Re: [Taler] Possible bugs: Sending wallet2wallet payment behaves weirdly

[Christian Grothoff]

Hi Florian,

Let me comment on the things where I can actually give a good answer, 
the wallet-devs should answer the rest...

On 12/6/22 00:44, Florian Jung via Taler wrote:
> Hi,
> When I now scan the QR code with the same phone (by making a photo with 
> my laptop camera first), I first got an error indicating that my wallet 
> cannot handle this link. (Is this because I'm trying to transfer from a 
> wallet to itself?)

No, it should be perfectly fine to transfer-to-self, I've done that 
repeatedly myself.

> After some time (writing this mail), I get a 404 on /contracts/blah 
> after scanning the code.

There is an expiration date (which should be configurable but currently 
is not), but it should by default for now be 2 days in the future. So 
not sure.

> I set PURSE-TIMEOUT to 365d (uint32_t truncation bug?) and

Not likely. Purse-timeout is an upper bound.

> PURSE-ACCOUNT-LIMIT (whatever that is) to 100. Can you explain what 
> PURSE-ACCOUNT-LIMIT does?

The number of purses that can be created for free without paying for 
anyone who 'opened' a reserve. The current wallet doesn't support 
'opening' reserves (which disables auto-close by the exchange), so today 
with just the normal wallet this doesn't do anything. And as your fees 
are all zero, it doubly doesn't do anything as even when the purse quota
were exceeded, you still had a fee of zero.

The idea is that this quota can be used to prevent someone from just 
setting up billions of invoices for fun, while still allowing a user
that passed KYC to create a 'reasonable' number of invoices without a fee.

> I've attached the exchange's log. What puzzles me is the line 
> "2022-12-05T23:21:50.220906+0000 
> taler-exchange-httpd-54(CVFPY019S8357C2FSN1YZKV7CW) WARNING Invalid coin 
> signature to deposit into purse". How can a coin have an invalid 
> signature in this setup?

Well, it obviously shouldn't happen (as in: clearly is a bug). The 
signature can be invalid whenever the wallet and the exchange disagree 
what to sign over...

> You can find my configuration in 
> https://github.com/Windfisch/taler-podman/tree/master/exchange-config.skel
>
>
> Even though this is a lot of stuff, I'd appreciate any help :D

We appreciate your efforts!

Happy hacking!

Christian