...and don't try to connect to the nodes we're already connected to.
Before this change we had a problem of discoverer throwing away good valid
addresses just because they are already known which lead to pool draining over
time (as address reuse was basically forbidden and getaddr may not get enough
new nodes).
Queuing one message is not reliable enough, the peer that gets it can fail to
actually make a request, so make this queue a bit deeper to have a higher
chance of success.
This makes writer side handle errors properly and fixes communication between
reader and writer goroutine to always correctly unregister the peer. This is
especially important for the case where error occurs before handshake
completes as in this case we don't even have goroutine in startProtocol()
running.
In the unlikely event of overlapping hash block written to the DB we might end
up with wrong hash list. That happened to me for some reason when synching
with the testnet leading to the following keys with respective values:
150000 -> 2000 hashes
152000 -> 2000 hashes
153999 -> 2000 hashes
Reading it hashes number 153999 and 154000 got the same values and the chain
couldn't sync correctly.
Same thing done in a2a8981979 for PUSHBYTES,
failing to read the amount of bytes specified should lead to FAULT. Also
makes readUint16() and readUint32() panic as this is the behavior we want in
these cases. Add some tests along the way.
Before:
NEO-GO-VM > loadgo h.go
READY: loaded 16 instructions
NEO-GO-VM > ip
instruction pointer at -1 (PUSH0)
After:
NEO-GO-VM > loadgo h.go
READY: loaded 16 instructions
NEO-GO-VM > ip
instruction pointer at -1 (NOP)
I think NOP is a little less scary.
Current NEO documentation lists them:
https://docs.neo.org/docs/en-us/tooldev/advanced/neo_vm.html
CALL_* instructions were left out because of conflict with golint (but they're
removed in NEO 3.0 anyway, so wasting time on them makes no sense).
Update autogenerated instruction_string.go accordingly.
The code that we have actually implements XTUCK and not TUCK. And it's a bit
broken, so fix it and add some tests. The most interesting one (that required
to touch stack code) is the one when we have 1 element on the stack and are
trying to tell XTUCK to push 2 elements deep.
ANSI X9.62 says that if x or y coordinate are greater than or equal to
curve.Params().P, the conversion should return an error (see ANSI X9.62:2005
Section A.5.8 Step b, which invokes Section A.5.5, which does the check and
rejects when x or y are too big.
See https://github.com/golang/go/issues/20482 for more details.
PublicKey() for PrivateKey now just can't fail and it makes no sense to return
an error from it. There is a lot of associated functionality for which this
also is true, so adjust it accordingly and simplify a lot of code.
Public key is just a point, so use the coordinates obtained previously to
initialize the PublicKey structure without jumping through the hoops of
encoding/decoding.
As NEO uses P256 we can use standard crypto/elliptic library for almost
everything, the only exception being decompression of the Y coordinate. For
some reason the standard library only supports uncompressed format in its
Marshal()/Unmarshal() functions. elliptic.P256() is known to have
constant-time implementation, so it fixes#245 (and the decompression using
big.Int operates on public key, so nobody really cares about that part being
constant-time).
New decompress function is inspired by
https://stackoverflow.com/questions/46283760, even though the previous one
really did the same thing just in a little less obvious way.
It makes no sense to provide an API for throw-away public keys, so obtain it
via a new real keypair generation where appropriate (and that's only needed
for testing).
Golint:
pkg/rpc/rpc.go:15:67: exported method GetBlock returns unexported type *rpc.response, which can be annoying to use
pkg/rpc/rpc.go:82:64: exported method GetRawTransaction returns unexported type *rpc.response, which can be annoying to use
pkg/rpc/rpc.go:97:52: exported method SendRawTransaction returns unexported type *rpc.response, which can be annoying to use
Refs. #213.
pkg/rpc/neoScanBalanceGetter.go:54:56: method parameter assetIdUint should be assetIDUint
pkg/rpc/neoScanBalanceGetter.go:62:3: var assetId should be assetID
pkg/rpc/server_test.go:27:5: var testRpcCases should be testRPCCases
pkg/rpc/txTypes.go:19:3: struct field assetId should be assetID
pkg/rpc/txTypes.go:39:35: interface method parameter assetId should be assetID
pkg/rpc/types.go:115:2: struct field TxId should be TxID
Refs. #213.
pkg/core/transaction/attribute.go:67:14: should omit type uint8 from declaration of var urllen; it will be inferred from the right-hand side
pkg/crypto/keys/publickey.go:184:8: should omit type []byte from declaration of var b; it will be inferred from the right-hand side
pkg/network/payload/version_test.go:15:12: should omit type bool from declaration of var relay; it will be inferred from the right-hand side
Refs. #213.
Golint:
pkg/core/blockchain.go:796:9: if block ends with a return statement, so drop
this else and outdent its block (move short variable declaration to its own
line if necessary)
Refs. #213.
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.
