Sha256 hash and base64 encode

I am trying to authenticate to OBS software (websockets) using ESP32

I can communicate send and receive data from ESP32 but can't authenticate. The process is as following:
send auth request and get challenge and salt
then process the data and send auth_response back
Pseudo Code Example:

password = "supersecretpassword"
challenge = "ztTBnnuqrqaKDzRM3xcVdbYm"
salt = "PZVbYpvAnZut2SS6JNJytDm9"

secret_string = password + salt
secret_hash = binary_sha256(secret_string)
secret = base64_encode(secret_hash)

auth_response_string = secret + challenge
auth_response_hash = binary_sha256(auth_response_string)
auth_response = base64_encode(auth_response_hash)

It works using different clients like JS example

In my ESP32 I can get first two steps working:

secret_string = password + salt
secret_hash = binary_sha256(secret_string)

but when I try:

secret = base64_encode(secret_hash)

I get a different result comparing to JS the example

Arduino references

#include "mbedtls/md.h"
#include <base64.h>

code:

String encoded = base64::encode("blablabla");     
Serial.println("encoded:  ");    
Serial.println(encoded);

Wondering why I get different results in Arduino core and JavaScript while using base64::encode

if I run this on an ESP32

#include <base64.h>

void setup()
{
  Serial.begin(115200);
  Serial.print("Base 64 encoding of \"blablabla\" is \"");
  Serial.print(base64::encode("blablabla")); 
  Serial.println("\"");
}

void loop() {}

Serial Monitor (@ 115200 bauds) shows

Base 64 encoding of "blablabla" is "YmxhYmxhYmxh"

if I double check with cryptii I do get the same thing

If anyone should help you find the problem, you must post the code that does not work. Usually the issue is not base64 but the hashing of data.

OK, I was doing a bad implementation of the base64 encoder. Now I have changed the way and works

      unsigned char secret[128];
      memset(secret, 0, sizeof(secret));
      mbedtls_base64_encode(secret, sizeof(secret), &hashb64_len, sha256, sizeof(sha256));