Creating a User-Friendly File Encryption Tool with Bash and Zenity

What this script does.

Password Handling

The prompt_password function uses zenity — password to securely prompt the user for a password without displaying it.

File Selection

For encryption, users can select multiple files.
For decryption, users can select a single file with the .enc extension.

Encryption and Decryption

Uses openssl enc -aes-256-cbc with the -pass pass:”$password” option for password-protected encryption and decryption.
Checks the success of openssl commands and provides appropriate feedback.

User Feedback

Uses show_message and show_error functions to provide feedback and error messages to the user.

Menu Interface

The main menu allows the user to choose between encryption and decryption using zenity — list — radiolist.

To run the script

Save it to a file, for example advanced_file_crypt.sh.
Make it executable with chmod +x advanced_file_crypt.sh.
Execute it by running ./advanced_file_crypt.sh.
Ensure zenity and openssl are installed on your system:

On Debian/Ubuntu: sudo apt-get install zenity openssl

On Fedora: sudo dnf install zenity openssl

On Arch Linux: sudo pacman -S zenity openssl

#!/bin/bash
show_message() {
    zenity --info --text="$1"
}
show_error() {
    zenity --error --text="$1"
}
prompt_password() {
    zenity --password --title="$1"
}
encrypt_files() {
    files_to_encrypt=$(zenity --file-selection --multiple --title="Select files to encrypt")
    
    if [[ -n "$files_to_encrypt" ]]; then
        IFS="|" read -r -a files <<< "$files_to_encrypt"
        password=$(prompt_password "Enter password for encryption")    
        if [[ -n "$password" ]]; then
            for file in "${files[@]}"; do
                output_file="${file}.enc"
                openssl enc -aes-256-cbc -salt -in "$file" -out "$output_file" -pass pass:"$password"
                if [[ $? -eq 0 ]]; then
                    show_message "Encryption complete for $file. Output saved to $output_file."
                else
                    show_error "Failed to encrypt $file."
                fi
            done
        else
            show_error "No password entered. Encryption aborted."
        fi
    else
        show_message "No files selected for encryption."
    fi
}
decrypt_files() {
    encrypted_file=$(zenity --file-selection --title="Select file to decrypt" --file-filter="*.enc")  
    if [[ -n "$encrypted_file" ]]; then
        password=$(prompt_password "Enter password for decryption")
        
        if [[ -n "$password" ]]; then
            output_file="${encrypted_file%.enc}.dec"
            openssl enc -aes-256-cbc -d -in "$encrypted_file" -out "$output_file" -pass pass:"$password"
            if [[ $? -eq 0 ]]; then
                show_message "Decryption complete. Output saved to $output_file."
            else
                show_error "Failed to decrypt $encrypted_file. Check your password and try again."
            fi
        else
            show_error "No password entered. Decryption aborted."
        fi
    else
        show_message "No file selected for decryption."
    fi
}
choice=$(zenity --list --radiolist \
    --title="File Encryption Tool" \
    --column="Select" --column="Action" \
    TRUE "Encrypt Files" FALSE "Decrypt Files")
case $choice in
    "Encrypt Files")
        encrypt_files
        ;;
    "Decrypt Files")
        decrypt_files
        ;;
    *)
        show_message "No action selected."
        ;;
esac