Some additional functions are used internally and also exposed in the API:

platform independent large file utils: rs_file_open(), rs_file_close(), rs_file_size(), rs_file_copy_cb().
encoding/decoding binary data: rs_base64(), rs_unbase64(), rs_hexify().
MD4 message digests: rs_mdfour(), rs_mdfour_begin(), rs_mdfour_update(), rs_mdfour_result().