change signing function

Signed-off-by: Dominic Woerner <dominic.woerner@dfinity.org>

README.md

@@ -21,6 +21,7 @@ Once the job completes, your application will be available at `http://localhost:
 ## ToDos
 
 - [ ] Implement key derivation
+- [ ] Require cycles
 - [ ] Try to get rid of `getrandom` dependency or provide proper implementation of custom function
 - [ ] Try to init key in `init` function. Maybe with timer.
 

canister_ids.json

@@ -0,0 +1,5 @@
+{
+  "schnorr_canister_backend": {
+    "ic": "htvbm-vaaaa-aaaap-qb5kq-cai"
+  }
+}

src/lib.rs

@@ -1,6 +1,6 @@
 use bip32::{Seed, XPrv};
 use candid::{CandidType, Deserialize, Principal};
-use k256::ecdsa::signature::hazmat::PrehashSigner;
+use k256::ecdsa::signature::Signer;
 use serde::Serialize;
 
 use ic_stable_structures::memory_manager::{MemoryId, MemoryManager, VirtualMemory};
@@ -164,10 +164,12 @@ fn sign_with_schnorr(arg: SignWithSchnorr) -> SignWithSchnorrReply {
 
     let signing_key = k256::schnorr::SigningKey::from_bytes(key_bytes.as_slice()).unwrap();
 
-    let signature = match signing_key.sign_prehash(message_hash.as_slice()) {
-        Ok(signature) => signature,
-        Err(_err) => ic_cdk::trap("Error signing message"),
-    };
+    // let signature = match signing_key.sign_prehash(message_hash.as_slice()) {
+    //     Ok(signature) => signature,
+    //     Err(_err) => ic_cdk::trap("Error signing message"),
+    // };
+
+    let signature = signing_key.sign(message_hash.as_slice());
 
     SignWithSchnorrReply {
         signature: signature.to_bytes().to_vec(),