fix: add sig check

catalyst-gateway/bin/Cargo.toml

@@ -68,3 +68,4 @@ anyhow = { workspace = true }
 handlebars = { workspace = true }
 cddl = { workspace = true }
 ciborium = { workspace = true }
+ed25519-dalek = "2.1.1"

catalyst-gateway/bin/src/cardano/cip36_registration/mod.rs

@@ -1,13 +1,18 @@
 //! Verify registration TXs
 
+use anyhow::Ok;
 use cardano_chain_follower::Network;
+use ciborium::{value::Integer, Value};
 use cryptoxide::{blake2b::Blake2b, digest::Digest};
+use ed25519_dalek::{Signature, Verifier, VerifyingKey};
 use pallas::ledger::{
     primitives::{conway::Metadatum, Fragment},
     traverse::MultiEraMeta,
 };
 use serde::{Deserialize, Serialize};
 
+use super::util::hash;
+
 /// Pub key
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 pub(crate) struct PubKey(Vec<u8>);
@@ -43,42 +48,6 @@ impl PubKey {
     }
 }
 
-/// Ed25519 signature.
-///
-/// This type represents a container for the byte serialization of an Ed25519
-/// signature, and does not necessarily represent well-formed field or curve
-/// elements.
-///
-/// Signature verification libraries are expected to reject invalid field
-/// elements at the time a signature is verified.
-#[derive(Copy, Clone, Eq, PartialEq, Debug)]
-#[repr(C)]
-pub struct Signature {
-    /// Component of an Ed25519 signature when serialized as bytes
-    r: [u8; Self::COMPONENT_SIZE],
-    /// Component of an Ed25519 signature when serialized as bytes
-    s: [u8; Self::COMPONENT_SIZE],
-}
-
-impl Signature {
-    /// Size of an encoded Ed25519 signature in bytes.
-    const BYTE_SIZE: usize = Self::COMPONENT_SIZE * 2;
-    /// Size of a single component of an Ed25519 signature.
-    const COMPONENT_SIZE: usize = 32;
-
-    /// Parse an Ed25519 signature from a byte slice.
-    fn from_bytes(bytes: &[u8; Self::BYTE_SIZE]) -> Self {
-        let mut r = <[u8; Self::COMPONENT_SIZE]>::default();
-        let mut s = <[u8; Self::COMPONENT_SIZE]>::default();
-
-        let components = bytes.split_at(Self::COMPONENT_SIZE);
-        r.copy_from_slice(components.0);
-        s.copy_from_slice(components.1);
-
-        Self { r, s }
-    }
-}
-
 /// The source of voting power for a given registration
 ///
 /// The voting power can either come from:
@@ -142,6 +111,7 @@ impl Cip36Metadata {
         let mut registration = None;
         let mut raw_metadata = None;
         let mut signature = None;
+        let mut raw_61284 = None;
         let mut errors_report = Vec::new();
 
         if let pallas::ledger::traverse::MultiEraMeta::AlonzoCompatible(tx_metadata) = tx_metadata {
@@ -157,6 +127,7 @@ impl Cip36Metadata {
                 },
                 Some,
             );
+
             for (key, metadata) in tx_metadata.iter() {
                 match *key {
                     CIP36_REGISTRATION_CBOR_KEY => {
@@ -168,6 +139,14 @@ impl Cip36Metadata {
                                 },
                                 Some,
                             );
+
+                        raw_61284 = original_61284_payload(metadata).map_or_else(
+                            |err| {
+                                errors_report.push(format!("{err}"));
+                                None
+                            },
+                            Some,
+                        );
                     },
                     CIP36_WITNESS_CBOR_KEY => {
                         signature = inspect_witness_from_metadata(metadata).map_or_else(
@@ -183,15 +162,48 @@ impl Cip36Metadata {
             }
         };
 
+        if let Some(raw_61284) = raw_61284 {
+            let _ =
+                validate_signature(&raw_61284, &registration.clone(), &signature).map_err(|err| {
+                    errors_report.push(format!("{err}"));
+                });
+        }
+
         Some(Self {
-            registration,
+            registration: registration.clone(),
             raw_metadata,
             signature,
             errors_report,
         })
     }
 }
 
+/// The signature is generated by:
+///  - CBOR encoding the registration
+///  - blake2b-256 hashing those bytes
+///  - signing the hash with the private key used to generate the stake key
+pub fn validate_signature(
+    raw_61284: &[u8], registration: &Option<Registration>, signature: &Option<Signature>,
+) -> anyhow::Result<()> {
+    let hash_bytes = hash(raw_61284);
+
+    let verifying_key = VerifyingKey::from_bytes(
+        registration
+            .clone()
+            .ok_or("no registration data".to_string())
+            .map_err(|err| anyhow::anyhow!("{err}"))?
+            .stake_key
+            .bytes()
+            .try_into()?,
+    )?;
+
+    let sig = signature
+        .ok_or("cannot verify payload without signature".to_string())
+        .map_err(|err| anyhow::anyhow!("{err}"))?;
+
+    Ok(verifying_key.verify(&hash_bytes, &sig)?)
+}
+
 /// Validate binary data against CIP-36 registration CDDL spec
 fn validate_cip36_registration(data: &[u8]) -> anyhow::Result<()> {
     /// Cip36 registration CDDL definition
@@ -270,16 +282,42 @@ fn inspect_signature(cbor_value: ciborium::value::Value) -> anyhow::Result<Signa
         .map_err(|_| anyhow::anyhow!("Invalid cip36 witness cbor, signature should be bytes"))?
         .try_into()
         .map_err(|vec: Vec<_>| {
-            anyhow::anyhow!(
-                "Invalid signature length, expected: {}, got {}",
-                Signature::BYTE_SIZE,
-                vec.len()
-            )
+            anyhow::anyhow!("Invalid signature length, expected:  got {}", vec.len())
         })?;
 
     Ok(Signature::from_bytes(&signature))
 }
 
+/// Rebuild 61284 from pallas metadata to match original signed 61284 payload, pallas does
+/// not preserve exact 61284 bytes which is required for signature verification. It must
+/// be rebuilt and re-serialized to perform signature verification.
+fn original_61284_payload(metadata: &Metadatum) -> anyhow::Result<Vec<u8>> {
+    /// 61284 CIP-36
+    const CIP_36_61284: usize = 61284;
+
+    let metadata_bytes = metadata
+        .encode_fragment()
+        .map_err(|err| anyhow::anyhow!("cannot encode metadata into bytes {err}"))?;
+
+    let cbor_value = ciborium::de::from_reader::<ciborium::Value, _>(metadata_bytes.as_slice())
+        .map_err(|err| anyhow::anyhow!("Cannot decode cbor object from bytes, err: {err}"))?;
+
+    let cbor_map = cbor_value.as_map().ok_or(anyhow::anyhow!(
+        "Not a valid cbor cip36 registration, should be a map"
+    ))?;
+
+    let registration_payload = Value::Map(vec![(
+        Value::Integer(Integer::from(CIP_36_61284)),
+        ciborium::Value::Map(cbor_map.clone()),
+    )]);
+
+    let mut raw_61284 = Vec::new();
+    ciborium::ser::into_writer(&registration_payload, &mut raw_61284)
+        .map_err(|err| anyhow::anyhow!("Cannot decode cbor object from bytes, err: {err}"))?;
+
+    Ok(raw_61284)
+}
+
 /// Extract registration from tx metadata
 fn inspect_registration_from_metadata(
     metadata: &Metadatum, network: Network,

catalyst-gateway/bin/src/cardano/util.rs

@@ -19,6 +19,20 @@ pub type StakeCredentialHash = String;
 /// Correct stake credential key in hex
 pub type StakeCredentialKey = String;
 
+/// Hash size
+pub(crate) const BLAKE_2B_256_HASH_SIZE: usize = 256 / 8;
+
+/// Helper function to generate the `blake2b_256` hash of a byte slice
+#[allow(dead_code)]
+pub(crate) fn hash(bytes: &[u8]) -> [u8; BLAKE_2B_256_HASH_SIZE] {
+    let mut digest = [0u8; BLAKE_2B_256_HASH_SIZE];
+    let mut context = Blake2b::new(BLAKE_2B_256_HASH_SIZE);
+    context.input(bytes);
+    context.result(&mut digest);
+
+    digest
+}
+
 #[derive(Default, Debug, Serialize)]
 /// Assets
 pub struct Asset {

catalyst-gateway/bin/src/event_db/cardano/cip36_registration/mod.rs

@@ -99,6 +99,7 @@ impl EventDB {
         let Some(cip36) = Cip36Metadata::generate_from_tx_metadata(&tx.metadata(), network) else {
             return Ok(());
         };
+
         let tx_hash = tx.hash().to_vec();
         let (stake_credential, voting_info, rewards_address, nonce) =
             if let Some(reg) = cip36.registration {

catalyst-gateway/tests/api_tests/snapshot_tool-56364174.json

@@ -205,7 +205,7 @@
     "voting_power": 403470717,
     "voting_purpose": 0,
     "tx_id": 1205915,
-    "nonce": 36168765
+    "nonce": 36151489
   },
   {
     "delegations": [
@@ -224,7 +224,7 @@
   {
     "delegations": [
       [
-        "0x030606c166a947a33bf60043e70f240eac1df7936aa056429f2521553f9d4220",
+        "0x926cddb15c7ec46a71db0323d1d8ab18a83f8f9d73e159000b2dcfc3f7050de0",
         1
       ]
     ],
@@ -233,7 +233,7 @@
     "voting_power": 894284145,
     "voting_purpose": 0,
     "tx_id": 1151432,
-    "nonce": 181865062
+    "nonce": 36190561
   },
   {
     "delegations": "0x1493fb2c46ef5e99928f08776b83166b2b18833389d06f8cb66e816e3829a627",