This removes a bunch of weird code around the counter overflow check in
concatKDF and makes it actually work for different hash output sizes.
The overflow check worked as follows: concatKDF applies the hash function N
times, where N is roundup(kdLen, hashsize) / hashsize. N should not
overflow 32 bits because that would lead to a repetition in the KDF output.
A couple issues with the overflow check:
- It used the hash.BlockSize, which is wrong because the
block size is about the input of the hash function. Luckily, all standard
hash functions have a block size that's greater than the output size, so
concatKDF didn't crash, it just generated too much key material.
- The check used big.Int to compare against 2^32-1.
- The calculation could still overflow before reaching the check.
The new code in concatKDF doesn't check for overflow. Instead, there is a
new check on ECIESParams which ensures that params.KeyLen is < 512. This
removes any possibility of overflow.
There are a couple of miscellaneous improvements bundled in with this
change:
- The key buffer is pre-allocated instead of appending the hash output
to an initially empty slice.
- The code that uses concatKDF to derive keys is now shared between Encrypt
and Decrypt.
- There was a redundant invocation of IsOnCurve in Decrypt. This is now removed
because elliptic.Unmarshal already checks whether the input is a valid curve
point since Go 1.5.
Co-authored-by: Felix Lange <fjl@twurst.com>
* build: use golangci-lint
This changes build/ci.go to download and run golangci-lint instead
of gometalinter.
* core/state: fix unnecessary conversion
* p2p/simulations: fix lock copying (found by go vet)
* signer/core: fix unnecessary conversions
* crypto/ecies: remove unused function cmpPublic
* core/rawdb: remove unused function print
* core/state: remove unused function xTestFuzzCutter
* core/vm: disable TestWriteExpectedValues in a different way
* core/forkid: remove unused function checksum
* les: remove unused type proofsData
* cmd/utils: remove unused functions prefixedNames, prefixFor
* crypto/bn256: run goimports
* p2p/nat: fix goimports lint issue
* cmd/clef: avoid using unkeyed struct fields
* les: cancel context in testRequest
* rlp: delete unreachable code
* core: gofmt
* internal/build: simplify DownloadFile for Go 1.11 compatibility
* build: remove go test --short flag
* .travis.yml: disable build cache
* whisper/whisperv6: fix ineffectual assignment in TestWhisperIdentityManagement
* .golangci.yml: enable goconst and ineffassign linters
* build: print message when there are no lint issues
* internal/build: refactor download a bit
Most of these changes are related to the Go 1.13 changes to test binary
flag handling.
* cmd/geth: make attach tests more reliable
This makes the test wait for the endpoint to come up by polling
it instead of waiting for two seconds.
* tests: fix test binary flags for Go 1.13
Calling flag.Parse during package initialization is prohibited
as of Go 1.13 and causes test failures. Call it in TestMain instead.
* crypto/ecies: remove useless -dump flag in tests
* p2p/simulations: fix test binary flags for Go 1.13
Calling flag.Parse during package initialization is prohibited
as of Go 1.13 and causes test failures. Call it in TestMain instead.
* build: remove workaround for ./... vendor matching
This workaround was necessary for Go 1.8. The Go 1.9 release changed
the expansion rules to exclude vendored packages.
* Makefile: use relative path for GOBIN
This makes the "Run ./build/bin/..." line look nicer.
* les: fix test binary flags for Go 1.13
Calling flag.Parse during package initialization is prohibited
as of Go 1.13 and causes test failures. Call it in TestMain instead.
Fedora/RedHat distros comply with US patent law and remove this curve,
which makes it impossible to run ethereum with distro provided Golang.
File crypto/ecies/README claims it is unsupported anyway.
