randombytes_buf always generate 000000000000000000000000

[qijun4tian]

hi
i want encrypt in brower and write clang use crypto_aead_chacha20poly1305_ietf_encrypt , use randombytes_buf to generate npub like below

 unsigned char n[crypto_aead_chacha20poly1305_IETF_NPUBBYTES];
    printf("\nnoce=");

    randombytes_buf(n, sizeof n);
    for (int i = 0; i < strlen(n); ++i){
        printf("%02x,", n[i]);
    }
    printf("\nout=");

    crypto_aead_chacha20poly1305_ietf_encrypt(out, &ciphertext_len,
                                              input, strlen(input),
                                              ADDITIONAL_DATA, ADDITIONAL_DATA_LEN,
                                              NULL, n, key);

and is work well on linux
so i generate the wasm file like below emcc -O0 -s FORCE_FILESYSTEM=1 -s EXPORTED_FUNCTIONS='[_randombytes_buf,_main]' -s EXIT_RUNTIME=1 -I/root/libsodium-stable/src/libsodium/include /root/libsodium-stable/libsodium-js-sumo/lib/libsodium.a main.c -o output.html
i run the output.html and randombytes_buf always generate 000000000000000000000000
and also the brower console error

Uncaught TypeError: Module.getRandomValue is not a function

[jedisct1]

The library must be initialized with "sodium_init()" before calling any other function. On all platforms.

[qijun4tian]

I call "sodium_init()" in main.c and crypto_aead_chacha20poly1305_ietf_encrypt work well

[qijun4tian]

  Module.onRuntimeInitialized = function() {
            Object.keys(_Module).forEach(function(k) {
              if (k !== 'getRandomValue') {
                delete _Module[k];
              }
            });
            Object.keys(Module).forEach(function(k) {
              _Module[k] = Module[k];
            });
            resolve();
          };

why delete getRandomValue in emscripten.js

[jedisct1]

The !== operator means "different". So, that loops seems to delete all functions except getRandomValue.

[qijun4tian]

3ks. i recompile it and is ok now， but i do not know why is was not ok before.