feat: [MR-591] Introduce a minimum supported certification version. (#1502)

This is a first step towards phasing out old certification versions. The
choice of
[V17](https://sourcegraph.com/github.com/dfinity/ic/-/blob/rs/canonical_state/certification_version/src/lib.rs?L43)
for `MIN_SUPPORTED_CERTIFICATION_VERSION` is the last version that's not
related to the new messaging model. This seems to be a good place to
have it for now.

Following this PR would be another PR where exception such as
[this](https://sourcegraph.com/github.com/dfinity/ic@0441f40482386397f7c688bf508ddd901ca6c1b7/-/blob/rs/messaging/src/routing/stream_handler.rs?L869)
are removed, as well as trimming down the test framework
([e.g.](https://sourcegraph.com/github.com/dfinity/ic@0441f40482386397f7c688bf508ddd901ca6c1b7/-/blob/rs/canonical_state/tests/compatibility.rs?L189)).

Author: stiegerc

rs/canonical_state/certification_version/src/lib.rs

@@ -80,6 +80,12 @@ impl std::convert::TryFrom<u32> for CertificationVersion {
 /// computed states.
 pub const CURRENT_CERTIFICATION_VERSION: CertificationVersion = CertificationVersion::V19;
 
+/// Minimum supported certification version.
+///
+/// The replica will panic if requested to certify using a version lower than
+/// this.
+pub const MIN_SUPPORTED_CERTIFICATION_VERSION: CertificationVersion = CertificationVersion::V17;
+
 /// Maximum supported certification version.
 ///
 /// The replica will panic if requested to certify using a version higher than
@@ -89,10 +95,13 @@ pub const MAX_SUPPORTED_CERTIFICATION_VERSION: CertificationVersion = Certificat
 /// Returns a list of all certification versions up to [MAX_SUPPORTED_CERTIFICATION_VERSION].
 pub fn all_supported_versions() -> impl std::iter::Iterator<Item = CertificationVersion> {
     use strum::IntoEnumIterator;
-    CertificationVersion::iter().take_while(|v| *v <= MAX_SUPPORTED_CERTIFICATION_VERSION)
+    CertificationVersion::iter().filter(|v| {
+        MIN_SUPPORTED_CERTIFICATION_VERSION <= *v && *v <= MAX_SUPPORTED_CERTIFICATION_VERSION
+    })
 }
 
 #[test]
-fn supported_version_ge_current() {
+fn version_constants_consistent() {
+    assert!(MIN_SUPPORTED_CERTIFICATION_VERSION <= CURRENT_CERTIFICATION_VERSION);
     assert!(CURRENT_CERTIFICATION_VERSION <= MAX_SUPPORTED_CERTIFICATION_VERSION);
 }

rs/canonical_state/src/lazy_tree_conversion.rs

@@ -5,7 +5,7 @@ use crate::{
         encode_controllers, encode_message, encode_metadata, encode_stream_header,
         encode_subnet_canister_ranges, encode_subnet_metrics,
     },
-    CertificationVersion, MAX_SUPPORTED_CERTIFICATION_VERSION,
+    CertificationVersion, MAX_SUPPORTED_CERTIFICATION_VERSION, MIN_SUPPORTED_CERTIFICATION_VERSION,
 };
 use ic_canonical_state_tree_hash::lazy_tree::{blob, fork, num, string, Lazy, LazyFork, LazyTree};
 use ic_crypto_tree_hash::Label;
@@ -285,10 +285,11 @@ fn invert_routing_table(
 pub fn replicated_state_as_lazy_tree(state: &ReplicatedState) -> LazyTree<'_> {
     let certification_version = state.metadata.certification_version;
     assert!(
-        certification_version <= MAX_SUPPORTED_CERTIFICATION_VERSION,
-        "Unable to certify state with version {:?}. Maximum supported certification version is {:?}",
+        MIN_SUPPORTED_CERTIFICATION_VERSION <= certification_version && certification_version <= MAX_SUPPORTED_CERTIFICATION_VERSION,
+        "Unable to certify state with version {:?}. Supported certification versions are {:?}..={:?}",
         certification_version,
-        MAX_SUPPORTED_CERTIFICATION_VERSION
+        MIN_SUPPORTED_CERTIFICATION_VERSION,
+        MAX_SUPPORTED_CERTIFICATION_VERSION,
     );
 
     fork(

rs/canonical_state/src/lib.rs

@@ -138,6 +138,7 @@ pub mod visitor;
 pub use ic_certification_version::{
     all_supported_versions, CertificationVersion, UnsupportedCertificationVersion,
     CURRENT_CERTIFICATION_VERSION, MAX_SUPPORTED_CERTIFICATION_VERSION,
+    MIN_SUPPORTED_CERTIFICATION_VERSION,
 };
 
 #[cfg(test)]

rs/replicated_state/src/metadata_state.rs

@@ -785,13 +785,7 @@ impl SystemMetadata {
             // committing each state.
             prev_state_hash: Default::default(),
             state_sync_version: CURRENT_STATE_SYNC_VERSION,
-            // NB. State manager relies on the root hash of the hash tree
-            // corresponding to the initial state to be a constant.  Thus we fix
-            // the certification version that we use for the initial state. If
-            // we used CURRENT_CERTIFICATION_VERSION here, the state hash would
-            // NOT be guaranteed to be constant, potentially leading to
-            // hard-to-track bugs in state manager.
-            certification_version: CertificationVersion::V0,
+            certification_version: CURRENT_CERTIFICATION_VERSION,
             heap_delta_estimate: NumBytes::from(0),
             subnet_metrics: Default::default(),
             expected_compiled_wasms: BTreeSet::new(),

rs/state_manager/src/manifest/split/tests.rs

@@ -1,12 +1,11 @@
+use super::*;
 use assert_matches::assert_matches;
 use ic_base_types::{CanisterId, SnapshotId};
 use ic_registry_routing_table::{CanisterIdRange, CanisterIdRanges};
 use ic_state_layout::{CheckpointLayout, ReadOnly};
 use ic_test_utilities_types::ids::{SUBNET_0, SUBNET_1};
 use ic_types::{state_sync::CURRENT_STATE_SYNC_VERSION, Height};
 
-use super::*;
-
 /// Expected hash of a zero length file.
 const EMPTY_FILE_HASH: [u8; 32] = [
     152, 19, 5, 215, 192, 178, 172, 224, 245, 63, 232, 34, 244, 7, 82, 120, 250, 40, 81, 30, 140,
@@ -396,23 +395,26 @@ fn expected_split_marker() -> (FileInfo, ChunkInfo) {
 
 /// Returns the expected `FileInfo` and `ChunkInfo` for the system metadata of
 /// `SUBNET_1`.
+///
+/// `SystemMetadata` encodes the `CURRENT_CERTIFICATION_VERSION`, therefore the hashes in this
+/// test must be updated every time the current certification version is bumped.
 fn expected_subnet_1_system_metadata() -> (FileInfo, ChunkInfo) {
     (
         FileInfo {
             relative_path: PathBuf::from(SYSTEM_METADATA_FILE),
-            size_bytes: 63,
+            size_bytes: 65,
             hash: [
-                122, 238, 38, 137, 170, 83, 240, 133, 62, 48, 18, 112, 233, 148, 191, 115, 239,
-                115, 135, 234, 25, 157, 24, 45, 161, 179, 219, 112, 242, 95, 10, 217,
+                135, 141, 106, 99, 2, 246, 244, 239, 255, 254, 121, 198, 217, 0, 168, 217, 254,
+                105, 171, 56, 159, 169, 160, 159, 87, 16, 106, 9, 168, 21, 6, 246,
             ],
         },
         ChunkInfo {
             file_index: 13,
-            size_bytes: 63,
+            size_bytes: 65,
             offset: 0,
             hash: [
-                167, 162, 133, 251, 148, 255, 80, 204, 229, 63, 140, 219, 43, 228, 234, 250, 69,
-                49, 7, 200, 173, 216, 136, 186, 183, 255, 101, 117, 229, 161, 238, 156,
+                48, 206, 112, 95, 239, 131, 62, 43, 197, 160, 224, 171, 236, 107, 12, 29, 127, 75,
+                227, 118, 27, 199, 106, 203, 192, 91, 53, 67, 219, 53, 31, 173,
             ],
         },
     )

rs/state_manager/src/tree_hash.rs

@@ -61,7 +61,7 @@ mod tests {
     use super::*;
     use hex::FromHex;
     use ic_base_types::{NumBytes, NumSeconds};
-    use ic_canonical_state::CertificationVersion;
+    use ic_canonical_state::{all_supported_versions, CertificationVersion};
     use ic_crypto_tree_hash::Digest;
     use ic_error_types::{ErrorCode, UserError};
     use ic_management_canister_types::{
@@ -99,7 +99,6 @@ mod tests {
         collections::{BTreeMap, BTreeSet},
         sync::Arc,
     };
-    use strum::{EnumCount, IntoEnumIterator};
 
     const INITIAL_CYCLES: Cycles = Cycles::new(1 << 36);
 
@@ -367,35 +366,17 @@ mod tests {
         // PLEASE INCREMENT THE CERTIFICATION VERSION AND PROVIDE APPROPRIATE
         // BACKWARD COMPATIBILITY CODE FOR OLD CERTIFICATION VERSIONS THAT
         // NEED TO BE SUPPORTED.
-        let expected_hashes: [&str; CertificationVersion::COUNT] = [
-            "1B931426F36191153996B82CE305BE659AAE65D8AE75B4839736176C0453BDF3",
-            "3B3F058CD6BAF16A990585223CDD9ED98BC5507B51403707E486B764F1FF5DAE",
-            "5F17DC054CBE03F1887400247E4255764AAF3CDBFBA0AD4F414CB7ABAA4782C2",
-            "2A615692EF107355C38439DC5AABDF85BAE4979C4135F761213485C655B6F196",
-            "2A615692EF107355C38439DC5AABDF85BAE4979C4135F761213485C655B6F196",
-            "2A615692EF107355C38439DC5AABDF85BAE4979C4135F761213485C655B6F196",
-            "F86FEBBF994627432621BE7DEBD9D59BECEBD922C9C8B4F7F37BD34A5709F16B",
-            "F86FEBBF994627432621BE7DEBD9D59BECEBD922C9C8B4F7F37BD34A5709F16B",
-            "410BD1929B6884DE65DDBACC54749FDCC2A5FA3585898B9B2644147DE2760678",
-            "410BD1929B6884DE65DDBACC54749FDCC2A5FA3585898B9B2644147DE2760678",
-            "4BAB4FD35605188FDDCA534204C8E8852C9E450CEB6BE53129FB84DF109D8905",
-            "1ED37E00D177681A4111B6D45F518DF3E414B0B614333BB6552EBC0D8492B687",
-            "62B2E77DFCD17C7E0CE3E762FD37281776C4B0A38CE1B83A1316614C3F849E39",
-            "80D4B528CC9E09C775273994261DD544D45EFFF90B655D90FC3A6E3F633ED718",
-            "970BC5155AEB4B4F81E470CBF6748EFA7D8805B936998A54AE70B7DD21F5DDCC",
-            "EA3B53B72150E3982CB0E6773F86634685EE7B153DCFE10D86D9927778409D97",
-            "D13F75C42D3E2BDA2F742510029088A9ADB119E30241AC969DE24936489168B5",
+        let expected_hashes: [&str; 3] = [
             "D13F75C42D3E2BDA2F742510029088A9ADB119E30241AC969DE24936489168B5",
             "E739B8EA1585E9BB97988C80ED0C0CDFDF064D4BC5A2B6B06EB414BFF6139CCE",
             "31F4593CC82CDB0B858F190E00112AF4599B5333F7AED9403EEAE88B656738D5",
         ];
+        assert_eq!(expected_hashes.len(), all_supported_versions().count());
 
-        for certification_version in CertificationVersion::iter() {
-            assert_partial_state_hash_matches(
-                certification_version,
-                // expected_hash
-                expected_hashes[certification_version as usize],
-            );
+        for (certification_version, expected_hash) in
+            all_supported_versions().zip(expected_hashes.iter())
+        {
+            assert_partial_state_hash_matches(certification_version, expected_hash);
         }
     }
 }