JJ: Description from the destination commit:

wip keys_post

JJ: Description from source commit:
+ verify_denom_signature

tools/offline_sig.ml

@@ -16,7 +16,6 @@ let denom_signature ~master_key
         fee_deposit;
         fee_refresh;
         fee_refund= _;
-        (* TODO check sigs *)
         denom_secmod_sig= _;
       } =
   let octets = DenominationKey.to_octets denom_pub in
@@ -43,14 +42,7 @@ let denom_signature ~master_key
 
 let signkey_signature ~master_key
     FutureSignKey.
-      {
-        key;
-        stamp_start;
-        stamp_expire;
-        stamp_end;
-        (* TODO check sigs *)
-        signkey_secmod_sig= _;
-      } =
+      { key; stamp_start; stamp_expire; stamp_end; signkey_secmod_sig= _ } =
   let master_sig =
     let open Api_sig.ExchangeSigningKeyValidityPS in
     sign ~key:master_key
@@ -68,7 +60,6 @@ let make_master_signatures ~master_key
       {
         future_denoms;
         future_signkeys;
-        (* TODO check sigs *)
         master_pub= _;
         denom_secmod_public_key= _;
         signkey_secmod_public_key= _;