Fix ssl_client mbedtls_pk_parse_key callback

Author: me-no-dev

libraries/WiFiClientSecure/src/ssl_client.cpp

@@ -53,15 +53,6 @@ void ssl_init(sslclient_context *ssl_client)
     mbedtls_ctr_drbg_init(&ssl_client->drbg_ctx);
 }
 
-#warning This needs to be properly filled
-static int ssl_rng(void *ctx, unsigned char *data, size_t len)
-{
-    // while (len-- != 0) {
-    //     *data++ = random();
-    // }
-    return 0;
-}
-
 int start_ssl_client(sslclient_context *ssl_client, const char *host, uint32_t port, int timeout, const char *rootCABuff, bool useRootCABundle, const char *cli_cert, const char *cli_key, const char *pskIdent, const char *psKey, bool insecure, const char **alpn_protos)
 {
     char buf[512];
@@ -254,7 +245,10 @@ int start_ssl_client(sslclient_context *ssl_client, const char *host, uint32_t p
         }
 
         log_v("Loading private key");
-        ret = mbedtls_pk_parse_key(&ssl_client->client_key, (const unsigned char *)cli_key, strlen(cli_key) + 1, NULL, 0, ssl_rng, NULL);
+        mbedtls_ctr_drbg_context ctr_drbg;
+        mbedtls_ctr_drbg_init( &ctr_drbg );
+        ret = mbedtls_pk_parse_key(&ssl_client->client_key, (const unsigned char *)cli_key, strlen(cli_key) + 1, NULL, 0, mbedtls_ctr_drbg_random, &ctr_drbg);
+        mbedtls_ctr_drbg_free( &ctr_drbg );
 
         if (ret != 0) {
             mbedtls_x509_crt_free(&ssl_client->client_cert); // cert+key are free'd in pair