Can't use ring on ```wasm32-unknown-unknown``` due to a missing import (for Envoy Proxy)

[libbkmz]

Hello, I'm trying to use the ring's SHA and HMAC for wasm32-unknown-unknown target. I'm building the WASM plugin for the envoy proxy. The build procedure works, but I can't load the WASM file into envoy's. Here is the reproducible source:
Cargo.toml:

[package]
name = "rust_wasm_test"
version = "0.1.0"
edition = "2021"

[lib]
crate-type = ["cdylib"]

[dependencies]
log = "0.4.14"
proxy-wasm = "0.1.4"
ring = "0.16.20"

src/lib.rs:

use proxy_wasm as wasm;
use ring;


#[no_mangle]
pub fn _start() {
    proxy_wasm::set_log_level(wasm::types::LogLevel::Trace);
    proxy_wasm::set_http_context(
        |_context_id, _root_context_id| -> Box<dyn wasm::traits::HttpContext> {
            Box::new(HelloWorld {  })
        },
    )
}

struct HelloWorld {}
impl wasm::traits::Context for HelloWorld {}
impl wasm::traits::HttpContext for HelloWorld {}

Example configuration for envoy:

static_resources:
  listeners:
    - name: main
      address:
        socket_address:
          address: 0.0.0.0
          port_value: 18000
      filter_chains:
        - filters:
            - name: envoy.http_connection_manager
              typed_config:
                "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
                stat_prefix: ingress_http
                codec_type: auto
                route_config:
                  name: local_route
                  virtual_hosts:
                    - name: local_service
                      domains:
                        - "*"
                      routes:
                        - match:
                            prefix: "/"
                          direct_response:
                            status: 200
                            body:
                              inline_string: "example body\n"
                http_filters:
                  - name: envoy.filters.http.wasm
                    typed_config:
                      "@type": type.googleapis.com/udpa.type.v1.TypedStruct
                      type_url: type.googleapis.com/envoy.extensions.filters.http.wasm.v3.Wasm
                      value:
                        config:
                          vm_config:
                            runtime: "envoy.wasm.runtime.v8"
                            code:
                              local:
                                filename: ".//target/wasm32-unknown-unknown/debug/rust_wasm_test.wasm"
                  - name: envoy.filters.http.router

admin:
  access_log_path: "/dev/null"
  address:
    socket_address:
      address: 0.0.0.0
      port_value: 8001

After building via cargo build --target=wasm32-unknown-unknown and running envoy via envoy --config-path envoy.yaml --concurrency 0 -l info I'm getting this error from the envoy side:

[2022-02-02 12:24:28.468][3533850][error][wasm] [source/extensions/common/wasm/wasm_vm.cc:38] Failed to load Wasm module due to a missing import: __wbindgen_externref_xform__.__wbindgen_externref_table_grow
[2022-02-02 12:24:28.468][3533850][error][wasm] [source/extensions/common/wasm/wasm_vm.cc:38] Failed to load Wasm module due to a missing import: __wbindgen_placeholder__.__wbindgen_describe
[2022-02-02 12:24:28.468][3533850][error][wasm] [source/extensions/common/wasm/wasm_vm.cc:38] Failed to load Wasm module due to a missing import: __wbindgen_externref_xform__.__wbindgen_externref_table_set_null
[2022-02-02 12:24:28.468][3533850][error][wasm] [source/extensions/common/wasm/wasm_vm.cc:38] Failed to load Wasm module due to a missing import: __wbindgen_placeholder__.__wbindgen_throw
[2022-02-02 12:24:28.468][3533850][error][wasm] [source/extensions/common/wasm/wasm.cc:109] Wasm VM failed Failed to initialize Wasm code
[2022-02-02 12:24:28.472][3533850][critical][wasm] [source/extensions/common/wasm/wasm.cc:471] Plugin configured to fail closed failed to load
[2022-02-02 12:24:28.481][3533850][critical][main] [source/server/server.cc:117] error initializing configuration 'envoy.yaml': Unable to create Wasm HTTP filter

There are a lot of libraries that depend on the ring, however, I can't use them because of the broken dependency...

[briansmith]

What wasm runtime does Envoy use? Knowing this would help me make progress in diagnosing this.

Could you try to reproduce this without Envoy, using just that wasm runtime, but without the Envoy-specific stuff?

[dio]

Envoy uses wee8/envoy.wasm.runtime.v8 (https://www.envoyproxy.io/docs/envoy/latest/configuration/other_features/wasm) turned on by default (at least for Linux x86_64).

Testing the above code with latest envoy from envoyproxy/envoy-dev:79205cdde2dd07cd92f175b0d699b443b516fc5d the errors are reduced:

[2022-07-22 11:47:22.235][2145515][error][wasm] [source/extensions/common/wasm/wasm_vm.cc:38] Failed to load Wasm module due to a missing import: __wbindgen_placeholder__.__wbindgen_describe
[2022-07-22 11:47:22.235][2145515][error][wasm] [source/extensions/common/wasm/wasm.cc:109] Wasm VM failed Failed to initialize Wasm code

The exact SHA used for wee8, https://github.com/envoyproxy/envoy/blob/79205cdde2dd07cd92f175b0d699b443b516fc5d/bazel/repository_locations.bzl#L889-L902

[paulyoung]

I'm also targeting wasm32-unknown-unknown and trying to use a dependency that relies on ring.

The error I'm seeing is: Module imports function 'LIMBS_are_zero' from 'env' that is not exported by the runtime.

Does anyone have any advice on a possible way forward? Thanks.

[paulyoung]

It seems like maybe #1176 is relevant and perhaps would have addressed the error I'm seeing.

There was a concern at the time around signing but I'm only interested in verifying when targeting wasm32-unknown-unknown. #1440 is linked there but it sounds like there are still some issues with it when targeting Wasm.

Does anyone know anything more?

[paulyoung]

I'm trying out the tip of main.

[paulyoung]

Now running into "could not find sysrand_chunk in super" as described in #1043

[paulyoung]

Trying this: #918 (comment)

[paulyoung]

This appears to have worked: codebase-labs@11aafb0

[paulyoung]

I spoke too soon. Everything built but I'm back to the LIMBS_are_zero issue.

Module imports function 'ring_core_0_17_0_not_released_yet_LIMBS_are_zero' from 'env' that is not exported by the runtime.

[paulyoung]

Actually I think it did work and I just ran into a stale lockfile issue.

[paulyoung]

Nope, I think the stale lockfile was giving me the impression that things were working when they weren't.

[paulyoung]

Trying this approach (env vars) next: #1483 (comment)

I've had no need for wasm-pack as of yet but maybe I need to use that or figure out what it's doing under the hood.