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Support escaping literal dots and special characters in domain names #144

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Merged
WyriHaximus merged 1 commit into from
Aug 8, 2019
Merged

Support escaping literal dots and special characters in domain names #144

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11 changes: 10 additions & 1 deletion src/Protocol/BinaryDumper.php
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Original file line number Diff line number Diff line change
Expand Up @@ -175,6 +175,15 @@ private function domainNameToBinary($host)
return "\0";
}

return $this->textsToBinary(\explode('.', $host . '.'));
// break up domain name at each dot that is not preceeded by a backslash (escaped notation)
return $this->textsToBinary(
\array_map(
'stripcslashes',
\preg_split(
'/(?<!\\\\)\./',
$host . '.'
)
)
);
}
}
14 changes: 13 additions & 1 deletion src/Protocol/Parser.php
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Expand Up @@ -270,7 +270,19 @@ private function readDomain($data, $consumed)
return array(null, null);
}

return array(implode('.', $labels), $consumed);
// use escaped notation for each label part, then join using dots
return array(
\implode(
'.',
\array_map(
function ($label) {
return \addcslashes($label, "\0..\40.\177");
},
$labels
)
),
$consumed
);
}

private function readLabels($data, $consumed)
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41 changes: 41 additions & 0 deletions tests/Protocol/BinaryDumperTest.php
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Expand Up @@ -177,6 +177,47 @@ public function testToBinaryForResponseWithSOARecord()
$this->assertSame($expected, $data);
}

public function testToBinaryForResponseWithPTRRecordWithSpecialCharactersEscaped()
{
$data = "";
$data .= "72 62 01 00 00 01 00 01 00 00 00 00"; // header
$data .= "08 5f 70 72 69 6e 74 65 72 04 5f 74 63 70 06 64 6e 73 2d 73 64 03 6f 72 67 00"; // question: _printer._tcp.dns-sd.org
$data .= "00 0c 00 01"; // question: type PTR, class IN
$data .= "08 5f 70 72 69 6e 74 65 72 04 5f 74 63 70 06 64 6e 73 2d 73 64 03 6f 72 67 00"; // answer: _printer._tcp.dns-sd.org
$data .= "00 0c 00 01"; // answer: type PTR, class IN
$data .= "00 01 51 80"; // answer: ttl 86400
$data .= "00 2f"; // answer: rdlength 47
$data .= "14 33 72 64 2e 20 46 6c 6f 6f 72 20 43 6f 70 79 20 52 6f 6f 6d"; // answer: answer: rdata "3rd. Floor Copy Room" …
$data .= "08 5f 70 72 69 6e 74 65 72 04 5f 74 63 70 06 64 6e 73 2d 73 64 03 6f 72 67 00"; // answer: … "._printer._tcp.dns-sd.org"

$expected = $this->formatHexDump($data);

$response = new Message();
$response->id = 0x7262;
$response->rd = true;
$response->rcode = Message::RCODE_OK;

$response->questions[] = new Query(
'_printer._tcp.dns-sd.org',
Message::TYPE_PTR,
Message::CLASS_IN
);

$response->answers[] = new Record(
'_printer._tcp.dns-sd.org',
Message::TYPE_PTR,
Message::CLASS_IN,
86400,
'3rd\.\ Floor\ Copy\ Room._printer._tcp.dns-sd.org'
);

$dumper = new BinaryDumper();
$data = $dumper->toBinary($response);
$data = $this->convertBinaryToHexDump($data);

$this->assertSame($expected, $data);
}

public function testToBinaryForResponseWithMultipleAnswerRecords()
{
$data = "";
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30 changes: 30 additions & 0 deletions tests/Protocol/ParserTest.php
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Expand Up @@ -629,6 +629,36 @@ public function testParsePTRResponse()
$this->assertSame('google-public-dns-b.google.com', $response->answers[0]->data);
}

public function testParsePTRResponseWithSpecialCharactersEscaped()
{
$data = "";
$data .= "5d d8 81 80 00 01 00 01 00 00 00 00"; // header
$data .= "08 5f 70 72 69 6e 74 65 72 04 5f 74 63 70 06 64 6e 73 2d 73 64 03 6f 72 67 00"; // question: _printer._tcp.dns-sd.org
$data .= "00 0c 00 01"; // question: type PTR, class IN
$data .= "c0 0c"; // answer: offset pointer to rdata
$data .= "00 0c 00 01"; // answer: type PTR, class IN
$data .= "00 01 51 7f"; // answer: ttl 86399
$data .= "00 17"; // answer: rdlength 23
$data .= "14 33 72 64 2e 20 46 6c 6f 6f 72 20 43 6f 70 79 20 52 6f 6f 6d"; // answer: rdata "3rd. Floor Copy Room" …
$data .= "c0 0c"; // answer: offset pointer to rdata

$data = $this->convertTcpDumpToBinary($data);

$response = $this->parser->parseMessage($data);

$this->assertCount(1, $response->questions);
$this->assertSame('_printer._tcp.dns-sd.org', $response->questions[0]->name);
$this->assertSame(Message::TYPE_PTR, $response->questions[0]->type);
$this->assertSame(Message::CLASS_IN, $response->questions[0]->class);

$this->assertCount(1, $response->answers);
$this->assertSame('_printer._tcp.dns-sd.org', $response->answers[0]->name);
$this->assertSame(Message::TYPE_PTR, $response->answers[0]->type);
$this->assertSame(Message::CLASS_IN, $response->answers[0]->class);
$this->assertSame(86399, $response->answers[0]->ttl);
$this->assertSame('3rd\.\ Floor\ Copy\ Room._printer._tcp.dns-sd.org', $response->answers[0]->data);
}

/**
* @expectedException InvalidArgumentException
*/
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