Empty optional data field and empty optional data hash in TD3 format will result in a invalid hash in the TD3CodeChecker

[KlaasJelmer]

Hi!

I have a Swiss passport with a MRZ in the TD3 format. On this document no optional data is used, hence its MRZ value is <<<<<<<<<<<<<<. The corresponding optional data hash is <.

I would expect that this would result in a valid MRZ readout, but this seems not the case. The empty values are not recognized as a valid value-hash pair: hash_is_ok("<<<<<<<<<<<<<<", "<") returns False. This in turn causes TD3CodeChecker(mrz) to cast to a False boolean.

[Arg0s1080]

Hi there!

Could you give an example?

I have done the following test:

from mrz.checker.td3 import TD3CodeChecker

# Case 1: Optional Data "<<<<<<<<<<<<<<", hash "0"
check1 = ("P<GB<MARTIN<<SARAH<<<<<<<<<<<<<<<<<<<<<<<<<<\n"
          "980XG47<<9GBR8501019F2612281<<<<<<<<<<<<<<06")

# Case 2 Optional Data "<<<<<<<<<<<<<<", hash "<"
check2 = ("P<GB<MARTIN<<SARAH<<<<<<<<<<<<<<<<<<<<<<<<<<\n"
          "980XG47<<9GBR8501019F2612281<<<<<<<<<<<<<<<6")

# Case 3 Optional Data "<<<<<<<<<<<<<<", hash "7"
check3 = ("P<GB<MARTIN<<SARAH<<<<<<<<<<<<<<<<<<<<<<<<<<\n"
          "980XG47<<9GBR8501019F2612281<<<<<<<<<<<<<<76")

print(TD3CodeChecker(check1))
print(TD3CodeChecker(check2))
print(TD3CodeChecker(check3))

And its output is:

True 
True
False

Is true that has_is_ok() function returns False, but that problem as it happened later was solved in optional_data_hash property.

I recognize that as you suggest this problem should be solved in hash_is_ok() (i take note)

Greetings