| 1 | <?php |
| 2 | /* |
| 3 | +--------------------------------------------------------------------+ |
| 4 | | Copyright CiviCRM LLC. All rights reserved. | |
| 5 | | | |
| 6 | | This work is published under the GNU AGPLv3 license with some | |
| 7 | | permitted exceptions and without any warranty. For full license | |
| 8 | | and copyright information, see https://civicrm.org/licensing | |
| 9 | +--------------------------------------------------------------------+ |
| 10 | */ |
| 11 | namespace Civi\API; |
| 12 | |
| 13 | /** |
| 14 | * A WhitelistRule is used to determine if an API call is authorized. |
| 15 | * For example: |
| 16 | * |
| 17 | * @code |
| 18 | * new WhitelistRule(array( |
| 19 | * 'entity' => 'Contact', |
| 20 | * 'actions' => array('get','getsingle'), |
| 21 | * 'required' => array('contact_type' => 'Organization'), |
| 22 | * 'fields' => array('id', 'display_name', 'sort_name', 'created_date'), |
| 23 | * )); |
| 24 | * @endcode |
| 25 | * |
| 26 | * This rule would allow API requests that attempt to get contacts of type "Organization", |
| 27 | * but only a handful of fields ('id', 'display_name', 'sort_name', 'created_date') |
| 28 | * can be filtered or returned. |
| 29 | * |
| 30 | * Class WhitelistRule |
| 31 | * @package Civi\API\Subscriber |
| 32 | */ |
| 33 | class WhitelistRule { |
| 34 | |
| 35 | public static $IGNORE_FIELDS = [ |
| 36 | 'check_permissions', |
| 37 | 'debug', |
| 38 | 'offset', |
| 39 | 'option_offset', |
| 40 | 'option_limit', |
| 41 | 'option_sort', |
| 42 | 'options', |
| 43 | 'return', |
| 44 | 'rowCount', |
| 45 | 'sequential', |
| 46 | 'sort', |
| 47 | 'version', |
| 48 | ]; |
| 49 | |
| 50 | /** |
| 51 | * Create a batch of rules from an array. |
| 52 | * |
| 53 | * @param array $rules |
| 54 | * @return array |
| 55 | */ |
| 56 | public static function createAll($rules) { |
| 57 | $whitelist = []; |
| 58 | foreach ($rules as $rule) { |
| 59 | $whitelist[] = new WhitelistRule($rule); |
| 60 | } |
| 61 | return $whitelist; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * @var int |
| 66 | */ |
| 67 | public $version; |
| 68 | |
| 69 | /** |
| 70 | * Entity name or '*' (all entities) |
| 71 | * |
| 72 | * @var string |
| 73 | */ |
| 74 | public $entity; |
| 75 | |
| 76 | /** |
| 77 | * List of actions which match, or '*' (all actions) |
| 78 | * |
| 79 | * @var string|array |
| 80 | */ |
| 81 | public $actions; |
| 82 | |
| 83 | /** |
| 84 | * List of key=>value pairs that *must* appear in $params. |
| 85 | * |
| 86 | * If there are no required fields, use an empty array. |
| 87 | * |
| 88 | * @var array |
| 89 | */ |
| 90 | public $required; |
| 91 | |
| 92 | /** |
| 93 | * List of fields which may be optionally inputted or returned, or '*" (all fields) |
| 94 | * |
| 95 | * @var array |
| 96 | */ |
| 97 | public $fields; |
| 98 | |
| 99 | public function __construct($ruleSpec) { |
| 100 | $this->version = $ruleSpec['version']; |
| 101 | |
| 102 | if ($ruleSpec['entity'] === '*') { |
| 103 | $this->entity = '*'; |
| 104 | } |
| 105 | else { |
| 106 | $this->entity = Request::normalizeEntityName($ruleSpec['entity'], $ruleSpec['version']); |
| 107 | } |
| 108 | |
| 109 | if ($ruleSpec['actions'] === '*') { |
| 110 | $this->actions = '*'; |
| 111 | } |
| 112 | else { |
| 113 | $this->actions = []; |
| 114 | foreach ((array) $ruleSpec['actions'] as $action) { |
| 115 | $this->actions[] = Request::normalizeActionName($action, $ruleSpec['version']); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | $this->required = $ruleSpec['required']; |
| 120 | $this->fields = $ruleSpec['fields']; |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * @return bool |
| 125 | */ |
| 126 | public function isValid() { |
| 127 | if (empty($this->version)) { |
| 128 | return FALSE; |
| 129 | } |
| 130 | if (empty($this->entity)) { |
| 131 | return FALSE; |
| 132 | } |
| 133 | if (!is_array($this->actions) && $this->actions !== '*') { |
| 134 | return FALSE; |
| 135 | } |
| 136 | if (!is_array($this->fields) && $this->fields !== '*') { |
| 137 | return FALSE; |
| 138 | } |
| 139 | if (!is_array($this->required)) { |
| 140 | return FALSE; |
| 141 | } |
| 142 | return TRUE; |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * @param array $apiRequest |
| 147 | * Parsed API request. |
| 148 | * @return string|TRUE |
| 149 | * If match, return TRUE. Otherwise, return a string with an error code. |
| 150 | */ |
| 151 | public function matches($apiRequest) { |
| 152 | if (!$this->isValid()) { |
| 153 | return 'invalid'; |
| 154 | } |
| 155 | |
| 156 | if ($this->version != $apiRequest['version']) { |
| 157 | return 'version'; |
| 158 | } |
| 159 | if ($this->entity !== '*' && $this->entity !== $apiRequest['entity']) { |
| 160 | return 'entity'; |
| 161 | } |
| 162 | if ($this->actions !== '*' && !in_array($apiRequest['action'], $this->actions)) { |
| 163 | return 'action'; |
| 164 | } |
| 165 | |
| 166 | // These params *must* be included for the API request to proceed. |
| 167 | foreach ($this->required as $param => $value) { |
| 168 | if (!isset($apiRequest['params'][$param])) { |
| 169 | return 'required-missing-' . $param; |
| 170 | } |
| 171 | if ($value !== '*' && $apiRequest['params'][$param] != $value) { |
| 172 | return 'required-wrong-' . $param; |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | // These params *may* be included at the caller's discretion |
| 177 | if ($this->fields !== '*') { |
| 178 | $activatedFields = array_keys($apiRequest['params']); |
| 179 | $activatedFields = preg_grep('/^api\./', $activatedFields, PREG_GREP_INVERT); |
| 180 | if ($apiRequest['action'] == 'get') { |
| 181 | // Kind'a silly we need to (re(re))parse here for each rule; would be more |
| 182 | // performant if pre-parsed by Request::create(). |
| 183 | $options = _civicrm_api3_get_options_from_params($apiRequest['params'], TRUE, $apiRequest['entity'], 'get'); |
| 184 | $return = \CRM_Utils_Array::value('return', $options, []); |
| 185 | $activatedFields = array_merge($activatedFields, array_keys($return)); |
| 186 | } |
| 187 | |
| 188 | $unknowns = array_diff( |
| 189 | $activatedFields, |
| 190 | array_keys($this->required), |
| 191 | $this->fields, |
| 192 | self::$IGNORE_FIELDS |
| 193 | ); |
| 194 | |
| 195 | if (!empty($unknowns)) { |
| 196 | return 'unknown-' . implode(',', $unknowns); |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | return TRUE; |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * Ensure that the return values comply with the whitelist's |
| 205 | * "fields" policy. |
| 206 | * |
| 207 | * Most API's follow a convention where the result includes |
| 208 | * a 'values' array (which in turn is a list of records). Unfortunately, |
| 209 | * some don't. If the API result doesn't meet our expectation, |
| 210 | * then we probably don't know what's going on, so we abort the |
| 211 | * request. |
| 212 | * |
| 213 | * This will probably break some of the layered-sugar APIs (like |
| 214 | * getsingle, getvalue). Just use the meat-and-potatoes API instead. |
| 215 | * Or craft a suitably targeted patch. |
| 216 | * |
| 217 | * @param array $apiRequest |
| 218 | * API request. |
| 219 | * @param array $apiResult |
| 220 | * API result. |
| 221 | * @return array |
| 222 | * Modified API result. |
| 223 | * @throws \API_Exception |
| 224 | */ |
| 225 | public function filter($apiRequest, $apiResult) { |
| 226 | if ($this->fields === '*') { |
| 227 | return $apiResult; |
| 228 | } |
| 229 | if (isset($apiResult['values']) && empty($apiResult['values'])) { |
| 230 | // No data; filtering doesn't matter. |
| 231 | return $apiResult; |
| 232 | } |
| 233 | if (is_array($apiResult['values'])) { |
| 234 | $firstRow = \CRM_Utils_Array::first($apiResult['values']); |
| 235 | if (is_array($firstRow)) { |
| 236 | $fields = $this->filterFields(array_keys($firstRow)); |
| 237 | $apiResult['values'] = \CRM_Utils_Array::filterColumns($apiResult['values'], $fields); |
| 238 | return $apiResult; |
| 239 | } |
| 240 | } |
| 241 | throw new \API_Exception(sprintf('Filtering failed for %s.%s. Unrecognized result format.', $apiRequest['entity'], $apiRequest['action'])); |
| 242 | } |
| 243 | |
| 244 | /** |
| 245 | * Determine which elements in $keys are acceptable under |
| 246 | * the whitelist policy. |
| 247 | * |
| 248 | * @param array $keys |
| 249 | * List of possible keys. |
| 250 | * @return array |
| 251 | * List of acceptable keys. |
| 252 | */ |
| 253 | protected function filterFields($keys) { |
| 254 | $r = []; |
| 255 | foreach ($keys as $key) { |
| 256 | if (in_array($key, $this->fields)) { |
| 257 | $r[] = $key; |
| 258 | } |
| 259 | elseif (preg_match('/^api\./', $key)) { |
| 260 | $r[] = $key; |
| 261 | } |
| 262 | } |
| 263 | return $r; |
| 264 | } |
| 265 | |
| 266 | } |