RC4_CHAR is a bit in the x86(-64) CPUID information that switches the
RC4 asm code from using an array of 256 uint32_t's to 256 uint8_t's. It
was originally written for the P4, where the uint8_t style was faster.
(On modern chips, setting RC4_CHAR took RC4-MD5 from 458 to 304 MB/s.
Although I wonder whether, on a server with many connections, using less
cache wouldn't be better.)
However, I'm not too worried about a slowdown of RC4 on P4 systems these
days (the last new P4 chip was released nine years ago) and I want the
code to be simplier.
Also, RC4_CHAR was set when the CPUID family was 15, but Intel actually
lists 15 as a special code meaning "also check the extended family
bits", which the asm didn't do.
The RC4_CHAR support remains in the RC4 asm code to avoid drift with
upstream.
Change-Id: If3febc925a83a76f453b9e9f8de5ee43759927c6
Reviewed-on: https://boringssl-review.googlesource.com/3550
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
We are leaking asm symbols in Android builds because the asm code isn't
affected by -fvisibility=hidden. This change hides all asm symbols.
This assumes that no asm symbols are public API and that should be true.
Some points to note:
In crypto/rc4/asm/rc4-md5-x86_64.pl there are |RC4_set_key| and
|RC4_options| functions which aren't getting marked as hidden. That's
because those functions aren't actually ever generated. (I'm just trying
to minimise drift with upstream here.)
In crypto/rc4/asm/rc4-x86_64.pl there's |RC4_options| which is "public"
API, except that we've never had it in the header files. So I've just
deleted it. Since we have an internal caller, we'll probably have to put
it back in the future, but it can just be done in rc4.c to save
problems.
BUG=448386
Change-Id: I3846617a0e3d73ec9e5ec3638a53364adbbc6260
Reviewed-on: https://boringssl-review.googlesource.com/3520
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
Initial fork from f2d678e6e89b6508147086610e985d4e8416e867 (1.0.2 beta).
(This change contains substantial changes from the original and
effectively starts a new history.)
