This warning, IIUC, means that the compiler doesn't like it when it
sees a NULL check _after_ we've already dereferenced the
variable. In such cases, it considers itself free to eliminate the
NULL check.
There are a couple of tricky cases:
One was the case related to the fact that tor_addr_to_in6() can
return NULL if it gets a non-AF_INET6 address. The fix was to
create a variant which asserts on the address type, and never
returns NULL.
We need to define this function when compiling with clang -m32 -ftrapv,
since otherwise we get link errors, since apparently some versions
of libclang_rt.builtins don't define a version of it that works? Or
clang doesn't know to look for it?
This definition is taken from the LLVM source at
https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/builtins/mulodi4.c
I've also included the license (dual BSD-ish/MIT-ish).
We know there are overflows in curve25519-donna-c32, so we'll have
to have that one be fwrapv.
Only apply the asan, ubsan, and trapv options to the code that does
not need to run in constant time. Those options introduce branches
to the code they instrument.
(These introduced branches should never actually be taken, so it
might _still_ be constant time after all, but branch predictors are
complicated enough that I'm not really confident here. Let's aim for
safety.)
Closes 17983.
* SHA-3/SHAKE use little endian for certain things, so byteswap as
needed.
* The code was written under the assumption that unaligned access to
quadwords is allowed, which isn't true particularly on non-Intel.
Yes, we could cast to unsigned char first, but it's probably safest
to just use our own (in test_util), or remove bad-idea features that
we don't use (in readpassphrase.c).
Fixes 18728.
The digest routines use init/update/sum, where sum will automatically
copy the internal state to support calculating running digests.
The XOF routines use init/absorb/squeeze, which behave exactly as stated
on the tin.
Apparently this only happens with clang (or with some particular
clang versions), and only on i386.
Fixes 16970; bug not in any released Tor.
Found by Teor; fix from Yawning.
This probably requires the user to manually set CFLAGS, but should
result in a net gain on 32 bit x86. Enabling SSE2 support would be
possible on x86_64, but will result in slower performance.
Implements feature #16535.
The code was always in our Ed25519 wrappers, so enable it when using
the ed25519-donna backend, and deal with the mocking related
crypto_rand silliness.
Implements feature 16533.
The only reason 16 byte alignment is required is for SSE2 load and
store operations, so only align datastructures to 16 byte boundaries
when building with SSE2 support.
This fixes builds with GCC SSP on platforms that don't have special
case code to do dynamic stack re-alignment (everything not x86/x86_64).
Fixes bug #16666.
This needs to be done to allow for the possibility of removing the
ref10 code at a later date, though it is not performance critical.
When integrated by kludging it into tor, it passes unit tests, and is
twice as fast.
Integrating it the "wrong" way into common/crypto_ed25519.c passes
`make check`, and there appear to be some known answer tests for this,
so I assume I got it right.
Blinding a public key goes from 139.10 usec to 70.78 usec using
ed25519-donna (NB: Turboboost/phase of moon), though the code isn't
critical path, so supporting it is mostly done for completeness.
Integrate ed25519-donna into the build process, and provide an
interface that matches the `ref10` code. Apart from the blinding and
Curve25519 key conversion, this functions as a drop-in replacement for
ref10 (verified by modifying crypto_ed25519.c).
Tests pass, and the benchmarks claim it is quite a bit faster, however
actually using the code requires additional integration work.
