implement client-server Proof Of Work

Mashed up a argon2-based PoW with token buckets and bloom filters.
This is intended to prevent a few abuses including:

* Using a keysafe server for general file storage, by storing a whole
  lot of chunks.
* An attacker guessing names that people will use, and uploading junk
  to keysafe servers under those names, to make it harder for others to use
  keysafe later.
* An attacker trying to guess the names used for objects on keysafe
  servers in order to download them and start password cracking.
  (As a second level of defense, since the name generation hash
  is expensive already.)

Completely untested, but it builds!

This commit was sponsored by Andreas on Patreon.

1 files changed, 1 insertions, 1 deletions

diff --git a/keysafe.hs b/keysafe.hs
index 569e678..98e1ecb 100644
--- a/keysafe.hs
+++ b/keysafe.hs
@@ -13,7 +13,7 @@ import qualified CmdLine
 import UI
 import Encryption
 import Entropy
-import ExpensiveHash
+import Benchmark
 import Tests
 import Cost
 import SecretKey