ID: 42855
Updated by: [EMAIL PROTECTED]
-Summary: dns_get_record() doesn't return all text from TXT
record
Reported By: misc at e2007 dot cynergi dot com
-Status: Assigned
+Status: Open
Bug Type: Network related
Operating System: RHEL4
PHP Version: 5.2.5
Assigned To: pollita
Previous Comments:
------------------------------------------------------------------------
[2008-03-02 12:08:52] a dot u dot savchuk at gmail dot com
i reproduce this and create a patch for problem solving.
it works for me:
$ ./sapi/cli/php -r '$x =
dns_get_record("bravo._domainkey.yahoogroups.co.uk", DNS_TXT);
var_dump($x);'
array(1) {
[0]=>
array(5) {
["host"]=>
string(34) "bravo._domainkey.yahoogroups.co.uk"
["type"]=>
string(3) "TXT"
["txt"]=>
string(179) "k=rsa;
p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhAKt1OprXeH+okFnh8XxMeVV9iYAbhIOMq3ODHpcBm7JSl3Orusqv53BIn55a0JaP1iqbIWu5j3TVIpqbG7MHZUKJQrqcmVSvG7oT3r7Fwo6aCHMMuL+IZdEpbb9ZU8xomQIDAP//"
["class"]=>
string(2) "IN"
["ttl"]=>
int(21130)
}
}
Here is code:
$ cat /home/sawoy/dns.c.patch
--- ../source/php-5.2.5/ext/standard/dns.c 2007-06-26
04:04:55.000000000 -0700
+++ ./ext/standard/dns.c 2008-03-02 03:56:21.000000000 -0800
@@ -474,12 +474,17 @@ static u_char *php_parserr(u_char *cp, q
break;
case DNS_T_TXT:
add_assoc_string(*subarray, "type", "TXT", 1);
- n = cp[0];
- tp = emalloc(n + 1);
- memcpy(tp, cp + 1, n);
- tp[n] = '\0';
+ tp = emalloc(dlen + 1);
+ int ll = 0;
+ while ( ll < dlen)
+ {
+ n = cp[ll];
+ memcpy(tp + ll , cp + ll + 1, n);
+ ll = ll + n + 1;
+ }
+ tp[dlen] = '\0';
cp += dlen;
- add_assoc_stringl(*subarray, "txt", tp, n, 0);
+ add_assoc_stringl(*subarray, "txt", tp, dlen,
0);
break;
case DNS_T_SOA:
add_assoc_string(*subarray, "type", "SOA", 1);
------------------------------------------------------------------------
[2007-10-06 00:28:01] [EMAIL PROTECTED]
Sara, please take a look, seems like this cryptic piece of code (so
messy) uses wrong length to get the piece of data here..
------------------------------------------------------------------------
[2007-10-04 13:24:20] misc at e2007 dot cynergi dot com
I'm tired... 3rd paragraph in the "description" should have read: "The
following code examples where compiled when under Windows the command
... returned:", and the "expected result" string length should be
greater than 127, of course.
------------------------------------------------------------------------
[2007-10-04 13:12:33] misc at e2007 dot cynergi dot com
Description:
------------
dns_get_record() doesn't return all text from TXT record.
RFC 1035 states that TXT record values can't have "compression", but
can have multiple strings for the same DNS record. Although uncommon,
such long TXT strings actualy exist to make publicly available public
key data for DomainKeys e-mail protocols (used by Yahoo! and Gmail).
The following code examples where compiled when under Windows, the
command "nslookup -type=TXT bravo._domainkey.yahoogroups.co.uk"
returned:
(...)
Non-authoritative answer:
bravo._domainkey.yahoogroups.co.uk text =
"k=rsa;
p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhAKt1OprXeH+okFnh8XxMeVV9iYAbhIOMq3ODHpcBm7JSl3Orusqv53BIn55a0JaP1iqbIWu5j3TVIpqbG7MHZU"
"KJQrqcmVSvG7oT3r7Fwo6aCHMMuL+IZdEpbb9ZU8xomQIDAP//"
Reproduce code:
---------------
$x = dns_get_record("bravo._domainkey.yahoogroups.co.uk", DNS_TXT);
var_dump($x);
Expected result:
----------------
array(1) {
[0]=>
array(5) {
["host"]=>
string(34) "bravo._domainkey.yahoogroups.co.uk"
["type"]=>
string(3) "TXT"
["txt"]=>
string(127) "k=rsa;
p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhAKt1OprXeH+okFnh8XxMeVV9iYAbhIOMq3ODHpcBm7JSl3Orusqv53BIn55a0JaP1iqbIWu5j3TVIpqbG7MHZUKJQrqcmVSvG7oT3r7Fwo6aCHMMuL+IZdEpbb9ZU8xomQIDAP//"
["class"]=>
string(2) "IN"
["ttl"]=>
int(17428)
}
}
Actual result:
--------------
array(1) {
[0]=>
array(5) {
["host"]=>
string(34) "bravo._domainkey.yahoogroups.co.uk"
["type"]=>
string(3) "TXT"
["txt"]=>
string(127) "k=rsa;
p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhAKt1OprXeH+okFnh8XxMeVV9iYAbhIOMq3ODHpcBm7JSl3Orusqv53BIn55a0JaP1iqbIWu5j3TVIpqbG7MHZU"
["class"]=>
string(2) "IN"
["ttl"]=>
int(17428)
}
}
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=42855&edit=1
