Merge pull request #17 from lambdaclass/tip_hash

Tip hash

Author: gabrielbosio

batcher/aligned-batcher/src/mina/mod.rs

@@ -1,82 +1,97 @@
-use std::array;
+use std::array::TryFromSliceError;
 
 use base64::prelude::*;
 use log::{debug, warn};
 
 const STATE_HASH_SIZE: usize = 32;
 
-pub fn verify_protocol_state_proof_integrity(proof: &[u8], public_input: &[u8]) -> bool {
+pub fn verify_proof_integrity(proof: &[u8], public_input: &[u8]) -> bool {
     debug!("Checking Mina protocol state proof");
-    if let Err(err) = check_protocol_state_proof(proof) {
+    if let Err(err) = check_proof(proof) {
         warn!("Protocol state proof check failed: {}", err);
         return false;
     }
 
     debug!("Checking Mina protocol state public inputs");
-    if let Err(err) = check_protocol_state_pub(public_input) {
+    if let Err(err) = check_pub_inputs(public_input) {
         warn!("Protocol state public inputs check failed: {}", err);
         return false;
     }
 
     true
 }
 
-pub fn check_protocol_state_proof(protocol_state_proof_bytes: &[u8]) -> Result<(), String> {
-    // TODO(xqft): check binprot deserialization
-    let protocol_state_proof_base64 =
-        std::str::from_utf8(protocol_state_proof_bytes).map_err(|err| err.to_string())?;
-    BASE64_URL_SAFE
-        .decode(protocol_state_proof_base64)
-        .map_err(|err| err.to_string())?;
+pub fn check_hash(pub_inputs: &[u8], offset: &mut usize) -> Result<(), String> {
+    pub_inputs
+        .get(*offset..*offset + STATE_HASH_SIZE)
+        .ok_or("Failed to slice candidate hash".to_string())?;
+
+    *offset += STATE_HASH_SIZE;
 
     Ok(())
 }
 
-pub fn check_protocol_state_pub(protocol_state_pub: &[u8]) -> Result<(), String> {
-    // TODO(xqft): check hash and binprot deserialization
-    let candidate_protocol_state_len =
-        check_protocol_state_and_hash(protocol_state_pub, STATE_HASH_SIZE)?;
+pub fn check_state(pub_inputs: &[u8], offset: &mut usize) -> Result<(), String> {
+    let state_len: usize = pub_inputs
+        .get(*offset..*offset + 4)
+        .ok_or("Failed to slice state len".to_string())
+        .and_then(|slice| {
+            slice
+                .try_into()
+                .map_err(|err: TryFromSliceError| err.to_string())
+        })
+        .map(u32::from_be_bytes)
+        .and_then(|len| usize::try_from(len).map_err(|err| err.to_string()))?;
+
+    pub_inputs
+        .get(*offset + 4..*offset + 4 + state_len)
+        .ok_or("Failed to slice state".to_string())
+        .and_then(|bytes| std::str::from_utf8(bytes).map_err(|err| err.to_string()))
+        .and_then(|base64| {
+            BASE64_STANDARD
+                .decode(base64)
+                .map_err(|err| err.to_string())
+        })?;
+    *offset += 4 + state_len;
+
+    Ok(())
+}
 
-    let _tip_protocol_state_len = check_protocol_state_and_hash(
-        protocol_state_pub,
-        STATE_HASH_SIZE + 4 + candidate_protocol_state_len + STATE_HASH_SIZE,
-    )?;
+pub fn check_pub_inputs(pub_inputs: &[u8]) -> Result<(), String> {
+    let mut offset = 0;
+
+    check_hash(pub_inputs, &mut offset)?; // candidate hash
+    check_hash(pub_inputs, &mut offset)?; // tip hash
+
+    check_state(pub_inputs, &mut offset)?; // candidate state
+    check_state(pub_inputs, &mut offset)?; // tip state
 
     Ok(())
 }
 
-fn check_protocol_state_and_hash(protocol_state_pub: &[u8], start: usize) -> Result<usize, String> {
-    let protocol_state_len_vec: Vec<_> = protocol_state_pub.iter().skip(start).take(4).collect();
-    let protocol_state_len_bytes: [u8; 4] = array::from_fn(|i| protocol_state_len_vec[i].clone());
-    let protocol_state_len = u32::from_be_bytes(protocol_state_len_bytes) as usize;
-
-    let protocol_state_bytes: Vec<_> = protocol_state_pub
-        .iter()
-        .skip(start + 4)
-        .take(protocol_state_len)
-        .map(|byte| byte.clone())
-        .collect();
-    let protocol_state_base64 =
-        std::str::from_utf8(protocol_state_bytes.as_slice()).map_err(|err| err.to_string())?;
-    BASE64_STANDARD
-        .decode(protocol_state_base64)
-        .map_err(|err| err.to_string())?;
-
-    Ok(protocol_state_len)
+pub fn check_proof(proof_bytes: &[u8]) -> Result<(), String> {
+    std::str::from_utf8(proof_bytes)
+        .map_err(|err| err.to_string())
+        .and_then(|base64| {
+            BASE64_URL_SAFE
+                .decode(base64)
+                .map_err(|err| err.to_string())
+        })?;
+    Ok(())
 }
 
 #[cfg(test)]
 mod test {
-    use super::verify_protocol_state_proof_integrity;
+    use super::verify_proof_integrity;
 
     const PROTOCOL_STATE_PROOF_BYTES: &[u8] =
         include_bytes!("../../../../batcher/aligned/test_files/mina/protocol_state.proof");
     const PROTOCOL_STATE_PUB_BYTES: &[u8] =
         include_bytes!("../../../../batcher/aligned/test_files/mina/protocol_state.pub");
 
     #[test]
-    fn verify_protocol_state_proof_integrity_does_not_fail() {
-        assert!(verify_protocol_state_proof_integrity(
+    fn verify_proof_integrity_does_not_fail() {
+        assert!(verify_proof_integrity(
             PROTOCOL_STATE_PROOF_BYTES,
             PROTOCOL_STATE_PUB_BYTES,
         ));

batcher/aligned-batcher/src/zk_utils/mod.rs

@@ -2,7 +2,7 @@ use crate::halo2::ipa::verify_halo2_ipa;
 use crate::halo2::kzg::verify_halo2_kzg;
 use crate::risc_zero::verify_risc_zero_proof;
 use crate::sp1::verify_sp1_proof;
-use crate::{gnark::verify_gnark, mina::verify_protocol_state_proof_integrity};
+use crate::{gnark::verify_gnark, mina::verify_proof_integrity};
 use aligned_sdk::core::types::{ProvingSystemId, VerificationData};
 use log::{debug, warn};
 
@@ -93,7 +93,7 @@ fn verify_internal(verification_data: &VerificationData) -> bool {
                 .pub_input
                 .as_ref()
                 .expect("Public input is required");
-            verify_protocol_state_proof_integrity(&verification_data.proof, pub_input)
+            verify_proof_integrity(&verification_data.proof, pub_input)
             // TODO(xqft): add Pickles aggregator checks which are run alongside the Kimchi
             // verifier. These checks are fast and if they aren't successful then the Pickles proof
             // isn't valid.