Reported live: mount error(79) again despite already switching to real
credentials + sec=ntlmssp — this time with a Samba password containing
special characters. Root cause confirmed directly: `read -r -s pw1`
without `IFS=` silently strips leading/trailing whitespace even when
reading into a single variable (verified: " P@ss word! " -> "P@ss word!",
10 chars instead of 12). A password with a leading/trailing space —
common from a password manager's copy-paste, or a stray keystroke — got
quietly trimmed on the way into the credentials file, so it no longer
matched what was actually set on the Samba account. That mismatch
surfaces as this same cryptic ENOKEY mount error, not an obvious "wrong
password".
Fixed with IFS= on both reads. Also echo the captured length (never the
password itself) right after entry, so a silently-stripped character is
something you can catch and cross-check yourself before the mount even
attempts, instead of only after it fails.