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Differential D16521 Diff 39805 src/parser/calendar/ics/PhutilICSParser.php

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src/parser/calendar/ics/PhutilICSParser.php

<?php <?php
final class PhutilICSParser extends Phobject { final class PhutilICSParser extends Phobject {
private $stack; private $stack;
private $node; private $node;
private $document; private $document;
private $lines;
private $cursor;
const PARSE_MISSING_END = 'missing-end';
const PARSE_INITIAL_UNFOLD = 'initial-unfold';
const PARSE_UNEXPECTED_CHILD = 'unexpected-child';
const PARSE_EXTRA_END = 'extra-end';
const PARSE_MISMATCHED_SECTIONS = 'mismatched-sections';
const PARSE_ROOT_PROPERTY = 'root-property';
const PARSE_BAD_BASE64 = 'bad-base64';
const PARSE_BAD_BOOLEAN = 'bad-boolean';
const PARSE_UNEXPECTED_TEXT = 'unexpected-text';
const PARSE_MALFORMED_DOUBLE_QUOTE = 'malformed-double-quote';
const PARSE_MALFORMED_PARAMETER_NAME = 'malformed-parameter';
const PARSE_MALFORMED_PROPERTY = 'malformed-property';
const PARSE_MISSING_VALUE = 'missing-value';
const PARSE_UNESCAPED_BACKSLASH = 'unescaped-backslash';
public function parseICSData($data) { public function parseICSData($data) {
$this->stack = array(); $this->stack = array();
$this->node = null; $this->node = null;
$this->document = null; $this->cursor = null;
$lines = $this->unfoldICSLines($data); $lines = $this->unfoldICSLines($data);
$this->lines = $lines;
$root = $this->newICSNode('<ROOT>');
$this->stack[] = $root;
$this->node = $root;
foreach ($lines as $line) { foreach ($lines as $key => $line) {
$this->cursor = $key;
$matches = null; $matches = null;
if (preg_match('(^BEGIN:(.*)\z)', $line, $matches)) { if (preg_match('(^BEGIN:(.*)\z)', $line, $matches)) {
$this->beginParsingNode($matches[1]); $this->beginParsingNode($matches[1]);
} else if (preg_match('(^END:(.*)\z)', $line, $matches)) { } else if (preg_match('(^END:(.*)\z)', $line, $matches)) {
$this->endParsingNode($matches[1]); $this->endParsingNode($matches[1]);
} else { } else {
$this->parseICSProperty($line); if (count($this->stack) < 2) {
}
}
if (!$this->document) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_ROOT_PROPERTY,
pht( pht(
'Expected ICS document to define a "VCALENDAR" section.')); 'Found unexpected property at ICS document root.'));
}
$this->parseICSProperty($line);
}
} }
if ($this->stack) { if (count($this->stack) > 1) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_MISSING_END,
pht( pht(
'Expected all "BEGIN:" sections in ICS document to have '. 'Expected all "BEGIN:" sections in ICS document to have '.
'corresponding "END:" sections.')); 'corresponding "END:" sections.'));
} }
$document = $this->document; $this->node = null;
$this->document = null; $this->lines = null;
$this->cursor = null;
return $document; return $root;
} }
private function getNode() { private function getNode() {
return $this->node; return $this->node;
} }
private function unfoldICSLines($data) { private function unfoldICSLines($data) {
$lines = phutil_split_lines($data, $retain_endings = false); $lines = phutil_split_lines($data, $retain_endings = false);
$this->lines = $lines;
// ICS files are wrapped at 75 characters, with overlong lines continued // ICS files are wrapped at 75 characters, with overlong lines continued
// on the following line with an initial space or tab. Unwrap all of the // on the following line with an initial space or tab. Unwrap all of the
// lines in the file. // lines in the file.
$last = null; $last = null;
foreach ($lines as $idx => $line) { foreach ($lines as $idx => $line) {
$this->cursor = $idx;
if (!preg_match('/^[ \t]/', $line)) { if (!preg_match('/^[ \t]/', $line)) {
$last = $idx; $last = $idx;
continue; continue;
} }
if ($last === null) { if ($last === null) {
throw new Exception( $this->raiseParseFailure(
self::PARSE_INITIAL_UNFOLD,
pht( pht(
'First line of ICS file begins with a space or tab, but this '. 'First line of ICS file begins with a space or tab, but this '.
'marks a continuation line.')); 'marks a line which should be unfolded.'));
} }
$lines[$last] = $lines[$last].substr($line, 1); $lines[$last] = $lines[$last].substr($line, 1);
unset($lines[$idx]); unset($lines[$idx]);
} }
return $lines; return $lines;
} }
private function beginParsingNode($type) { private function beginParsingNode($type) {
$node = $this->getNode(); $node = $this->getNode();
$new_node = $this->newICSNode($type); $new_node = $this->newICSNode($type);
if ($node) {
if ($node instanceof PhutilCalendarContainerNode) { if ($node instanceof PhutilCalendarContainerNode) {
$node->appendChild($new_node); $node->appendChild($new_node);
} else { } else {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_UNEXPECTED_CHILD,
pht( pht(
'Found unexpected node "%s" inside node "%s".', 'Found unexpected node "%s" inside node "%s".',
$new_node->getAttribute('ics.type'), $new_node->getAttribute('ics.type'),
$node->getAttribute('ics.type'))); $node->getAttribute('ics.type')));
} }
} else {
if ($new_node instanceof PhutilCalendarDocumentNode) {
if ($this->document) {
$this->raiseParseFailure(
pht(
'Found multiple "VCALENDAR" nodes in ICS document, '.
'expected only one.'));
} else {
$this->document = $new_node;
}
} else {
$this->raiseParseFailure(
pht(
'Expected ICS document to begin "BEGIN:VCALENDAR".'));
}
}
$this->stack[] = $new_node; $this->stack[] = $new_node;
$this->node = $new_node; $this->node = $new_node;
return $this; return $this;
} }
private function newICSNode($type) { private function newICSNode($type) {
switch ($type) { switch ($type) {
case '<ROOT>':
$node = new PhutilCalendarRootNode();
break;
case 'VCALENDAR': case 'VCALENDAR':
$node = new PhutilCalendarDocumentNode(); $node = new PhutilCalendarDocumentNode();
break; break;
case 'VEVENT': case 'VEVENT':
$node = new PhutilCalendarEventNode(); $node = new PhutilCalendarEventNode();
break; break;
default: default:
$node = new PhutilCalendarRawNode(); $node = new PhutilCalendarRawNode();
break; break;
} }
$node->setAttribute('ics.type', $type); $node->setAttribute('ics.type', $type);
return $node; return $node;
} }
private function endParsingNode($type) { private function endParsingNode($type) {
$node = $this->getNode(); $node = $this->getNode();
if (!$node) { if ($node instanceof PhutilCalendarRootNode) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_EXTRA_END,
pht( pht(
'Found unexpected "END" without a "BEGIN".')); 'Found unexpected "END" without a "BEGIN".'));
} }
$old_type = $node->getAttribute('ics.type'); $old_type = $node->getAttribute('ics.type');
if ($old_type != $type) { if ($old_type != $type) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_MISMATCHED_SECTIONS,
pht( pht(
'Found mismatched "BEGIN" ("%s") and "END" ("%s") sections.', 'Found mismatched "BEGIN" ("%s") and "END" ("%s") sections.',
$old_type, $old_type,
$type)); $type));
} }
array_pop($this->stack); array_pop($this->stack);
if ($this->stack) {
$this->node = last($this->stack); $this->node = last($this->stack);
} else {
$this->node = null;
}
return $this; return $this;
} }
private function parseICSProperty($line) { private function parseICSProperty($line) {
$matches = null; $matches = null;
// Properties begin with an alphanumeric name with no escaping, followed // Properties begin with an alphanumeric name with no escaping, followed
// by either a ";" (to begin a list of parameters) or a ":" (to begin // by either a ";" (to begin a list of parameters) or a ":" (to begin
// the actual field body). // the actual field body).
$ok = preg_match('(^([^;:]+)([;:])(.*)\z)', $line, $matches); $ok = preg_match('(^([A-Za-z0-9-]+)([;:])(.*)\z)', $line, $matches);
if (!$ok) { if (!$ok) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_MALFORMED_PROPERTY,
pht( pht(
'Found malformed line in ICS document: %s', 'Found malformed property in ICS document.'));
$line));
} }
$name = $matches[1]; $name = $matches[1];
$body = $matches[3]; $body = $matches[3];
$has_parameters = ($matches[2] == ';'); $has_parameters = ($matches[2] == ';');
$parameters = array(); $parameters = array();
if ($has_parameters) { if ($has_parameters) {
// Parameters are a sensible name, a literal "=", a pile of magic, // Parameters are a sensible name, a literal "=", a pile of magic,
// and then maybe a comma and another parameter. // and then maybe a comma and another parameter.
while (true) { while (true) {
// We're going to get the first couple of parts first. // We're going to get the first couple of parts first.
$ok = preg_match('(^([^=]+)=)', $body, $matches); $ok = preg_match('(^([^=]+)=)', $body, $matches);
if (!$ok) { if (!$ok) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_MALFORMED_PARAMETER_NAME,
pht( pht(
'Found malformed property in ICS document: %s', 'Found malformed property in ICS document: %s',
$body)); $body));
} }
$param_name = $matches[1]; $param_name = $matches[1];
$body = substr($body, strlen($matches[0])); $body = substr($body, strlen($matches[0]));
// Now we're going to match zero or more values. // Now we're going to match zero or more values.
$param_values = array(); $param_values = array();
while (true) { while (true) {
// The value can either be a double-quoted string or an unquoted // The value can either be a double-quoted string or an unquoted
// string, with some characters forbidden. // string, with some characters forbidden.
if (strlen($body) && $body[0] == '"') { if (strlen($body) && $body[0] == '"') {
$is_quoted = true; $is_quoted = true;
$ok = preg_match( $ok = preg_match(
'(^"([^\x00-\x08\x10-\x19"]*)")', '(^"([^\x00-\x08\x10-\x19"]*)")',
$body, $body,
$matches); $matches);
if (!$ok) { if (!$ok) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_MALFORMED_DOUBLE_QUOTE,
pht( pht(
'Found malformed double-quoted string in ICS document '. 'Found malformed double-quoted string in ICS document '.
'parameter value: %s', 'parameter value.'));
$body));
} }
} else { } else {
$is_quoted = false; $is_quoted = false;
$ok = preg_match(
'(^([^\x00-\x08\x10-\x19";:,]*))', // It's impossible for this not to match since it can match
$body, // nothing, and it's valid for it to match nothing.
$matches); preg_match('(^([^\x00-\x08\x10-\x19";:,]*))', $body, $matches);
if (!$ok) {
$this->raiseParseFailure(
pht(
'Found malformed unquoted string in ICS document '.
'parameter value: %s',
$body));
}
} }
// NOTE: RFC5545 says "Property parameter values that are not in // NOTE: RFC5545 says "Property parameter values that are not in
// quoted-strings are case-insensitive." -- that is, the quoted and // quoted-strings are case-insensitive." -- that is, the quoted and
// unquoted representations are not equivalent. Thus, preserve the // unquoted representations are not equivalent. Thus, preserve the
// original formatting in case we ever need to respect this. // original formatting in case we ever need to respect this.
$param_values[] = array( $param_values[] = array(
'value' => $this->unescapeParameterValue($matches[1]), 'value' => $this->unescapeParameterValue($matches[1]),
'quoted' => $is_quoted, 'quoted' => $is_quoted,
); );
$body = substr($body, strlen($matches[0])); $body = substr($body, strlen($matches[0]));
if (!strlen($body)) { if (!strlen($body)) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_MISSING_VALUE,
pht( pht(
'Expected ":" after parameters in ICS document property.')); 'Expected ":" after parameters in ICS document property.'));
} }
// If we have a comma now, we're going to read another value. Strip // If we have a comma now, we're going to read another value. Strip
// it off and keep going. // it off and keep going.
if ($body[0] == ',') { if ($body[0] == ',') {
$body = substr($body, 1); $body = substr($body, 1);
continue; continue;
} }
// If we have a semicolon, we're going to read another parameter.
if ($body[0] == ';') {
break;
}
// If we have a colon, this is the last value and also the last // If we have a colon, this is the last value and also the last
// property. Break, then handle the colon below. // property. Break, then handle the colon below.
if ($body[0] == ':') { if ($body[0] == ':') {
break; break;
} }
$short_body = id(new PhutilUTF8StringTruncator())
->setMaximumGlyphs(32)
->truncateString($body);
// We aren't expecting anything else. // We aren't expecting anything else.
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_UNEXPECTED_TEXT,
pht( pht(
'Found unexpected text after reading parameter value: %s', 'Found unexpected text ("%s") after reading parameter value.',
$body)); $short_body));
} }
$parameters[] = array( $parameters[] = array(
'name' => $param_name, 'name' => $param_name,
'values' => $param_values, 'values' => $param_values,
); );
if ($body[0] == ';') {
$body = substr($body, 1);
continue;
}
if ($body[0] == ':') { if ($body[0] == ':') {
$body = substr($body, 1); $body = substr($body, 1);
break; break;
} }
} }
} }
$value = $this->unescapeFieldValue($name, $parameters, $body); $value = $this->unescapeFieldValue($name, $parameters, $body);
$node = $this->getNode(); $node = $this->getNode();
$raw = $node->getAttribute('ics.properties', array()); $raw = $node->getAttribute('ics.properties', array());
$raw[] = array( $raw[] = array(
'name' => $name, 'name' => $name,
'parameters' => $parameters, 'parameters' => $parameters,
'value' => $value, 'value' => $value,
); );
$node->setAttribute('ics.properties', $raw); $node->setAttribute('ics.properties', $raw);
} }
▲ Show 20 Lines • Show All 115 Lines • ▼ Show 20 Lines private function unescapeFieldValue($name, array $parameters, $data) {
foreach ($parameters as $parameter) { foreach ($parameters as $parameter) {
if ($parameter['name'] == 'VALUE') { if ($parameter['name'] == 'VALUE') {
$value_type = idx(head($parameter['values']), 'value'); $value_type = idx(head($parameter['values']), 'value');
} }
} }
switch ($value_type) { switch ($value_type) {
case 'BINARY': case 'BINARY':
$result = base64_decode($data); $result = base64_decode($data, true);
if ($result === false) { if ($result === false) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_BAD_BASE64,
pht( pht(
'Unable to decode base64 data: %s', 'Unable to decode base64 data: %s',
$data)); $data));
} }
break; break;
case 'BOOLEAN': case 'BOOLEAN':
$map = array( $map = array(
'true' => true, 'true' => true,
'false' => false, 'false' => false,
); );
$result = phutil_utf8_strtolower($data); $result = phutil_utf8_strtolower($data);
if (!isset($map[$result])) { if (!isset($map[$result])) {
$this->raiseParseFailure( $this->raiseParseFailure(
self::PARSE_BAD_BOOLEAN,
pht( pht(
'Unexpected BOOLEAN value "%s".', 'Unexpected BOOLEAN value "%s".',
$data)); $data));
} }
$result = $map[$result]; $result = $map[$result];
break; break;
case 'CAL-ADDRESS': case 'CAL-ADDRESS':
$result = $data; $result = $data;
▲ Show 20 Lines • Show All 76 Lines • ▼ Show 20 Lines foreach (phutil_utf8v($data) as $c) {
default: default:
$buf .= $c; $buf .= $c;
break; break;
} }
} }
} }
if ($esc) { if ($esc) {
$this->raiseParsFailure( $this->raiseParseFailure(
self::PARSE_UNESCAPED_BACKSLASH,
pht( pht(
'ICS document contains TEXT value ending with unescaped '. 'ICS document contains TEXT value ending with unescaped '.
'backslash.')); 'backslash.'));
} }
$result[] = $buf; $result[] = $buf;
return $result; return $result;
} }
private function raiseParseFailure($message) { private function raiseParseFailure($code, $message) {
throw new Exception($message); if ($this->lines && isset($this->lines[$this->cursor])) {
$message = pht(
"ICS Parse Error near line %s:\n\n>>> %s\n\n%s",
$this->cursor + 1,
$this->lines[$this->cursor],
$message);
} else {
$message = pht(
'ICS Parse Error: %s',
$message);
}
throw id(new PhutilICSParserException($message))
->setParserFailureCode($code);
} }
} }
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