Key conversion from Base32 to UTF-8/Hex

[Meridien]

Hi @lucadentella

I was able to successfully use your library, thanks for making this in the first place!

One thing I found challenging was translating my existing TOTP keys from the more common Base32 key into the hex values needed in the sketch (FullExample_WiFi_NTP_OTP.ino).

// enter your hmacKey (10 digits)
uint8_t hmacKey[] = {0x73, 0x65, 0x63, 0x72, 0x65, 0x74, 0x6b, 0x65, 0x79, 0x30};

I used python to do the translation.

import base64

base32_key = input("Enter the Base32-encoded TOTP key: ")

try:
    # Decode the Base32 string into raw binary data
    binary_data = base64.b32decode(base32_key, casefold=True)

    # Convert binary data into a UTF-8 string
    UTF8_STRING = binary_data.decode('utf-8')

    print("UTF-8 string:", UTF8_STRING)

except (base64.binascii.Error, UnicodeDecodeError) as e:
    print("Error: Unable to decode. The input may not be valid Base32 or UTF-8 encoded.")

print('////////////Copy below to ino//////////////')
print("uint8_t hmacKey[] = {", ", ".join(hex(ord(char)) for char in UTF8_STRING),'};')
print("TOTP totp = TOTP(hmacKey, ",len(UTF8_STRING),");")

I'd like to submit this as as a pull request if you are open to that.

Cheers,
Daniel