Counting number of TNT bits in Long TNT packets

[k-sareen]

I was going through the source code for your proxy fast implementation (for both Edge-PT and PTrix), and I came upon something that seemed odd to me: the case for a Long TNT packet [1] does not update the ctx_tnt_counter variable. From the comments, it seems like the ctx_tnt_counter variable is supposed to keep track of the number of TNT bits seen in the current program slice. This checks out as the case for a Short TNT packet updates it with the number of valid TNT bits. Am I misunderstanding what the variable is used for or is was this an engineering design decision?

Thanks
[1]: https://github.com/junxzm1990/afl-pt/blob/master/afl-2.42b/pt_mode/pt_proxy/pt_parser_fast.h#L518

[junxzm1990]

Hi, That's a good catch. It should be counted. But I roughly remember we never encountered any long TNT. That's probably why we were less careful in that part. Thanks for the message, -Jun

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________________________________ From: k-sareen <[email protected]> Sent: Monday, July 27, 2020 8:50 AM To: junxzm1990/afl-pt <[email protected]> Cc: Subscribed <[email protected]> Subject: [junxzm1990/afl-pt] Counting number of TNT bits in Long TNT packets (#10) I was going through the source code for your proxy fast implementation (for both Edge-PT and PTrix), and I came upon something that seemed odd to me: the case for a Long TNT packet [1] does not update the ctx_tnt_counter variable. From the comments, it seems like the ctx_tnt_counter variable is supposed to keep track of the number of TNT bits seen in the current program slice. Am I misunderstanding what the variable is used for or is was this an engineering design decision? Thanks [1]: https://github.com/junxzm1990/afl-pt/blob/master/afl-2.42b/pt_mode/pt_proxy/pt_parser_fast.h#L518<https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fjunxzm1990%2Fafl-pt%2Fblob%2Fmaster%2Fafl-2.42b%2Fpt_mode%2Fpt_proxy%2Fpt_parser_fast.h%23L518&data=02%7C01%7Cjxu69%40stevens.edu%7Cb7354244034244dcba2e08d83244c430%7C8d1a69ec03b54345ae21dad112f5fb4f%7C0%7C1%7C637314618311071160&sdata=4NvK0M7Y9oCy7m1P6%2F72HKVzTDON3WLvg705zS9guOk%3D&reserved=0> — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fjunxzm1990%2Fafl-pt%2Fissues%2F10&data=02%7C01%7Cjxu69%40stevens.edu%7Cb7354244034244dcba2e08d83244c430%7C8d1a69ec03b54345ae21dad112f5fb4f%7C0%7C1%7C637314618311071160&sdata=S%2BIq4tpAqJB%2FCOI7aHaX0wwaHL6ktXvr5b7inUu96cM%3D&reserved=0>, or unsubscribe<https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fnotifications%2Funsubscribe-auth%2FABMOZAOMNCLHRI5KCSXO55DR5WO3ZANCNFSM4PI45IDA&data=02%7C01%7Cjxu69%40stevens.edu%7Cb7354244034244dcba2e08d83244c430%7C8d1a69ec03b54345ae21dad112f5fb4f%7C0%7C1%7C637314618311081153&sdata=lgpMDWsfY2ySorrj5Y5BCLZJHcOk%2Bkmp5OhEtDIoA5M%3D&reserved=0>.

[k-sareen]

Hmm... I see. I'm currently working on refactoring some of the above codebase. I'll add the above change to my list for the PR. Thanks for the quick response.

~Kunal

[junxzm1990]

Thanks.

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-Jun

________________________________ From: k-sareen <[email protected]> Sent: Monday, July 27, 2020 8:59 AM To: junxzm1990/afl-pt <[email protected]> Cc: Jun Xu <[email protected]>; Comment <[email protected]> Subject: Re: [junxzm1990/afl-pt] Counting number of TNT bits in Long TNT packets (#10) Hmm... I see. I'm currently working on refactoring some of the above codebase. I'll add the above change to my list for the PR. Thanks for the quick response. ~Kunal — You are receiving this because you commented. Reply to this email directly, view it on GitHub<https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fjunxzm1990%2Fafl-pt%2Fissues%2F10%23issuecomment-664483781&data=02%7C01%7Cjxu69%40stevens.edu%7Ca03bbd93534d41564b2108d832460cbe%7C8d1a69ec03b54345ae21dad112f5fb4f%7C0%7C0%7C637314623725812110&sdata=8I8gXBGddf4b%2FnS41IVti58L%2F9u8T4KUR3jLFDQ%2BljM%3D&reserved=0>, or unsubscribe<https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fnotifications%2Funsubscribe-auth%2FABMOZAOHPJZUUS2ZKRZ6DVTR5WP6FANCNFSM4PI45IDA&data=02%7C01%7Cjxu69%40stevens.edu%7Ca03bbd93534d41564b2108d832460cbe%7C8d1a69ec03b54345ae21dad112f5fb4f%7C0%7C0%7C637314623725822106&sdata=EuFhDWXHAHM2LwU%2BJ6gmBrazC1EMq2JorXaDUlKVB%2F0%3D&reserved=0>.