1 | <?php |
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2 | |
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3 | |
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4 | class rsa{ |
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5 | |
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6 | var $e; |
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7 | var $d; |
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8 | var $n; |
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9 | |
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10 | function rsa(){ |
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11 | session_start(); |
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12 | if (!isset($_SESSION['phpgw_session']['publ_key'])) |
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13 | { |
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14 | $p=$this->genPrim(); |
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15 | $q=$this->genPrim(); |
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16 | $this->n=bcmul($p,$q); |
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17 | $z=bcmul(bcsub($p,1),bcsub($q,1)); |
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18 | $this->d=$this->calc_d($z); |
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19 | $this->e=$this->calc_e($this->d,$z); |
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20 | $_SESSION['phpgw_session']['publ_key'] = $this->d; |
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21 | $_SESSION['phpgw_session']['priv_key'] = $this->e; |
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22 | $_SESSION['phpgw_session']['modulus'] = $this->n; |
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23 | } |
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24 | else |
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25 | { |
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26 | $this->e = $_SESSION['phpgw_session']['publ_key']; |
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27 | $this->d = $_SESSION['phpgw_session']['priv_key']; |
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28 | $this->n = $_SESSION['phpgw_session']['modulus'] ; |
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29 | } |
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30 | session_write_close(); |
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31 | } |
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32 | function encode($string){ |
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33 | $result = ""; |
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34 | for($i=0; $i < strlen($string); $i+=3) |
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35 | $result .= $this->encode_(ord($string[$i]).ord($string[$i+1]).ord($string[$i+2]),$this->e,$this->n)." "; |
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36 | return $result; |
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37 | } |
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38 | function decode($string){ |
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39 | $nums = split(" ",$string); |
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40 | foreach($nums as $todec) |
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41 | if (ord($todec) > 1){ |
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42 | $num = $this->decode_($todec,$this->d,$this->n); |
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43 | $num1 = substr($num,0,3); |
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44 | $num2 = substr($num,3,3); |
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45 | $num3 = substr($num,6,3); |
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46 | ($num1 > 1) && $result .= chr($num1); |
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47 | ($num2 > 1) && $result .= chr($num2); |
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48 | ($num3 > 1) && $result .= chr($num3); |
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49 | |
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50 | } |
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51 | return $result; |
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52 | } |
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53 | function get_publKey(){ |
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54 | return $_SESSION['phpgw_session']['publ_key']; |
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55 | } |
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56 | function get_mod(){ |
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57 | return $_SESSION['phpgw_session']['modulus']; |
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58 | } |
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59 | private function isPrime($Num){ |
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60 | $result = true; |
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61 | if($Num == 2 || $Num == 3) |
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62 | return true; |
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63 | if($Num % 2 == 0) |
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64 | return false; |
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65 | for($Divisor = 3; $Divisor < (sqrt($Num)+1); $Divisor+=2) |
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66 | { |
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67 | $Res = $Num % $Divisor; |
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68 | if($Res == 0) |
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69 | { |
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70 | $result=false; |
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71 | break; |
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72 | } |
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73 | } |
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74 | return $result; |
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75 | } |
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76 | |
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77 | private function genPrim(){ |
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78 | $num=rand(100000,5000000); |
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79 | $i=$num; |
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80 | while($i++) |
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81 | if ($this->isPrime($i)) |
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82 | return $i; |
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83 | } |
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84 | private function GCD($e,$m) { |
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85 | $y = $e; |
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86 | $x = $m; |
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87 | |
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88 | while (bccomp($y, 0) != 0) { |
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89 | // modulus function |
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90 | $w = bcsub($x, bcmul($y, bcdiv($x, $y, 0)));; |
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91 | $x = $y; |
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92 | $y = $w; |
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93 | } |
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94 | |
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95 | return $x; |
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96 | } |
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97 | |
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98 | // |
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99 | // Calculating E under conditions: |
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100 | // GCD(N,E) = 1 and 1<E<N |
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101 | // |
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102 | private function calc_d($m){ |
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103 | $e = '3'; |
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104 | if(bccomp($this->GCD($e, $m), '1') != 0){ |
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105 | $e = '5'; |
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106 | $step = '2'; |
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107 | |
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108 | while(bccomp($this->GCD($e, $m), '1') != 0){ |
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109 | $e = bcadd($e, $step); |
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110 | |
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111 | if($step == '2'){ |
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112 | $step = '4'; |
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113 | }else{ |
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114 | $step = '2'; |
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115 | } |
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116 | } |
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117 | } |
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118 | return $e; |
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119 | } |
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120 | private function calc_e ($Ee,$Em) { |
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121 | $u1 = '1'; |
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122 | $u2 = '0'; |
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123 | $u3 = $Em; |
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124 | $v1 = '0'; |
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125 | $v2 = '1'; |
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126 | $v3 = $Ee; |
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127 | |
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128 | while (bccomp($v3, 0) != 0) { |
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129 | $qq = bcdiv($u3, $v3, 0); |
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130 | $t1 = bcsub($u1, bcmul($qq, $v1)); |
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131 | $t2 = bcsub($u2, bcmul($qq, $v2)); |
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132 | $t3 = bcsub($u3, bcmul($qq, $v3)); |
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133 | $u1 = $v1; |
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134 | $u2 = $v2; |
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135 | $u3 = $v3; |
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136 | $v1 = $t1; |
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137 | $v2 = $t2; |
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138 | $v3 = $t3; |
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139 | $z = '1'; |
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140 | } |
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141 | |
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142 | $uu = $u1; |
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143 | $vv = $u2; |
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144 | |
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145 | if (bccomp($vv, 0) == -1) { |
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146 | $inverse = bcadd($vv, $Em); |
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147 | } else { |
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148 | $inverse = $vv; |
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149 | } |
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150 | |
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151 | return $inverse; |
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152 | } |
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153 | |
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154 | |
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155 | private function encode_($val,$e,$n){ |
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156 | return bcpowmod($val,$e,$n); |
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157 | } |
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158 | private function decode_($val,$d,$n){ |
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159 | return bcpowmod($val,$d,$n); |
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160 | } |
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161 | |
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162 | } |
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163 | |
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164 | ?> |
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165 | |
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