n]),n,p);
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173 | else
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174 | memset(&(t[n2]),0,n2*sizeof(BN_ULONG));
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175 | bn_mul_recursive(r,a,b,n,p);
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176 | bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),n,p);
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177 | }
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178 |
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179 | /* t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign
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180 | * r[10] holds (a[0]*b[0])
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181 | * r[32] holds (b[1]*b[1])
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182 | */
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183 |
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184 | c1=(int)(bn_add_words(t,r,&(r[n2]),n2));
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185 |
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186 | if (neg) /* if t[32] is negative */
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187 | {
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188 | c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2));
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189 | }
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190 | else
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191 | {
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192 | /* Might have a carry */
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193 | c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),t,n2));
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194 | }
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195 |
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196 | /* t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1])
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197 | * r[10] holds (a[0]*b[0])
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198 | * r[32] holds (b[1]*b[1])
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199 | * c1 holds the carry bits
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200 | */
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201 | c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2));
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202 | if (c1)
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203 | {
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204 | p= &(r[n+n2]);
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205 | lo= *p;
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206 | ln=(lo+c1)&BN_MASK2;
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207 | *p=ln;
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208 |
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209 | /* The overflow will stop before we over write
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210 | * words we should not overwrite */
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211 | if (ln < (BN_ULONG)c1)
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212 | {
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213 | do {
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214 | p++;
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215 | lo= *p;
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216 | ln=(lo+1)&BN_MASK2;
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217 | *p=ln;
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218 | } while (ln == 0);
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219 | }
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220 | }
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221 | }
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222 |
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223 | /* n+tn is the word length
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224 | * t needs to be n*4 is size, as does r */
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225 | void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int tn,
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226 | int n, BN_ULONG *t)
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227 | {
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228 | int c1,c2,i,j,n2=n*2;
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229 | unsigned int neg,zero;
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230 | BN_ULONG ln,lo,*p;
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231 |
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232 | # ifdef BN_COUNT
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233 | printf(" bn_mul_part_recursive %d * %d\n",tn+n,tn+n);
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234 | # endif
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235 | if (n < 8)
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236 | {
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237 | i=tn+n;
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238 | bn_mul_normal(r,a,i,b,i);
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239 | return;
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240 | }
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241 |
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242 | /* r=(a[0]-a[1])*(b[1]-b[0]) */
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243 | c1=bn_cmp_words(a,&(a[n]),n);
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244 | c2=bn_cmp_words(&(b[n]),b,n);
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245 | zero=neg=0;
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246 | switch (c1*3+c2)
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247 | {
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248 | case -4:
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249 | bn_sub_words(t, &(a[n]),a, n); /* - */
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250 | bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
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251 | break;
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252 | case -3:
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253 | zero=1;
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254 | /* break; */
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255 | case -2:
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256 | bn_sub_words(t, &(a[n]),a, n); /* - */
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257 | bn_sub_words(&(t[n]),&(b[n]),b, n); /* + */
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258 | neg=1;
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259 | break;
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260 | case -1:
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261 | case 0:
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262 | case 1:
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263 | zero=1;
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264 | /* break; */
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265 | case 2:
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266 | bn_sub_words(t, a, &(a[n]),n); /* + */
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267 | bn_sub_words(&(t[n]),b, &(b[n]),n); /* - */
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268 | neg=1;
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269 | break;
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270 | case 3:
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271 | zero=1;
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272 | /* break; */
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273 | case 4:
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274 | bn_sub_words(t, a, &(a[n]),n);
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275 | bn_sub_words(&(t[n]),&(b[n]),b, n);
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276 | break;
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277 | }
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278 | /* The zero case isn't yet implemented here. The speedup
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279 | would probably be negligible. */
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280 | # if 0
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281 | if (n == 4)
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282 | {
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283 | bn_mul_comba4(&(t[n2]),t,&(t[n]));
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284 | bn_mul_comba4(r,a,b);
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285 | bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);
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286 | memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2-tn*2));
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287 | }
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288 | else
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289 | # endif
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290 | if (n == 8)
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291 | {
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292 | bn_mul_comba8(&(t[n2]),t,&(t[n]));
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293 | bn_mul_comba8(r,a,b);
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294 | bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);
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295 | memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2-tn*2));
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296 | }
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297 | else
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298 | {
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299 | p= &(t[n2*2]);
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300 | bn_mul_recursive(&(t[n2]),t,&(t[n]),n,p);
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301 | bn_mul_recursive(r,a,b,n,p);
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302 | i=n/2;
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303 | /* If there is only a bottom half to the number,
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304 | * just do it */
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305 | j=tn-i;
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306 | if (j == 0)
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307 | {
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308 | bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),i,p);
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309 | memset(&(r[n2+i*2]),0,sizeof(BN_ULONG)*(n2-i*2));
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310 | }
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311 | else if (j > 0) /* eg, n == 16, i == 8 and tn == 11 */
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312 | {
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313 | bn_mul_part_recursive(&(r[n2]),&(a[n]),&(b[n]),
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314 | j,i,p);
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315 | memset(&(r[n2+tn*2]),0,
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316 | sizeof(BN_ULONG)*(n2-tn*2));
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317 | }
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318 | else /* (j < 0) eg, n == 16, i == 8 and tn == 5 */
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319 | {
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320 | memset(&(r[n2]),0,sizeof(BN_ULONG)*n2);
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321 | if (tn < BN_MUL_RECURSIVE_SIZE_NORMAL)
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322 | {
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323 | bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn);
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324 | }
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325 | else
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326 | {
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327 | for (;;)
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328 | {
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329 | i/=2;
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330 | if (i < tn)
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331 | {
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332 | bn_mul_part_recursive(&(r[n2]),
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333 | &(a[n]),&(b[n]),
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334 | tn-i,i,p);
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335 | break;
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336 | }
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337 | else if (i == tn)
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338 | {
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339 | bn_mul_recursive(&(r[n2]),
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340 | &(a[n]),&(b[n]),
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341 | i,p);
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342 | break;
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343 | }
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344 | }
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345 | }
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346 | }
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347 | }
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348 |
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349 | /* t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign
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350 | * r[10] holds (a[0]*b[0])
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351 | * r[32] holds (b[1]*b[1])
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352 | */
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353 |
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354 | c1=(int)(bn_add_words(t,r,&(r[n2]),n2));
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355 |
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356 | if (neg) /* if t[32] is negative */
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357 | {
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358 | c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2));
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359 | }
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360 | else
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361 | {
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362 | /* Might have a carry */
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363 | c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),t,n2));
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364 | }
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365 |
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366 | /* t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1])
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367 | * r[10] holds (a[0]*b[0])
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368 | * r[32] holds (b[1]*b[1])
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369 | * c1 holds the carry bits
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370 | */
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371 | c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2));
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372 | if (c1)
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373 | {
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374 | p= &(r[n+n2]);
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375 | lo= *p;
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376 | ln=(lo+c1)&BN_MASK2;
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377 | *p=ln;
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378 |
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379 | /* The overflow will stop before we over write
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380 | * words we should not overwrite */
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381 | if (ln < (BN_ULONG)c1)
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382 | {
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383 | do {
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384 | p++;
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385 | lo= *p;
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386 | ln=(lo+1)&BN_MASK2;
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387 | *p=ln;
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388 | } while (ln == 0);
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389 | }
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390 | }
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391 | }
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392 |
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393 | /* a and b must be the same size, which is n2.
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394 | * r needs to be n2 words and t needs to be n2*2
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395 | */
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396 | void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
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397 | BN_ULONG *t)
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398 | {
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399 | int n=n2/2;
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400 |
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401 | # ifdef BN_COUNT
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402 | printf(" bn_mul_low_recursive %d * %d\n",n2,n2);
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403 | # endif
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404 |
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405 | bn_mul_recursive(r,a,b,n,&(t[0]));
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406 | if (n >= BN_MUL_LOW_RECURSIVE_SIZE_NORMAL)
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407 | {
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408 | bn_mul_low_recursive(&(t[0]),&(a[0]),&(b[n]),n,&(t[n2]));
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409 | bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);
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410 | bn_mul_low_recursive(&(t[0]),&(a[n]),&(b[0]),n,&(t[n2]));
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411 | bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);
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412 | }
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413 | else
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414 | {
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415 | bn_mul_low_normal(&(t[0]),&(a[0]),&(b[n]),n);
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416 | bn_mul_low_normal(&(t[n]),&(a[n]),&(b[0]),n);
|
---|
417 | bn_add_words(&(r[n]),&(r[n]),&(t[0]),n);
|
---|
418 | bn_add_words(&(r[n]),&(r[n]),&(t[n]),n);
|
---|
419 | }
|
---|
420 | }
|
---|
421 |
|
---|
422 | /* a and b must be the same size, which is n2.
|
---|
423 | * r needs to be n2 words and t needs to be n2*2
|
---|
424 | * l is the low words of the output.
|
---|
425 | * t needs to be n2*3
|
---|
426 | */
|
---|
427 | void bn_mul_high(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, BN_ULONG *l, int n2,
|
---|
428 | BN_ULONG *t)
|
---|
429 | {
|
---|
430 | int i,n;
|
---|
431 | int c1,c2;
|
---|
432 | int neg,oneg,zero;
|
---|
433 | BN_ULONG ll,lc,*lp,*mp;
|
---|
434 |
|
---|
435 | # ifdef BN_COUNT
|
---|
436 | printf(" bn_mul_high %d * %d\n",n2,n2);
|
---|
437 | # endif
|
---|
438 | n=n2/2;
|
---|
439 |
|
---|
440 | /* Calculate (al-ah)*(bh-bl) */
|
---|
441 | neg=zero=0;
|
---|
442 | c1=bn_cmp_words(&(a[0]),&(a[n]),n);
|
---|
443 | c2=bn_cmp_words(&(b[n]),&(b[0]),n);
|
---|
444 | switch (c1*3+c2)
|
---|
445 | {
|
---|
446 | case -4:
|
---|
447 | bn_sub_words(&(r[0]),&(a[n]),&(a[0]),n);
|
---|
448 | bn_sub_words(&(r[n]),&(b[0]),&(b[n]),n);
|
---|
449 | break;
|
---|
450 | case -3:
|
---|
451 | zero=1;
|
---|
452 | break;
|
---|
453 | case -2:
|
---|
454 | bn_sub_words(&(r[0]),&(a[n]),&(a[0]),n);
|
---|
455 | bn_sub_words(&(r[n]),&(b[n]),&(b[0]),n);
|
---|
456 | neg=1;
|
---|
457 | break;
|
---|
458 | case -1:
|
---|
459 | case 0:
|
---|
460 | case 1:
|
---|
461 | zero=1;
|
---|
462 | break;
|
---|
463 | case 2:
|
---|
464 | bn_sub_words(&(r[0]),&(a[0]),&(a[n]),n);
|
---|
465 | bn_sub_words(&(r[n]),&(b[0]),&(b[n]),n);
|
---|
466 | neg=1;
|
---|
467 | break;
|
---|
468 | case 3:
|
---|
469 | zero=1;
|
---|
470 | break;
|
---|
471 | case 4:
|
---|
472 | bn_sub_words(&(r[0]),&(a[0]),&(a[n]),n);
|
---|
473 | bn_sub_words(&(r[n]),&(b[n]),&(b[0]),n);
|
---|
474 | break;
|
---|
475 | }
|
---|
476 |
|
---|
477 | oneg=neg;
|
---|
478 | /* t[10] = (a[0]-a[1])*(b[1]-b[0]) */
|
---|
479 | /* r[10] = (a[1]*b[1]) */
|
---|
480 | # ifdef BN_MUL_COMBA
|
---|
481 | if (n == 8)
|
---|
482 | {
|
---|
483 | bn_mul_comba8(&(t[0]),&(r[0]),&(r[n]));
|
---|
484 | bn_mul_comba8(r,&(a[n]),&(b[n]));
|
---|
485 | }
|
---|
486 | else
|
---|
487 | # endif
|
---|
488 | {
|
---|
489 | bn_mul_recursive(&(t[0]),&(r[0]),&(r[n]),n,&(t[n2]));
|
---|
490 | bn_mul_recursive(r,&(a[n]),&(b[n]),n,&(t[n2]));
|
---|
491 | }
|
---|
492 |
|
---|
493 | /* s0 == low(al*bl)
|
---|
494 | * s1 == low(ah*bh)+low((al-ah)*(bh-bl))+low(al*bl)+high(al*bl)
|
---|
495 | * We know s0 and s1 so the only unknown is high(al*bl)
|
---|
496 | * high(al*bl) == s1 - low(ah*bh+s0+(al-ah)*(bh-bl))
|
---|
497 | * high(al*bl) == s1 - (r[0]+l[0]+t[0])
|
---|
498 | */
|
---|
499 | if (l != NULL)
|
---|
500 | {
|
---|
501 | lp= &(t[n2+n]);
|
---|
502 | c1=(int)(bn_add_words(lp,&(r[0]),&(l[0]),n));
|
---|
503 | }
|
---|
504 | else
|
---|
505 | {
|
---|
506 | c1=0;
|
---|
507 | lp= &(r[0]);
|
---|
508 | }
|
---|
509 |
|
---|
510 | if (neg)
|
---|
511 | neg=(int)(bn_sub_words(&(t[n2]),lp,&(t[0]),n));
|
---|
512 | else
|
---|
513 | {
|
---|
514 | bn_add_words(&(t[n2]),lp,&(t[0]),n);
|
---|
515 | neg=0;
|
---|
516 | }
|
---|
517 |
|
---|
518 | if (l != NULL)
|
---|
519 | {
|
---|
520 | bn_sub_words(&(t[n2+n]),&(l[n]),&(t[n2]),n);
|
---|
521 | }
|
---|
522 | else
|
---|
523 | {
|
---|
524 | lp= &(t[n2+n]);
|
---|
525 | mp= &(t[n2]);
|
---|
526 | for (i=0; i<n; i++)
|
---|
527 | lp[i]=((~mp[i])+1)&BN_MASK2;
|
---|
528 | }
|
---|
529 |
|
---|
530 | /* s[0] = low(al*bl)
|
---|
531 | * t[3] = high(al*bl)
|
---|
532 | * t[10] = (a[0]-a[1])*(b[1]-b[0]) neg is the sign
|
---|
533 | * r[10] = (a[1]*b[1])
|
---|
534 | */
|
---|
535 | /* R[10] = al*bl
|
---|
536 | * R[21] = al*bl + ah*bh + (a[0]-a[1])*(b[1]-b[0])
|
---|
537 | * R[32] = ah*bh
|
---|
538 | */
|
---|
539 | /* R[1]=t[3]+l[0]+r[0](+-)t[0] (have carry/borrow)
|
---|
540 | * R[2]=r[0]+t[3]+r[1](+-)t[1] (have carry/borrow)
|
---|
541 | * R[3]=r[1]+(carry/borrow)
|
---|
542 | */
|
---|
543 | if (l != NULL)
|
---|
544 | {
|
---|
545 | lp= &(t[n2]);
|
---|
546 | c1= (int)(bn_add_words(lp,&(t[n2+n]),&(l[0]),n));
|
---|
547 | }
|
---|
548 | else
|
---|
549 | {
|
---|
550 | lp= &(t[n2+n]);
|
---|
551 | c1=0;
|
---|
552 | }
|
---|
553 | c1+=(int)(bn_add_words(&(t[n2]),lp, &(r[0]),n));
|
---|
554 | if (oneg)
|
---|
555 | c1-=(int)(bn_sub_words(&(t[n2]),&(t[n2]),&(t[0]),n));
|
---|
556 | else
|
---|
557 | c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),&(t[0]),n));
|
---|
558 |
|
---|
559 | c2 =(int)(bn_add_words(&(r[0]),&(r[0]),&(t[n2+n]),n));
|
---|
560 | c2+=(int)(bn_add_words(&(r[0]),&(r[0]),&(r[n]),n));
|
---|
561 | if (oneg)
|
---|
562 | c2-=(int)(bn_sub_words(&(r[0]),&(r[0]),&(t[n]),n));
|
---|
563 | else
|
---|
564 | c2+=(int)(bn_add_words(&(r[0]),&(r[0]),&(t[n]),n));
|
---|
565 |
|
---|
566 | if (c1 != 0) /* Add starting at r[0], could be +ve or -ve */
|
---|
567 | {
|
---|
568 | i=0;
|
---|
569 | if (c1 > 0)
|
---|
570 | {
|
---|
571 | lc=c1;
|
---|
572 | do {
|
---|
573 | ll=(r[i]+lc)&BN_MASK2;
|
---|
574 | r[i++]=ll;
|
---|
575 | lc=(lc > ll);
|
---|
576 | } while (lc);
|
---|
577 | }
|
---|
578 | else
|
---|
579 | {
|
---|
580 | lc= -c1;
|
---|
581 | do {
|
---|
582 | ll=r[i];
|
---|
583 | r[i++]=(ll-lc)&BN_MASK2;
|
---|
584 | lc=(lc > ll);
|
---|
585 | } while (lc);
|
---|
586 | }
|
---|
587 | }
|
---|
588 | if (c2 != 0) /* Add starting at r[1] */
|
---|
589 | {
|
---|
590 | i=n;
|
---|
591 | if (c2 > 0)
|
---|
592 | {
|
---|
593 | lc=c2;
|
---|
594 | do {
|
---|
595 | ll=(r[i]+lc)&BN_MASK2;
|
---|
596 | r[i++]=ll;
|
---|
597 | lc=(lc > ll);
|
---|
598 | } while (lc);
|
---|
599 | }
|
---|
600 | else
|
---|
601 | {
|
---|
602 | lc= -c2;
|
---|
603 | do {
|
---|
604 | ll=r[i];
|
---|
605 | r[i++]=(ll-lc)&BN_MASK2;
|
---|
606 | lc=(lc > ll);
|
---|
607 | } while (lc);
|
---|
608 | }
|
---|
609 | }
|
---|
610 | }
|
---|
611 | #endif /* BN_RECURSION */
|
---|
612 |
|
---|
613 | int BN_mul(BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
|
---|
614 | {
|
---|
615 | int top,al,bl;
|
---|
616 | BIGNUM *rr;
|
---|
617 | int ret = 0;
|
---|
618 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
|
---|
619 | int i;
|
---|
620 | #endif
|
---|
621 | #ifdef BN_RECURSION
|
---|
622 | BIGNUM *t;
|
---|
623 | int j,k;
|
---|
624 | #endif
|
---|
625 |
|
---|
626 | #ifdef BN_COUNT
|
---|
627 | printf("BN_mul %d * %d\n",a->top,b->top);
|
---|
628 | #endif
|
---|
629 |
|
---|
630 | bn_check_top(a);
|
---|
631 | bn_check_top(b);
|
---|
632 | bn_check_top(r);
|
---|
633 |
|
---|
634 | al=a->top;
|
---|
635 | bl=b->top;
|
---|
636 |
|
---|
637 | if ((al == 0) || (bl == 0))
|
---|
638 | {
|
---|
639 | BN_zero(r);
|
---|
640 | return(1);
|
---|
641 | }
|
---|
642 | top=al+bl;
|
---|
643 |
|
---|
644 | BN_CTX_start(ctx);
|
---|
645 | if ((r == a) || (r == b))
|
---|
646 | {
|
---|
647 | if ((rr = BN_CTX_get(ctx)) == NULL) goto err;
|
---|
648 | }
|
---|
649 | else
|
---|
650 | rr = r;
|
---|
651 | rr->neg=a->neg^b->neg;
|
---|
652 |
|
---|
653 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
|
---|
654 | i = al-bl;
|
---|
655 | #endif
|
---|
656 | #ifdef BN_MUL_COMBA
|
---|
657 | if (i == 0)
|
---|
658 | {
|
---|
659 | # if 0
|
---|
660 | if (al == 4)
|
---|
661 | {
|
---|
662 | if (bn_wexpand(rr,8) == NULL) goto err;
|
---|
663 | rr->top=8;
|
---|
664 | bn_mul_comba4(rr->d,a->d,b->d);
|
---|
665 | goto end;
|
---|
666 | }
|
---|
667 | # endif
|
---|
668 | if (al == 8)
|
---|
669 | {
|
---|
670 | if (bn_wexpand(rr,16) == NULL) goto err;
|
---|
671 | rr->top=16;
|
---|
672 | bn_mul_comba8(rr->d,a->d,b->d);
|
---|
673 | goto end;
|
---|
674 | }
|
---|
675 | }
|
---|
676 | #endif /* BN_MUL_COMBA */
|
---|
677 | #ifdef BN_RECURSION
|
---|
678 | if ((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL))
|
---|
679 | {
|
---|
680 | if (i == 1 && !BN_get_flags(b,BN_FLG_STATIC_DATA))
|
---|
681 | {
|
---|
682 | if (bn_wexpand(b,al) == NULL) goto err;
|
---|
683 | b->d[bl]=0;
|
---|
684 | bl++;
|
---|
685 | i--;
|
---|
686 | }
|
---|
687 | else if (i == -1 && !BN_get_flags(a,BN_FLG_STATIC_DATA))
|
---|
688 | {
|
---|
689 | if (bn_wexpand(a,bl) == NULL) goto err;
|
---|
690 | a->d[al]=0;
|
---|
691 | al++;
|
---|
692 | i++;
|
---|
693 | }
|
---|
694 | if (i == 0)
|
---|
695 | {
|
---|
696 | /* symmetric and > 4 */
|
---|
697 | /* 16 or larger */
|
---|
698 | j=BN_num_bits_word((BN_ULONG)al);
|
---|
699 | j=1<<(j-1);
|
---|
700 | k=j+j;
|
---|
701 | t = BN_CTX_get(ctx);
|
---|
702 | if (al == j) /* exact multiple */
|
---|
703 | {
|
---|
704 | if (bn_wexpand(t,k*2) == NULL) goto err;
|
---|
705 | if (bn_wexpand(rr,k*2) == NULL) goto err;
|
---|
706 | bn_mul_recursive(rr->d,a->d,b->d,al,t->d);
|
---|
707 | }
|
---|
708 | else
|
---|
709 | {
|
---|
710 | if (bn_wexpand(a,k) == NULL) goto err;
|
---|
711 | if (bn_wexpand(b,k) == NULL) goto err;
|
---|
712 | if (bn_wexpand(t,k*4) == NULL) goto err;
|
---|
713 | if (bn_wexpand(rr,k*4) == NULL) goto err;
|
---|
714 | for (i=a->top; i<k; i++)
|
---|
715 | a->d[i]=0;
|
---|
716 | for (i=b->top; i<k; i++)
|
---|
717 | b->d[i]=0;
|
---|
718 | bn_mul_part_recursive(rr->d,a->d,b->d,al-j,j,t->d);
|
---|
719 | }
|
---|
720 | rr->top=top;
|
---|
721 | goto end;
|
---|
722 | }
|
---|
723 | }
|
---|
724 | #endif /* BN_RECURSION */
|
---|
725 | if (bn_wexpand(rr,top) == NULL) goto err;
|
---|
726 | rr->top=top;
|
---|
727 | bn_mul_normal(rr->d,a->d,al,b->d,bl);
|
---|
728 |
|
---|
729 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
|
---|
730 | end:
|
---|
731 | #endif
|
---|
732 | bn_fix_top(rr);
|
---|
733 | if (r != rr) BN_copy(r,rr);
|
---|
734 | ret=1;
|
---|
735 | err:
|
---|
736 | BN_CTX_end(ctx);
|
---|
737 | return(ret);
|
---|
738 | }
|
---|
739 |
|
---|
740 | void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb)
|
---|
741 | {
|
---|
742 | BN_ULONG *rr;
|
---|
743 |
|
---|
744 | #ifdef BN_COUNT
|
---|
745 | printf(" bn_mul_normal %d * %d\n",na,nb);
|
---|
746 | #endif
|
---|
747 |
|
---|
748 | if (na < nb)
|
---|
749 | {
|
---|
750 | int itmp;
|
---|
751 | BN_ULONG *ltmp;
|
---|
752 |
|
---|
753 | itmp=na; na=nb; nb=itmp;
|
---|
754 | ltmp=a; a=b; b=ltmp;
|
---|
755 |
|
---|
756 | }
|
---|
757 | rr= &(r[na]);
|
---|
758 | rr[0]=bn_mul_words(r,a,na,b[0]);
|
---|
759 |
|
---|
760 | for (;;)
|
---|
761 | {
|
---|
762 | if (--nb <= 0) return;
|
---|
763 | rr[1]=bn_mul_add_words(&(r[1]),a,na,b[1]);
|
---|
764 | if (--nb <= 0) return;
|
---|
765 | rr[2]=bn_mul_add_words(&(r[2]),a,na,b[2]);
|
---|
766 | if (--nb <= 0) return;
|
---|
767 | rr[3]=bn_mul_add_words(&(r[3]),a,na,b[3]);
|
---|
768 | if (--nb <= 0) return;
|
---|
769 | rr[4]=bn_mul_add_words(&(r[4]),a,na,b[4]);
|
---|
770 | rr+=4;
|
---|
771 | r+=4;
|
---|
772 | b+=4;
|
---|
773 | }
|
---|
774 | }
|
---|
775 |
|
---|
776 | void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
|
---|
777 | {
|
---|
778 | #ifdef BN_COUNT
|
---|
779 | printf(" bn_mul_low_normal %d * %d\n",n,n);
|
---|
780 | #endif
|
---|
781 | bn_mul_words(r,a,n,b[0]);
|
---|
782 |
|
---|
783 | for (;;)
|
---|
784 | {
|
---|
785 | if (--n <= 0) return;
|
---|
786 | bn_mul_add_words(&(r[1]),a,n,b[1]);
|
---|
787 | if (--n <= 0) return;
|
---|
788 | bn_mul_add_words(&(r[2]),a,n,b[2]);
|
---|
789 | if (--n <= 0) return;
|
---|
790 | bn_mul_add_words(&(r[3]),a,n,b[3]);
|
---|
791 | if (--n <= 0) return;
|
---|
792 | bn_mul_add_words(&(r[4]),a,n,b[4]);
|
---|
793 | r+=4;
|
---|
794 | b+=4;
|
---|
795 | }
|
---|
796 | }
|
---|