WIP

Author: cjpatton

crates/mtc_api/src/subtree_cosignature.rs

@@ -8,10 +8,11 @@ use ed25519_dalek::{
     VerifyingKey as Ed25519VerifyingKey,
 };
 use length_prefixed::WriteLengthPrefixedBytesExt;
-use signed_note::{compute_key_id, KeyName, NoteError, NoteSignature, NoteVerifier, SignatureType};
+use sha2::{Digest, Sha256};
+use signed_note::{KeyName, NoteError, NoteSignature, NoteVerifier};
 use tlog_tiles::{CheckpointSigner, CheckpointText, Hash, LeafIndex, UnixTimestamp};
 
-use crate::RelativeOid;
+use crate::{RelativeOid, ID_RDNA_TRUSTANCHOR_ID};
 
 pub type TrustAnchorID = RelativeOid;
 
@@ -21,14 +22,9 @@ pub struct MTCSubtreeCosigner {
 }
 
 impl MTCSubtreeCosigner {
-    pub fn new(
-        cosigner_id: TrustAnchorID,
-        log_id: TrustAnchorID,
-        name: KeyName,
-        k: Ed25519SigningKey,
-    ) -> Self {
+    pub fn new(cosigner_id: TrustAnchorID, log_id: TrustAnchorID, k: Ed25519SigningKey) -> Self {
         Self {
-            v: MTCSubtreeNoteVerifier::new(cosigner_id, log_id, name, k.verifying_key()),
+            v: MTCSubtreeNoteVerifier::new(cosigner_id, log_id, k.verifying_key()),
             k,
         }
     }
@@ -115,18 +111,24 @@ impl MTCSubtreeNoteVerifier {
     pub fn new(
         cosigner_id: TrustAnchorID,
         log_id: TrustAnchorID,
-        name: KeyName,
         verifying_key: Ed25519VerifyingKey,
     ) -> Self {
+        let name = KeyName::new(format!(
+            "oid/{}.{}",
+            ID_RDNA_TRUSTANCHOR_ID.to_string(),
+            cosigner_id.to_string()
+        ))
+        .unwrap();
+
         let id = {
-            // TODO what signature algorithm to use for mtc-subtree/v1?
-            let pubkey = [
-                &[SignatureType::Undefined as u8],
-                verifying_key.to_bytes().as_slice(),
-            ]
-            .concat();
-            compute_key_id(&name, &pubkey)
+            let mut hasher = Sha256::new();
+            hasher.update(name.as_str().as_bytes());
+            hasher.update(&[0x0A, 0xFF]);
+            hasher.update(b"mtc-subtree/v1");
+            let result = hasher.finalize();
+            u32::from_be_bytes(result[0..4].try_into().unwrap())
         };
+
         Self {
             cosigner_id,
             log_id,
@@ -245,11 +247,9 @@ mod tests {
         let tree = TreeWithTimestamp::new(tree_size, record_hash(b"hello world"), timestamp);
         let signer = {
             let sk = Ed25519SigningKey::generate(&mut rng);
-            let name = KeyName::new("my-signer".into()).unwrap();
             MTCSubtreeCosigner::new(
                 TrustAnchorID::from_str("1.2.3").unwrap(),
                 TrustAnchorID::from_str("4.5.6").unwrap(),
-                name,
                 sk,
             )
         };

crates/mtc_worker/src/lib.rs

@@ -60,11 +60,10 @@ pub(crate) fn load_ed25519_key(
 }
 
 pub(crate) fn load_cosigner(env: &Env, name: &str) -> MTCSubtreeCosigner {
-    let origin = load_origin(name);
     let log_id = TrustAnchorID::from_str(&CONFIG.logs[name].log_id).unwrap();
     let cosigner_id = TrustAnchorID::from_str(&CONFIG.logs[name].cosigner_id).unwrap();
     let signing_key = load_signing_key(env, name).unwrap().clone();
-    MTCSubtreeCosigner::new(cosigner_id, log_id, origin.clone(), signing_key)
+    MTCSubtreeCosigner::new(cosigner_id, log_id, signing_key)
 }
 
 pub(crate) fn load_origin(name: &str) -> KeyName {