RAND_bytes rarely uses large enough inputs for bsaes to be worth it.
https://boringssl-review.googlesource.com/c/boringssl/+/33589 includes some
rough benchmarks of various bits here. Some observations:
- 8 blocks of bsaes costs roughly 6.5 blocks of vpaes. Note the comparison
isn't quite accurate because I'm measuring bsaes_ctr32_encrypt_blocks against
vpaes_encrypt and vpaes in CTR mode today must make do with a C loop. Even
assuming a cutoff of 6 rather than 7 blocks, it's rare to ask for 96 bytes
of entropy at a time.
- CTR-DRBG performs some stray block operations (ctr_drbg_update), which bsaes
is bad at without extra work to fold them into the CTR loop (not really worth
it).
- CTR-DRBG calculates a couple new key schedules every RAND_bytes call. We
don't currently have a constant-time bsaes key schedule. Unfortunately, even
plain vpaes loses to the current aes_nohw used by bsaes, but it's not
constant-time. Also taking CTR-DRBG out of the bsaes equation
- Machines without AES hardware (clients) are not going to be RNG-bound. It's
mostly servers pushing way too many CBC IVs that care. This means bsaes's
current side channel tradeoffs make even less sense here.
I'm not sure yet what we should do for the rest of the bsaes mess, but it seems
clear that we want to stick with vpaes for the RNG.
Bug: 256
Change-Id: Iec8f13af232794afd007cb1065913e8117eeee24
Reviewed-on: https://boringssl-review.googlesource.com/c/34744
Reviewed-by: Adam Langley <agl@google.com>
The change seems to have stuck, so bring us closer to C/++11 static asserts.
(If we later find we need to support worse toolchains, we can always use
__LINE__ or __COUNTER__ to avoid duplicate typedef names and just punt on
embedding the message into the type name.)
Change-Id: I0e5bb1106405066f07740728e19ebe13cae3e0ee
Reviewed-on: https://boringssl-review.googlesource.com/c/33145
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
An EVP_AEAD_CTX used to be a small struct that contained a pointer to
an AEAD-specific context. That involved heap allocating the
AEAD-specific context, which was a problem for users who wanted to setup
and discard these objects quickly.
Instead this change makes EVP_AEAD_CTX large enough to contain the
AEAD-specific context inside itself. The dominant AEAD is AES-GCM, and
that's also the largest. So, in practice, this shouldn't waste too much
memory.
Change-Id: I795cb37afae9df1424f882adaf514a222e040c80
Reviewed-on: https://boringssl-review.googlesource.com/c/32506
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
crypto/{asn1,x509,x509v3,pem} were skipped as they are still OpenSSL
style.
Change-Id: I3cd9a60e1cb483a981aca325041f3fbce294247c
Reviewed-on: https://boringssl-review.googlesource.com/19504
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Similarly, add EVP_AEAD_CTX_tag_len which computes the exact tag length
for required by EVP_AEAD_CTX_seal_scatter.
Change-Id: I069b0ad16fab314fd42f6048a3c1dc45e8376f7f
Reviewed-on: https://boringssl-review.googlesource.com/18324
Reviewed-by: Adam Langley <agl@google.com>
These behave like EVP_AEAD_CTX_{seal,open} respectively, but receive
ciphertext and authentication tag as separate arguments, rather than one
contiguous out or in buffer.
Change-Id: Ia4f1b83424bc7067c55dd9e5a68f18061dab4d07
Reviewed-on: https://boringssl-review.googlesource.com/16924
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
