1 | /* abac.c */ |
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2 | |
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3 | #include <assert.h> |
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4 | #include <err.h> |
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5 | #include <sys/types.h> |
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6 | #include <sys/stat.h> |
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7 | #include <unistd.h> |
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8 | #include <dirent.h> |
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9 | |
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10 | #include "abac.h" |
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11 | #include "abac_list.h" |
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12 | #include "abac_graph.h" |
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13 | #include "abac_util.h" |
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14 | #include "abac_verifier.h" |
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15 | |
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16 | int debug=0; |
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17 | abac_id_cert_t **abac_context_principals(abac_context_t *ctx); |
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18 | void abac_context_id_credentials_free(abac_id_cert_t **id_credentials); |
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19 | |
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20 | struct _abac_context_t { |
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21 | /* list of principal id credentials, abac_id_cert_t */ |
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22 | abac_list_t *id_certs; |
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23 | abac_graph_t *graph; |
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24 | abac_keyid_map_t *keymap; |
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25 | }; |
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26 | |
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27 | /** |
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28 | * Init the library. |
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29 | */ |
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30 | void libabac_init(void) { |
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31 | void libabac_deinit(void); |
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32 | static int has_been_init = 0; |
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33 | |
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34 | // called every time a context is created, so only do it once |
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35 | if (!has_been_init) { |
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36 | abac_verifier_init(); |
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37 | atexit(libabac_deinit); |
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38 | has_been_init = 1; |
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39 | } |
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40 | } |
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41 | |
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42 | /** |
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43 | * Deinit the library. |
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44 | */ |
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45 | void libabac_deinit(void) { |
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46 | abac_verifier_deinit(); |
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47 | } |
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48 | |
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49 | /** |
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50 | * Create a new abac context. |
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51 | */ |
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52 | abac_context_t *abac_context_new(void) { |
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53 | libabac_init(); |
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54 | |
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55 | abac_context_t *ctx = abac_xmalloc(sizeof(abac_context_t)); |
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56 | ctx->graph = abac_graph_new(); |
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57 | ctx->id_certs=abac_list_new(); |
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58 | ctx->keymap = abac_keyid_map_new(); |
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59 | return ctx; |
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60 | } |
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61 | |
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62 | /** |
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63 | * Deep copy an abac context. |
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64 | */ |
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65 | abac_context_t *abac_context_dup(abac_context_t *ctx) { |
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66 | assert(ctx != NULL); |
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67 | |
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68 | abac_context_t *dup = abac_xmalloc(sizeof(abac_context_t)); |
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69 | dup->graph = abac_graph_dup(ctx->graph); |
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70 | dup->id_certs=abac_list_new(); |
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71 | |
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72 | abac_id_cert_t *id_cert; |
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73 | abac_list_foreach(ctx->id_certs, id_cert, |
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74 | abac_list_add(dup->id_certs, abac_id_cert_dup(id_cert)); |
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75 | ); |
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76 | |
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77 | dup->keymap = abac_keyid_map_clone(ctx->keymap); |
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78 | return dup; |
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79 | } |
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80 | |
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81 | /** |
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82 | * Free an abac context. |
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83 | */ |
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84 | void abac_context_free(abac_context_t *ctx) { |
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85 | assert(ctx != NULL); |
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86 | |
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87 | abac_graph_free(ctx->graph); |
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88 | |
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89 | abac_id_cert_t *id_cert; |
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90 | abac_list_foreach(ctx->id_certs, id_cert, |
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91 | abac_id_cert_free(id_cert); |
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92 | ); |
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93 | abac_list_free(ctx->id_certs); |
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94 | abac_keyid_map_free(ctx->keymap); |
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95 | free(ctx); |
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96 | } |
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97 | |
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98 | /** |
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99 | * Load an ID cert from a file. |
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100 | */ |
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101 | int abac_context_load_id_file(abac_context_t *ctx, char *filename) { |
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102 | assert(ctx != NULL); assert(filename != NULL); |
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103 | return abac_verifier_load_id_file(ctx->id_certs,filename, ctx->keymap); |
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104 | } |
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105 | |
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106 | /** |
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107 | * Load an ID cert from a chunk. |
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108 | */ |
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109 | int abac_context_load_id_chunk(abac_context_t *ctx, abac_chunk_t cert_chunk) { |
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110 | assert(ctx != NULL); |
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111 | return abac_verifier_load_id_chunk(ctx->id_certs,cert_chunk, ctx->keymap); |
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112 | } |
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113 | |
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114 | /** |
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115 | * Load an attribute cert from a file. |
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116 | */ |
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117 | int abac_context_load_attribute_file(abac_context_t *ctx, char *filename) { |
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118 | int ret, add_ret; |
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119 | abac_list_t *cred_list=abac_list_new(); // could be more than 1 |
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120 | abac_credential_t *cred; |
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121 | |
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122 | assert(ctx != NULL); assert(filename != NULL); |
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123 | |
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124 | ret = abac_verifier_load_attribute_cert_file(ctx->id_certs, filename, cred_list, ctx->keymap); |
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125 | |
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126 | if (ret == ABAC_CERT_SUCCESS) { |
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127 | int size = abac_list_size(cred_list); |
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128 | if(size) { |
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129 | abac_list_foreach(cred_list, cred, |
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130 | add_ret = abac_graph_add_credential(ctx->graph, cred); |
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131 | assert(add_ret != ABAC_GRAPH_CRED_INVALID); |
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132 | abac_credential_free(cred); |
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133 | ); |
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134 | } |
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135 | } |
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136 | abac_list_free(cred_list); |
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137 | return ret; |
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138 | } |
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139 | |
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140 | /** |
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141 | * Load an attribute cert from a chunk. |
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142 | */ |
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143 | int abac_context_load_attribute_chunk(abac_context_t *ctx, abac_chunk_t cert_chunk) { |
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144 | int ret, add_ret; |
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145 | abac_list_t *cred_list=abac_list_new(); // could be more than 1 |
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146 | abac_credential_t *cred; |
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147 | |
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148 | assert(ctx != NULL); |
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149 | |
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150 | ret = abac_verifier_load_attribute_cert_chunk(ctx->id_certs, cert_chunk, cred_list, ctx->keymap); |
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151 | if (ret == ABAC_CERT_SUCCESS) { |
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152 | int size = abac_list_size(cred_list); |
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153 | if(size) { |
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154 | abac_list_foreach(cred_list, cred, |
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155 | add_ret = abac_graph_add_credential(ctx->graph, cred); |
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156 | assert(add_ret != ABAC_GRAPH_CRED_INVALID); |
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157 | abac_credential_free(cred); |
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158 | ); |
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159 | abac_list_free(cred_list); |
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160 | } |
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161 | } |
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162 | |
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163 | return ret; |
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164 | } |
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165 | |
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166 | #define ID_PAT "/*_ID.{der,pem}" |
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167 | #define ATTR_PAT "/*_attr.xml" |
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168 | |
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169 | static int is_regular_file(char *filename) |
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170 | { |
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171 | struct stat sb; |
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172 | if(stat(filename,&sb) == -1) |
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173 | return 0; |
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174 | if((sb.st_mode & S_IFMT) == S_IFREG) |
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175 | return 1; |
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176 | return 0; |
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177 | } |
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178 | |
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179 | /** |
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180 | * Load a directory full of certs. |
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181 | */ |
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182 | void abac_context_load_directory(abac_context_t *ctx, char *path) { |
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183 | DIR *dp; |
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184 | struct dirent *ep; |
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185 | |
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186 | dp = opendir (path); |
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187 | if (dp != NULL) { |
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188 | while (ep = readdir (dp)) { |
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189 | if(is_regular_file(ep->d_name)) { |
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190 | int ret = abac_context_load_id_file(ctx, ep->d_name); |
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191 | if (ret == ABAC_CERT_SUCCESS) { |
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192 | if(debug) fprintf(stderr,"abac_context_load_directory, found an id %s\n",ep->d_name); |
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193 | continue; |
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194 | } |
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195 | ret = abac_context_load_attribute_file(ctx, ep->d_name); |
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196 | if (ret == ABAC_CERT_SUCCESS) { |
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197 | if(debug) fprintf(stderr,"abac_context_load_directory, found an attr %s\n",ep->d_name); |
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198 | } |
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199 | } |
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200 | } |
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201 | (void) closedir (dp); |
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202 | } else fprintf(stderr, "abac_load_directory, Couldn't open the directory\n"); |
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203 | } |
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204 | |
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205 | /** |
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206 | * Run a query on the data in an abac context. Returns a NULL-terminated array |
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207 | * of abac_credential_t. Success/failure in *success. |
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208 | */ |
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209 | abac_credential_t **abac_context_query(abac_context_t *ctx, char *role, char *principal, int *success) { |
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210 | abac_credential_t **credentials = NULL, *cur; |
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211 | int i = 0; |
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212 | |
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213 | assert(ctx != NULL); |
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214 | assert(role != NULL); |
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215 | assert(principal != NULL); |
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216 | assert(success != NULL); |
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217 | |
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218 | abac_graph_t *result_graph = abac_graph_query(ctx->graph, role, principal); |
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219 | abac_list_t *result = abac_graph_credentials(result_graph); |
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220 | |
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221 | abac_graph_free(result_graph); |
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222 | |
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223 | int size = abac_list_size(result); |
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224 | if (size > 0) |
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225 | *success = 1; |
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226 | |
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227 | // if there is no actual path, return everything that can reach the role |
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228 | else { |
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229 | *success = 0; |
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230 | abac_list_free(result); |
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231 | result_graph = abac_graph_new(); |
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232 | |
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233 | // TODO: This can probably be better, but it now returns an |
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234 | // approximation of a partial proof. It returns all the attributes the |
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235 | // principal can reach and all the attributes that will lead to a |
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236 | // success. |
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237 | |
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238 | /* Get all the attributes of the principal. This calls sub-queries to |
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239 | * flesh out the indirect proofs. */ |
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240 | result_graph = abac_graph_principal_creds(ctx->graph, principal); |
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241 | |
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242 | /* This gets all the attributes linked to the target en route to the |
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243 | * principal. */ |
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244 | result = abac_graph_postorder_credentials(ctx->graph, role); |
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245 | |
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246 | /* Merge responses */ |
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247 | abac_list_foreach(result, cur, |
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248 | abac_graph_add_credential(result_graph, cur); |
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249 | ); |
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250 | abac_list_free(result); |
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251 | abac_graph_derive_links(result_graph); |
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252 | |
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253 | result = abac_graph_credentials(result_graph); |
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254 | abac_graph_free(result_graph); |
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255 | |
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256 | size = abac_list_size(result); |
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257 | } |
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258 | |
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259 | // make the array (leave space to NULL terminate it) |
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260 | // n.b., even if the list is empty, we still return an array that |
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261 | // only contains the NULL terminator |
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262 | credentials = abac_xmalloc(sizeof(abac_credential_t *) * (size + 1)); |
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263 | abac_list_foreach(result, cur, |
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264 | credentials[i++] = cur; |
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265 | ); |
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266 | credentials[i] = NULL; |
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267 | |
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268 | abac_list_free(result); |
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269 | |
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270 | return credentials; |
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271 | } |
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272 | |
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273 | |
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274 | /** |
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275 | * A NULL-terminated array of all the credentials in the context. |
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276 | */ |
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277 | abac_credential_t **abac_context_credentials(abac_context_t *ctx) { |
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278 | abac_credential_t *cred; |
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279 | int i = 0; |
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280 | |
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281 | assert(ctx != NULL); |
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282 | |
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283 | abac_list_t *cred_list = abac_graph_credentials(ctx->graph); |
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284 | int size = abac_list_size(cred_list); |
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285 | |
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286 | abac_credential_t **credentials = abac_xmalloc(sizeof(abac_credential_t *) * (size + 1)); |
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287 | abac_list_foreach(cred_list, cred, |
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288 | credentials[i++] = cred; |
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289 | ); |
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290 | credentials[i] = NULL; |
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291 | |
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292 | abac_list_free(cred_list); |
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293 | |
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294 | if(debug) { |
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295 | abac_id_cert_t **ilist=abac_context_principals(ctx); |
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296 | abac_id_cert_t *cert; |
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297 | if (ilist != NULL) |
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298 | for (i = 0; ilist[i] != NULL; ++i) { |
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299 | cert = ilist[i]; |
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300 | printf("id[%d] %s\n",i, abac_id_cert_keyid(cert)); |
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301 | } |
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302 | abac_context_id_credentials_free(ilist); |
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303 | } |
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304 | |
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305 | return credentials; |
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306 | } |
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307 | |
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308 | /* |
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309 | * Replace known keyids with their nicknames (mnemonic names). If a non-NULL |
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310 | * string is returned it needs to be freed by the caller. |
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311 | */ |
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312 | char *abac_context_expand_key(abac_context_t *ctxt, char *s ) { |
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313 | if ( ctxt->keymap ) |
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314 | return abac_keyid_map_expand_key(ctxt->keymap, s); |
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315 | else |
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316 | return NULL; |
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317 | } |
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318 | |
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319 | /* |
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320 | * Replace known nicknames(mnemonic names) with their keyids. If a non-NULL |
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321 | * string is returned it needs to be freed by the caller. |
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322 | */ |
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323 | char *abac_context_expand_nickname(abac_context_t *ctxt, char *s ) { |
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324 | if ( ctxt->keymap ) |
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325 | return abac_keyid_map_expand_nickname(ctxt->keymap, s); |
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326 | else |
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327 | return NULL; |
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328 | } |
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329 | |
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330 | /* |
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331 | * Add a nickname to the context. The keyid must be known to the context. If |
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332 | * the nickname is in use, it is disambiguated. Call abac_context_expand_key |
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333 | * to see the assigned name if that is required. Existing nickname for keyid |
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334 | * is overwritten. Returns true if the change was successful. |
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335 | */ |
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336 | int abac_context_set_nickname(abac_context_t *ctxt, char *key, char*nick) { |
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337 | char *p = NULL; |
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338 | |
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339 | if ( !ctxt->keymap) return 0; |
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340 | /* Make sure we know the key. Free the returned nickname */ |
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341 | if ( !(p = abac_keyid_map_key_to_nickname(ctxt->keymap, key))) return 0; |
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342 | else free(p); |
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343 | |
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344 | abac_keyid_map_remove_keyid(ctxt->keymap, key); |
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345 | return abac_keyid_map_add_nickname(ctxt->keymap, key, nick); |
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346 | } |
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347 | |
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348 | /* |
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349 | * Get direct access to the context's keyid mapping. Used internally. This |
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350 | * does not make a reference to the map, use abac_keyid_map_dup if that is |
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351 | * required. |
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352 | */ |
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353 | abac_keyid_map_t *abac_context_get_keyid_map(abac_context_t *ctxt) { |
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354 | return ctxt->keymap; |
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355 | } |
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356 | |
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357 | |
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358 | /** |
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359 | * A NULL-terminated array of all the principals in the context. |
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360 | */ |
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361 | abac_id_cert_t **abac_context_principals(abac_context_t *ctx) |
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362 | { |
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363 | abac_id_cert_t **principals = NULL, *cur; |
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364 | assert(ctx != NULL); |
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365 | |
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366 | int size = abac_list_size(ctx->id_certs); |
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367 | |
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368 | // make the array (leave space to NULL terminate it) |
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369 | // n.b., even if the list is empty, we still return an array that |
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370 | // only contains the NULL terminator |
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371 | principals = abac_xmalloc(sizeof(abac_id_cert_t *) * (size + 1)); |
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372 | int i = 0; |
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373 | abac_id_cert_t *id_cert; |
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374 | abac_list_foreach(ctx->id_certs, id_cert, |
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375 | principals[i]=abac_id_cert_dup(id_cert); |
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376 | i++; |
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377 | ); |
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378 | principals[i] = NULL; |
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379 | |
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380 | return principals; |
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381 | } |
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382 | |
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383 | |
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384 | /** |
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385 | * Frees a NULL-terminated list of credentials. |
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386 | */ |
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387 | void abac_context_credentials_free(abac_credential_t **credentials) { |
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388 | int i; |
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389 | |
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390 | if (credentials == NULL) |
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391 | return; |
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392 | |
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393 | for (i = 0; credentials[i] != NULL; ++i) |
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394 | abac_credential_free(credentials[i]); |
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395 | free(credentials); |
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396 | } |
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397 | |
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398 | /** |
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399 | * Frees a NULL-terminated list of id credentials |
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400 | */ |
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401 | void abac_context_id_credentials_free(abac_id_cert_t **id_credentials) { |
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402 | int i; |
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403 | |
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404 | if (id_credentials == NULL) |
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405 | return; |
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406 | |
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407 | for (i = 0; id_credentials[i] != NULL; ++i) { |
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408 | abac_id_cert_free(id_credentials[i]); |
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409 | } |
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410 | free(id_credentials); |
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411 | } |
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412 | |
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413 | |
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