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>
EVP_AEAD reused portions of EVP_CIPHER's GCM128_CONTEXT which contains both the
key and intermediate state for each operation. (The legacy OpenSSL EVP_CIPHER
API has no way to store just a key.) Split out a GCM128_KEY and store that
instead.
Change-Id: Ibc550084fa82963d3860346ed26f9cf170dceda5
Reviewed-on: https://boringssl-review.googlesource.com/32004
Commit-Queue: David Benjamin <davidben@google.com>
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>
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>
