Maleability testing?

[s2]

Does anyone have any scripts or suggestions on how to test malleability issues in my wallet?

I.e. how do people make sure they handle this correctly?

[amaclin1]

how do people make sure they handle this correctly?

... reading and understanding the program code?

[s2]

Thanks but I'm interested in knowing what sort of malleability attacks are easy to do that I can test with?

Seems difficult to protect against it without usecases I could try on testnet.

[Jolyquinzel]

how do people make sure they handle this correctly?

... reading and understanding the program code?

genius
aaand what if u dont understand any in code?

[amaclin1]

how do people make sure they handle this correctly?

... reading and understanding the program code?

genius
aaand what if u dont understand any in code?

you will not understand testing results either 

[s2]

Anyone actually know how to do this?

This seems like a good read but no obvious script examples.
https://bitcointalk.org/index.php?topic=8392.msg122410#msg122410

[amaclin1]

Anyone actually know how to do this?

How to do what?
Test your sources for finding malleability issues?
Ready to pay? I am a great pretender expert in malleability

[s2]

  Thanks amaclin1.

I'm looking for steps to do a malleability test.  E.g. a python script or steps to issue a double spend using a malleability issue.

The only malleability attack I knew of before was the high/low S value, I'm certain there are others but not sure what they are or where to find them.

Guess what would be awesome is something that can run on testnet which issued two tx's for transferring funds from A->B but had two different txids...


come to mention it, perhaps that's all that is required?  I could just sign two identical transactions and issue them at the same time?

[amaclin1]

come to mention it, perhaps that's all that is required? 
I could just sign two identical transactions and issue them at the same time?

This case is not a "true" malleability.
You always can create two transactions spending funds to two different destinations.
And only one will be confirmed.
Usually we care about Man-in-the-Middle. He should not do anything with your data.

There were several sources of malleability for standard (this is important!) bitcoin scripts.
The last was fixed with segwit transactions

[tomtomtom7]

You could look at the malleability integration test in the Core repo:

https://github.com/bitcoin/bitcoin/blob/master/test/functional/txn_clone.py