create-user

#!/bin/bash

# -- Single File PHP File Browser - User Management Script --
# This script will create (or remove) a file to store credentials.
# The upload section on index.php will only show up with this file.
# It will create and delete users, and it will hash passwords.
# Tarso Galvão - 19/09/2024 - Debian 12
# github.com/surtarso/single-file-php-file-browser


# Set file to store credentials
# If changed here, it also needs to be changed in index.php
# Global variable: $credentialsFile = './.users'; and vice-versa
credentialsFile=".users"

# Get username and password from arguments
username="$1"
password="$2"

# Bash colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
NC='\033[0m' # No Color

# ------------------------------- FUNCTIONS ----------------------------------
# Function to display an error message and exit the script
function exit_with_error() { 
    case "$1" in
        wrong-args)
        echo -e "${YELLOW}Single File PHP File Browser${NC}"
        echo -e "User management script usage:"
        echo -e "Add user: ${YELLOW}$0 ${GREEN}username password${NC}"
        echo -e "Del user: ${YELLOW}$0 ${GREEN}username ${RED}--delete${NC}"
        ;;
        file-create)
        echo -e "${RED}Error: Could not create ${YELLOW}'$credentialsFile'${RED}. Check permissions.${NC}"
        ;;
        file-write)
        echo -e "${RED}Write Error: Could not write to ${YELLOW}'$credentialsFile'${RED}. Check permissions.${NC}"
        ;;
        file-delete)
        echo -e "${RED}Error: Could not remove ${YELLOW}'$credentialsFile'${RED}. Check permissions.${NC}"
        ;;
        file-read)
        echo -e "${RED}Read Error: Could not scan for ${YELLOW}'$username'${RED}. Check file permissions.${NC}"
        ;;
        delete-user)
        echo -e "${RED}Error: Could not delete ${YELLOW}'$username'${RED}. Check file permissions.${NC}"
        ;;
        username-null)
        echo -e "${RED}Error: Username ${YELLOW}'$username'${RED} doesn't exit.${NC}"
        ;;
        username-exists)
        echo -e "${RED}Error: Username ${YELLOW}'$username'${RED} already exists.${NC}"
        ;;
        validation-failed)
        echo -e "${RED}Error: Invalid credentials! Please use only numbers and letters."
        echo -e "Username: Must be 4-20 characters long."
        echo -e "Password: Must be 8-20 characters long.${NC}"
        ;;
        hashing-failed)
        echo -e "${RED}Error: Could not hash the password. Do you have PHP installed?${NC}"
        ;;
        *)
        echo -e "${RED}Error: ${YELLOW}Uh oh... Unknown error${RED}.${NC}"
        echo -e "Please create an issue on 'github.com/surtarso/single-file-php-file-browser'"
        echo -e "and reproduce the steps taken for this message to show. Thanks! <3"
        ;;
    esac
    exit 1 
}

# Function to validade credentials
function validate_credentials() {
    usernameRegex="^[a-zA-Z0-9_]{4,20}$"
    passwordRegex="^[a-zA-Z0-9_]{8,20}$"
    
    if [[ ! "$username" =~ $usernameRegex ]] ||
        [[ ! "$password" =~ $passwordRegex ]]; then
        return 1
    fi

    return 0
}

# Function to check if user exists
function user_exists() {
    if [[ ! -f "$credentialsFile" ]]; then
        return 1
    fi

    grep -q "^$username:" "$credentialsFile" || exit_with_error file-read
}

# Function to delete empty .users file
function delete_credentials_file() {
    if [[ ! -f "$credentialsFile" ]]; then
        echo -e "${RED}Error: File ${YELLOW}'$credentialsFile'${RED} not found.${NC}"
        return 1
    fi

    # Scan file for content
    while IFS= read -r line; do
        if [[ -n "$line" ]]; then
            return 0 # Non-empty line found
        fi
    done <"$credentialsFile"

    # If the loop completes without returning, the file is empty, so delete it.
    rm -f "$credentialsFile" "$credentialsFile.tmp" 2>/dev/null || exit_with_error file-delete
    echo -e "${YELLOW}'$username'${NC} was the last user credential."
    echo -e "${YELLOW}Uploads are now disabled.${NC}"
}

# Function to delete a user
function delete_user() {
    if ! user_exists; then
        exit_with_error username-null
    fi

    # Get username from arguments and remove from users file
    grep -v "^$username:" "$credentialsFile" >"$credentialsFile".tmp &&
        mv "$credentialsFile".tmp "$credentialsFile" || exit_with_error delete-user
    echo -e "User ${YELLOW}'$username'${NC} deleted."
}

# Function to create the file where credentials will be stored
function create_credentials_file () {
    if [[ -f "$credentialsFile" ]]; then 
        return 0
    fi

    # If credentials are on the very first line of the file,
    # this script is unable to remove it later for some reason.
    # So we echo an empty line to overcome this.
    echo "" >>"$credentialsFile" || exit_with_error file-create
    echo -e "${GREEN}Uploads are now enabled.${NC}"
}

# Function to create a user
function create_user() {
    # Hash the password using PHP
    hashedPassword=$(php -r "echo password_hash('$password', PASSWORD_DEFAULT);") || exit_with_error hashing-failed

    # Append the user and hashed password to the users file
    echo "$username:$hashedPassword" >>"$credentialsFile" || exit_with_error file-write
    echo -e "User ${YELLOW}'$username'${NC} added."
}

# -------------------------- MAIN LOGIC ---------------------------
# Check for required arguments
if [[ $# -ne 2 ]]; then
    exit_with_error wrong-args
fi

# DELETION --------------------------------------------------------
# Check if it's a deletion
if [[ "$password" = "--delete" ]]; then
    # Attempt to delete the user
    delete_user
    # Delete credentials file if empty
    delete_credentials_file
    exit 0
fi

# CREATION --------------------------------------------------------
# Check if given username already exists
if user_exists; then
    exit_with_error username-exists

# Check if given username and password are valid using regex
elif ! validate_credentials; then
    exit_with_error validation-failed

else
    # Create credentials file if none exists
    create_credentials_file

    # Attempt to create the user
    create_user
    exit 0
fi