Crate wasmtime_wasi_tls

Wasmtime’s wasi-tls (Transport Layer Security) Implementation

This crate provides the Wasmtime host implementation for the wasi-tls API. The wasi-tls world allows WebAssembly modules to perform SSL/TLS operations, such as establishing secure connections to servers. TLS often relies on other wasi networking systems to provide the stream so it will be common to enable the wasi:cli world as well with the networking features enabled.

An example of how to configure wasi-tls is the following:

use wasmtime_wasi::p2::{IoView, WasiCtx, WasiCtxBuilder, WasiView};
use wasmtime::{
    component::{Linker, ResourceTable},
    Store, Engine, Result, Config
};
use wasmtime_wasi_tls::{LinkOptions, WasiTls, WasiTlsCtx, WasiTlsCtxBuilder};

struct Ctx {
    table: ResourceTable,
    wasi_ctx: WasiCtx,
    wasi_tls_ctx: WasiTlsCtx,
}

impl IoView for Ctx {
    fn table(&mut self) -> &mut ResourceTable {
        &mut self.table
    }
}

impl WasiView for Ctx {
    fn ctx(&mut self) -> &mut WasiCtx {
        &mut self.wasi_ctx
    }
}

#[tokio::main]
async fn main() -> Result<()> {
    let ctx = Ctx {
        table: ResourceTable::new(),
        wasi_ctx: WasiCtxBuilder::new()
            .inherit_stderr()
            .inherit_network()
            .allow_ip_name_lookup(true)
            .build(),
        wasi_tls_ctx: WasiTlsCtxBuilder::new()
            // Optionally, configure a different TLS provider:
            // .provider(Box::new(wasmtime_wasi_tls_nativetls::NativeTlsProvider::default()))
            .build(),
    };

    let mut config = Config::new();
    config.async_support(true);
    let engine = Engine::new(&config)?;

    // Set up wasi-cli
    let mut store = Store::new(&engine, ctx);
    let mut linker = Linker::new(&engine);
    wasmtime_wasi::p2::add_to_linker_async(&mut linker)?;

    // Add wasi-tls types and turn on the feature in linker
    let mut opts = LinkOptions::default();
    opts.tls(true);
    wasmtime_wasi_tls::add_to_linker(&mut linker, &mut opts, |h: &mut Ctx| {
        WasiTls::new(&h.wasi_tls_ctx, &mut h.table)
    })?;

    // ... use `linker` to instantiate within `store` ...
    Ok(())
}

Modules

bindings

Auto-generated bindings.

Structs

HostClientConnection

Represents the client connection and used to shut down the tls stream

HostClientHandshake

Represents the ClientHandshake which will be used to configure the handshake

HostFutureClientStreams

Future streams provides the tls streams after the handshake is completed

LinkOptions

Link-time configurations.

RustlsProvider

The rustls provider.

WasiTls

Capture the state necessary for use in the wasi-tls API implementation.

WasiTlsCtx

Wasi TLS context needed for internal wasi-tls state.

WasiTlsCtxBuilder

Builder-style structure used to create a WasiTlsCtx.

Traits

TlsProvider

A TLS implementation.

TlsStream

A TLS connection.

TlsTransport

The data stream that carries the encrypted TLS data. Typically this is a TCP stream.

Functions

add_to_linker

Add the wasi-tls world’s types to a [wasmtime::component::Linker].