17 Commits

Author SHA1 Message Date
LemonBoy
057bf1afc9 std: Add more error checking in hexToBytes
Prevent the function from turning into an endless loop that may or may
not perform OOB accesses.
2021-02-21 12:19:03 +02:00
Frank Denis
6c2e0c2046 Year++ 2020-12-31 15:45:24 -08:00
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
0c7a99b38d Move ed25519 key pairs to a KeyPair structure 2020-10-25 21:55:05 +01:00
Frank Denis
28fb97f188 Add (X)Salsa20 and NaCl boxes
The NaCl constructions are available in pretty much all programming
languages, making them a solid choice for applications that require
interoperability.

Go includes them in the standard library, JavaScript has the popular
tweetnacl.js module, and reimplementations and ports of TweetNaCl
have been made everywhere.

Zig has almost everything that NaCl has at this point, the main
missing component being the Salsa20 cipher, on top on which NaCl's
secretboxes, boxes, and sealedboxes can be implemented.

So, here they are!

And clean the X25519 API up a little bit by the way.
2020-10-25 18:04:12 +01:00
Frank Denis
2d9befe9bf Implement multiscalar edwards25519 point multiplication 2020-10-22 09:58:26 +02:00
Frank Denis
0fb6fdd7eb Support variable-time edwards25519 scalar multiplication
This is useful to save some CPU cycles when the scalar is public,
such as when verifying signatures.
2020-10-22 09:58:26 +02:00
Frank Denis
ff658abe79 std/crypto/25519: use Barrett reduction for scalars (mod l) 2020-10-22 09:58:26 +02:00
Frank Denis
8e79b3cf23 std/crypto/25519: add support for batch Ed25519 signature verification 2020-10-22 09:58:26 +02:00
Frank Denis
f3667e8a80 std/crypto/25519: do cofactored ed25519 verification
This is slightly slower but makes our verification function compatible
with batch signatures. Which, in turn, makes blockchain people happy.
And we want to make our users happy.

Add convenience functions to substract edwards25519 points and to
clear the cofactor.
2020-10-15 18:49:10 -04:00
Frank Denis
fc55cd458a Hash functions now accept an option set
- This avoids having multiple `init()` functions for every combination
of optional parameters
- The API is consistent across all hash functions
- New options can be added later without breaking existing applications.
  For example, this is going to come in handy if we implement parallelization
  for BLAKE2 and BLAKE3.
- We don't have a mix of snake_case and camelCase functions any more, at
least in the public crypto API

Support for BLAKE2 salt and personalization (more commonly called context)
parameters have been implemented by the way to illustrate this.
2020-08-21 00:51:14 +02:00
Frank Denis
6f9ea9eaef Breaking: sort std/crypto functions into categories
Instead of having all primitives and constructions share the same namespace,
they are now organized by category and function family.

Types within the same category are expected to share the exact same API.
2020-08-20 23:02:05 +02:00
Andrew Kelley
4a69b11e74 add license header to all std lib files
add SPDX license identifier
copyright ownership is zig contributors
2020-08-20 16:07:04 -04:00
Frank Denis
bcef123d90 Address more review issues 2020-08-16 22:35:27 -07:00
Frank Denis
ed558bfbaa Address @daurnimator feedback 2020-08-16 22:35:27 -07:00
Frank Denis
5f9953f41f Remove mem.timingSafeEqual() for now
This requires assembly implementations, and is not needed for
signature verification.

Thanks @daurnimator
2020-08-16 22:35:27 -07:00
Frank Denis
3f0d80f25e Improve curve25519-based crypto
This is a rewrite of the x25519 code, that generalizes support for
common primitives based on the same finite field.

- Low-level operations can now be performed over the curve25519 and
edwards25519 curves, as well as the ristretto255 group.
- Ed25519 signatures have been implemented.
- X25519 is now about twice as fast.
- mem.timingSafeEqual() has been added for constant-time comparison.

Domains have been clearly separated, making it easier to later add
platform-specific implementations.
2020-08-16 22:35:27 -07:00