1 | |
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2 | // include the GNU extension of asprintf |
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3 | #define _GNU_SOURCE |
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4 | |
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5 | #include <assert.h> |
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6 | |
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7 | #include <library.h> |
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8 | #include <credentials/certificates/certificate.h> |
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9 | #include <credentials/certificates/x509.h> |
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10 | #include <credentials/certificates/ac.h> |
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11 | |
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12 | #include "abac_verifier.h" |
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13 | |
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14 | #include "abac_list.h" |
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15 | #include "abac_util.h" |
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16 | #include "abac_rt0.h" |
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17 | |
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18 | typedef struct _abac_id_cert_t { |
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19 | char *keyid; |
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20 | char *cn; |
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21 | certificate_t *cert; |
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22 | |
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23 | UT_hash_handle hh; |
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24 | } abac_id_cert_t; |
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25 | |
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26 | |
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27 | struct _abac_credential_t { |
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28 | abac_role_t *head; |
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29 | abac_role_t *tail; |
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30 | certificate_t *cert; |
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31 | certificate_t *issuer; |
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32 | char *clause; |
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33 | |
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34 | int refcount; |
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35 | }; |
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36 | |
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37 | typedef struct _abac_str_cred_t { |
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38 | char *strid; |
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39 | abac_credential_t *cred; |
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40 | |
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41 | UT_hash_handle hh; |
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42 | } abac_str_cred_t; |
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43 | |
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44 | abac_id_cert_t *id_certs = NULL; |
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45 | abac_str_cred_t *str_creds = NULL; |
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46 | |
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47 | // convert a chunk to a lowercase binary string |
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48 | // malloc's the string |
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49 | static char *_chunk_to_string(chunk_t chunk) { |
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50 | int i; |
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51 | |
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52 | char *ret = abac_xmalloc(chunk.len * 2 + 1); |
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53 | |
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54 | for (i = 0; i < chunk.len; ++i) |
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55 | sprintf(ret + 2 * i, "%02x", chunk.ptr[i]); |
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56 | |
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57 | return ret; |
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58 | } |
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59 | |
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60 | // verify that cert was issued by issuer |
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61 | // cert and issuer can be the same, in which case the self-sig is validated |
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62 | static int _verify_signature(certificate_t *issuer, certificate_t *cert) { |
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63 | if (cert->issued_by(cert, issuer)) |
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64 | if (cert->get_validity(cert, NULL, NULL, NULL)) |
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65 | return 1; |
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66 | return 0; |
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67 | } |
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68 | |
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69 | /** |
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70 | * Init the verifier subsystem. |
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71 | */ |
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72 | void abac_verifier_init(void) { |
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73 | // silence all debugging |
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74 | |
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75 | if (!library_init(NULL)) |
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76 | exit(SS_RC_LIBSTRONGSWAN_INTEGRITY); |
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77 | |
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78 | if (!lib->plugins->load(lib->plugins, NULL, |
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79 | lib->settings->get_str(lib->settings, "pki.load", PLUGINS))) |
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80 | exit(SS_RC_INITIALIZATION_FAILED); |
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81 | } |
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82 | |
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83 | /** |
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84 | * Uninitialize the system, free up any allocated memory. |
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85 | */ |
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86 | void abac_verifier_deinit(void) { |
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87 | abac_id_cert_t *id; |
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88 | while ((id = id_certs) != NULL) { |
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89 | HASH_DEL(id_certs, id); |
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90 | |
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91 | free(id->keyid); |
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92 | free(id->cn); |
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93 | id->cert->destroy(id->cert); |
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94 | free(id); |
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95 | } |
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96 | |
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97 | abac_str_cred_t *id2; |
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98 | while ((id2 = str_creds) != NULL) { |
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99 | HASH_DEL(str_creds, id2); |
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100 | |
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101 | free(id2->strid); |
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102 | free(id2); |
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103 | } |
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104 | |
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105 | library_deinit(); |
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106 | } |
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107 | |
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108 | /** |
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109 | * Load an ID certificate. |
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110 | */ |
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111 | static int _load_id(certificate_t *cert) { |
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112 | abac_id_cert_t *id_cert = NULL; |
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113 | char *keyid = NULL; |
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114 | chunk_t id; |
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115 | int ret; |
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116 | x509_t *x509 = (x509_t *)cert; |
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117 | |
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118 | assert(cert != NULL); |
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119 | |
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120 | // get the key ID |
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121 | id = x509->get_subjectKeyIdentifier(x509); |
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122 | keyid = _chunk_to_string(id); |
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123 | |
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124 | /* XXX MEI */ |
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125 | /** |
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126 | identification_t *issuer=cert->get_subject(cert); |
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127 | char *str=(char *)abac_xmalloc(strlen((char *)issuer)); |
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128 | sprintf(str,"%Y",issuer); |
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129 | **/ |
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130 | char *str; |
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131 | int rv = asprintf(&str, "%Y", cert->get_issuer(cert)); |
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132 | |
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133 | char *cn=(char *)abac_xmalloc(strlen(str)+1); |
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134 | cn[0]='p'; |
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135 | int n=sscanf(str,"CN=%s", &(cn[1])); |
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136 | if ( n!=1 ) { |
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137 | ret = ABAC_CERT_BAD_CN; |
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138 | goto error; |
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139 | } |
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140 | |
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141 | printf ("XXX keyid %s \n", keyid); |
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142 | printf( "XXX issuer '%s' \n", str); |
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143 | printf ("XXX cn %s \n", cn); |
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144 | free(str); |
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145 | |
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146 | // if we already have this cert 'error' with success |
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147 | HASH_FIND_STR(id_certs, keyid, id_cert); |
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148 | if (id_cert != NULL) { |
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149 | ret = ABAC_CERT_SUCCESS; |
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150 | goto error; |
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151 | } |
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152 | |
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153 | // validate sig |
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154 | ret = _verify_signature(cert, cert); |
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155 | if (!ret) { |
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156 | ret = ABAC_CERT_BAD_SIG; |
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157 | goto error; |
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158 | } |
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159 | |
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160 | // success, add the key to the map of certificates |
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161 | id_cert = abac_xmalloc(sizeof(abac_id_cert_t)); |
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162 | id_cert->keyid = keyid; |
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163 | id_cert->cert = cert; |
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164 | id_cert->cn = cn; |
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165 | HASH_ADD_KEYPTR(hh, id_certs, id_cert->keyid, strlen(id_cert->keyid), id_cert); |
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166 | |
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167 | return ABAC_CERT_SUCCESS; |
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168 | |
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169 | error: |
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170 | if (keyid != NULL) free(keyid); |
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171 | if (cn != NULL) free(cn); |
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172 | |
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173 | return ret; |
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174 | } |
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175 | |
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176 | /** |
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177 | * Load an ID cert from a file. |
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178 | */ |
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179 | int abac_verifier_load_id_file(char *filename) { |
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180 | if (lib == NULL) |
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181 | errx(1, "looks like you didn't call libabac_init() (lib is NULL)"); |
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182 | |
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183 | // load the cert |
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184 | certificate_t *cert = lib->creds->create( |
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185 | lib->creds, CRED_CERTIFICATE, CERT_X509, |
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186 | BUILD_FROM_FILE, filename, |
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187 | BUILD_X509_FLAG, X509_AA, // attribute authority, dumb |
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188 | BUILD_END |
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189 | ); |
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190 | if (cert == NULL) |
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191 | return ABAC_CERT_INVALID; |
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192 | return _load_id(cert); |
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193 | } |
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194 | |
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195 | /** |
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196 | * Load an ID cert from a chunk. |
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197 | */ |
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198 | int abac_verifier_load_id_chunk(chunk_t chunk) { |
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199 | // load the cert |
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200 | certificate_t *cert = lib->creds->create( |
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201 | lib->creds, CRED_CERTIFICATE, CERT_X509, |
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202 | BUILD_BLOB_ASN1_DER, chunk, |
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203 | BUILD_X509_FLAG, X509_AA, // attribute authority, dumb |
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204 | BUILD_END |
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205 | ); |
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206 | if (cert == NULL) |
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207 | return ABAC_CERT_INVALID; |
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208 | return _load_id(cert); |
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209 | } |
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210 | |
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211 | |
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212 | /** |
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213 | * Load an attribute cert. |
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214 | * Returns true only if the certificate is valid and is issued by the proper |
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215 | * authority. |
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216 | */ |
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217 | static int _load_attribute_cert(certificate_t *cert, abac_credential_t **cred_ret) { |
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218 | ietf_attributes_t *attr_cert = NULL; |
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219 | abac_role_t *head_role = NULL; |
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220 | abac_role_t *tail_role = NULL; |
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221 | abac_id_cert_t *issuer; |
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222 | char *attr_string_copy; |
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223 | int ret, i; |
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224 | |
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225 | // get the attr |
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226 | ac_t *ac = (ac_t *)cert; |
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227 | attr_cert = ac->get_groups(ac); |
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228 | if (attr_cert == NULL) { |
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229 | ret = ABAC_CERT_INVALID; |
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230 | goto error; |
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231 | } |
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232 | |
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233 | char *attr_string = attr_cert->get_string(attr_cert); |
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234 | if (attr_string == NULL) { |
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235 | ret = ABAC_CERT_INVALID; |
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236 | goto error; |
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237 | } |
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238 | |
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239 | printf("YYY-->attr_string(%s)%d\n", attr_string, strlen(attr_string)); |
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240 | /* call into yacc parser */ |
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241 | attr_string_copy = strdup(attr_string); |
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242 | abac_reset_yyfptr(attr_string_copy); |
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243 | abac_yyinit(); |
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244 | int rc=yyparse(); |
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245 | if (rc) { |
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246 | ret = ABAC_CERT_INVALID; |
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247 | goto error; |
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248 | } |
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249 | |
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250 | char *head_tail[2]; |
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251 | abac_split(attr_string, " <- ", head_tail, &ret); |
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252 | if (ret != 2) { |
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253 | ret = ABAC_CERT_INVALID; |
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254 | goto error; |
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255 | } |
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256 | |
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257 | // must be a role |
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258 | head_role = abac_role_from_string(head_tail[0]); |
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259 | if (head_role == NULL) goto error; |
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260 | if (!abac_role_is_role(head_role)) { |
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261 | ret = ABAC_CERT_INVALID; |
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262 | goto error; |
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263 | } |
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264 | |
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265 | // make sure the tail's valid too |
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266 | tail_role = abac_role_from_string(head_tail[1]); |
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267 | if (tail_role == NULL) { |
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268 | ret = ABAC_CERT_INVALID; |
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269 | goto error; |
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270 | } |
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271 | |
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272 | // get the issuer based on keyid |
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273 | char *principal = abac_role_principal(head_role); |
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274 | HASH_FIND_STR(id_certs, principal, issuer); |
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275 | if (issuer == NULL) { |
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276 | ret = ABAC_CERT_MISSING_ISSUER; |
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277 | goto error; |
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278 | } |
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279 | |
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280 | // make sure the issuer's signed it |
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281 | ret = _verify_signature(issuer->cert, cert); |
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282 | if (!ret) { |
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283 | ret = ABAC_CERT_BAD_SIG; |
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284 | goto error; |
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285 | } |
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286 | |
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287 | // at this point we know we have a good attribute cert |
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288 | abac_credential_t *cred = abac_xmalloc(sizeof(abac_credential_t)); |
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289 | cred->head = head_role; |
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290 | cred->tail = tail_role; |
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291 | cred->cert = cert; |
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292 | cred->issuer = issuer->cert->get_ref(issuer->cert); |
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293 | cred->clause = abac_get_yap_clause(); |
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294 | cred->refcount = 1; |
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295 | *cred_ret = cred; |
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296 | |
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297 | // success, add the key to the map of certificates |
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298 | abac_str_cred_t *str_cred; |
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299 | str_cred=abac_xmalloc(sizeof(abac_str_cred_t)); |
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300 | str_cred->strid=attr_string_copy; |
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301 | str_cred->cred=cred; |
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302 | HASH_ADD_KEYPTR(hh, str_creds, str_cred->strid, strlen(str_cred->strid), str_cred); |
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303 | |
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304 | // free up some crap |
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305 | attr_cert->destroy(attr_cert); |
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306 | |
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307 | return ABAC_CERT_SUCCESS; |
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308 | |
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309 | error: |
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310 | if (cert != NULL) cert->destroy(cert); |
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311 | if (attr_cert != NULL) attr_cert->destroy(attr_cert); |
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312 | if (head_role != NULL) abac_role_free(head_role); |
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313 | if (tail_role != NULL) abac_role_free(tail_role); |
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314 | if (attr_string_copy != NULL) free(attr_string_copy); |
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315 | abac_free_yap_clause(); |
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316 | |
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317 | return ret; |
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318 | } |
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319 | |
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320 | #ifdef OLD |
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321 | /** |
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322 | * Load an attribute cert. |
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323 | * Returns true only if the certificate is valid and is issued by the proper |
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324 | * authority. |
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325 | */ |
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326 | static int _load_attribute_cert(certificate_t *cert, abac_credential_t **cred_ret) { |
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327 | ietf_attributes_t *attr_cert = NULL; |
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328 | abac_role_t *head_role = NULL; |
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329 | abac_role_t *tail_role = NULL; |
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330 | abac_id_cert_t *issuer; |
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331 | int ret, i; |
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332 | |
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333 | // get the attr |
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334 | ac_t *ac = (ac_t *)cert; |
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335 | attr_cert = ac->get_groups(ac); |
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336 | if (attr_cert == NULL) { |
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337 | ret = ABAC_CERT_INVALID; |
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338 | goto error; |
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339 | } |
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340 | |
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341 | char *attr_string = attr_cert->get_string(attr_cert); |
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342 | if (attr_string == NULL) { |
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343 | ret = ABAC_CERT_INVALID; |
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344 | goto error; |
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345 | } |
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346 | |
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347 | printf("YYY-->attr_string(%s)%d\n", attr_string, strlen(attr_string)); |
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348 | |
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349 | // split into head/tail parts |
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350 | char *head_tail[2]; |
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351 | abac_split(attr_string, " <- ", head_tail, &ret); |
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352 | if (ret != 2) { |
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353 | ret = ABAC_CERT_INVALID; |
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354 | goto error; |
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355 | } |
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356 | |
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357 | // must be a role |
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358 | head_role = abac_role_from_string(head_tail[0]); |
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359 | if (head_role == NULL) goto error; |
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360 | if (!abac_role_is_role(head_role)) { |
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361 | ret = ABAC_CERT_INVALID; |
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362 | goto error; |
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363 | } |
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364 | |
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365 | // make sure the tail's valid too |
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366 | tail_role = abac_role_from_string(head_tail[1]); |
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367 | if (tail_role == NULL) { |
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368 | ret = ABAC_CERT_INVALID; |
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369 | goto error; |
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370 | } |
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371 | |
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372 | // get the issuer based on keyid |
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373 | char *principal = abac_role_principal(head_role); |
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374 | HASH_FIND_STR(id_certs, principal, issuer); |
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375 | if (issuer == NULL) { |
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376 | ret = ABAC_CERT_MISSING_ISSUER; |
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377 | goto error; |
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378 | } |
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379 | |
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380 | printf("YYY principal found is %s\n", principal); |
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381 | |
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382 | // make sure the issuer's signed it |
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383 | ret = _verify_signature(issuer->cert, cert); |
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384 | if (!ret) { |
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385 | ret = ABAC_CERT_BAD_SIG; |
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386 | goto error; |
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387 | } |
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388 | |
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389 | // at this point we know we have a good attribute cert |
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390 | abac_credential_t *cred = abac_xmalloc(sizeof(abac_credential_t)); |
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391 | cred->head = head_role; |
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392 | cred->tail = tail_role; |
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393 | cred->cert = cert; |
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394 | cred->issuer = issuer->cert->get_ref(issuer->cert); |
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395 | cred->refcount = 1; |
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396 | *cred_ret = cred; |
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397 | |
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398 | // free up some crap |
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399 | attr_cert->destroy(attr_cert); |
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400 | |
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401 | return ABAC_CERT_SUCCESS; |
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402 | |
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403 | error: |
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404 | if (cert != NULL) cert->destroy(cert); |
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405 | if (attr_cert != NULL) attr_cert->destroy(attr_cert); |
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406 | if (head_role != NULL) abac_role_free(head_role); |
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407 | if (tail_role != NULL) abac_role_free(tail_role); |
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408 | |
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409 | return ret; |
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410 | } |
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411 | #endif |
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412 | |
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413 | /** |
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414 | * Load an attribute cert from a file. |
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415 | */ |
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416 | int abac_verifier_load_attribute_cert_file(char *filename, abac_credential_t **cred) { |
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417 | // load the cert |
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418 | certificate_t *cert = lib->creds->create( |
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419 | lib->creds, CRED_CERTIFICATE, CERT_X509_AC, |
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420 | BUILD_FROM_FILE, filename, |
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421 | BUILD_END |
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422 | ); |
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423 | if (cert == NULL) |
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424 | return ABAC_CERT_INVALID; |
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425 | return _load_attribute_cert(cert, cred); |
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426 | } |
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427 | |
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428 | /** |
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429 | * Load an attribute cert from a chunk. |
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430 | */ |
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431 | int abac_verifier_load_attribute_cert_chunk(chunk_t chunk, abac_credential_t **cred) { |
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432 | // load the cert |
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433 | certificate_t *cert = lib->creds->create( |
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434 | lib->creds, CRED_CERTIFICATE, CERT_X509_AC, |
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435 | BUILD_BLOB_ASN1_DER, chunk, |
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436 | BUILD_END |
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437 | ); |
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438 | if (cert == NULL) |
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439 | return ABAC_CERT_INVALID; |
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440 | return _load_attribute_cert(cert, cred); |
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441 | } |
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442 | |
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443 | /** |
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444 | * Return the head role. |
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445 | */ |
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446 | abac_role_t *abac_credential_head(abac_credential_t *cred) { |
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447 | return cred->head; |
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448 | } |
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449 | |
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450 | /** |
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451 | * Return the tail role. |
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452 | */ |
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453 | abac_role_t *abac_credential_tail(abac_credential_t *cred) { |
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454 | return cred->tail; |
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455 | } |
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456 | |
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457 | /** |
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458 | * Return the encoding of the attribute cert. |
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459 | */ |
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460 | abac_chunk_t abac_credential_attribute_cert(abac_credential_t *cred) { |
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461 | chunk_t encoding = cred->cert->get_encoding(cred->cert); |
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462 | abac_chunk_t ret = { encoding.ptr, encoding.len }; |
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463 | return ret; |
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464 | } |
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465 | |
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466 | /** |
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467 | * Return the encoding of the issuer cert. |
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468 | */ |
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469 | abac_chunk_t abac_credential_issuer_cert(abac_credential_t *cred) { |
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470 | chunk_t encoding = cred->issuer->get_encoding(cred->issuer); |
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471 | abac_chunk_t ret = { encoding.ptr, encoding.len }; |
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472 | return ret; |
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473 | } |
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474 | |
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475 | /** |
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476 | * Return the clause of the cert |
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477 | */ |
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478 | char * abac_credential_clause(abac_credential_t *cred) { |
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479 | return cred->clause; |
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480 | } |
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481 | |
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482 | /** |
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483 | * Increase the ref count of a credential. |
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484 | */ |
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485 | abac_credential_t *abac_credential_dup(abac_credential_t *cred) { |
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486 | assert(cred != NULL); |
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487 | |
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488 | ++cred->refcount; |
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489 | return cred; |
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490 | } |
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491 | |
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492 | /** |
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493 | * lookup for a credential. |
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494 | */ |
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495 | abac_credential_t *abac_credential_lookup(char* cred_string) { |
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496 | abac_str_cred_t *str_cred; |
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497 | HASH_FIND_STR(str_creds, cred_string, str_cred); |
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498 | if (str_cred == NULL) { |
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499 | return NULL; |
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500 | } |
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501 | return str_cred->cred; |
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502 | } |
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503 | |
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504 | /** |
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505 | * Decrease the reference count of a credential, freeing it when it reaches 0. |
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506 | */ |
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507 | void abac_credential_free(abac_credential_t *cred) { |
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508 | if (cred == NULL) |
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509 | return; |
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510 | |
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511 | --cred->refcount; |
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512 | if (cred->refcount > 0) |
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513 | return; |
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514 | |
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515 | abac_role_free(cred->head); |
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516 | abac_role_free(cred->tail); |
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517 | cred->cert->destroy(cred->cert); |
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518 | cred->issuer->destroy(cred->issuer); // reference counted |
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519 | if (cred->clause) |
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520 | free(cred->clause); |
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521 | |
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522 | free(cred); |
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523 | } |
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524 | |
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525 | /* retrieve the cn that is associated with this sha_string */ |
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526 | char *abac_cn_with_sha(char *sha_string) { |
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527 | |
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528 | // get the issuer based on keyid |
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529 | abac_id_cert_t *id_cert; |
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530 | HASH_FIND_STR(id_certs, sha_string, id_cert); |
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531 | if (id_cert == NULL) { |
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532 | return NULL; |
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533 | } |
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534 | return id_cert->cn; |
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535 | } |
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536 | |
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537 | /* retrieve the cn that is associated with the principal of this role */ |
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538 | char *abac_cn_with_role(abac_role_t *head_role) { |
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539 | |
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540 | // get the issuer based on keyid |
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541 | char *principal = abac_role_principal(head_role); |
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542 | return abac_cn_with_sha(principal); |
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543 | } |
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544 | |
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