Pinentry

echo -e 'SETTITLE YUBI\nSETDESC YUBI\nSETPROMPT YUBI\nSETERROR YUBI\nGETPIN\n' | /usr/bin/pinentry | grep '^D'

sample-pinentry.sh ::

#!/bin/bash

# Ensure pinentry is installed
command -v pinentry >/dev/null 2>&1 || {
    echo "ERROR: pinentry not found"
    exit 1
}

# Talk to pinentry using its text protocol
response=$(
{
    echo "SETTITLE Credential Prompt"
    echo "SETPROMPT Passphrase:"
    echo "SETDESC Please enter your passphrase."
    echo "GETPIN"
} | pinentry
)

# Extract the entered PIN/password
pin=$(echo "$response" | awk '/^D / {print substr($0,3)}')

if [[ -n "$pin" ]]; then
    echo "Passphrase was entered."
    echo "Length: ${#pin}"
    # Do something with $pin here
else
    echo "No passphrase entered or dialog cancelled."
fi

secure-sample-pinentry.sh ::

#!/bin/bash

pin=$(
{
    echo "SETTITLE Secure Prompt"
    echo "SETPROMPT Password:"
    echo "GETPIN"
} | pinentry | sed -n 's/^D //p'
)

if [[ -z "$pin" ]]; then
    echo "Cancelled"
    exit 1
fi

# Use the secret
echo "Received secret"

# Clear the variable when done
unset pin

Info

When the user enters a value, pinentry returns lines similar to:

OK Pleased to meet you
D MySecretPassword
OK

The line beginning with D contains the entered secret, which is why the script extracts it.

gpg-agent version

Example 1: Ask for a passphrase via gpg-agent

#!/bin/bash

# Establish a connection to gpg-agent
GPG_CONNECT=$(gpg-connect-agent /bye 2>/dev/null)

if [[ $? -ne 0 ]]; then
    echo "gpg-agent is not running"
    exit 1
fi

# Request a passphrase
response=$(
gpg-connect-agent <<EOF
GET_PASSPHRASE --data mycacheid X X "Enter your password"
/bye
EOF
)

password=$(echo "$response" | sed -n 's/^D //p')

if [[ -z "$password" ]]; then
    echo "User cancelled"
    exit 1
fi

echo "Password received"
unset password

This caches the password, so if you call it again, it will have it stored.

--

Example 2: Trigger the user's configured pinentry

This example lets gpg-agent display the configured Pinentry GUI:

#!/bin/bash

result=$(
gpg-connect-agent <<'EOF'
GET_PASSPHRASE myapp-login X X "Please enter your password"
/bye
EOF
)

secret=$(echo "$result" | sed -n 's/^D //p')

if [[ -n "$secret" ]]; then
    echo "Success"
else
    echo "Cancelled"
fi

--

Example 3: Cache the secret

A nice feature of gpg-agent is passphrase caching:

#!/bin/bash

CACHE_ID="my-company-tool"

secret=$(
gpg-connect-agent <<EOF |
GET_PASSPHRASE $CACHE_ID X X "Authentication Required"
/bye
EOF
sed -n 's/^D //p'
)

echo "Secret obtained"

This one didn't seem to work for me?

--- Setup --

export GPG_TTY=$(tty)
gpg-connect-agent updatestartuptty /bye

Configure ~/.gnupg/gpg-agent.conf

 pinentry-program /usr/bin/pinentry-tty
 pinentry-program /usr/bin/pinentry-curses

--- manually test --

gpg-connect-agent <<EOF
GET_PASSPHRASE mytest X X "Enter Password"
EOF

Direct Pin Entry Example

#!/bin/bash

output=$(
{
    echo "SETTITLE Login"
    echo "SETPROMPT Password:"
    echo "SETDESC Please enter your password."
    echo "GETPIN"
} | pinentry
)

secret=$(sed -n 's/^D //p' <<< "$output")

if [[ -z "$secret" ]]; then
    echo "Cancelled"
    exit 1
fi

echo "Got password (${#secret} chars)"

Normal Usage

echo "hello" > test.txt
gpg -c test.txt

will trigger:

gpg
  -> gpg-agent
      -> pinentry

reusable password prompt via gpg-agent

gpg-preset-passphrase
# or
gpg-agent --daemon

Quick and dirty

{
 echo "SETTITLE Login"
 echo "SETPROMPT Password:"
 echo "GETPIN"
} | pinentry

#!/bin/bash

output=$(
{
    echo "SETTITLE Test"
    echo "SETPROMPT Password:"
    echo "GETPIN"
} | pinentry
)

echo "----- RAW OUTPUT -----"
printf '%s\n' "$output"
echo "----------------------"

if "D secret", then:

secret=$(printf '%s\n' "$output" | sed -n 's/^D //p')

If it contains percent-encoding: "D abc%20def", then you will need to decode before use

Another Try

export GPG_TTY=$(tty)
gpg-connect-agent updatestartuptty /bye

gpg-connect-agent <<EOF
GET_PASSPHRASE mytest X X "Enter Password"
EOF

Decode with:

xxd -r -p

{
gpg-connect-agent <<EOF
GET_PASSPHRASE mytest X X "Enter Password"
EOF
} | xxd -r -p

# echo "pinentry-program /usr/bin/pinentry-tty" >> ~/.gnupg/gpg-agent.conf
echo "pinentry-program /usr/bin/pinentry-gtk" >> ~/.gnupg/gpg-agent.conf
gpgconf --kill gpg-agent

---

~/.gnupg/gpg-agent.conf

# pinentry-tty renders cleanly in the Copilot CLI terminal (no curses/mouse junk)
pinentry-program /usr/bin/pinentry-tty
# Allow non-interactive passphrase paths
allow-loopback-pinentry
allow-preset-passphrase
# Keep the passphrase cached for a full workday so signing is silent after one unlock
default-cache-ttl 34200
max-cache-ttl 34200

another try

Fix #3: Use a dedicated TTY

A trick for scripts is to communicate over stdin/stdout while pinentry accesses /dev/tty:

#!/bin/bash

exec 3<> /dev/tty

output=$(
{
    echo "SETTITLE Login"
    echo "SETPROMPT Password:"
    echo "GETPIN"
} | pinentry 2>&1
)

echo "$output"

---

gpg-connect-agent <<EOF
GET_PASSPHRASE mytest X X "Test"
EOF

---

{
echo "GETPIN"
} | pinentry

---

export GPG_TTY=$(tty)

pinentry-curses <<EOF
SETTITLE Login
SETPROMPT Password:
GETPIN
EOF

decode version

#!/bin/bash

response=$(
gpg-connect-agent <<EOF
GET_PASSPHRASE mytest X X "Enter Password"
EOF
)

hex=$(awk '/^OK / {print $2}' <<< "$response")

password=$(printf '%s' "$hex" | xxd -r -p)

echo "Password: $password"