Merge latest changes from master

Signed-off-by: Thane Thomson <[email protected]>

.gitignore

@@ -8,3 +8,6 @@ Cargo.lock
 
 # These are backup files generated by rustfmt
 **/*.rs.bk
+
+# These are log files emitted by model-based tests
+**/*.log

CHANGELOG.md

@@ -1,3 +1,12 @@
+## Unreleased
+
+### BUG FIXES:
+
+- `[light-client]` Fix bug where a commit with only absent signatures would be
+  deemed valid instead of invalid ([#650])
+
+[#652]: https://github.com/informalsystems/tendermint-rs/issues/650
+
 ## v0.17.0-rc1
 
 *Oct 15, 2020*

light-client/src/operations/commit_validator.rs

@@ -53,18 +53,22 @@ impl CommitValidator for ProdCommitValidator {
         signed_header: &SignedHeader,
         validator_set: &ValidatorSet,
     ) -> Result<(), VerificationError> {
-        // TODO: `self.commit.block_id` cannot be zero in the same way as in Go
-        //       Clarify if this another encoding related issue
-        if signed_header.commit.signatures.len() == 0 {
+        let signatures = &signed_header.commit.signatures;
+
+        // Check the the commit contains at least one non-absent signature.
+        // See https://github.com/informalsystems/tendermint-rs/issues/650
+        let has_present_signatures = signatures.iter().any(|cs| !cs.is_absent());
+        if !has_present_signatures {
             bail!(VerificationError::ImplementationSpecific(
                 "no signatures for commit".to_string()
             ));
         }
 
-        if signed_header.commit.signatures.len() != validator_set.validators().len() {
+        // Check that that the number of signatures matches the number of validators.
+        if signatures.len() != validator_set.validators().len() {
             bail!(VerificationError::ImplementationSpecific(format!(
                 "pre-commit length: {} doesn't match validator length: {}",
-                signed_header.commit.signatures.len(),
+                signatures.len(),
                 validator_set.validators().len()
             )));
         }

light-client/src/predicates.rs

@@ -261,6 +261,13 @@ pub fn verify(
         &trusted.signed_header.header,
     )?;
 
+    // Verify that more than 2/3 of the validators correctly committed the block.
+    vp.has_sufficient_signers_overlap(
+        &untrusted.signed_header,
+        &untrusted.validators,
+        voting_power_calculator,
+    )?;
+
     let trusted_next_height = trusted.height().increment();
 
     if untrusted.height() == trusted_next_height {
@@ -285,12 +292,5 @@ pub fn verify(
         )?;
     }
 
-    // Verify that more than 2/3 of the validators correctly committed the block.
-    vp.has_sufficient_signers_overlap(
-        &untrusted.signed_header,
-        &untrusted.validators,
-        voting_power_calculator,
-    )?;
-
     Ok(())
 }

testgen/src/commit.rs

@@ -110,7 +110,7 @@ impl Generator<block::Commit> for Commit {
         let block_header = header.generate()?;
         let block_id = block::Id {
             hash: block_header.hash(),
-            part_set_header: PartSetHeader::default(),
+            part_set_header: PartSetHeader::new(1, block_header.hash()),
         };
         let votes = match &self.votes {
             None => self.clone().generate_default_votes().votes.unwrap(),

testgen/src/header.rs

@@ -49,6 +49,22 @@ impl Header {
     set_option!(height, u64);
     set_option!(time, u64);
     set_option!(proposer, usize);
+
+    pub fn next(&self) -> Self {
+        let height = self.height.expect("Missing previous header's height");
+        let time = self.time.unwrap_or(height); // if no time is found, then we simple correspond it to the header height
+        let validators = self.validators.clone().expect("Missing validators");
+        let next_validators = self.next_validators.clone().unwrap_or(validators);
+
+        Self {
+            validators: Some(next_validators.clone()),
+            next_validators: Some(next_validators),
+            chain_id: self.chain_id.clone(),
+            height: Some(height + 1),
+            time: Some(time + 1),
+            proposer: self.proposer, // TODO: proposer must be incremented
+        }
+    }
 }
 
 impl std::str::FromStr for Header {
@@ -106,7 +122,9 @@ impl Generator<block::Header> for Header {
             tendermint::Time::now()
         };
         let header = block::Header {
-            version: block::header::Version { block: 0, app: 0 },
+            // block version in Tendermint-go is hardcoded with value 11
+            // so we do the same with MBT for now for compatibility
+            version: block::header::Version { block: 11, app: 0 },
             chain_id,
             height: block::Height::try_from(self.height.unwrap_or(1))
                 .map_err(|_| SimpleError::new("height out of bounds"))?,

testgen/src/lib.rs

@@ -6,13 +6,17 @@ pub mod commit;
 pub mod consensus;
 pub mod generator;
 pub mod header;
+pub mod light_block;
+pub mod light_chain;
 pub mod time;
 pub mod validator;
 pub mod vote;
 
 pub use commit::Commit;
 pub use generator::Generator;
 pub use header::Header;
+pub use light_block::LightBlock;
+pub use light_chain::LightChain;
 pub use time::Time;
 pub use validator::Validator;
 pub use vote::Vote;