Commit Graph

10 Commits

Author SHA1 Message Date
Christian Grothoff
bd77bcb52d
-towards fixing the protocol 2022-02-14 23:02:25 +01:00
Christian Grothoff
db8cdc8c4c
-remove addessed documentation FIXMEs 2022-02-12 12:10:33 +01:00
Christian Grothoff
3b1e742dde
-simplify: nonce no longer hashed 2022-02-11 18:00:20 +01:00
Christian Grothoff
0995bdd1d0
-get tests to pass 2022-02-11 09:36:01 +01:00
Christian Grothoff
d58d89dcab
-get recoup/refresh to pass 2022-02-10 20:15:17 +01:00
Christian Grothoff
ed5ef2b5f7
also pass ewvs during recoup-refresh 2022-02-09 22:05:10 +01:00
Christian Grothoff
e735475623
-work on refresh_common FTBFS 2022-02-06 19:00:01 +01:00
Christian Grothoff
f173296c3c
-fix refresh FTBFS 2022-02-06 18:39:28 +01:00
Christian Grothoff
e7aeec04f4
The current recoup API is broken. I guess this is another example where "trivial" API changes turn out to have (multiple!) unexpected consequences.
The current "/recoup" API does not have clear idempotency semantics, as we've discussed on the phone.  This is already bad by itself, as it makes it hard to write down what the API does other than "whatever the implementation does".

However, it actually breaks correctness in this (admittedly kinda contrived, but not impossible) case:

Say that we have a coin A obtained via withdrawal and a coin B obtained via refreshing coin A. Now the denominations of A gets revoked..

The wallet does a recoup of A for EUR:1.

Now the denomination of B also gets revoked.  The wallet recoups B (incidentally also for EUR:1) and now A can be recouped again for EUR:1.  But now the exchange is in a state where it will refuse a legitimate recoup request for A because the detection for an idempotent request kicks in.

This is IMHO bad API design, and the exchange should simply always recoup the maximum amount.

Furthermore, we usually follow the principle of "API calls that take up DB space are paid".  With the current recoup API, I can do many tiny recoup requests which the exchange then has to store, right?

I guess it would not be a big change to remove the "amount" value from the recoup/recoup-refresh request bodies, right?

- Florian
2022-01-11 12:47:35 +01:00
Christian Grothoff
87376e02eb
protocol v12 changes (/recoup split, signature changes) plus database sharding plus O(n^2)=>O(n) worst-case complexity reduction on coin balance checks 2021-12-25 13:56:40 +01:00