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1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
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2 * |
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3 * LibTomCrypt is a library that provides various cryptographic |
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4 * algorithms in a highly modular and flexible manner. |
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5 * |
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6 * The library is free for all purposes without any express |
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7 * guarantee it works. |
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8 * |
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9 * Tom St Denis, [email protected], http://libtomcrypt.org |
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10 */ |
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11 |
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12 /* RC6 code by Tom St Denis */ |
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13 #include "mycrypt.h" |
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14 |
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15 #ifdef RC6 |
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16 |
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17 const struct _cipher_descriptor rc6_desc = |
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18 { |
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19 "rc6", |
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20 3, |
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21 8, 128, 16, 20, |
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22 &rc6_setup, |
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23 &rc6_ecb_encrypt, |
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24 &rc6_ecb_decrypt, |
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25 &rc6_test, |
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26 &rc6_keysize |
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27 }; |
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28 |
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29 static const ulong32 stab[44] = { |
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30 0xb7e15163UL, 0x5618cb1cUL, 0xf45044d5UL, 0x9287be8eUL, 0x30bf3847UL, 0xcef6b200UL, 0x6d2e2bb9UL, 0x0b65a572UL, |
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31 0xa99d1f2bUL, 0x47d498e4UL, 0xe60c129dUL, 0x84438c56UL, 0x227b060fUL, 0xc0b27fc8UL, 0x5ee9f981UL, 0xfd21733aUL, |
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32 0x9b58ecf3UL, 0x399066acUL, 0xd7c7e065UL, 0x75ff5a1eUL, 0x1436d3d7UL, 0xb26e4d90UL, 0x50a5c749UL, 0xeedd4102UL, |
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33 0x8d14babbUL, 0x2b4c3474UL, 0xc983ae2dUL, 0x67bb27e6UL, 0x05f2a19fUL, 0xa42a1b58UL, 0x42619511UL, 0xe0990ecaUL, |
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34 0x7ed08883UL, 0x1d08023cUL, 0xbb3f7bf5UL, 0x5976f5aeUL, 0xf7ae6f67UL, 0x95e5e920UL, 0x341d62d9UL, 0xd254dc92UL, |
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35 0x708c564bUL, 0x0ec3d004UL, 0xacfb49bdUL, 0x4b32c376UL }; |
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36 |
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37 #ifdef CLEAN_STACK |
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38 static int _rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) |
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39 #else |
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40 int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) |
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41 #endif |
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42 { |
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43 ulong32 L[64], S[50], A, B, i, j, v, s, l; |
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44 |
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45 _ARGCHK(key != NULL); |
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46 _ARGCHK(skey != NULL); |
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47 |
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48 /* test parameters */ |
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49 if (num_rounds != 0 && num_rounds != 20) { |
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50 return CRYPT_INVALID_ROUNDS; |
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51 } |
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52 |
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53 /* key must be between 64 and 1024 bits */ |
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54 if (keylen < 8 || keylen > 128) { |
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55 return CRYPT_INVALID_KEYSIZE; |
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56 } |
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57 |
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58 /* copy the key into the L array */ |
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59 for (A = i = j = 0; i < (ulong32)keylen; ) { |
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60 A = (A << 8) | ((ulong32)(key[i++] & 255)); |
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61 if (!(i & 3)) { |
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62 L[j++] = BSWAP(A); |
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63 A = 0; |
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64 } |
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65 } |
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66 |
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67 /* handle odd sized keys */ |
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68 if (keylen & 3) { |
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69 A <<= (8 * (4 - (keylen&3))); |
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70 L[j++] = BSWAP(A); |
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71 } |
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72 |
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73 /* setup the S array */ |
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74 memcpy(S, stab, 44 * sizeof(stab[0])); |
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75 |
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76 /* mix buffer */ |
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77 s = 3 * MAX(44, j); |
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78 l = j; |
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79 for (A = B = i = j = v = 0; v < s; v++) { |
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80 A = S[i] = ROL(S[i] + A + B, 3); |
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81 B = L[j] = ROL(L[j] + A + B, (A+B)); |
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82 if (++i == 44) { i = 0; } |
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83 if (++j == l) { j = 0; } |
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84 } |
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85 |
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86 /* copy to key */ |
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87 for (i = 0; i < 44; i++) { |
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88 skey->rc6.K[i] = S[i]; |
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89 } |
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90 return CRYPT_OK; |
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91 } |
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92 |
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93 #ifdef CLEAN_STACK |
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94 int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) |
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95 { |
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96 int x; |
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97 x = _rc6_setup(key, keylen, num_rounds, skey); |
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98 burn_stack(sizeof(ulong32) * 122); |
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99 return x; |
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100 } |
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101 #endif |
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102 |
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103 #ifdef CLEAN_STACK |
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104 static void _rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key) |
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105 #else |
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106 void rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key) |
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107 #endif |
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108 { |
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109 ulong32 a,b,c,d,t,u, *K; |
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110 int r; |
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111 |
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112 _ARGCHK(key != NULL); |
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113 _ARGCHK(pt != NULL); |
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114 _ARGCHK(ct != NULL); |
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115 LOAD32L(a,&pt[0]);LOAD32L(b,&pt[4]);LOAD32L(c,&pt[8]);LOAD32L(d,&pt[12]); |
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116 |
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117 b += key->rc6.K[0]; |
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118 d += key->rc6.K[1]; |
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119 |
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120 #define RND(a,b,c,d) \ |
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121 t = (b * (b + b + 1)); t = ROL(t, 5); \ |
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122 u = (d * (d + d + 1)); u = ROL(u, 5); \ |
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123 a = ROL(a^t,u) + K[0]; \ |
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124 c = ROL(c^u,t) + K[1]; K += 2; |
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125 |
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126 K = key->rc6.K + 2; |
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127 for (r = 0; r < 20; r += 4) { |
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128 RND(a,b,c,d); |
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129 RND(b,c,d,a); |
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130 RND(c,d,a,b); |
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131 RND(d,a,b,c); |
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132 } |
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133 |
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134 #undef RND |
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135 |
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136 a += key->rc6.K[42]; |
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137 c += key->rc6.K[43]; |
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138 STORE32L(a,&ct[0]);STORE32L(b,&ct[4]);STORE32L(c,&ct[8]);STORE32L(d,&ct[12]); |
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139 } |
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140 |
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141 #ifdef CLEAN_STACK |
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142 void rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key) |
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143 { |
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144 _rc6_ecb_encrypt(pt, ct, key); |
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145 burn_stack(sizeof(ulong32) * 6 + sizeof(int)); |
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146 } |
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147 #endif |
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148 |
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149 #ifdef CLEAN_STACK |
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150 static void _rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key) |
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151 #else |
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152 void rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key) |
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153 #endif |
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154 { |
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155 ulong32 a,b,c,d,t,u, *K; |
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156 int r; |
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157 |
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158 _ARGCHK(key != NULL); |
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159 _ARGCHK(pt != NULL); |
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160 _ARGCHK(ct != NULL); |
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161 |
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162 LOAD32L(a,&ct[0]);LOAD32L(b,&ct[4]);LOAD32L(c,&ct[8]);LOAD32L(d,&ct[12]); |
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163 a -= key->rc6.K[42]; |
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164 c -= key->rc6.K[43]; |
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165 |
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166 #define RND(a,b,c,d) \ |
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167 t = (b * (b + b + 1)); t = ROL(t, 5); \ |
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168 u = (d * (d + d + 1)); u = ROL(u, 5); \ |
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169 c = ROR(c - K[1], t) ^ u; \ |
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170 a = ROR(a - K[0], u) ^ t; K -= 2; |
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171 |
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172 K = key->rc6.K + 40; |
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173 |
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174 for (r = 0; r < 20; r += 4) { |
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175 RND(d,a,b,c); |
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176 RND(c,d,a,b); |
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177 RND(b,c,d,a); |
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178 RND(a,b,c,d); |
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179 } |
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180 |
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181 #undef RND |
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182 |
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183 b -= key->rc6.K[0]; |
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184 d -= key->rc6.K[1]; |
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185 STORE32L(a,&pt[0]);STORE32L(b,&pt[4]);STORE32L(c,&pt[8]);STORE32L(d,&pt[12]); |
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186 } |
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187 |
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188 #ifdef CLEAN_STACK |
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189 void rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key) |
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190 { |
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191 _rc6_ecb_decrypt(ct, pt, key); |
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192 burn_stack(sizeof(ulong32) * 6 + sizeof(int)); |
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193 } |
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194 #endif |
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195 |
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196 int rc6_test(void) |
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197 { |
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198 #ifndef LTC_TEST |
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199 return CRYPT_NOP; |
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200 #else |
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201 static const struct { |
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202 int keylen; |
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203 unsigned char key[32], pt[16], ct[16]; |
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204 } tests[] = { |
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205 { |
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206 16, |
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207 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, |
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208 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, |
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209 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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210 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, |
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211 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79, |
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212 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 }, |
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213 { 0x52, 0x4e, 0x19, 0x2f, 0x47, 0x15, 0xc6, 0x23, |
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214 0x1f, 0x51, 0xf6, 0x36, 0x7e, 0xa4, 0x3f, 0x18 } |
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215 }, |
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216 { |
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217 24, |
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218 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, |
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219 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, |
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220 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0, |
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221 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, |
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222 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79, |
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223 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 }, |
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224 { 0x68, 0x83, 0x29, 0xd0, 0x19, 0xe5, 0x05, 0x04, |
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225 0x1e, 0x52, 0xe9, 0x2a, 0xf9, 0x52, 0x91, 0xd4 } |
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226 }, |
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227 { |
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228 32, |
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229 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, |
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230 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, |
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231 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0, |
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232 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe }, |
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233 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79, |
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234 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 }, |
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235 { 0xc8, 0x24, 0x18, 0x16, 0xf0, 0xd7, 0xe4, 0x89, |
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236 0x20, 0xad, 0x16, 0xa1, 0x67, 0x4e, 0x5d, 0x48 } |
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237 } |
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238 }; |
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239 unsigned char tmp[2][16]; |
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240 int x, y, err; |
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241 symmetric_key key; |
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242 |
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243 for (x = 0; x < (int)(sizeof(tests) / sizeof(tests[0])); x++) { |
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244 /* setup key */ |
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245 if ((err = rc6_setup(tests[x].key, tests[x].keylen, 0, &key)) != CRYPT_OK) { |
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246 return err; |
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247 } |
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248 |
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249 /* encrypt and decrypt */ |
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250 rc6_ecb_encrypt(tests[x].pt, tmp[0], &key); |
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251 rc6_ecb_decrypt(tmp[0], tmp[1], &key); |
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252 |
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253 /* compare */ |
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254 if (memcmp(tmp[0], tests[x].ct, 16) || memcmp(tmp[1], tests[x].pt, 16)) { |
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255 #if 0 |
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256 printf("\n\nFailed test %d\n", x); |
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257 if (memcmp(tmp[0], tests[x].ct, 16)) { |
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258 printf("Ciphertext: "); |
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259 for (y = 0; y < 16; y++) printf("%02x ", tmp[0][y]); |
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260 printf("\nExpected : "); |
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261 for (y = 0; y < 16; y++) printf("%02x ", tests[x].ct[y]); |
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262 printf("\n"); |
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263 } |
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264 if (memcmp(tmp[1], tests[x].pt, 16)) { |
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265 printf("Plaintext: "); |
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266 for (y = 0; y < 16; y++) printf("%02x ", tmp[0][y]); |
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267 printf("\nExpected : "); |
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268 for (y = 0; y < 16; y++) printf("%02x ", tests[x].pt[y]); |
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269 printf("\n"); |
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270 } |
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271 #endif |
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272 return CRYPT_FAIL_TESTVECTOR; |
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273 } |
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274 |
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275 /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */ |
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276 for (y = 0; y < 16; y++) tmp[0][y] = 0; |
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277 for (y = 0; y < 1000; y++) rc6_ecb_encrypt(tmp[0], tmp[0], &key); |
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278 for (y = 0; y < 1000; y++) rc6_ecb_decrypt(tmp[0], tmp[0], &key); |
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279 for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR; |
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280 } |
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281 return CRYPT_OK; |
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282 #endif |
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283 } |
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284 |
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285 int rc6_keysize(int *desired_keysize) |
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286 { |
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287 _ARGCHK(desired_keysize != NULL); |
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288 if (*desired_keysize < 8) { |
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289 return CRYPT_INVALID_KEYSIZE; |
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290 } else if (*desired_keysize > 128) { |
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291 *desired_keysize = 128; |
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292 } |
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293 return CRYPT_OK; |
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294 } |
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295 |
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296 #endif /*RC6*/ |
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297 |
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298 |
