1 | #include <assert.h> |
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2 | #include <termios.h> |
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3 | |
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4 | #include "creddy.h" |
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5 | #include "id.h" |
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6 | |
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7 | /* Size of password memory allocation */ |
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8 | #define PWLEN 128 |
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9 | |
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10 | // |
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11 | // ID object |
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12 | // |
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13 | struct _creddy_id_t { |
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14 | char *keyid; |
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15 | char *cn; |
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16 | certificate_t *cert; |
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17 | private_key_t *key; |
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18 | }; |
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19 | |
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20 | /* Callback configuration */ |
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21 | struct cb_opts { |
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22 | bool use_prompt; /* Print a prompt to stderr */ |
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23 | bool use_echo; /* If true, turn off input echo on stdin */ |
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24 | unsigned int tries; /* Number of attempts allowed */ |
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25 | char prompt[20]; /* The prompt to display if use_echo is true */ |
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26 | }; |
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27 | |
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28 | static chunk_t _passphrase_callback(void *user, int try); |
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29 | |
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30 | /** |
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31 | * Load an ID cert from a file. |
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32 | */ |
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33 | creddy_id_t *creddy_id_from_file(char *filename) { |
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34 | certificate_t *cert = lib->creds->create(lib->creds, |
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35 | CRED_CERTIFICATE, CERT_X509, |
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36 | BUILD_FROM_FILE, filename, |
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37 | BUILD_X509_FLAG, X509_AA, |
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38 | BUILD_END |
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39 | ); |
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40 | |
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41 | if (cert == NULL) |
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42 | return NULL; |
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43 | |
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44 | creddy_id_t *id = xmalloc(sizeof(creddy_id_t)); |
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45 | id->keyid = NULL; |
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46 | id->cn = NULL; |
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47 | id->cert = cert; |
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48 | id->key = NULL; |
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49 | |
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50 | // get the keyid |
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51 | x509_t *x509 = (x509_t *)cert; |
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52 | chunk_t keyid = x509->get_subjectKeyIdentifier(x509); |
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53 | chunk_t string = chunk_to_hex(keyid, NULL, 0); |
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54 | id->keyid = string.ptr; |
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55 | |
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56 | // TODO get CN |
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57 | |
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58 | return id; |
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59 | } |
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60 | |
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61 | int creddy_id_load_privkey(creddy_id_t *id, char *filename) { |
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62 | struct cb_opts c_opts = { 1, 0, 3, "Key password:" }; |
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63 | |
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64 | assert(id != NULL); |
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65 | |
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66 | // load signer key |
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67 | private_key_t *key = lib->creds->create(lib->creds, |
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68 | CRED_PRIVATE_KEY, KEY_RSA, |
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69 | BUILD_FROM_FILE, filename, |
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70 | /* Ask for password if the key's encrypted */ |
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71 | BUILD_PASSPHRASE_CALLBACK, _passphrase_callback, &c_opts, |
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72 | BUILD_END |
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73 | ); |
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74 | if (key == NULL) |
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75 | return 0; |
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76 | |
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77 | id->key = key; |
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78 | } |
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79 | |
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80 | char *creddy_id_keyid(creddy_id_t *id) { |
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81 | assert(id != NULL); |
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82 | |
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83 | return id->keyid; |
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84 | } |
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85 | |
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86 | certificate_t *creddy_id_cert(creddy_id_t *id) { |
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87 | assert(id != NULL); |
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88 | |
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89 | return id->cert; |
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90 | } |
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91 | |
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92 | private_key_t *creddy_id_privkey(creddy_id_t *id) { |
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93 | assert(id != NULL); |
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94 | |
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95 | return id->key; |
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96 | } |
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97 | |
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98 | void creddy_id_free(creddy_id_t *id) { |
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99 | if (id == NULL) |
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100 | return; |
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101 | |
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102 | DESTROY_IF(id->cert); |
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103 | DESTROY_IF(id->key); |
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104 | |
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105 | free(id->keyid); |
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106 | free(id); |
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107 | } |
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108 | |
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109 | // |
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110 | // Helper functions below |
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111 | // |
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112 | |
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113 | static chunk_t _passphrase_callback(void *user, int try) { |
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114 | /* Get a password from stdin and return it as a chunk_t. If too many tries |
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115 | * have occurred or there is any other problem, return an empty chunk_t, |
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116 | * which libstrongswan takes as giving up. The chunk is alloated here |
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117 | * (inside getline), and presumably freed by libstrongswan. User points to |
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118 | * a cb_opts struct, which affects this routine in the obvious ways. |
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119 | */ |
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120 | /* Configuration options */ |
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121 | struct cb_opts *opts = (struct cb_opts *) user; |
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122 | chunk_t rv = chunk_empty; /* Return value, starts empty */ |
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123 | |
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124 | if (try -1 < opts->tries ) { |
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125 | struct termios t; /* Terminal settings */ |
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126 | size_t len = 0; /* Length of string from getline */ |
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127 | tcflag_t orig = 0; /* Holds the original local flags (echo in here) */ |
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128 | |
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129 | if (!opts->use_echo) { |
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130 | /* Use tc{get,set}attr to turn echo off and restore the intial |
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131 | * echo settings */ |
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132 | if (!tcgetattr(0, &t)) { |
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133 | orig = t.c_lflag; |
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134 | |
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135 | t.c_lflag &= ~ECHO; |
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136 | if ( tcsetattr(0, TCSANOW, &t) ) { |
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137 | perror("Cannot turn off echo"); |
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138 | return rv; |
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139 | } |
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140 | } |
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141 | else { |
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142 | perror("Cannot turn get attributes to off echo"); |
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143 | return rv; |
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144 | } |
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145 | } |
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146 | if (opts->use_prompt) printf("%s", opts->prompt); |
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147 | |
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148 | /* Because rv.ptr starts as NULL, getline allocates memory. The size |
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149 | * of the allocation returns in rv.len and the size of the string |
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150 | * (including newline and NUL) is in len. */ |
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151 | if ((rv.ptr = (u_char *) malloc(rv.len = PWLEN))) { |
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152 | if ( fgets(rv.ptr, rv.len, stdin) ) { |
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153 | /* Readjust the chunk_t's len field to the size of the string |
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154 | * w/o the newline or NUL */ |
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155 | /* would prefer strnlen, but no such luck in FBSD7 or earlier*/ |
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156 | size_t len = strlen(rv.ptr); |
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157 | |
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158 | if (rv.ptr[len-2] == '\n') rv.len = len-2; |
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159 | else rv.len = len -1; |
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160 | } |
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161 | else { |
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162 | /* Read failed. Deallocate and clear rv */ |
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163 | free(rv.ptr); |
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164 | rv = chunk_empty; |
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165 | } |
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166 | } |
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167 | else { |
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168 | /* Failed malloc. Restore rv to empty and return it */ |
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169 | perror("malloc"); |
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170 | rv = chunk_empty; |
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171 | return rv; |
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172 | } |
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173 | |
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174 | if (!opts->use_echo ) { |
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175 | /* Pop echo beck to its original setting. */ |
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176 | t.c_lflag = orig; |
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177 | |
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178 | if ( tcsetattr(0, TCSANOW, &t) ) |
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179 | perror("Cannot restore echo setting?"); |
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180 | |
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181 | if (opts->use_prompt) printf("\n"); |
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182 | } |
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183 | } |
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184 | else fprintf(stderr, "Too many tries (%d)", try-1); |
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185 | return rv; |
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186 | } |
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