feat: add well-known 0.13.2-style block hashes for Sepolia testnet

We will use these 0.13.2 block hashes for all pre-0.13.2 blocks
to verify data we receive from peers via P2P.

Cargo.toml

@@ -1,5 +1,6 @@
 [workspace]
 members = [
+    "crates/block-hashes",
     "crates/common",
     "crates/compiler",
     "crates/crypto",

crates/block-hashes/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "pathfinder-block-hashes"
+version = { workspace = true }
+authors = { workspace = true }
+edition = { workspace = true }
+license = { workspace = true }
+rust-version = { workspace = true }
+
+[dependencies]
+pathfinder-common = { path = "../common" }
+pathfinder-crypto = { path = "../crypto" }

crates/block-hashes/src/lib.rs

@@ -0,0 +1,21 @@
+use pathfinder_common::{BlockHash, BlockNumber, Chain};
+
+mod sepolia;
+
+#[derive(Clone)]
+pub struct BlockHashDb {
+    chain: Chain,
+}
+
+impl BlockHashDb {
+    pub fn new(chain: Chain) -> Self {
+        Self { chain }
+    }
+
+    pub fn block_hash(&self, block_number: BlockNumber) -> Option<BlockHash> {
+        match self.chain {
+            Chain::SepoliaTestnet => sepolia::block_hash(block_number),
+            _ => None,
+        }
+    }
+}

crates/block-hashes/src/sepolia.rs

@@ -0,0 +1,16 @@
+use pathfinder_common::{BlockHash, BlockNumber};
+use pathfinder_crypto::Felt;
+
+const FIRST_0_13_2_BLOCK: usize = 86311;
+static BLOCK_HASHES: &[u8; 32 * FIRST_0_13_2_BLOCK] =
+    include_bytes!("../fixtures/sepolia_block_hashes.bin");
+
+pub(super) fn block_hash(block_number: BlockNumber) -> Option<BlockHash> {
+    if block_number.get() >= FIRST_0_13_2_BLOCK as u64 {
+        None
+    } else {
+        let offset = (block_number.get() as usize) * 32;
+        let felt = Felt::from_be_slice(&BLOCK_HASHES[offset..offset + 32]).unwrap();
+        Some(BlockHash(felt))
+    }
+}

crates/pathfinder/examples/compute_pre0132_hashes.rs

@@ -18,7 +18,7 @@ use pathfinder_lib::state::block_hash::{
     BlockHeaderData,
 };
 
-const VERSION_CUTOFF: StarknetVersion = StarknetVersion::new(0, 13, 2, 0);
+const VERSION_CUTOFF: StarknetVersion = StarknetVersion::V_0_13_2;
 
 /// Computes block hashes for all blocks under the 0.13.2 cutoff in 0.13.2 style
 /// and stores them in a CSV file "block_hashes.csv" with the format:
@@ -48,7 +48,8 @@ fn main() -> anyhow::Result<()> {
     };
 
     // Open a file where we'll save the computed hashes
-    let mut file = std::fs::File::create("block_hashes.csv")?;
+    let mut csv_file = std::fs::File::create("block_hashes.csv")?;
+    let mut binary_file = std::fs::File::create("block_hashes.bin")?;
 
     // Iterate through all pre-0.13.2 blocks
     for block_number in 0..latest_block_number.get() {
@@ -64,6 +65,12 @@ fn main() -> anyhow::Result<()> {
             .context("Fetching block header")?
             .context("Block header missing")?;
 
+        // As soon as we reach blocks in 0.13.2 we're done
+        if header.starknet_version == VERSION_CUTOFF {
+            println!("\rBlock {}. Done!", block_number);
+            break;
+        }
+
         // Load block tx's (to compute receipt commitment)
         let txn_data_for_block = tx
             .transaction_data_for_block(block_id)?
@@ -122,15 +129,16 @@ fn main() -> anyhow::Result<()> {
         let new_block_hash = compute_final_hash(&header_data).context("Computing block hash")?;
 
         // Write to the CSV file
-        writeln!(file, "{},{}", block_number, new_block_hash)?;
+        writeln!(csv_file, "{},{}", block_number, new_block_hash)?;
 
-        // As soon as we reach blocks in 0.13.2 we're done
-        if header.starknet_version == VERSION_CUTOFF {
-            println!("\rBlock {}. Done!", block_number);
-            break;
-        }
+        // Write to the binary file
+        binary_file
+            .write_all(new_block_hash.0.as_be_bytes())
+            .context("Writing block hash to binary file")?;
     }
 
+    println!("\nResults are in `block_hashes.csv` and `block_hashes.bin`");
+
     Ok(())
 }