Encode header to base64

esp32_device/main/crypto.h

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <stdbool.h>
+#include <stddef.h>
 
 #ifdef __cplusplus
 extern "C"
@@ -31,6 +32,13 @@ extern "C"
      */
     char *crypto_get_csr();
 
+    /**
+     * Encode buffer to base64 safe URL string
+     *
+     * @return A buffer that needs to be freed or NULL in case of failure
+     */
+    char *crypto_encode_base64_safe_url(const char *src, size_t srclen);
+
 #ifdef __cplusplus
 }
 #endif