This project contains a script which extracts n from RSA public key files and Dockerfile for fastgcd. Refer to https://factorable.net/index.html about fastgcd.
Build your fastgcd container.
$ docker build -t fastgcd/docker .
Put all RSA public key files in a directory and extract n from them, then run fastgcd. Supported files are PGP, X.509 certificate, RSA public key and SSH in PEM format.
$ python3 ./extract.py keydir/ > moduli
$ ./fastgcd.sh moduli
Result files are copyed on the host.
vulnerable_moduli
gcds