generate-non-interactive-gpg-private-key.sh

#!/bin/bash

# Function to display help message
usage() {
  echo "Usage: $0 --email <email> [--name <name>] [--passphrase <passphrase>]"
  echo "Generate an Ed25519 GPG private key non-interactively."
  echo ""
  echo "Options:"
  echo "  --email      Email address for the GPG key (required)"
  echo "  --name       Name for the GPG key (optional, defaults to email)"
  echo "  --passphrase Passphrase for the key (optional, empty for no passphrase)"
  echo "  --help       Display this help message"
  exit 1
}

# Parse command-line arguments
EMAIL=""
NAME=""
PASSPHRASE=""

while [[ $# -gt 0 ]]; do
  case "$1" in
  --email)
    EMAIL="$2"
    shift 2
    ;;
  --name)
    NAME="$2"
    shift 2
    ;;
  --passphrase)
    PASSPHRASE="$2"
    shift 2
    ;;
  --help)
    usage
    ;;
  *)
    echo "Unknown option: $1"
    usage
    ;;
  esac
done

# Validate email
if [ -z "$EMAIL" ]; then
  echo "Error: --email is required."
  usage
fi

# Set default name to email if not provided
if [ -z "$NAME" ]; then
  NAME="$EMAIL"
fi

# Create temporary configuration file for GPG key generation
TEMP_CONFIG=$(mktemp)
cat >"$TEMP_CONFIG" <<EOF
Key-Type: eddsa
Key-Curve: Ed25519
Key-Usage: sign
Subkey-Type: ecdh
Subkey-Curve: Curve25519
Subkey-Usage: encrypt
Name-Real: $NAME
Name-Email: $EMAIL
Expire-Date: 0
EOF

# Add passphrase or no-protection based on input
if [ -n "$PASSPHRASE" ]; then
  echo "Passphrase: $PASSPHRASE" >>"$TEMP_CONFIG"
else
  echo "%no-protection" >>"$TEMP_CONFIG"
fi

echo "%commit" >>"$TEMP_CONFIG"

# Generate the GPG key non-interactively
if ! gpg --batch --generate-key "$TEMP_CONFIG" 2>gpg_error.log; then
  echo "Error generating GPG key."
  cat gpg_error.log
  rm -f gpg_error.log "$TEMP_CONFIG"
  exit 1
fi

# Clean up
rm -f gpg_error.log "$TEMP_CONFIG"

echo "GPG Ed25519 key generated for $EMAIL"