A little function to complement the existing crypto.utils.timingSafeEql
function with a way to compare large numbers serialized as arrays.
This is useful to compare nonces and to check that group elements are
in canonical form.
Absence of side channels remains a best effort, reusing the common
pattern we use elsewhere.
std.crypto.random
* cross platform, even freestanding
* can't fail. on initialization for some systems requires calling
os.getrandom(), in which case there are rare but theoretically
possible errors. The code panics in these cases, however the
application may choose to override the default seed function and then
handle the failure another way.
* thread-safe
* supports the full Random interface
* cryptographically secure
* no syscall required to initialize on Linux (AT_RANDOM)
* calls arc4random on systems that support it
`std.crypto.randomBytes` is removed in favor of `std.crypto.random.bytes`.
I moved some of the Random implementations into their own files in the
interest of organization.
stage2 no longer requires passing a RNG; instead it uses this API.
Closes#6704
This is a trivial implementation that just does a or[xor] loop.
However, this pattern is used by virtually all crypto libraries and
in practice, even without assembly barriers, LLVM never turns it into
code with conditional jumps, even if one of the parameters is constant.
This has been verified to still be the case with LLVM 11.0.0.
