fix(wasm): load without script-src 'unsafe-eval' - #717
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embind generates its invoker functions at run time with `new Function`, which CSP treats as eval, so `Odr.load()` threw an `EvalError` under any policy that did not grant `'unsafe-eval'` — the one thing a page whose selling point is that documents are processed locally would rather not grant. The glue contains no literal `eval(`, which makes it easy to misdiagnose. `-sDYNAMIC_EXECUTION=0` picks embind's closure-based path instead. What it costs is `emscripten_run_script`, `dlopen`, and `ccall`/`cwrap` for anything not exported in advance — none of which the bindings use. `script-src 'self' 'wasm-unsafe-eval'` is now enough. Closes #709 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01XDs5aK3ZGSZsEvqUUwBBXU
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015d5RcmsA777vwXiuafjx6k
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Closes #709.
embind generates its invoker functions at run time with
new Function, which CSP treats as eval — soOdr.load()threwunder the policy a page whose selling point is that documents are processed locally would actually want to ship. The glue contains no literal
eval(, which is what makes it easy to misdiagnose.-sDYNAMIC_EXECUTION=0picks embind's closure-based path instead (#if DYNAMIC_EXECUTION == 0inembind.js, present in the pinned emsdk 3.1.73). What it costs isemscripten_run_script,dlopen, andccall/cwrapfor anything not exported in advance — none of which the bindings use.script-src 'self' 'wasm-unsafe-eval'is now enough.Verified
Built locally with the
emscripten-wasmprofile, emsdk 3.1.73:new Function/eval(inodr-core.mjsEvalErroratinitRuntimeodr-core.wasm, brotliThe "blocked" run is a child process with
globalThis.Functionproxied to throw on construct and apply, standing in for a policy without'unsafe-eval'; it rendersmixed-layout.odtend to end afterwards. That is the first of the two tests inwasm/tests/csp.test.mjs; the second asserts statically that the shipped glue builds no code at run time, so dropping the flag fails the suite rather than only failing in a browser.Note: this documents only the module's own
script-srcline, under Hosting. What the rendered output needs — #710 — is a separate section in a separate PR; the two do not overlap.