readpassphrase
if (readpassphrase(prompt, pw, pwlen, RPP_REQUIRE_TTY) == NULL)
if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
char * readpassphrase(const char *, char *, size_t, int);
if (readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF) == NULL)