| 1 | <?php |
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| 2 | |
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| 3 | /** |
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| 4 | * Validates the attributes of a token. Doesn't manage required attributes |
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| 5 | * very well. The only reason we factored this out was because RemoveForeignElements |
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| 6 | * also needed it besides ValidateAttributes. |
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| 7 | */ |
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| 8 | class HTMLPurifier_AttrValidator |
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| 9 | { |
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| 10 | |
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| 11 | /** |
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| 12 | * Validates the attributes of a token, returning a modified token |
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| 13 | * that has valid tokens |
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| 14 | * @param $token Reference to token to validate. We require a reference |
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| 15 | * because the operation this class performs on the token are |
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| 16 | * not atomic, so the context CurrentToken to be updated |
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| 17 | * throughout |
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| 18 | * @param $config Instance of HTMLPurifier_Config |
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| 19 | * @param $context Instance of HTMLPurifier_Context |
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| 20 | */ |
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| 21 | public function validateToken(&$token, &$config, $context) { |
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| 22 | |
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| 23 | $definition = $config->getHTMLDefinition(); |
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| 24 | $e =& $context->get('ErrorCollector', true); |
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| 25 | |
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| 26 | // initialize IDAccumulator if necessary |
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| 27 | $ok =& $context->get('IDAccumulator', true); |
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| 28 | if (!$ok) { |
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| 29 | $id_accumulator = HTMLPurifier_IDAccumulator::build($config, $context); |
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| 30 | $context->register('IDAccumulator', $id_accumulator); |
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| 31 | } |
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| 32 | |
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| 33 | // initialize CurrentToken if necessary |
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| 34 | $current_token =& $context->get('CurrentToken', true); |
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| 35 | if (!$current_token) $context->register('CurrentToken', $token); |
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| 36 | |
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| 37 | if ( |
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| 38 | !$token instanceof HTMLPurifier_Token_Start && |
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| 39 | !$token instanceof HTMLPurifier_Token_Empty |
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| 40 | ) return $token; |
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| 41 | |
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| 42 | // create alias to global definition array, see also $defs |
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| 43 | // DEFINITION CALL |
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| 44 | $d_defs = $definition->info_global_attr; |
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| 45 | |
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| 46 | // reference attributes for easy manipulation |
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| 47 | $attr =& $token->attr; |
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| 48 | |
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| 49 | // do global transformations (pre) |
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| 50 | // nothing currently utilizes this |
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| 51 | foreach ($definition->info_attr_transform_pre as $transform) { |
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| 52 | $attr = $transform->transform($o = $attr, $config, $context); |
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| 53 | if ($e && ($attr != $o)) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr); |
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| 54 | } |
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| 55 | |
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| 56 | // do local transformations only applicable to this element (pre) |
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| 57 | // ex. <p align="right"> to <p style="text-align:right;"> |
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| 58 | foreach ($definition->info[$token->name]->attr_transform_pre as $transform) { |
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| 59 | $attr = $transform->transform($o = $attr, $config, $context); |
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| 60 | if ($e && ($attr != $o)) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr); |
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| 61 | } |
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| 62 | |
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| 63 | // create alias to this element's attribute definition array, see |
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| 64 | // also $d_defs (global attribute definition array) |
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| 65 | // DEFINITION CALL |
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| 66 | $defs = $definition->info[$token->name]->attr; |
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| 67 | |
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| 68 | $attr_key = false; |
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| 69 | $context->register('CurrentAttr', $attr_key); |
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| 70 | |
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| 71 | // iterate through all the attribute keypairs |
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| 72 | // Watch out for name collisions: $key has previously been used |
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| 73 | foreach ($attr as $attr_key => $value) { |
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| 74 | |
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| 75 | // call the definition |
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| 76 | if ( isset($defs[$attr_key]) ) { |
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| 77 | // there is a local definition defined |
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| 78 | if ($defs[$attr_key] === false) { |
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| 79 | // We've explicitly been told not to allow this element. |
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| 80 | // This is usually when there's a global definition |
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| 81 | // that must be overridden. |
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| 82 | // Theoretically speaking, we could have a |
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| 83 | // AttrDef_DenyAll, but this is faster! |
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| 84 | $result = false; |
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| 85 | } else { |
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| 86 | // validate according to the element's definition |
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| 87 | $result = $defs[$attr_key]->validate( |
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| 88 | $value, $config, $context |
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| 89 | ); |
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| 90 | } |
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| 91 | } elseif ( isset($d_defs[$attr_key]) ) { |
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| 92 | // there is a global definition defined, validate according |
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| 93 | // to the global definition |
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| 94 | $result = $d_defs[$attr_key]->validate( |
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| 95 | $value, $config, $context |
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| 96 | ); |
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| 97 | } else { |
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| 98 | // system never heard of the attribute? DELETE! |
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| 99 | $result = false; |
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| 100 | } |
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| 101 | |
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| 102 | // put the results into effect |
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| 103 | if ($result === false || $result === null) { |
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| 104 | // this is a generic error message that should replaced |
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| 105 | // with more specific ones when possible |
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| 106 | if ($e) $e->send(E_ERROR, 'AttrValidator: Attribute removed'); |
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| 107 | |
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| 108 | // remove the attribute |
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| 109 | unset($attr[$attr_key]); |
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| 110 | } elseif (is_string($result)) { |
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| 111 | // generally, if a substitution is happening, there |
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| 112 | // was some sort of implicit correction going on. We'll |
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| 113 | // delegate it to the attribute classes to say exactly what. |
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| 114 | |
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| 115 | // simple substitution |
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| 116 | $attr[$attr_key] = $result; |
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| 117 | } |
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| 118 | |
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| 119 | // we'd also want slightly more complicated substitution |
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| 120 | // involving an array as the return value, |
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| 121 | // although we're not sure how colliding attributes would |
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| 122 | // resolve (certain ones would be completely overriden, |
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| 123 | // others would prepend themselves). |
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| 124 | } |
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| 125 | |
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| 126 | $context->destroy('CurrentAttr'); |
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| 127 | |
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| 128 | // post transforms |
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| 129 | |
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| 130 | // global (error reporting untested) |
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| 131 | foreach ($definition->info_attr_transform_post as $transform) { |
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| 132 | $attr = $transform->transform($o = $attr, $config, $context); |
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| 133 | if ($e && ($attr != $o)) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr); |
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| 134 | } |
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| 135 | |
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| 136 | // local (error reporting untested) |
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| 137 | foreach ($definition->info[$token->name]->attr_transform_post as $transform) { |
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| 138 | $attr = $transform->transform($o = $attr, $config, $context); |
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| 139 | if ($e && ($attr != $o)) $e->send(E_NOTICE, 'AttrValidator: Attributes transformed', $o, $attr); |
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| 140 | } |
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| 141 | |
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| 142 | // destroy CurrentToken if we made it ourselves |
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| 143 | if (!$current_token) $context->destroy('CurrentToken'); |
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| 144 | |
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| 145 | } |
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| 146 | |
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| 147 | |
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| 148 | } |
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| 149 | |
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