There is a security issue found in github.com/btcsuite/btcd that we don't care
about (we're only using 256k1 implementation), but GitHub complains about
it. We could update to github.com/btcsuite/btcd/btcec/v2, but it's now just a
thin wrapper over github.com/decred/dcrd/dcrec/secp256k1/v4, so we better use
it directly.
Which allows to create verification scripts without keys.PublicKey which is
convenient in some cases where we already have serialized key and don't want
to waste time decompressing it.
They're misleading now that we have variable number of committee
members/validators. The standby list can be seen in the configuration and the
appropriate numbers can be received from it also.
Attempts to reuse elliptic.Unmarshal() and elliptic.UnmarshalCompressed() lead
to this:
name old time/op new time/op delta
PublicDecodeBytes-8 59.5µs ± 2% 61.8µs ± 1% +3.78% (p=0.000 n=10+9)
name old alloc/op new alloc/op delta
PublicDecodeBytes-8 3.99kB ± 0% 4.27kB ± 0% +6.81% (p=0.000 n=9+10)
name old allocs/op new allocs/op delta
PublicDecodeBytes-8 136 ± 0% 135 ± 0% -0.74% (p=0.000 n=10+10)
So it makes no sense. Refs. #1319.
Go 1.15 provides native (*ecdsa.PublicKey).Equal method, but we can't drop our
own Equal because the types are different and there is still code using our
Equal (forcing it to convert types is counterproductive), while changing
(*PublicKey).Equal to use (*ecdsa.PublicKey).Equal internally with some kind of
(*ecdsa.PublicKey)(p).Equal((*ecdsa.PublicKey)(key))
slows it down:
name old time/op new time/op delta
PublicEqual-8 14.9ns ± 1% 18.4ns ± 2% +23.55% (p=0.000 n=9+10)
name old alloc/op new alloc/op delta
PublicEqual-8 0.00B 0.00B ~ (all equal)
name old allocs/op new allocs/op delta
PublicEqual-8 0.00 0.00 ~ (all equal)
So leave it as is, but add this micro-bench. Refs. #1319.
The cost of Y calculation from X is comparable with signature check, so it
reduces witness check overhead by ~30% for cached keys and gives ~5% overall
boost in TPS.
It's not needed any more with Go 1.13 as we have wrapping/unwrapping in base
packages. All errors.Wrap calls are replaced with fmt.Errorf, some strings are
improved along the way.
Now we have not only Random EC curve, but also Koblitz curve, so
it will be useful to have information about the curve for each
particular EC point. ecdsa.PublicKey has this information.
Frequently one needs to check if struct serializes/deserializes
properly. This commit implements helpers for such cases including:
1. JSON
2. io.Serializable interface
