The function returns an associative array with the elements "errcode" and, if "errcode "is FALSE, "outbuff" (string), "outLth "(long) and "macbuff" (string).
cybercash_decr() retourne un tableau associatif, contenant les éléments "errcode "et, si "errcode" vaut FALSE, "outbuff "(string), "outLth" (long) et "macbuff "(string).