11 Commits

Author SHA1 Message Date
Frank Denis
ca6951ff79
std.crypto: timing-safe functions to add&subtract serialized integers (#8977)
This is useful to increment nonces and for scalar reduction.

It will avoid code duplication in crypto/25519 and crypto/pcurves/*
2021-06-06 16:37:58 +02:00
Andrew Kelley
5619ce2406 Merge remote-tracking branch 'origin/master' into stage2-whole-file-astgen
Conflicts:
 * doc/langref.html.in
 * lib/std/enums.zig
 * lib/std/fmt.zig
 * lib/std/hash/auto_hash.zig
 * lib/std/math.zig
 * lib/std/mem.zig
 * lib/std/meta.zig
 * test/behavior/alignof.zig
 * test/behavior/bitcast.zig
 * test/behavior/bugs/1421.zig
 * test/behavior/cast.zig
 * test/behavior/ptrcast.zig
 * test/behavior/type_info.zig
 * test/behavior/vector.zig

Master branch added `try` to a bunch of testing function calls, and some
lines also had changed how to refer to the native architecture and other
`@import("builtin")` stuff.
2021-05-08 14:45:21 -07:00
Veikka Tuominen
fd77f2cfed std: update usage of std.testing 2021-05-08 15:15:30 +03:00
Andrew Kelley
c90e52b74c std: remove redundant comptime const 2021-04-28 15:15:44 -07:00
Andrew Kelley
df24ce52b1 Merge remote-tracking branch 'origin/master' into stage2-whole-file-astgen
In particular I wanted to take advantage of the new hex float parsing
code.
2021-04-28 14:57:38 -07:00
Frank Denis
d3361c41db Change timingSafeCompare() to accept slices 2021-04-26 22:32:22 +02:00
Frank Denis
0747591c3d Add std.crypto.utils.timingSafeCompare
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.
2021-04-25 17:07:11 +02:00
Andrew Kelley
507a8096d2 std: fix compile errors caught by stage2 AstGen
* `comptime const` is redundant
 * don't use `extern enum`; specify a tag type.
   `extern enum` is only when you need tags to alias. But aliasing tags
   is a smell. I will be making a proposal shortly to remove `extern enum`
   from the language.
 * there is no such thing as `packed enum`.
 * instead of `catch |_|`, omit the capture entirely.
 * unused function definition with missing parameter name
 * using `try` outside of a function or test
2021-04-22 18:07:46 -07:00
Andrew Kelley
013efaf139 std: introduce a thread-local CSPRNG for general use
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
2020-12-18 12:22:46 -07:00
Frank Denis
7f9e3e419c Use @reduce 2020-11-07 20:30:13 +01:00
Frank Denis
bd07154242 Add mem.timingSafeEql() for constant-time array comparison
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.
2020-11-07 20:18:43 +01:00