Only a little bit of generalized logic for DER encoding is needed and so
it can live inside the Certificate namespace.
This commit removes the generic "parse object id" function which is no
longer used in favor of more specific, smaller sets of object ids used
with ComptimeStringMap.
When scanning the file system for root certificates, expired
certificates are skipped and therefore not used for verification in TLS
sessions. There is only this one check, however, so a long-running
server will need to periodically rescan for a new Certificate.Bundle
and strategically start using it for new sessions. In this commit I made
the judgement call that applications would like to opt-in to root
certificate rescanning at a point in time that makes sense for that
application, as opposed to having the system clock potentially start
causing connections to fail.
Certificate verification checks the subject only, as opposed to both the
subject and the issuer. The idea is that the trust chain analysis will
always check the subject, leading to every certificate in the chain's
validity being checked exactly once, with the root certificate's
validity checked upon scanning.
Furthermore, this commit adjusts the scanning logic to fully parse
certificates, even though only the subject is technically needed. This
allows relying on parsing to succeed later on.
In sponge-based constructions, the block size is not the same as
the state size. For practical purposes, it's the same as the rate.
Size this is a constant for a given type, we don't need to keep
a copy of that value in the state itself. Just use the constant
directly. This saves some bytes and may even be slightly faster.
More importantly:
Fixes#14128
The HKDF extract function uses HMAC under the hood, but requiring
applications to directly use HMAC functions reduces clarity and
feels like the wrong abstraction.
So, in order to get the PRK length, add a `prk_length` constant
that applications can use directly.
Also add an `extractInit()` function for cases where the keying
material has to be provided as multiple chunks.
Does what the name says: rejects generators of low-order groups.
`clearCofactor()` was previously used to do it, but for e.g.
cofactored signature verification, we don't need the result of an
actual multiplication. Only check that we didn't end up with a
low-order point, which is a faster operation.
If the noise parameter was null, we didn't use any noise at all.
We unconditionally generated random noise (`noise2`) but didn't use it.
Spotted by @cryptocode, thanks!
* Update the AEGIS specification URL to the current draft
* std.crypto.auth: add AEGIS MAC
The Pelican-based authentication function of the AEGIS construction
can be used independently from authenticated encryption, as a faster
and more secure alternative to GHASH/POLYVAL/Poly1305.
We already expose GHASH, POLYVAL and Poly1305 for use outside AES-GCM
and ChaChaPoly, so there are no reasons not to expose the MAC from AEGIS
as well.
Like other 128-bit hash functions, finding a collision only requires
~2^64 attempts or inputs, which may still be acceptable for many
practical applications.
Benchmark (Apple M1):
siphash128-1-3: 3222 MiB/s
ghash: 8682 MiB/s
aegis-128l mac: 12544 MiB/s
Benchmark (Zen 2):
siphash128-1-3: 4732 MiB/s
ghash: 5563 MiB/s
aegis-128l mac: 19270 MiB/s
POLYVAL is GHASH's little brother, required by the AES-GCM-SIV
construction. It's defined in RFC8452.
The irreducible polynomial is a mirror of GHASH's (which doesn't
change anything in our implementation that didn't reverse the raw
bits to start with).
But most importantly, POLYVAL encodes byte strings as little-endian
instead of big-endian, which makes it a little bit faster on the
vast majority of modern CPUs.
So, both share the same code, just with comptime magic to use the
correct endianness and only double the key for GHASH.
