1 | |
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2 | // $Id$ |
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3 | |
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4 | #include <stdio.h> |
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5 | #include <stdlib.h> |
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6 | #include <string.h> |
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7 | #include <stdint.h> |
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8 | #include "panon.h" |
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9 | |
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10 | static uint8_t m_key[16]; |
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11 | static uint8_t m_pad[16]; |
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12 | |
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13 | #define CACHEBITS 20 |
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14 | #define CACHESIZE (1 << CACHEBITS) |
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15 | |
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16 | //static uint32_t enc_cache[CACHESIZE]; |
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17 | |
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18 | static uint32_t *enc_cache = 0; |
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19 | static uint32_t fullcache[2][2]; |
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20 | |
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21 | |
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22 | |
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23 | void panon_init_cache() { |
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24 | if (enc_cache == 0) { |
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25 | enc_cache = (uint32_t *)malloc(CACHESIZE * sizeof(uint32_t)); |
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26 | } |
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27 | memset(enc_cache,0,(CACHESIZE * sizeof(uint32_t))); |
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28 | fullcache[0][0] = 0; |
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29 | fullcache[0][1] = 0; |
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30 | fullcache[1][0] = 0; |
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31 | fullcache[1][1] = 0; |
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32 | } |
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33 | static void cache_update(uint32_t scan) { |
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34 | uint8_t rin_output[16]; |
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35 | uint8_t rin_input[16]; |
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36 | uint32_t orig_addr = 0; |
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37 | uint32_t result = 0; |
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38 | uint32_t first4bytes_pad, first4bytes_input; |
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39 | int pos; |
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40 | |
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41 | memcpy(rin_input, m_pad, 16); |
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42 | first4bytes_pad = (((uint32_t) m_pad[0]) << 24) + |
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43 | (((uint32_t) m_pad[1]) << 16 ) + |
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44 | (((uint32_t) m_pad[2]) << 8) + |
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45 | (uint32_t) m_pad[3]; |
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46 | |
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47 | |
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48 | memcpy(rin_input, m_pad, 16); |
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49 | orig_addr = (scan << (32 - CACHEBITS)); |
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50 | result = 0; |
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51 | for (pos = 0; pos < CACHEBITS; pos++) { |
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52 | |
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53 | if (pos == 0) { |
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54 | first4bytes_input = first4bytes_pad; |
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55 | } else { |
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56 | first4bytes_input = |
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57 | ((orig_addr >> (32 - pos)) << (32 - pos)) | |
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58 | ((first4bytes_pad << pos) >> pos); |
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59 | } |
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60 | rin_input[0] = (uint8_t) (first4bytes_input >> 24); |
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61 | rin_input[1] = (uint8_t) ((first4bytes_input << 8) >> 24); |
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62 | rin_input[2] = (uint8_t) ((first4bytes_input << 16) >> 24); |
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63 | rin_input[3] = (uint8_t) ((first4bytes_input << 24) >> 24); |
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64 | |
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65 | blockEncrypt(rin_input, 128, rin_output); |
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66 | |
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67 | result |= (rin_output[0] >> 7) << (31 - pos); |
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68 | } |
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69 | enc_cache[scan] = (result >> (32 - CACHEBITS)); |
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70 | |
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71 | } |
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72 | static uint32_t lookup_cache(uint32_t orig_addr) { |
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73 | uint32_t lookup_addr = (orig_addr >> (32 - CACHEBITS)); |
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74 | if (enc_cache[lookup_addr] == 0) { |
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75 | cache_update(lookup_addr); |
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76 | } |
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77 | return enc_cache[lookup_addr]; |
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78 | } |
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79 | |
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80 | void panon_init(const uint8_t * key) { |
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81 | // initialise the 128-bit secret key |
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82 | memcpy(m_key, key, 16); |
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83 | // initialise the Rijndael cipher |
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84 | rijndael_init(ECB, Encrypt, key, Key16Bytes,0); |
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85 | blockEncrypt(key + 16, 128, m_pad); |
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86 | panon_init_cache(); |
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87 | } |
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88 | void panon_init_decrypt(const uint8_t * key) { |
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89 | memcpy(m_key, key, 16); |
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90 | rijndael_init(ECB, Decrypt, key, Key16Bytes,0); |
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91 | blockEncrypt(key + 16, 128, m_pad); |
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92 | } |
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93 | |
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94 | uint32_t pp_anonymize(const uint32_t orig_addr) { |
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95 | uint8_t rin_output[16]; |
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96 | uint8_t rin_input[16]; |
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97 | |
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98 | uint32_t result = 0; |
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99 | uint32_t first4bytes_pad, first4bytes_input; |
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100 | int pos; |
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101 | |
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102 | memcpy(rin_input, m_pad, 16); |
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103 | first4bytes_pad = (((uint32_t) m_pad[0]) << 24) + |
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104 | (((uint32_t) m_pad[1]) << 16 ) + |
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105 | (((uint32_t) m_pad[2]) << 8) + |
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106 | (uint32_t) m_pad[3]; |
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107 | |
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108 | // For each prefix with length 0 to 31, generate a bit using the |
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109 | // rijndael cipher, which is used as a pseudorandom function here. |
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110 | // The bits generated in every round are combined into a pseudorandom |
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111 | // one-time-pad. |
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112 | |
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113 | for (pos = 0; pos <= 31; pos++) { |
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114 | // Padding: The most significant pos bits are taken from orig_addr. |
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115 | // The other 128-pos bits are taken from m_pad. The variables |
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116 | // first4bytes_pad and first4bytes_input are used to handle the annoying |
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117 | // byte order problem |
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118 | |
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119 | if (pos == 0) { |
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120 | first4bytes_input = first4bytes_pad; |
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121 | } else { |
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122 | first4bytes_input = ((orig_addr >> (32 - pos)) << (32 - pos)) | |
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123 | ((first4bytes_pad << pos) >> pos); |
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124 | } |
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125 | rin_input[0] = (uint8_t) (first4bytes_input >> 24); |
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126 | rin_input[1] = (uint8_t) ((first4bytes_input << 8) >> 24); |
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127 | rin_input[2] = (uint8_t) ((first4bytes_input << 16) >> 24); |
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128 | rin_input[3] = (uint8_t) ((first4bytes_input << 24) >> 24); |
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129 | |
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130 | // Encryption: The rijndael cipher is used as a pseudorandom function. |
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131 | // During each round, only the first bit of rin_output is used. |
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132 | blockEncrypt(rin_input, 128, rin_output); |
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133 | |
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134 | // Combination: the bits are combined into a pseudorandom one-time-pad. |
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135 | result |= (rin_output[0] >> 7) << (31 - pos); |
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136 | } |
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137 | |
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138 | return result ^ orig_addr; |
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139 | } |
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140 | |
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141 | |
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142 | uint32_t cpp_anonymize(const uint32_t orig_addr) { |
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143 | uint8_t rin_output[16]; |
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144 | uint8_t rin_input[16]; |
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145 | |
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146 | uint32_t firstnbits; |
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147 | |
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148 | uint32_t result = 0; |
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149 | uint32_t first4bytes_pad, first4bytes_input; |
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150 | int pos; |
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151 | |
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152 | |
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153 | if (fullcache[0][0] == orig_addr) { |
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154 | return fullcache[0][1]; |
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155 | } else if (fullcache[1][0] == orig_addr) { |
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156 | uint32_t tmp = fullcache[1][1]; |
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157 | // move to "top" of "cache" |
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158 | fullcache[1][0] = fullcache[0][0]; |
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159 | fullcache[1][1] = fullcache[0][1]; |
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160 | fullcache[0][0] = orig_addr; |
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161 | fullcache[0][1] = tmp; |
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162 | return tmp; |
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163 | } |
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164 | |
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165 | memcpy(rin_input, m_pad, 16); |
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166 | first4bytes_pad = (((uint32_t) m_pad[0]) << 24) + |
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167 | (((uint32_t) m_pad[1]) << 16 ) + |
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168 | (((uint32_t) m_pad[2]) << 8) + |
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169 | (uint32_t) m_pad[3]; |
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170 | |
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171 | // Look up the first CACHESIZE bits from enc_cache and start the |
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172 | // result with this, then proceed |
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173 | |
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174 | firstnbits = (uint32_t) orig_addr >> (32 - CACHEBITS); |
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175 | //result = (enc_cache[firstnbits] << (32 - CACHEBITS)); |
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176 | |
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177 | |
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178 | result = (lookup_cache(orig_addr) << (32 - CACHEBITS)); |
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179 | // For each prefix with length CACHEBITS to 31, generate a bit using the |
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180 | // rijndael cipher, which is used as a pseudorandom function here. |
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181 | // The bits generated in every round are combined into a pseudorandom |
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182 | // one-time-pad. |
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183 | |
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184 | for (pos = CACHEBITS ; pos <= 31; pos++) { |
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185 | // Padding: The most significant pos bits are taken from orig_addr. |
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186 | // The other 128-pos bits are taken from m_pad. The variables |
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187 | // first4bytes_pad and first4bytes_input are used to handle the annoying |
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188 | // byte order problem |
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189 | |
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190 | if (pos == 0) { |
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191 | first4bytes_input = first4bytes_pad; |
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192 | } else { |
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193 | first4bytes_input = ((orig_addr >> (32 - pos)) << (32 - pos)) | |
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194 | ((first4bytes_pad << pos) >> pos); |
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195 | } |
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196 | rin_input[0] = (uint8_t) (first4bytes_input >> 24); |
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197 | rin_input[1] = (uint8_t) ((first4bytes_input << 8) >> 24); |
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198 | rin_input[2] = (uint8_t) ((first4bytes_input << 16) >> 24); |
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199 | rin_input[3] = (uint8_t) ((first4bytes_input << 24) >> 24); |
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200 | |
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201 | // Encryption: The rijndael cipher is used as a pseudorandom function. |
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202 | // During each round, only the first bit of rin_output is used. |
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203 | blockEncrypt(rin_input, 128, rin_output); |
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204 | |
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205 | // Combination: the bits are combined into a pseudorandom one-time-pad. |
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206 | result |= (rin_output[0] >> 7) << (31 - pos); |
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207 | } |
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208 | |
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209 | fullcache[1][0] = fullcache[0][0]; |
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210 | fullcache[1][1] = fullcache[0][1]; |
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211 | fullcache[0][0] = orig_addr; |
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212 | fullcache[0][1] = result ^ orig_addr; |
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213 | |
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214 | return result ^ orig_addr; |
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215 | } |
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216 | |
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217 | uint32_t anonymize(const uint32_t orig_addr) { |
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218 | uint8_t rin_output[16]; |
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219 | uint8_t rin_input[16]; |
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220 | |
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221 | uint32_t result = 0; |
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222 | |
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223 | memcpy(rin_input, m_pad, 16); |
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224 | |
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225 | rin_input[0] = (uint8_t) (orig_addr >> 24); |
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226 | rin_input[1] = (uint8_t) ((orig_addr << 8) >> 24); |
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227 | rin_input[2] = (uint8_t) ((orig_addr << 16) >> 24); |
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228 | rin_input[3] = (uint8_t) ((orig_addr << 24) >> 24); |
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229 | |
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230 | blockEncrypt(rin_input, 128, rin_output); |
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231 | |
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232 | result = 0; |
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233 | result += (rin_output[0] <<24); |
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234 | result += (rin_output[1] <<16); |
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235 | result += (rin_output[2] <<8); |
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236 | result += (rin_output[3]); |
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237 | return result; |
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238 | } |
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239 | |
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