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1 /* crypto/rsa/rsa_gen.c */ |
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2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
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3 * All rights reserved. |
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4 * |
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5 * This package is an SSL implementation written |
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6 * by Eric Young (eay@cryptsoft.com). |
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7 * The implementation was written so as to conform with Netscapes SSL. |
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8 * |
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9 * This library is free for commercial and non-commercial use as long as |
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10 * the following conditions are aheared to. The following conditions |
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11 * apply to all code found in this distribution, be it the RC4, RSA, |
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12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
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13 * included with this distribution is covered by the same copyright terms |
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14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
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15 * |
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16 * Copyright remains Eric Young's, and as such any Copyright notices in |
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17 * the code are not to be removed. |
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18 * If this package is used in a product, Eric Young should be given attribution |
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19 * as the author of the parts of the library used. |
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20 * This can be in the form of a textual message at program startup or |
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21 * in documentation (online or textual) provided with the package. |
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22 * |
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23 * Redistribution and use in source and binary forms, with or without |
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24 * modification, are permitted provided that the following conditions |
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25 * are met: |
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26 * 1. Redistributions of source code must retain the copyright |
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27 * notice, this list of conditions and the following disclaimer. |
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28 * 2. Redistributions in binary form must reproduce the above copyright |
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29 * notice, this list of conditions and the following disclaimer in the |
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30 * documentation and/or other materials provided with the distribution. |
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31 * 3. All advertising materials mentioning features or use of this software |
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32 * must display the following acknowledgement: |
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33 * "This product includes cryptographic software written by |
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34 * Eric Young (eay@cryptsoft.com)" |
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35 * The word 'cryptographic' can be left out if the rouines from the library |
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36 * being used are not cryptographic related :-). |
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37 * 4. If you include any Windows specific code (or a derivative thereof) from |
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38 * the apps directory (application code) you must include an acknowledgement: |
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39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
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40 * |
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41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
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42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
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45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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51 * SUCH DAMAGE. |
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52 * |
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53 * The licence and distribution terms for any publically available version or |
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54 * derivative of this code cannot be changed. i.e. this code cannot simply be |
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55 * copied and put under another distribution licence |
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56 * [including the GNU Public Licence.] |
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57 */ |
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58 |
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59 |
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60 /* NB: these functions have been "upgraded", the deprecated versions (which are |
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61 * compatibility wrappers using these functions) are in rsa_depr.c. |
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62 * - Geoff |
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63 */ |
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64 |
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65 #include <stdio.h> |
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66 #include <time.h> |
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67 #include "cryptlib.h" |
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68 #include <openssl/bn.h> |
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69 #include <openssl/rsa.h> |
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70 |
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71 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb); |
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72 |
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73 /* NB: this wrapper would normally be placed in rsa_lib.c and the static |
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74 * implementation would probably be in rsa_eay.c. Nonetheless, is kept here so |
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75 * that we don't introduce a new linker dependency. Eg. any application that |
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76 * wasn't previously linking object code related to key-generation won't have to |
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77 * now just because key-generation is part of RSA_METHOD. */ |
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78 EXPORT_C int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) |
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79 { |
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80 if(rsa->meth->rsa_keygen) |
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81 return rsa->meth->rsa_keygen(rsa, bits, e_value, cb); |
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82 return rsa_builtin_keygen(rsa, bits, e_value, cb); |
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83 } |
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84 |
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85 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) |
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86 { |
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87 BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp; |
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88 BIGNUM local_r0,local_d,local_p; |
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89 BIGNUM *pr0,*d,*p; |
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90 int bitsp,bitsq,ok= -1,n=0; |
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91 BN_CTX *ctx=NULL; |
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92 |
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93 ctx=BN_CTX_new(); |
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94 if (ctx == NULL) goto err; |
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95 BN_CTX_start(ctx); |
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96 r0 = BN_CTX_get(ctx); |
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97 r1 = BN_CTX_get(ctx); |
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98 r2 = BN_CTX_get(ctx); |
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99 r3 = BN_CTX_get(ctx); |
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100 if (r3 == NULL) goto err; |
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101 |
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102 bitsp=(bits+1)/2; |
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103 bitsq=bits-bitsp; |
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104 |
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105 /* We need the RSA components non-NULL */ |
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106 if(!rsa->n && ((rsa->n=BN_new()) == NULL)) goto err; |
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107 if(!rsa->d && ((rsa->d=BN_new()) == NULL)) goto err; |
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108 if(!rsa->e && ((rsa->e=BN_new()) == NULL)) goto err; |
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109 if(!rsa->p && ((rsa->p=BN_new()) == NULL)) goto err; |
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110 if(!rsa->q && ((rsa->q=BN_new()) == NULL)) goto err; |
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111 if(!rsa->dmp1 && ((rsa->dmp1=BN_new()) == NULL)) goto err; |
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112 if(!rsa->dmq1 && ((rsa->dmq1=BN_new()) == NULL)) goto err; |
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113 if(!rsa->iqmp && ((rsa->iqmp=BN_new()) == NULL)) goto err; |
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114 |
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115 BN_copy(rsa->e, e_value); |
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116 |
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117 /* generate p and q */ |
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118 for (;;) |
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119 { |
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120 if(!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb)) |
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121 goto err; |
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122 if (!BN_sub(r2,rsa->p,BN_value_one())) goto err; |
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123 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err; |
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124 if (BN_is_one(r1)) break; |
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125 if(!BN_GENCB_call(cb, 2, n++)) |
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126 goto err; |
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127 } |
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128 if(!BN_GENCB_call(cb, 3, 0)) |
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129 goto err; |
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130 for (;;) |
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131 { |
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132 /* When generating ridiculously small keys, we can get stuck |
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133 * continually regenerating the same prime values. Check for |
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134 * this and bail if it happens 3 times. */ |
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135 unsigned int degenerate = 0; |
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136 do |
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137 { |
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138 if(!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb)) |
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139 goto err; |
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140 } while((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3)); |
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141 if(degenerate == 3) |
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142 { |
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143 ok = 0; /* we set our own err */ |
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144 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,RSA_R_KEY_SIZE_TOO_SMALL); |
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145 goto err; |
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146 } |
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147 if (!BN_sub(r2,rsa->q,BN_value_one())) goto err; |
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148 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err; |
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149 if (BN_is_one(r1)) |
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150 break; |
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151 if(!BN_GENCB_call(cb, 2, n++)) |
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152 goto err; |
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153 } |
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154 if(!BN_GENCB_call(cb, 3, 1)) |
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155 goto err; |
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156 if (BN_cmp(rsa->p,rsa->q) < 0) |
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157 { |
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158 tmp=rsa->p; |
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159 rsa->p=rsa->q; |
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160 rsa->q=tmp; |
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161 } |
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162 |
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163 /* calculate n */ |
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164 if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err; |
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165 |
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166 /* calculate d */ |
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167 if (!BN_sub(r1,rsa->p,BN_value_one())) goto err; /* p-1 */ |
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168 if (!BN_sub(r2,rsa->q,BN_value_one())) goto err; /* q-1 */ |
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169 if (!BN_mul(r0,r1,r2,ctx)) goto err; /* (p-1)(q-1) */ |
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170 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
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171 { |
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172 pr0 = &local_r0; |
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173 BN_with_flags(pr0, r0, BN_FLG_CONSTTIME); |
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174 } |
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175 else |
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176 pr0 = r0; |
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177 if (!BN_mod_inverse(rsa->d,rsa->e,pr0,ctx)) goto err; /* d */ |
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178 |
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179 /* set up d for correct BN_FLG_CONSTTIME flag */ |
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180 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
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181 { |
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182 d = &local_d; |
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183 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
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184 } |
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185 else |
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186 d = rsa->d; |
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187 /* calculate d mod (p-1) */ |
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188 if (!BN_mod(rsa->dmp1,d,r1,ctx)) goto err; |
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189 |
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190 /* calculate d mod (q-1) */ |
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191 if (!BN_mod(rsa->dmq1,d,r2,ctx)) goto err; |
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192 |
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193 /* calculate inverse of q mod p */ |
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194 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
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195 { |
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196 p = &local_p; |
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197 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); |
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198 } |
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199 else |
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200 p = rsa->p; |
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201 if (!BN_mod_inverse(rsa->iqmp,rsa->q,p,ctx)) goto err; |
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202 |
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203 ok=1; |
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204 err: |
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205 if (ok == -1) |
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206 { |
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207 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,ERR_LIB_BN); |
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208 ok=0; |
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209 } |
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210 if (ctx != NULL) |
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211 { |
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212 BN_CTX_end(ctx); |
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213 BN_CTX_free(ctx); |
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214 } |
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215 |
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216 return ok; |
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217 } |
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218 |