feat: perform randomness hashing in the kernel (#1842)

* feat: perform randomness hashing in the kernel

* address review

* bump test vectors

fvm/Cargo.toml

@@ -38,6 +38,8 @@ rand = "0.8.5"
 quickcheck = { version = "1", optional = true }
 once_cell = "1.18"
 minstant = "0.1.2"
+blake2b_simd = "1.0.0"
+byteorder = "1.4.3"
 
 [dev-dependencies]
 pretty_assertions = "1.3.0"

fvm/src/externs/mod.rs

@@ -23,21 +23,11 @@ pub trait Consensus {
 pub trait Rand {
     /// Gets 32 bytes of randomness for ChainRand paramaterized by the DomainSeparationTag,
     /// ChainEpoch, Entropy from the ticket chain.
-    fn get_chain_randomness(
-        &self,
-        pers: i64,
-        round: ChainEpoch,
-        entropy: &[u8],
-    ) -> anyhow::Result<[u8; 32]>;
+    fn get_chain_randomness(&self, round: ChainEpoch) -> anyhow::Result<[u8; 32]>;
 
     /// Gets 32 bytes of randomness for ChainRand paramaterized by the DomainSeparationTag,
     /// ChainEpoch, Entropy from the latest beacon entry.
-    fn get_beacon_randomness(
-        &self,
-        pers: i64,
-        round: ChainEpoch,
-        entropy: &[u8],
-    ) -> anyhow::Result<[u8; 32]>;
+    fn get_beacon_randomness(&self, round: ChainEpoch) -> anyhow::Result<[u8; 32]>;
 }
 
 /// Chain information provider.

fvm/src/kernel/default.rs

@@ -6,6 +6,8 @@ use std::panic::{self, UnwindSafe};
 use std::path::PathBuf;
 
 use anyhow::{anyhow, Context as _};
+use blake2b_simd::Params;
+use byteorder::WriteBytesExt;
 use cid::Cid;
 use filecoin_proofs_api::{self as proofs, ProverId, PublicReplicaInfo, SectorId};
 use fvm_ipld_blockstore::Blockstore;
@@ -27,6 +29,7 @@ use lazy_static::lazy_static;
 use multihash::MultihashDigest;
 use rayon::iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator};
 use rayon::prelude::ParallelDrainRange;
+use std::io::Write;
 
 use super::blocks::{Block, BlockRegistry};
 use super::error::Result;
@@ -745,6 +748,24 @@ where
     }
 }
 
+fn draw_randomness(
+    rbase: &[u8; RANDOMNESS_LENGTH],
+    pers: i64,
+    round: ChainEpoch,
+    entropy: &[u8],
+) -> anyhow::Result<[u8; RANDOMNESS_LENGTH]> {
+    let mut state = Params::new().hash_length(32).to_state();
+    state.write_i64::<byteorder::BigEndian>(pers)?;
+    state.write_all(rbase)?;
+    state.write_i64::<byteorder::BigEndian>(round)?;
+    state.write_all(entropy)?;
+    state
+        .finalize()
+        .as_bytes()
+        .try_into()
+        .map_err(anyhow::Error::from)
+}
+
 impl<C> RandomnessOps for DefaultKernel<C>
 where
     C: CallManager,
@@ -763,12 +784,17 @@ where
 
         // TODO(M2): Check error code
         // Specifically, lookback length?
-        t.record(
+
+        let digest = t.record(
             self.call_manager
                 .externs()
-                .get_chain_randomness(personalization, rand_epoch, entropy)
+                .get_chain_randomness(rand_epoch)
                 .or_illegal_argument(),
-        )
+        )?;
+
+        draw_randomness(&digest, personalization, rand_epoch, entropy).map_err(|e| {
+            syscall_error!(IllegalArgument; "failed to draw chain randmness {}", e).into()
+        })
     }
 
     fn get_randomness_from_beacon(
@@ -785,12 +811,16 @@ where
 
         // TODO(M2): Check error code
         // Specifically, lookback length?
-        t.record(
+        let digest = t.record(
             self.call_manager
                 .externs()
-                .get_beacon_randomness(personalization, rand_epoch, entropy)
+                .get_beacon_randomness(rand_epoch)
                 .or_illegal_argument(),
-        )
+        )?;
+
+        draw_randomness(&digest, personalization, rand_epoch, entropy).map_err(|e| {
+            syscall_error!(IllegalArgument; "failed to draw beacon randmness {}", e).into()
+        })
     }
 }
 

fvm/src/lib.rs

@@ -77,9 +77,7 @@ mod test {
     impl Rand for DummyExterns {
         fn get_chain_randomness(
             &self,
-            _pers: i64,
             _round: fvm_shared::clock::ChainEpoch,
-            _entropy: &[u8],
         ) -> anyhow::Result<[u8; 32]> {
             let msg = "mel was here".as_bytes();
             let mut out = [0u8; 32];
@@ -89,9 +87,7 @@ mod test {
 
         fn get_beacon_randomness(
             &self,
-            _pers: i64,
             _round: fvm_shared::clock::ChainEpoch,
-            _entropy: &[u8],
         ) -> anyhow::Result<[u8; 32]> {
             todo!()
         }

fvm/tests/dummy.rs

@@ -35,18 +35,14 @@ impl Externs for DummyExterns {}
 impl Rand for DummyExterns {
     fn get_chain_randomness(
         &self,
-        _pers: i64,
         _round: fvm_shared::clock::ChainEpoch,
-        _entropy: &[u8],
     ) -> anyhow::Result<[u8; 32]> {
         todo!()
     }
 
     fn get_beacon_randomness(
         &self,
-        _pers: i64,
         _round: fvm_shared::clock::ChainEpoch,
-        _entropy: &[u8],
     ) -> anyhow::Result<[u8; 32]> {
         todo!()
     }

testing/conformance/src/externs.rs

@@ -25,22 +25,12 @@ impl TestExterns {
 impl Externs for TestExterns {}
 
 impl Rand for TestExterns {
-    fn get_chain_randomness(
-        &self,
-        pers: i64,
-        round: ChainEpoch,
-        entropy: &[u8],
-    ) -> anyhow::Result<[u8; 32]> {
-        self.rand.get_chain_randomness(pers, round, entropy)
+    fn get_chain_randomness(&self, round: ChainEpoch) -> anyhow::Result<[u8; 32]> {
+        self.rand.get_chain_randomness(round)
     }
 
-    fn get_beacon_randomness(
-        &self,
-        pers: i64,
-        round: ChainEpoch,
-        entropy: &[u8],
-    ) -> anyhow::Result<[u8; 32]> {
-        self.rand.get_beacon_randomness(pers, round, entropy)
+    fn get_beacon_randomness(&self, round: ChainEpoch) -> anyhow::Result<[u8; 32]> {
+        self.rand.get_beacon_randomness(round)
     }
 }
 

testing/conformance/src/rand.rs

@@ -20,11 +20,11 @@ pub struct ReplayingRand {
 pub struct TestFallbackRand;
 
 impl Rand for TestFallbackRand {
-    fn get_chain_randomness(&self, _: i64, _: ChainEpoch, _: &[u8]) -> anyhow::Result<[u8; 32]> {
+    fn get_chain_randomness(&self, _: ChainEpoch) -> anyhow::Result<[u8; 32]> {
         Ok(*b"i_am_random_____i_am_random_____")
     }
 
-    fn get_beacon_randomness(&self, _: i64, _: ChainEpoch, _: &[u8]) -> anyhow::Result<[u8; 32]> {
+    fn get_beacon_randomness(&self, _: ChainEpoch) -> anyhow::Result<[u8; 32]> {
         Ok(*b"i_am_random_____i_am_random_____")
     }
 }
@@ -50,40 +50,26 @@ impl ReplayingRand {
 }
 
 impl Rand for ReplayingRand {
-    fn get_chain_randomness(
-        &self,
-        dst: i64,
-        epoch: ChainEpoch,
-        entropy: &[u8],
-    ) -> anyhow::Result<[u8; 32]> {
+    fn get_chain_randomness(&self, epoch: ChainEpoch) -> anyhow::Result<[u8; 32]> {
         let rule = RandomnessRule {
             kind: RandomnessKind::Chain,
-            dst,
             epoch,
-            entropy: entropy.to_vec(),
         };
         if let Some(bz) = self.matches(rule) {
             Ok(bz)
         } else {
-            self.fallback.get_chain_randomness(dst, epoch, entropy)
+            self.fallback.get_chain_randomness(epoch)
         }
     }
-    fn get_beacon_randomness(
-        &self,
-        dst: i64,
-        epoch: ChainEpoch,
-        entropy: &[u8],
-    ) -> anyhow::Result<[u8; 32]> {
+    fn get_beacon_randomness(&self, epoch: ChainEpoch) -> anyhow::Result<[u8; 32]> {
         let rule = RandomnessRule {
             kind: RandomnessKind::Beacon,
-            dst,
             epoch,
-            entropy: entropy.to_vec(),
         };
         if let Some(bz) = self.matches(rule) {
             Ok(bz)
         } else {
-            self.fallback.get_beacon_randomness(dst, epoch, entropy)
+            self.fallback.get_beacon_randomness(epoch)
         }
     }
 }

testing/conformance/src/vector.rs

@@ -117,10 +117,7 @@ pub enum RandomnessKind {
 #[derive(Debug, Deserialize_tuple, PartialEq, Eq, Clone)]
 pub struct RandomnessRule {
     pub kind: RandomnessKind,
-    pub dst: i64,
     pub epoch: ChainEpoch,
-    #[serde(with = "base64_bytes")]
-    pub entropy: Vec<u8>,
 }
 
 #[derive(Debug, Deserialize, Clone)]

testing/integration/src/dummy.rs

@@ -14,9 +14,7 @@ impl Externs for DummyExterns {}
 impl Rand for DummyExterns {
     fn get_chain_randomness(
         &self,
-        _pers: i64,
         _round: fvm_shared::clock::ChainEpoch,
-        _entropy: &[u8],
     ) -> anyhow::Result<[u8; 32]> {
         let rng: String = thread_rng()
             .sample_iter(&Alphanumeric)
@@ -29,9 +27,7 @@ impl Rand for DummyExterns {
 
     fn get_beacon_randomness(
         &self,
-        _pers: i64,
         _round: fvm_shared::clock::ChainEpoch,
-        _entropy: &[u8],
     ) -> anyhow::Result<[u8; 32]> {
         let rng: String = thread_rng()
             .sample_iter(&Alphanumeric)