ASN1: make sure constructed bit is what it ought to be

This commit is contained in:
terrafrost 2021-04-03 13:15:58 -05:00
parent 6be326e7e7
commit 8b8cbecb9b

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@ -433,13 +433,16 @@ class File_ASN1
switch ($tag) {
case FILE_ASN1_TYPE_BOOLEAN:
// "The contents octets shall consist of a single octet." -- paragraph 8.2.1
if (strlen($content) != 1) {
if ($constructed || strlen($content) != 1) {
return false;
}
$current['content'] = (bool) ord($content[$content_pos]);
break;
case FILE_ASN1_TYPE_INTEGER:
case FILE_ASN1_TYPE_ENUMERATED:
if ($constructed) {
return false;
}
$current['content'] = new Math_BigInteger(substr($content, $content_pos), -256);
break;
case FILE_ASN1_TYPE_REAL: // not currently supported
@ -497,12 +500,15 @@ class File_ASN1
break;
case FILE_ASN1_TYPE_NULL:
// "The contents octets shall not contain any octets." -- paragraph 8.8.2
if (strlen($content)) {
if ($constructed || strlen($content)) {
return false;
}
break;
case FILE_ASN1_TYPE_SEQUENCE:
case FILE_ASN1_TYPE_SET:
if (!$constructed) {
return false;
}
$offset = 0;
$current['content'] = array();
$content_len = strlen($content);
@ -523,6 +529,9 @@ class File_ASN1
}
break;
case FILE_ASN1_TYPE_OBJECT_IDENTIFIER:
if ($constructed) {
return false;
}
$current['content'] = $this->_decodeOID(substr($content, $content_pos));
if ($current['content'] === false) {
return false;
@ -556,10 +565,16 @@ class File_ASN1
case FILE_ASN1_TYPE_UTF8_STRING:
// ????
case FILE_ASN1_TYPE_BMP_STRING:
if ($constructed) {
return false;
}
$current['content'] = substr($content, $content_pos);
break;
case FILE_ASN1_TYPE_UTC_TIME:
case FILE_ASN1_TYPE_GENERALIZED_TIME:
if ($constructed) {
return false;
}
$current['content'] = class_exists('DateTime') ?
$this->_decodeDateTime(substr($content, $content_pos), $tag) :
$this->_decodeUnixTime(substr($content, $content_pos), $tag);