ecollect / node-fe1-fpe Goto Github PK

Hi,
I see that currently it supports only numbers, is there a reason why ASCII alphabets and Unicode is not supported?

Thanks.

The calculation of left in decryption can result in a negative number when modulu is less than 0,

this leads to a failure to recover the original value.

The value produced should be based on - modulu in all cases (to ensure a positive result):

 left = (modulu > 0) ? firstFactor - modulu : - modulu; 

You can confirm this change is an improvement by

• first removing all expectedEV assertions from the unit tests (tests should still pass with less assertions)
• modifying the format() function to return ... % 100n to force the modulu <= 0 case to occur, (tests now fail).
• then updating the code as above. (tests pass again, because the code was fixed).

Then remember to

• restore the current format() function.
• restore the current test code (all original tests will still pass with all assertions).

Should I expect to get the same encrypted result as what is shown in the README?
I get 5011 instead of 4984:

$ node
Welcome to Node.js v12.14.1.
> const fe1 = require('node-fe1-fpe');
> const v = fe1.encrypt(10001, 1, 'my-secret-key', 'my-non-secret-tweak');
> console.log(v)
5011
> const d = fe1.decrypt(10001, v, 'my-secret-key', 'my-non-secret-tweak');
> console.log(d);
1

// curious what 4984 decrypts to:
> const d2 = fe1.decrypt(10001, 4984, 'my-secret-key', 'my-non-secret-tweak');
> console.log(d2);
6786

Hi, it looks like currently modulo is supported up to 10 000 000. But for 15-digit credit card, don't we need 10^15 modulo?

Hi, I noticed that the round is hard-coded, how about providing an optional round argument?

fwiw, botan also has round as an argument https://botan.randombit.net/manual/fpe.html