On 11/12/09 18:51, Daniel Johnson wrote:
> Daniel Johnson wrote on 2008-12-12:
>> When I began testing OpenVPN v2.1_rc9 I was having trouble
>> authenticating to the MS Active Directory through auth-pam and Samba.
>> I used the following line in my configs (without the linebreak of
>> course):
>
>> plugin /opt/openvpn/openvpn-auth-pam.so
>> "openvpn login OURDOMAIN+USERNAME password PASSWORD"
>
>> Finally I turned on more verbose logging and found that the plugin
>> did not recognize "USERNAME" as something to replace, because it
>> expected the string to be surrounded by whitespace. I wrote the
>> following patch to correct this. I hope you find it useful,
>
>> http://thor.chguernsey.com/temp/auth-pam.patch (2kb)
>> http://thor.chguernsey.com/temp/auth-pam.patch.sig
>> MD5: 6560cbdfe24b3469dcb551d8963efdfa *auth-pam.patch
>
>> Daniel Johnson
>> [email protected]
>
> I've seen no replies to this, and the patch did not make it into
> v2.1.0. The patch cleanly applies to v2.1.0, is there any interest
> in merging this functionality?
>
I just decided to do a quick review, I don't believe this has made it
into openvpn-2.1.0. But from what I see, I have one concern in regards
to a potential memory leak.
The pam_server() function receives a "message" which puts the
information into a "static" memory area which is using struct user_pass.
This is fine. Then it calls pam_auth() with a pointer to this memory
region.
The pam_auth() function calls my_conv(), and if this function gets a
match on USERNAME or PASSWORD value in the block around line 562, it
calls searchandreplace() which does a strdup(). This is dynamically
allocated with strdup() and saved into return_value. But! In line 569,
you have this line:
aresp[i].resp = strdup (return_value);
I presume that the aresp[] struct is freed somehow, I have not dug into
that now. But you have here a double strdup() situation if you get a
match on USERNAME or PASSWORD. It's almost like saying:
char *ptr = strdup (strdup ("string"));
free(ptr);
This code will give you a memory leak.
Please confirm if my assumptions are correct. I would probably suggest
to move the strdup() on line 569 and skip using the return_value at all.
Just use aresp[i].resp directly.
kind regards,
David Sommerseth
