OpenFHE Build Issues

Library Questions
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1

I’m attempting to build OpenFHE for WebAssembly using emcmake and encountered a couple of issues. Since openfhe-wasm is still a work in progress, I analyzed and tried to fix them. Would appreciate feedback on whether my solutions are appropriate or if there are better alternatives.

Issue 1: MAX_MODULUS_SIZE vs. AUXMODSIZE Mismatch

In src/pke/lib/scheme/ckksrns/ckksrns-parametergeneration.cpp, AUXMODSIZE is set to 60 for non-128-bit platforms, but Emscripten fails in FirstPrime when nBits > MAX_MODULUS_SIZE (which is 57).

Proposed Fix:
Modified the condition to handle Emscripten separately:

#if NATIVEINT == 128 && !defined(__EMSCRIPTEN__)
    const size_t AUXMODSIZE = 119;
#else
    #ifdef __EMSCRIPTEN__
        const size_t AUXMODSIZE = 57;
    #else
        const size_t AUXMODSIZE = 60;
    #endif
#endif

Issue 2: blake2xb Compilation Error

The error occurs due to an incompatible iterator type:

error: no matching function for call to 'blake2xb'  
note: candidate function not viable: no known conversion from 'iterator' to 'void *'

Proposed Fix:
Replaced .begin() with .data() for raw pointer access:

if (blake2xb(m_buffer.data(), m_buffer.size() * sizeof(PRNG::result_type), 
             &m_counter, sizeof(m_counter),
             m_seed.data(), m_seed.size() * sizeof(PRNG::result_type)) != 0) {
    OPENFHE_THROW("PRNG: blake2xb failed");
}

Questions:

  1. Are these fixes correct, or is there a more robust way to handle them?
  2. Are there any known workarounds or ongoing efforts to improve Emscripten compatibility?

Thanks in advance for your help!

2

Thank you for reaching out. We are planning to re-add support for Emscripten to OpenFHE (we will try to do it as part of v1.3, the next significant version). We will get back to you once we get a chance to experiment with the compilation of the latest OpenFHE version (by the end of this month).

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