ssh-askpass-pinentry/ssh-askpass

#!/bin/zsh

PINENTRY=@pinentry_mac@/Applications/pinentry-mac.app/Contents/MacOS/pinentry-mac

function send() {
    print -p "$@"
    read -p
}

function getpin() {
    send GETPIN
    test "${REPLY:0:3}" = ERR && { coproc : ; exit 1 }
    echo ${REPLY:2}
}

coproc $PINENTRY
PINENTRY_PID=$!
trap "kill -TERM $PINENTRY_PID" INT TERM
read -p

send SETDESC $@
send SETPROMPT Password:

case "$@" in
    "Confirm user presence"*)
        send SETOK Hide
        send CONFIRM --one-button
    ;;
    *PIN*)
        send SETPROMPT PIN:
        send OPTION allow-external-password-cache
        send SETKEYINFO ssh-askpass-pin
        getpin
    ;;
    *)
        getpin
    ;;
esac

# Close the coproc
coproc :