* common/math: optimize PaddedBigBytes, use it more
name old time/op new time/op delta
PaddedBigBytes-8 71.1ns ± 5% 46.1ns ± 1% -35.15% (p=0.000 n=20+19)
name old alloc/op new alloc/op delta
PaddedBigBytes-8 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=20+20)
* all: unify big.Int zero checks
Various checks were in use. This commit replaces them all with Int.Sign,
which is cheaper and less code.
eg templates:
func before(x *big.Int) bool { return x.BitLen() == 0 }
func after(x *big.Int) bool { return x.Sign() == 0 }
func before(x *big.Int) bool { return x.BitLen() > 0 }
func after(x *big.Int) bool { return x.Sign() != 0 }
func before(x *big.Int) int { return x.Cmp(common.Big0) }
func after(x *big.Int) int { return x.Sign() }
* common/math, crypto/secp256k1: make ReadBits public in package math
- Use defined constants instead of hard-coding their integer value.
- Allocate secp256k1 structs on the C stack instead of converting []byte
- Remove dead code
* change gas cost for contract creating txs
* invalidate signature with s value greater than secp256k1 N / 2
* OOG contract creation if not enough gas to store code
* new difficulty adjustment algorithm
* new DELEGATECALL op code
The C library treats the recovery ID as trusted input and crashes
the process for invalid values, so it needs to be verified before
calling into C. This will inhibit the crash in #1983.
Also remove VerifySignature because we don't use it.
Linux build documentation is mostly geared towards Ubuntu 14.04 (LTS).
Appropriate package is called `libgmp-dev` there.
Note that on pristine installations building `geth` with godep will
fail because this header is missing. This is not documented in the
top-level README, but is on the wiki:
https://github.com/ethereum/go-ethereum/wiki/Installation-Instructions-for-Ubuntu#building-geth-command-line-client
That page recommends `libgmp3-dev`, which ATM provides same version
as `libgmp-dev`.
* Move random entropy functions to new package randentropy
* Add function to get n bytes entropy where up to first 32
bytes are mixed with OS entropy sources