Commit graph

237 commits

Author SHA1 Message Date
Evgeniy Stratonikov
100f2db3fb native: implement CryptoLib contract 2021-03-10 19:24:19 +03:00
Evgeniy Stratonikov
7160675ac1 compiler/interop: improve conversion to bytes interops
Allow to convert to both `Buffer` and `ByteString`
and explicitly mention VM types. Rename `ToByteArray` to `ToBytes`
to avoid ambiguity.
2021-03-10 13:38:44 +03:00
Evgeniy Stratonikov
fd4174ad31 core/state: remove IsConst from StorageItem 2021-03-09 11:59:08 +03:00
Evgeniy Stratonikov
dcbfe856cd compiler/interop: fix contract.GetCallFlags 2021-03-05 10:17:35 +03:00
Evgeniy Stratonikov
ffd85dd51d native/policy: remove MaxBlockSize and MaxBlockSystemFee 2021-03-04 16:59:19 +03:00
Evgeniy Stratonikov
7b8533b67c native/policy: move MaxTransactionsPerBlock to config 2021-03-04 16:59:19 +03:00
Evgeniy Stratonikov
d66ce43239 compiler/interop: replace int64 with int 2021-03-04 13:20:43 +03:00
Evgeniy Stratonikov
1138143a50 compiler/interop: add flag type for PutEx 2021-03-04 13:13:12 +03:00
Evgeniy Stratonikov
1e2944f492 compiler/interop: return proper type from contract.GetCallFlags 2021-03-04 13:09:03 +03:00
Evgeniy Stratonikov
0b54870bfe compiler: add missing math routines
Add interops for ABS, SIGN, MIN, MAX, WITHIN opcodes
2021-03-04 13:05:33 +03:00
Evgeniy Stratonikov
56fe6574c9 compiler: simplify convert.To* processing
With inlining there is no need for special logic in compiler.
2021-03-04 13:05:33 +03:00
Evgeniy Stratonikov
5f4385d3fa compiler: implement syscalls for POW and SQRT opcodes 2021-03-04 13:05:33 +03:00
Evgeniy Stratonikov
578bbabd1d compiler: allow to emit opcodes directly 2021-03-04 13:03:05 +03:00
Roman Khimov
58ea4607d0
Merge pull request #1805 from nspcc-dev/interop/convertcontext-fix
interop: fix ConvertContextToReadOnly interop
2021-03-04 12:31:36 +03:00
Anna Shaleva
0c464083ed interop: fix ConvertContextToReadOnly interop
The same bug as in #1804.
2021-03-04 11:51:32 +03:00
Anna Shaleva
52e4d69c82 interop: fix CreateMultisigAccount interop
Introduced in #1720.
2021-03-04 11:39:49 +03:00
Evgeniy Stratonikov
f9f1fe03b2 core: refactor native call
1. `System.Contract.CallNative` expects version on stack.
2. Actual method is determined based on current
   instruction pointer.
3. Native hashes don't longer depend on NEF checksum.
2021-02-26 10:59:09 +03:00
Roman Khimov
f264996f74
Merge pull request #1777 from nspcc-dev/fix/vote
core: fix native method call flags
2021-02-25 18:55:10 +03:00
Evgeniy Stratonikov
cbda20aca3 core: fix native method call flags
Replace `WriteStates` with `States`.

Follow neo-project/neo#2339.
Close #1775.
Related #1725.
2021-02-25 18:07:33 +03:00
Evgeniy Stratonikov
ac91de80e7 interop: fix Base58Decode interop 2021-02-25 15:11:52 +03:00
Evgeniy Stratonikov
df5314f286 compiler: refactor syscall handling
Close #941.
2021-02-24 12:51:15 +03:00
Anna Shaleva
c82b11eebe compiler: add CreateMultisigAccount interop 2021-02-19 17:34:23 +03:00
Roman Khimov
ca08a559fa interop: allow transfer calls to read states
Follow-up to #1734.
2021-02-12 12:56:15 +03:00
Evgeniy Stratonikov
18b7584cb4 compiler/interop: add Manifest to Contract struct 2021-02-08 13:13:11 +03:00
Evgeniy Stratonikov
69c011b3e7 compiler: implement Ledger contract wrapper 2021-02-08 13:09:41 +03:00
Evgeniy Stratonikov
7bee28b81e compiler: implement Management contract wrapper 2021-02-08 13:09:41 +03:00
Evgeniy Stratonikov
9988f4ed1c compiler: implement Notary contract wrapper 2021-02-08 11:44:39 +03:00
Evgeniy Stratonikov
2f26490e59 compiler: implement RoleManagement contract wrapper 2021-02-08 11:44:39 +03:00
Evgeniy Stratonikov
77fcfeccff compiler: implement Policy contract wrapper 2021-02-08 11:44:39 +03:00
Evgeniy Stratonikov
3c237e2a29 compiler: implement NameService contract wrapper 2021-02-08 11:44:39 +03:00
Evgeniy Stratonikov
779fba3001 compiler: implement Oracle contract wrapper 2021-02-08 11:44:39 +03:00
Evgeniy Stratonikov
34a6eef8ce compiler: implement GAS contract wrapper 2021-02-08 11:44:39 +03:00
Evgeniy Stratonikov
6e866b622a compiler: implement NEO contract wrapper 2021-02-08 11:44:39 +03:00
Roman Khimov
ac527650eb native: add Ledger contract, fix #1696
But don't change the way we process/store transactions and blocks. Effectively
it's just an interface for smart contracts that replaces old syscalls.

Transaction definition is moved temporarily to runtime package and Block
definition is removed (till we solve #1691 properly).
2021-02-04 13:12:11 +03:00
Evgeniy Stratonikov
9b1a7021ba core: add PickN flags to Storage.Find
Allow to pick items by index from serialized struct or array.
2021-01-15 21:12:10 +03:00
Evgeniy Stratonikov
44af99fd07 core: add Deserialize flag to Storage.Find
Allow to deserialize values being iterated over.
2021-01-15 21:12:10 +03:00
Evgeniy Stratonikov
7fc0c04dba core: add flags to Storage.Find
It can be iterated over keys, values or both.
Prefix can be stripped.
2021-01-15 21:12:08 +03:00
Evgeniy Stratonikov
2130e17f0c core,vm: remove System.Enumerator.* interops
Map iterator now returns key-value pair, while array/byte-array
iterators work like old enumerators.
Follow neo-project/neo#2190.
2021-01-15 21:11:32 +03:00
Evgeniy Stratonikov
d04b000748 vm: remove iterator/enumerator Concat API
Follow neo-project/neo#2170.
2021-01-15 21:08:59 +03:00
Evgenii Stratonikov
1c0c331e25 core: update System.Contract.Call syscall
1. Remove `System.Contract.CallEx`.
2. Extend number of parameters.
3. Add return value count to `VM.Context`.
2021-01-14 18:23:36 +03:00
Roman Khimov
ab12eee346 native: move contract deployment to management contract
See neo-project/neo#2119.
2020-12-14 15:23:46 +03:00
Anna Shaleva
fadbae8997 core: rename call flags
Also new States flag is added and ReadOnly flag is adjusted.
2020-12-11 10:34:01 +03:00
Evgenii Stratonikov
37a8550215 compiler: add contract.CallEx interop 2020-12-10 13:45:10 +03:00
Evgenii Stratonikov
b807fd9e7f compiler: rename engine.AppCall() to contract.Call() 2020-12-10 13:45:10 +03:00
Roman Khimov
286d9185f4 smartcontract: remove contract features
We're featureless now, all contracts have access to storage and payable status
is to be determined via new NEP. Follow neo-project/neo#2060.
2020-11-13 21:26:23 +03:00
Evgenii Stratonikov
d193e16662 compiler: support System.Binary.Atoi/Itoa syscalls 2020-11-10 16:15:10 +03:00
Roman Khimov
eaa260474f trigger/core: split System trigger into OnPerist and PostPersist
Follow neo-project/neo#2022.
2020-10-29 19:17:07 +03:00
Roman Khimov
5f22bdfecf
Merge pull request #1375 from nspcc-dev/compiler/types
Smartcontract types definition in interops
2020-09-16 14:43:50 +03:00
Evgenii Stratonikov
bcc11cbd74 compiler: support removing slice elements
Go-way of removing elements from slice is via `append` builtin.
There is a separate opcode for removing elements from
Arrays, which is cheaper and supported in this commit.
2020-09-15 16:33:43 +03:00
Evgenii Stratonikov
b319f127e7 interop: make Base*Encode return string 2020-09-09 13:10:38 +03:00
Evgenii Stratonikov
37f7363386 interop: return struct pointers where needed
`Transaction`, `Block` and `Contract` are represented as
`Array`s in VM, so we must return pointers.

Revert a1f98f92.
2020-09-09 13:10:04 +03:00
Evgenii Stratonikov
cee1836183 interop: provide missing smartcontract parameter type defs
Contract can have Hash160, Hash256, Signature etc. types which
all map to a `[]byte` in Go. Having synonyms helps us to generate
proper manifest file.
2020-09-09 13:06:44 +03:00
Roman Khimov
9c72ea1d64 core/interop: add base58 encoding/decoding syscalls
Follow neo-project/neo#1833.
2020-08-23 17:19:56 +03:00
Roman Khimov
e7d13e6db2 *: fix misspellings found in Go Report Card 2020-08-14 12:16:24 +03:00
Evgenii Stratonikov
f2cb1d5f02 compiler: use constants in interops
We now support using exported constants, so there is no
need in declaring functions. All functions from `interop/`
are not to be compiled.

Fix #1298.
2020-08-10 17:52:31 +03:00
Evgenii Stratonikov
28e0661f82 interop: update AppCall comment
Do not require contract hash to be known at compile time.
2020-07-27 13:00:35 +03:00
Evgenii Stratonikov
d2ddf7b7cb *: support invoking methods by offset
Allow to invoke methods by offset:
1. Every invoked contract must have manifest.
2. Check arguments count on invocation.
3. Change AppCall to a regular syscall.
4. Add test suite for `System.Contract.Call`.
2020-07-27 13:00:35 +03:00
Roman Khimov
d8a1c3de46
Merge pull request #1221 from nspcc-dev/neo3/interop/post-preview2_adjustment3
interop: post-preview2 adjustment, part 3
2020-07-23 20:35:53 +03:00
Anna Shaleva
76acef18ad core: adjust System.Runtime.Platform interop
Part of #1055.

Added `Platform` method to compiler.
2020-07-23 07:51:24 +03:00
Anna Shaleva
c9ef7425ac core: adjust System.Iterator.Create interop
Closes #1201.

It should be able to iterate over primitive byte-array-like types also.
2020-07-23 07:51:55 +03:00
Anna Shaleva
459ac34839 core: adjust System.Enumerator.Create interop
Part of #1201.

It should be able to create enumerator from primitive byte-array-like
stack items too.
2020-07-23 07:51:24 +03:00
Anna Shaleva
b8d82b49ec core: add Neo.Crypto.RIPEMD160 interop
Closes #1193.
2020-07-22 16:58:32 +03:00
Anna Shaleva
84bf87df52 core: adjust System.Storage.PutEx interop
Part of #1055.

Added System.Storage.PutEx to compiler. Added StorageFlag in order to
denote whether item is constant or not.
2020-07-22 16:58:23 +03:00
Evgenii Stratonikov
3d7fa9de93 *: make Notify interop accept event name 2020-07-20 13:33:32 +03:00
Anna Shaleva
74d2f437f4 core: add System.Binary.Base64Encode(Decode) interops
Part of #1055
2020-07-17 12:36:18 +03:00
Anna Shaleva
f31ce9289d core: add System.Contract.GetCallFlags interop
Part of #1055.

It returns calling flags of the current context.
2020-07-17 12:35:02 +03:00
Anna Shaleva
842feb2533 core: adjust System.Contract.Update interop
Part of #1055.

We should check contract scripthash against the one provided in manifest
and manifest groups. We shouldn't put on stack anything after return.
And ofcourse, we mast not destroy the old contract at the end, as
`contractDestroy` removes all storage items associated with the
old contract ID (which equals to the new contract ID). We just remove
old contract state - it's enough.
2020-07-17 12:33:44 +03:00
Anna Shaleva
fddad0b475 core: adjust System.Contract.Create interop
Part of #1055.

It should check given scripthash against manifest groups and return the
contract state as a struct (not interop interface).
2020-07-17 09:28:52 +03:00
Anna Shaleva
d2ec0fed3d core: adjust System.Blockchain.GetContract interop
Part of #1055.

It should put on stack an array instead of interop interface.
2020-07-17 09:28:52 +03:00
Anna Shaleva
063a7f683c compiler: add CheckMultisig interops
Part of #918
2020-07-14 16:21:38 +03:00
Anna Shaleva
a3e306ff78 core: implement Secp256k1 Verify and CheckMultisig interops
Closes #918.
2020-07-14 16:21:34 +03:00
Anna Shaleva
17233e1d8e core: rename Neo.Crypto.Verify to Neo.Crypto.VerifyWithECDsaSecp256r1
Part of #918
2020-07-14 16:19:12 +03:00
Roman Khimov
b3e450477d interop/runtime: synchronize trigger values with smartcontract/trigger
Neo 3.0 has new updated and improved constants. A better (non-function-based)
fix requires #1154 to be solved.
2020-07-07 20:25:52 +03:00
Roman Khimov
d81d826bfc core: fix Storage.Get to return Null when there is no value
Match C# implementation and fix state inconsistency at block 249920 of
preview2 testnet. Make our Go Storage.Get return nil and adapt
examples/tests.
2020-06-24 10:43:58 +03:00
Evgenii Stratonikov
61cae8d8b1 compiler: implement missing System.Contract.* interops
Support System.Contract.IsStandard/CreateStandardAccount syscall.
2020-06-17 11:38:34 +03:00
Evgenii Stratonikov
3762ebdd08 core: implement System.Runtime.GetInvocationCounter syscall 2020-06-17 11:24:11 +03:00
Evgenii Stratonikov
75e597f880 core: implement System.Runtime.GetNotifications syscall 2020-06-17 11:24:11 +03:00
Evgenii Stratonikov
a4e4439967 core,vm: implement System.Runtime.GasLeft syscall 2020-06-17 11:24:11 +03:00
Evgenii Stratonikov
ad2a75a500 core: move System.ExecutionEngine.* interops to System.Runtime.* 2020-06-16 12:30:55 +03:00
Evgenii Stratonikov
becb8a0f72 compiler: support System.Json.* syscalls 2020-06-16 11:35:08 +03:00
Evgenii Stratonikov
18066143bd core,vm: adjust binary (de-)serialization syscalls
Related #1027.

1. Move System.Runtime.(De)serialize to System.Binary.*
2. Rename compiler stubs.
3. Adjust opcode prices.
2020-06-16 11:00:38 +03:00
Evgenii Stratonikov
f8a11f61b6 core: update *.Contract.* interops
1. Remove GetScript, IsPayable, GetStorageContext.
2. Revert 82319538 related to GetStorageContext.
3. Rename Migrate to Update.
4. Move remaining to System.Contract.*.

Related #1031.
2020-06-11 10:50:35 +03:00
Evgenii Stratonikov
df958caf93 core: add Manifest to state.Contract 2020-06-11 10:45:24 +03:00
Evgenii Stratonikov
38d020d1a2 core: move Neo.Storage.* interops to System.* 2020-06-10 12:13:35 +03:00
Evgenii Stratonikov
0472a0b0b1 core: move Neo.Runtime/Enumerator/Iterator.* interops to System.* 2020-06-10 12:13:35 +03:00
Evgenii Stratonikov
3d3fe9398e core: remove Neo.Header/Witness/Account.* interops
They are not present in NEO3.
2020-06-10 12:13:18 +03:00
Anna Shaleva
8b7abd36c9 core: remove Block.GetTransactions, Block.GetTransactionsCount interops
Updated System.Blockchain.GetBlock interop replaced the functionality of
the following interops:
	System.Block.GetTransactions
	System.Block.GetTransactionCount
	Neo.Block.GetTransactions
	Neo.Block.GetTransactionsCount
2020-06-09 23:24:11 +03:00
Anna Shaleva
7a2d37cf7e core: update System.Blockchain.GetBlock interop
closes #1025

Now we put on stack stackitem.Array instead of Interop, so we're able to
use all available block properties without extra interop getters.
Removed Neo.Blockchain.GetBlock interop as we don't need it anymore.
2020-06-09 23:24:04 +03:00
Anna Shaleva
e2187c0a96 core: remove Block.GetTransaction interops
Removed Neo.Block.GetTransaction and System.Block.GetTransaction
interops. These interops were replaced by new
System.Blockchain.GetTransactionFromBlock interop.
2020-06-09 22:54:21 +03:00
Anna Shaleva
d692de5ea4 core: add System.Blockchain.GetTransactionFromBlock interop 2020-06-09 22:54:16 +03:00
Anna Shaleva
1e63ae4b3f core: update System.Blockchain.GetTransactionHeight interop
Update System.Blockchain.GetTransactionHeight and removed
Neo.Blockchain.GetTransactionHeight interop as we don't need it.
2020-06-09 22:04:18 +03:00
Anna Shaleva
53655c5ac2 core: implement new System.Blockchain.GetTransaction interop
closes #1023

Now we put on stack stackitem.Array instead of Interop, so we don't
need old transaction-related interops anymore. Removed the following
interops:
	System.Transaction.GetHash
	Neo.Transaction.GetAttributes
	Neo.Transaction.GetHash
	Neo.Transaction.GetWitnesses
	Neo.Attribute.GetData
	Neo.Attribute.GetUsage

Also removed the following duplicated NEO interop:
	Neo.Blockchain.GetTransaction
2020-06-09 22:04:13 +03:00
Roman Khimov
a986e2a064 *: drop support for old on-chain assets
You no longer can transfer them, so creating/renewing/storing doesn't make
much sense.
2020-06-05 19:21:37 +03:00
Roman Khimov
709146f295 transaction: drop Inputs and Outputs, forget UTXO 2020-06-05 19:20:16 +03:00
Roman Khimov
21efccd300 transaction: remove type field, set Version to 0
Two changes being done here, because they require a lot of updates to
tests. Now we're back into version 0 and we only have one type of
transaction.

It also removes GetType and GetScript interops, both are obsolete in Neo 3.
2020-06-05 19:20:16 +03:00
Roman Khimov
0a09a20900 transaction: drop Register transaction type
And everything associated like SystemFee configuration.
2020-06-05 19:20:16 +03:00
Roman Khimov
169c5ae775 transaction: drop Issue TX support 2020-06-05 19:20:16 +03:00
Roman Khimov
f445f7c602 transaction: drop Contract transaction type 2020-06-05 19:20:16 +03:00
Roman Khimov
dfc7a9bfd1 transaction: drop Claim TX type 2020-06-05 19:20:16 +03:00
Evgenii Stratonikov
f39b51deee compiler: restore support for GetUnspentCoins
Revert a587274.
2020-05-27 12:01:50 +03:00
Roman Khimov
77b92de074 interop: add some top-level doc.go 2020-05-27 12:01:50 +03:00
Roman Khimov
7e96f82a5b compiler/interop: add support for working with witnesses 2020-05-27 12:01:50 +03:00
Roman Khimov
87e7e157ae interop/util: extend documentation 2020-05-27 12:01:50 +03:00
Roman Khimov
85cc0639bb interop/transaction: update documentation 2020-05-27 12:01:50 +03:00
Roman Khimov
e32d0e01af compiler|transaction: remove transaction.GetUnspentCoins support
It's useless. Even though there is Neo.Transaction.GetUnspentCoins syscall
that can be used, its return type is an interop structure that's not accepted
by any other syscall, so you can't really do anything with it. And there is no
such interface for the .net Framework.
2020-05-27 12:01:50 +03:00
Roman Khimov
1cbd75ab9e compiler|transaction: fix transaction.GetScript build, add to interop
There is no such syscall as Neo.Transaction.GetScript and GetScript should be
available for contract's use.
2020-05-27 12:01:50 +03:00
Roman Khimov
559e8a16da compiler/storage: add read-only related interops 2020-05-27 12:01:50 +03:00
Roman Khimov
bfd8fe5960 interop/storage: update documentation 2020-05-27 12:01:50 +03:00
Roman Khimov
ddb9497649 interop/runtime: update documentation, fix Notify
Notify doesn't return anything!
2020-05-27 12:01:50 +03:00
Roman Khimov
6d2b2d7263 compiler/iterator: add missing iterator.Concat function
We have a syscall for it, so it should be exposed.
2020-05-27 12:01:50 +03:00
Roman Khimov
01b5299355 interop/iterator: documentation update 2020-05-26 20:07:44 +03:00
Roman Khimov
2bf7329a15 interop/input|output: update documentation 2020-05-26 20:07:37 +03:00
Roman Khimov
80b39649aa interop/header: update documentation 2020-05-26 20:07:31 +03:00
Roman Khimov
a0e9673c3e interop/enumerator: update doc, fix Next return value 2020-05-26 20:06:33 +03:00
Roman Khimov
a44bdea890 interop/engine: update documentation 2020-05-26 20:05:17 +03:00
Roman Khimov
71f29c1f9f interop/crypto: update documentation 2020-05-26 20:02:46 +03:00
Roman Khimov
1e83a5e318 interop/contract: update documentation, fix some interfaces
Some functions were just not correct in their interfaces.
2020-05-26 19:58:59 +03:00
Roman Khimov
14409addd9 compiler/interop: expose GetTransactionHeight
And sort syscall names as they change the indentation anyway.
2020-05-26 19:55:21 +03:00
Roman Khimov
afe23ce239 interop/blockchain: update documentation 2020-05-26 19:53:51 +03:00
Roman Khimov
aaf65729bf interop/block: update documentation, fix GetTransaction
GetTransaction never worked with hash, it works with indexes.
2020-05-26 19:53:39 +03:00
Roman Khimov
60bea7e224 interop/attribute: update documentation 2020-05-26 19:52:57 +03:00
Roman Khimov
ff583a10a5 asset: update documentation and fix Create/Renew
Both Create and Renew have things returned from them.
2020-05-26 19:52:39 +03:00
Roman Khimov
7c1a54b725 account: add missing IsStandard interop function
There is a Neo.Account.IsStandard syscall, but we didn't have a wrapper for
it.
2020-05-26 19:51:32 +03:00
Roman Khimov
19c21452c9 interop/account: update and extend documentation 2020-05-26 19:51:20 +03:00
Evgenii Stratonikov
519b31a704 vm: remove crypto-related opcodes
All cryptography has moved to interops in NEO3.
There is no SHA256 interop RN, but it is to appear later.
Closes #777.
2020-04-29 19:16:38 +03:00
Evgenii Stratonikov
2fd63387c0 compiler: support CONVERT interops
When result is needed to have certain type, we should have ability
to convert it, with the help of CONVERT opcode.
2020-04-28 16:44:06 +03:00
Evgenii Stratonikov
4ad29d0867 compiler: emit Neo.Crypto.ECDsaVerify syscall instead of CHECKSIG
Also change the name of `VerifySignature` interop, to match
syscall's name. It also accepts arguments in different order.
2020-04-13 13:47:39 +03:00
Evgenii Stratonikov
948729137f vm: remove HASH160/HASH256 opcodes 2020-04-13 13:47:39 +03:00
Anna Shaleva
37cb60a0b5 compiler/interop: add missing methods to interop.Iterator
Add Next() and Value() to interop.Iterator and corresponding syscalls to
compiler
2020-03-26 16:39:10 +03:00
Roman Khimov
e41d434a49 *: move all packages from CityOfZion to nspcc-dev 2020-03-03 17:21:42 +03:00
Evgenii Stratonikov
52d8d58593 compiler,interop: make AppCall accept varargs 2020-02-10 10:51:29 +03:00
Evgenii Stratonikov
330db36168 compiler: implement engine.AppCall interop 2020-01-27 13:14:36 +03:00
Evgenii Stratonikov
bd37359393 compiler: implement ECDSA signature verification
Add VerifySignature interop for signature verification.
It is converted to VERIFY opcode.
2020-01-23 10:56:15 +03:00
Vsevolod Brekelov
8ee421db14 fix spelling and godoc comments 2019-10-22 17:56:03 +03:00
Roman Khimov
6bfcc615b2 *: fix some misspellings
Found by goreport.
2019-09-03 18:20:05 +03:00
Roman Khimov
a9b9c9226d *: add/fix godoc comments to satisfy golint
Fixes things like:
 * exported type/method/function X should have comment or be unexported
 * comment on exported type/method/function X should be of the form "X ..."
   (with optional leading article)

Refs. #213.
2019-09-03 17:57:51 +03:00
Roman Khimov
a1e3655560 interop: move into pkg/interop, replace pkg/vm/api
neo-storm has developed more wrappers for syscall APIs, so they can and should
be used as a drop-in replacement for pkg/vm/api. Moving it out of vm, as it's
not exactly related to the VM itself.
2019-08-15 19:41:51 +03:00