Does dryoc support run in browser?

[uuhan]

Add this to Cargo.toml

[target.'cfg(target_arch = "wasm32")'.dependencies]
getrandom = { version = "0.3", features = ["wasm_js"] }

Then compile to wasm by:
RUSTFLAGS='--cfg getrandom_backend="wasm_js"' cargo build --target wasm32-unknown-unknown

Error ocurs:

   --> src/constants.rs:156:26
    |
156 |     min(SODIUM_SIZE_MAX, 4398046510080),
    |                          ^^^^^^^^^^^^^
    |
    = note: the literal `4398046510080` does not fit into the type `usize` whose range is `0..=4294967295`
    = note: `#[deny(overflowing_literals)]` on by default

error: literal out of range for `usize`
   --> src/constants.rs:184:26
    |
184 |     min(SODIUM_SIZE_MAX, 4398046510080),
    |                          ^^^^^^^^^^^^^
    |
    = note: the literal `4398046510080` does not fit into the type `usize` whose range is `0..=4294967295`

error: could not compile `dryoc` (lib) due to 2 previous errors

[brndnmtthws]

Sorry for the very slow reply. Proper WebAssembly support was added only recently, and yes, dryoc now works in the browser with the current 2.0 release.

The compile error you hit was caused by the Argon2 maximum memory-limit constants (CRYPTO_PWHASH_ARGON2I_MEMLIMIT_MAX and CRYPTO_PWHASH_ARGON2ID_MEMLIMIT_MAX) using a 64-bit literal (4398046510080) in a usize expression, which failed on 32-bit wasm32. That was fixed in #118 (first released in 0.9.0); in 2.0.0 (#183), dryoc caps the Argon2 maximum memory limit at 2 GiB on 32-bit targets, as libsodium does.

With dryoc 2.0, you only need:

[dependencies]
dryoc = "2"

cargo build --target wasm32-unknown-unknown

On wasm32-unknown-unknown, dryoc turns on getrandom 0.4's wasm_js backend itself (which draws randomness from crypto.getRandomValues via wasm-bindgen), so you can drop the extra getrandom dependency and the --cfg getrandom_backend="wasm_js" RUSTFLAGS unless another crate in your dependency tree still pulls in getrandom 0.3.

You can also compile in WebAssembly SIMD (simd128) kernels (#186) with:

RUSTFLAGS=-Ctarget-feature=+simd128 cargo build --target wasm32-unknown-unknown

WebAssembly has no runtime CPU feature detection, so this is chosen at compile time: without the flag the build uses dryoc's portable code, and a +simd128 build only runs on engines with WebAssembly SIMD (Chrome 91+, Firefox 89+, Safari 16.4+).

One API caveat: dryoc::protected (page-locked, guard-page protected memory) is only available on Unix and Windows, not on wasm. Everything else in the default feature set builds and runs.

CI runs the test suite on wasm32-unknown-unknown under Node with and without simd128, and a quick wasm-bindgen --target web check in headless Chromium passed as well. See the README section on WebAssembly for details, and please open an issue if you run into any problems.