dsprenkels / randombytes

A portable C library for generating cypto-secure random bytes
MIT License
96 stars 37 forks source link

Support Electron apps #47

Open DogeProtocol opened 9 months ago

DogeProtocol commented 9 months ago

https://github.com/dsprenkels/randombytes/blob/1c0c6665640535a9a851bf5c2df2e0369273b6ad/randombytes.c#L302

The code under randombytes_js_randombytes_nodejs doesn't seem to work for Electron apps webassembly. Since many implementations don't check for return value of randombytes, downstream code was silently passing and causing security issues.

We have an updated version for randombytes_js_randombytes_nodejs that worked for electronjs app as well (as per Mozilla docs, window.crypto is a CSPRNG) https://developer.mozilla.org/en-US/docs/Web/API/Crypto

Example: https://github.com/DogeProtocol/hybrid-pqc/blob/d13f9d3944515ccdd7eee4fe98b08562b71564ef/random/randombytes.c#L322C1-L327C4

`#if defined(EMSCRIPTEN) static int randombytes_js_randombytes_nodejs(void *buf, size_t n) {

const int ret = EM_ASM_INT({

    if (window.crypto && window.crypto.getRandomValues) { 
        var randBuffer = new Uint8Array($1);
        window.crypto.getRandomValues(randBuffer);
        writeArrayToMemory(randBuffer, $0);
        return 0;
    }

    var cryptoMod;
    try {
        cryptoMod = require('crypto');
    } catch (error) {
        return -2;
    }
    try {
        writeArrayToMemory(cryptoMod.randomBytes($1), $0);
        return 0;
    } catch (error) {
        return -1;
    }
}, buf, n);
switch (ret) {
case 0:
    return 0;
case -1:
    errno = EINVAL;
    return -1;
case -2:
    errno = ENOSYS;
    return -1;
}
return -3;
assert(false); // Unreachable

}

endif / defined(EMSCRIPTEN) /`