* Ensure that sapling::keys::TransmissionKey jubjub point is always in the prime order group
* Adjust TransmissionKey check; add AuthorizingKey check
* Move ValueCommitment small order check to deserialization
* Apply suggestions from code review
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* Use is_torsion_free() instead of is_identity() and is_prime_order()
* Add EphemeralPublicKey small order check on instantiation; remove old checks
* Use VerificationKey instead of VerificationKeyBytes; fix tests
* Use ValidatingKey instead of VerificationKeyBytes for rk
* Reject identity when creating an Orchard EphemeralPublicKey
* Make documentation more consistent, use generator in tests
* s/JubJub/Jubjub/
* Fix zebra-consensus tests (insert_fake_orchard_shielded_data)
* Create NotSmallOrderValueCommitment, since intermediate values can be the identity
* Clarify documentation
* rustdoc
* Tidy rustdoc
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
Co-authored-by: Pili Guerra <mpguerra@users.noreply.github.com>
* Create a strategy for block heights after Sapling
Provides an arbitrary network (mainnet or testnet) and a block height
between the Sapling activation height on that network and the maximum
block height.
* Create a helper function to select block heights
Allows generating block heights inside a range using a scale factor
between 0 and 1.
* Allow specifying the outpoint index for mock UTXOs
Avoid creating multiple transparent transfers in the same transaction
with the same source UTXO, which would lead to a double spend.
* Create helper function to mock multiple transfers
Given relative block height scale factors, create a mock transparent
transfer for each one of them.
Also add a constant that serves as a guideline for the maximum number of
transparent transfers to mock.
* Create helper function to sanitize tx. version
Make sure the arbitrary transaction version is valid for the network
(testnet or mainnet) at the specified block height.
* Create `mock_transparent_transaction` helper func.
Creates a V4 or V5 mock transaction that only includes transparent
inputs and outputs.
* Create helper function for transaction validation
Performs the actual tested action of verifying a transaction. It sets up
the verifier and uses it to obtain the verification result.
* Test if zero lock time means unlocked
Generate arbitrary transactions with zero lock time, and check that they
are accepted by the transaction verifier.
* Allow changing the sequence number of an input
Add a setter method for a `transparent::Input`'s sequence number. This
setter is only available for testing.
* Test if sequence numbers can disable lock time
Create arbitrary transactions and set the sequence numbers of all of its
inputs to `u32::MAX` to see if that disables the lock time and the
transactions are accepted by the verifier.
* Test block height lock times
Make sure that the transaction verifier rejects transactions that are
still locked at a certain block height.
* Test block time lock times
Test that the transaction verifier rejects a transaction that is
validated at a block time that's before the transaction's lock time.
* Test unlocking by block height
Test that transactions unlocked at an earlier block height are accepted
by the transaction verifier.
* Test transactions unlocked by the block time
Test that transactions that were unlocked at a previous block time are
accepted by the transaction verifier.
* Fix an incorrect method comment
Co-authored-by: teor <teor@riseup.net>
* Tweak crawler timings so peers are more likely to be available
* Tweak min peer connection interval so we try all peers
* Let other tasks run between fanouts, so we're more likely to choose different peers
* Let other tasks run between retries, so we're more likely to choose different peers
* Let other tasks run after peer crawler DemandDrop
This makes it more likely that peers will become ready.
* Integrate JoinSplit verifier with transaction verifier
* Add test with malformed Groth16 Output proof
* Use TryFrom instead of From in ItemWrapper to correctly propagate malformed proof errors
* Simplify by removing ItemWrapper and directly TryFrom into Item
* Fix existing tests to work with JoinSplit validation
* Apply suggestions from code review
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
Co-authored-by: Pili Guerra <mpguerra@users.noreply.github.com>
* Do prelim checking of Sprout anchors in non-finalized state
Does not check intra-transaction interstitial states yet
* Populate sprout anchors to allow other state tests to pass
* Preliminary interstitial sprout note commitment tree anchor checks implementation
* Make sure only prior anchors are checked in the same transaction
* Add tests
* Refactor a comment
* Refactor rustdoc
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* Use the first `JoinSplit`s from mainnet
* Print debug messages
* Use correct blocks for the tests
Co-authored-by: Marek <mail@marek.onl>
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* fix parse_coinbase_height()
* move tests and create test for parse_coinbase_height()
* add a coinbase height round trip prop test
* fix range
Co-authored-by: teor <teor@riseup.net>
* extend examples in test
* add more round trip testing
* extend the range of test
Co-authored-by: teor <teor@riseup.net>
* add test for single byte
Co-authored-by: teor <teor@riseup.net>
* Stop checking the entire AddressBook for each connection attempt
* Stop redundant peer time checks within the address book
* Stop calling `Instant::now` 3 times for each address book update
* Only get the time once each time an address book method is called
* Update outdated comment
* Use an OrderedMap to efficiently store address book peers
* Add address book order tests
Zebra's latest beta continues implementing zero-knowledge proof and note commitment tree validation. In this release, we have finished implementing transaction header, transaction amount, and Zebra-specific NU5 validation. (NU5 mainnet validation is waiting on an `orchard` crate update, and some consensus parameter updates.)
We also fix a number of security issues that could pose a local denial of service risk, or make it easier for an attacker to make a node follow a false chain.
As of this release, Zebra will automatically download and cache the Sprout and Sapling Groth16 circuit parameters. The cache uses around 1 GB of disk space. These cached parameters are shared across all Zebra and `zcashd` instances run by the same user.
See CHANGELOG.md for the full list of changes in this release.
* Add Transaction::sprout_joinsplits()
* Add Anchor variants to ValidateContextError
* Make Chain anchor collections pub(crate)
* tracing::instrument several methods in state
* Add contains_*_anchors methods to FinalizedState
* Add check::anchors module and function
* Verify that anchors_refer_to_earlier_treestates in when updating chains in non-finalized state
* Update zebra-state/src/service/check/anchors.rs
Co-authored-by: teor <teor@riseup.net>
* Add anchors() to sapling::ShieldedData
* Add sapling_anchors() to Transaction
* Use Transaction::sapling_anchors() in the anchors_refer_to_earlier_treestates() check
* Whoops, itertools
* Add a comment for improvement
Co-authored-by: teor <teor@riseup.net>
* Add & use a cfg(test) method on FinalizedState to prep test state with anchors to allow other tests to pass contextual checks
* Allow test nullifier checks to pass by populating anchor sets, allowing test anchor checks to pass
* Add mainnet block 419202 and its sapling note commitment tree root to test vectors
* Test sapling anchor verification using the first few Sapling blocks data
* Correct comment
* assert_eq instead of assert(bool)
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Update zebra-state/src/service/non_finalized_state.rs
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Marek <mail@marek.onl>
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Download and load Sprout parameters using zcash_proofs
Also update some librustzcash dependencies, to avoid duplicate dependencies.
* Update upstream orchard to avoid a compilation error
* Skip librustzcash batch refactor for now, to avoid compilation errors
* Change the cache ID, so we actually cache Sprout
* Move existing file checks into zcash_proofs
* Add a 1 hour timeout to parameter file downloads
* Give other tasks priority, before spawning the download task
* Update to the latest version of our modified librustzcash fork
* Change the cache key for Sprout
* Add 40 minutes to CI timeouts for occasional sprout downloads
* Update to zcash_proofs with split downloads
* Check file sizes to help debug parameter load failures in zcash_proofs
* Start the second download once the first has finished in zcash_proofs
* Document the parameter download task
* Stop hashing existing files twice
* validate consensus rule: negative fee not allowed
* fix a test TODO
* fix imports
* move import back
* fix panic text
* join consensus rule check code
* match assertion better in tests
* fix test
* fix consensus rule validation
* remove panics
* Delete a TODO
Co-authored-by: teor <teor@riseup.net>
* Create a `LockTime::unlocked` helper constructor
Returns a `LockTime` that is unlocked at the genesis block.
* Return `Option<LockTime>` from `lock_time` method
Prepare to return `None` for when a transaction has its lock time
disabled.
* Return `None` instead of zero `LockTime`
Because a zero lock time means that the transaction was unlocked at the
genesis block, so it was never actually locked.
* Rephrase zero lock time check comment
Clarify that the check is not redundant, and is necessary for the
genesis transaction.
Co-authored-by: teor <teor@riseup.net>
* Add a `transparent::Input::sequence` getter method
Retrieve a transparent input's sequence number.
* Check if lock time is enabled by a sequence number
Validate the consensus rule that the lock time is only enabled if at
least one transparent input has a value different from `u32::MAX` as its
sequence number.
* Add more Zcash specific details to comment
Explain the Zcash specific lock time behaviors.
Co-authored-by: teor <teor@riseup.net>
* Add `time` field to `Request::Block` variant
The block time to use to check if the transaction was unlocked and
allowed to be included in the block.
* Add `Request::block_time` getter
Returns the block time for the block that owns the transaction being
validated or the current time plus a tolerance for mempool transactions.
* Validate transaction lock times
If they are enabled by a transaction's transparent input sequence
numbers, make sure that they are in the past.
* Add comments with consensus rule parts
Make it easier to map what part of the consensus rule each match arm is
responsible for.
Co-authored-by: teor <teor@riseup.net>
* add testnet test blocks around nu5
* validate coinbase expiration height
* change const name and doc
Co-authored-by: teor <teor@riseup.net>
* change commit location
Co-authored-by: teor <teor@riseup.net>
* use pre Nu5 rules when there is no activation height
* add sapling final root to nu5 test vectors
* fix tests
Co-authored-by: teor <teor@riseup.net>
* Implement incremental note commitment Merkle tree for Sprout
* Add tests for Sprout note commitment tree
* Remove the `Arbitrary` attribute
* Reverse the vector of empty roots
* Add more tests
* Refactor rustdoc
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* Refactor rustdoc
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* rustdoc
* Rustdoc
* rustdoc links
* Oops, need the trait in scope to use it
* Avoid accessing the wrapped hash directly
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* rustfmt
* Add typing
* Avoid accessing the wrapped hash directly
* Implement incremental note commitment Merkle tree for Sprout
* Add tests for Sprout note commitment tree
* Remove the `Arbitrary` attribute
* Reverse the vector of empty roots
* Add more tests
* Refactor rustdoc
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* Refactor rustdoc
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* rustdoc
* Rustdoc
* rustdoc links
* Oops, need the trait in scope to use it
* Avoid accessing the wrapped hash directly
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* rustfmt
* Add typing
* Avoid accessing the wrapped hash directly
* Add Overwinter final roots (test vectors)
* Test sprout note commitments trees on Overwinter blocks
* Add new test vectors
* Finish the tests for the note commitment trees
* Make the wrapped hash in `Root` private
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
Co-authored-by: Deirdre Connolly <durumcrustulum@gmail.com>
* First pass at async Halo2 verification service
Stubs out a batch verifier for the future.
The dependencies for orchard, halo2, librustzcash, zcash_primitives, have
not been resolved.
* Halo2 verifier service and test
* Remove redundant conversion
* Test async halo2 verifier service with pre-computed Orchard shielded data test vectors
* Fix typo
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Assert future result is_ok() in Halo2 verifier test
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Shorten tower::Service trait constraints for Halo2 verifier tests
* Remove commented out trait constraints
* .expect() vs .unwrap() to parse orchard::redpallas::VerificationKey
* Use .to_vec() for some test vectors
* Fix self-referential Display impl
* Fix deps
* Distinguish orchard vs zebra_chain::orchard imports
* Add test that halo2 verifier fails with malformed proof inputs
* Use thiserror for Halo2Error
* Use ZcashFoundation/orchard instead of dconnolly/orchard
* Add a link to the issue to remove the zfnd fork of orchard crate
* Update zebra-consensus/Cargo.toml
Co-authored-by: teor <teor@riseup.net>
* Add note
* Move artificial Orchard shielded data test vectors to zebra-test
* Align brackets
* Tidy some trait constraints and debug statements
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: teor <teor@riseup.net>
* Upgrade aes and fpe
* Upgrade bellman, bls12_381, jubjub to latest
* Upgrade x25519-dalek to 1.2.0 and curve25519-dalek to 3.2.0 in the Cargo.lock
* Skip outdated hdrhistogram rather than its dependencies
Co-authored-by: teor <teor@riseup.net>
* Cleanup a function that calls zcash_script
* Remove zebra_test::prelude macros that conflict with the Rust prelude
* Add sigops count support to zebra-script
* Check MAX_BLOCK_SIGOPS in the block verifier
* Test MAX_BLOCK_SIGOPS on generated and historic blocks
* Add SAFETY comments for all unsafe zebra-script code
* Explain where the consensus rule comes from
* Remove unused pretty_assertions dependency
* Allow large test block generation functions with the proptest-impl feature
* Replace `as` with `try_into` for integer conversions in unsafe code
* Expand SAFETY comments
* Revert "Remove commented-out code"
This reverts commit 9e69777925f103ee11e5940bba95b896c828839b.
* Implement deserialization for `addrv2` messages
* Limit addr and addrv2 messages to MAX_ADDRS_IN_MESSAGE
* Clarify address version comments
* Minor cleanups and fixes
* Add preallocation tests for AddrV2
* Add serialization tests for AddrV2
* Use prop_assert in AddrV2 proptests
* Use a generic utility method for deserializing IP addresses in `addrv2`
* Document the purpose of a conversion to MetaAddr
* Fix a comment typo, and clarify that comment
* Clarify the unsupported AddrV2 network ID error and enum variant names
```sh
fastmod AddrV2UnimplementedError UnsupportedAddrV2NetworkIdError zebra-network
fastmod Unimplemented Unsupported zebra-network
```
* Fix and clarify unsupported AddrV2 comments
* Replace `panic!` with `unreachable!`
* Clarify a comment about skipping a length check in a test
* Remove a redundant test
* Basic addr (v1) and addrv2 deserialization tests
* Test deserialized IPv4 and IPv6 values in addr messages
* Remove redundant io::Cursor
* Add comments with expected values of address test vectors
* Add a `Duration32::from_days` constructor
Make it simpler to construct a `Duration32` representing a certain
number of days.
* Add `MetaAddr::was_not_recently_seen` method
A helper method to check if a peer was never seen before or if it was
last seen a long time ago. This will be one of the conditions to
consider a peer as unreachable.
* Add `MetaAddr::is_probably_unreachable` method
A helper method to check if a peer should be considered unreachable. It
is considered unreachable if recent connection attempts have failed and
it was not recently seen.
If a peer is considered unreachable, Zebra shouldn't attempt to connect
to it again.
* Do not keep trying to connect to unreachable peer
A peer is probably unreachable if it was last seen a long time ago and
if it's last connection attempt failed.
* Test `was_not_recently_seen`
Redo the calculation on arbitrary `MetaAddr`s.
* Test `is_probably_unreachable`
Redo the calculation on arbitrary `MetaAddr`s.
* Test if probably unreachable peers are ignored
Given an `AddressBook` with a list of arbitrary `MetaAddr`s, check that
none of the peers listed for a reconnection is probably unreachable.
* Rename unit test to improve clarity
Remove the double negative from the name.
Co-authored-by: teor <teor@riseup.net>
* Rename constant to `MAX_RECENT_PEER_AGE`
Make the purpose of the constant clearer.
Co-authored-by: teor <teor@riseup.net>
* Rename method to `last_seen_is_recent`
Remove the double negative from the name.
* Rename method to `is_probably_reachable`
Avoid having to negate the result of the method in security critical
filter.
* Move check into `is_ready_for_connection_attempt`
Make sure the check is used in any place that requires a peer that's
ready for a connection attempt.
* Improve test documention
Describe the goal of the test better.
Co-authored-by: teor <teor@riseup.net>
* Improve `is_probably_reachable` documentation
List the conditions as bullet points.
Co-authored-by: teor <teor@riseup.net>
* Document what happens when peers have no last seen time
Co-authored-by: teor <teor@riseup.net>
* Implement addr v1 serialization using a separate AddrV1 type
* Remove commented-out code
* Split the address serialization code into modules
* Reorder v1 and in_version fields in serialization order
* Fix a missed search-and-replace
* Explain conversion to MetaAddr
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Add CompactSize64 and CompactSizeMessage types
But don't remove read_compactsize and write_compactsize yet.
* Fix CompactSize capitalisation
```sh
fastmod compactSize CompactSize zebra* book
fastmod compactsize CompactSize zebra* book
```
* Make CompactSize patterns consistent with integer lengths
* Replace unwrap_err with asserting is_err
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Replace a panic with an assertion
* Make generic serialization use CompactSizeMessage
* Fix type inference and borrow-checker errors
* Doctest fixes
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* ZIP-401 weighted random mempool eviction
* rename zcash.mempool.total_cost.bytes to zcash.mempool.cost.bytes
Co-authored-by: teor <teor@riseup.net>
* Remove duplicated lines
* Add cost() method to UnminedTx
Update serialization failure messages
* More docs quoting ZIP-401 rules
* Change mempool::Storage::new() to handle Copy-less HashMap, HashSet
* mempool: tidy cost types and evict_one()
* More consensus rule docs
* Refactor calculating mempool costs for Unmined transactions
* Add a note on asympotic performance of calculating weights of txs in mempool
* Bump test mempool / storage config to avoid weighted random cost limits
* Use mempool tx_cost_limit = u64::MAX for some tests
* Remove failing tests for now
* Allow(clippy::field-reassign-with-default) because of a move on a type that doesn't impl Copy
* Fix mistaken doctest formatting
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Increase test timeout for Windows builds
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Limit tx size
Zebra now limits the transaction size in the `zcash_deserialize()` method for
`Transaction`.
* Remove unused error variants (#2941)
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Limit tx size
Zebra now limits the transaction size in the `zcash_deserialize()` method for
`Transaction`.
* Test the tx deserialization limit
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Increment the crates that have new commits since the last version
* Increment the crates that depend on crates that have changed
* Increment the version of `zebra-script`
* Use the `zebrad` version in the `zebra-network` user agent string
* Use the `v1.0.0-alpha.19` git tag in `README.md`
* Copy the draft changelog into `CHANGELOG.md`
* Delete bumps
* Update CHANGELOG.md
Co-authored-by: teor <teor@riseup.net>
* Add newly merged PRs
Co-authored-by: teor <teor@riseup.net>
* Create a new VerifiedUnminedTx containing the miner fee
* Use VerifiedUnminedTx in mempool verification responses
And do a bunch of other cleanups.
* Use VerifiedUnminedTx in mempool download and verifier
* Use VerifiedUnminedTx in mempool storage and verified set
* Impl Display for VerifiedUnminedTx, and some convenience methods
* Use VerifiedUnminedTx in existing tests
* Limit the size of rejection lists when there is a spend conflict
Previously, `insert` would return early with an error,
and skip limiting the rejection list sizes.
* Use prop_assert macros in proptests, rather than assert
* Add `HashSet`s to help spend conflict detection
Keep track of the spent transparent outpoints and the revealed
nullifiers.
Clippy complained that the `ActiveState` had variants with large size
differences, but that was expected, so I disabled that lint on that
`enum`.
* Clear the `HashSet`s when clearing the mempool
Clear them so that they remain consistent with the set of verified
transactions.
* Use `HashSet`s to check for spend conflicts
Store new outputs into its respective `HashSet`, and abort if a
duplicate output is found.
* Remove inserted outputs when aborting
Restore the `HashSet` to its previous state.
* Remove tracked outputs when removing a transaction
Keep the mempool storage in a consistent state when a transaction is
removed.
* Remove tracked outputs when evicting from mempool
Ensure eviction also keeps the tracked outputs consistent with the
verified transactions.
* Refactor to create a `VerifiedSet` helper type
Move the code to handle the output caches into the new type. Also move
the eviction code to make things a little simpler.
* Refactor to have a single `remove` method
Centralize the code that handles the removal of a transaction to avoid
mistakes.
* Move mempool size limiting back to `Storage`
Because the evicted transactions must be added to the rejected list.
* Remove leftover `dbg!` statement
Leftover from some temporary testing code.
Co-authored-by: teor <teor@riseup.net>
* Remove unnecessary `TODO`
It is more speculation than planning, so it doesn't add much value.
Co-authored-by: teor <teor@riseup.net>
* Fix typo in documentation
The verb should match the subject "transactions" which is plural.
Co-authored-by: teor <teor@riseup.net>
* Add a comment to warn about correctness
There's a subtle but important detail in the implementation that should
be made more visible to avoid mistakes in the future.
Co-authored-by: teor <teor@riseup.net>
* Remove outdated comment
Left-over from the attempt to move the eviction into the `VerifiedSet`.
* Improve comment explaining lint removal
Rewrite the comment explaining why the Clippy lint was ignored.
* Check for spend conflicts in `VerifiedSet`
Refactor to avoid API misuse.
* Test rejected transaction rollback
Using two transactions, perform the same test adding a conflict to both
of them to check if the second inserted transaction is properly
rejected. Then remove any conflicts from the second transaction and add
it again. That should work, because if it doesn't it means that when the
second transaction was rejected it left things it shouldn't in the
cache.
* Test removal of multiple transactions
When removing multiple transactions from the mempool storage, all of the
ones requested should be removed and any other transaction should be
still be there afterwards.
* Increase mempool size to 4, so that spend conflict tests work
If the mempool size is smaller than 4,
these tests don't fail on a trivial removal bug.
Because we need a minimum number of transactions in the mempool
to trigger the bug.
Also commit a proptest seed that fails on a trivial removal bug.
(This seed fails if we remove indexes in order,
because every index past the first removes the wrong transaction.)
* Summarise transaction data in proptest error output
* Summarise spend conflict field data in proptest error output
* Summarise multiple removal field data in proptest error output
And replace the very large proptest debug output with the new summary.
Co-authored-by: teor <teor@riseup.net>
* Update versions for zebra v1.0.0-alpha.18 release
* WIP: Initial PR list
* Remove uninteresting version bumps from CHANGELOG
* Categorise and group PRs in CHANGELOG, removing uninteresting PRs
* Further refine and categorise changelog entries
* Fix tag url
* Final changes to CHANGELOG
* Add a changelog description
* Spacing
* Clarify and fix changelog PR descriptions
* Add PRs that are about to be merged
* More slight clarifications
* Spacing
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Alfredo Garcia
teor
Deirdre Connolly
Conrado Gouvea
Janito Vaqueiro Ferreira Filho
dependabot[bot]
Marek
Pili Guerra
Dimitris Apostolou