Problem with exiting in rsa_modExp about rsa-library HOT 7 OPEN

I have the same issue

from rsa-library.

echo $? shows that it exited on an error, I'd run a debugger and step through it.

from rsa-library.

I analyzed it, and this is because the function long long rsa_modExp(long long b, long long e, long long m) fails if any of its parameters is 0, which is fairly often.
This would be fine if it didn't exit instead of aborting its function and provides no reason for the users to see

from rsa-library.

Hi, I seem to have resolved the issue by replacing long long with unsigned long long throughout the library. Need your feedback on this solution. I believe the multiplication in rsa_modExp(b * b % m, e/2, m), line 56 of rsa.c was causing the overflow.

from rsa-library.

change the line 56 of rsa.c into return ( rsa_modExp(((b % m) * b) % m, e/2, m) % m );

from rsa-library.

Hi, I seem to have resolved the issue by replacing long long with unsigned long long throughout the library. Need your feedback on this solution. I believe the multiplication in rsa_modExp(b * b % m, e/2, m), line 56 of rsa.c was causing the overflow.

yup what you said did work, still dont know why the dev did not care about the overflow issues....

from rsa-library.

hi, i have created a fork that adresses this issue and provides further encryption (OAEP): https://github.com/oskarvonephesos/RSA-Library

from rsa-library.