Package sha3 recommends the SHAKE functions for new uses, but this is
currently somewhat inconvenient because ShakeHash does not implement
hash.Hash. This is understandable, as SHAKE supports arbitrary-length
outputs whereas hash.Hash only supports fixed-length outputs. But
there's a natural fixed-length output to provide: the minimum output
that still provides SHAKE's full-strength generic security.
While here, tweak Sum so that its temporary buffer can be stack
allocated.
Also, tweak the panic message in Write so that the error text is more
readily understandable to Go programmers without needing to be
familiar with crypto jargon, and add a similar check in Sum.
Change-Id: Icf037d3990a71de5630f8825606614443f8c5245
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/526937
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Adam Langley <agl@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
Clone() made a copy of the Keccak state after invoking clone(), which is not
supported, since the "buf" slice in the Keccak state must point to the "storage"
array, and if the state is copied directly it will keep pointing to the storage
returned by clone().
Fix it by embedding a pointer to the Keccak state instead of the state itself.
Change-Id: I7d392963ec65d784a360f6c12a7935a9a9a788b5
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/173018
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
1. API:
This exposes a minimal API: the SHA-3 functions implement hash.Hash. The
SHAKE functions implement a new "ShakeHash" interface that implements
io.Reader, io.Writer, and Reset().
(The previous Barrier() function has been removed.)
(Alternative proposal: Don't implement io.Reader, but instead provide a
"Digest(d []byte) error" function that performs a hash.Hash style copy.
Somewhat more minimal, but very easy to use incorrectly.)
2. Tests
Added the complete set of ShortMsgKATs from
https://github.com/gvanas/KeccakCodePackage
3. Correctness
In sync with draft FIPS-202.
4. Documentation
A summary of the security properties of the SHA-3 and SHAKE functions is
provided in doc.go; some concrete recommendations as well.
Fixes 8563.
R=golang-codereviews, agl
CC=golang-codereviews
https://golang.org/cl/130950043
Filippo Valsorda
Yawning Angel
Mauri de Souza Meneguzzo
Matthew Dempsky
Conrado P. L. Gouvea
Kris Kwiatkowski
Michael Munday
Kyle Spiers
David Leon Gil