wifi-qr.py

import base64
import os
import pathlib
import sys

import qrcode



def gen_constr(ssid:bytes, psk:bytes, hidden:bool=False) -> bytes:
    """https://en.wikipedia.org/wiki/QR_code#Joining_a_Wi%E2%80%91Fi_network"""
    
    for c in b'\\:;':
        ssid = ssid.replace(bytes([c]), bytes([92, c]))  # 92 = backslash
        psk = psk.replace(bytes([c]), bytes([92, c]))
    
    hidden = b'true' if hidden else b'false'
    constr = b'WIFI:S:' + ssid + b';T:WPA;P:' + psk + b';H:' + hidden + b';;'
    return constr
    

def cli():
    print('Use CTRL+Z to go back and CTRL+C to exit')
    print('For binary inputs, start with "hex:"')
    
    try:
        # ssid
        while True:
            try:
                ssid = input('SSID: ')
                if not ssid: continue
            except EOFError:
                continue
            
            
            if ssid.startswith('hex:'):
                ssid = ssid[4:].strip()
                try:
                    ssid = bytes.fromhex(ssid)
                except ValueError:
                    print("That isn't hex")
                    continue
                print('SSID entered as binary value')
            else:
                ssid = ssid.encode()
                
            if len(ssid) > 32:
                print(f'Your SSID is too long ({len(ssid)}) must be 32 or less.')
                continue
                
            # password
            while True:
                try:
                    pw = input('Password: ')
                    if not pw: continue
                except EOFError:
                    break
                
                
                if pw.startswith('hex:'):
                    pw = pw[4:].strip()
                    try:
                        pw = bytes.fromhex(pw)
                    except ValueError:
                        print("That isn't hex")
                        continue
                    print('Password entered as binary value')
                else:
                    pw = pw.encode()
                
                if len(pw) > 63:
                    print(f'Your password is too long ({len(pw)}) must be 63 or less.')
                    continue
                
                # hidden
                while True:
                    try:
                        hidden = input('hidden (y/[n]): ').strip().lower()
                    except EOFError:
                        break
                    
                    if not hidden:
                        print('Hidden set to "no"')
                        hidden = 'n'
                    else:    
                        hidden = hidden[0]
                                        
                    if hidden not in 'yn':
                        print('Please answer y or n')
                        continue
                    
                    hidden = True if hidden == 'y' else False

                    # build the connection string and show QR image
                    constr = gen_constr(ssid, pw, hidden)
                    
                    print('Your connection string:')
                    print('B64:   ', base64.b64encode(constr).decode())
                    print('UTF8:  ', constr.decode('utf8', errors='replace'))
                    print('Latin1:', constr.decode('latin1', errors='replace'))
                    
                    print('\nHere comes your QR Code!!')
                    qrcode.make(constr).save('wifi.png')
                    
                    try:
                        r = os.system('wifi.png')
                        if r != 0:
                            raise Exception
                    except:
                        p = pathlib.Path('wifi.png').absolute()
                        print(f'Well, that didnt\'t work :( Try looking here:\n"{p}"')
                    
                    return
                    
                        
    except KeyboardInterrupt:
        return


def main():
    cli()
    print('\nDone.', file=sys.stdout)


        
if __name__ == '__main__':
    main()