[ALEXCTF]-CR4:Poor RSA

Change the name of file key.pub to public.pem
Use this command to analysis the public.pem file
We can get n and e

Factor n get p and q then combine q,p with e we will get private key.
p = 863653476616376575308866344984576466644942572246900013156919
q = 965445304326998194798282228842484732438457170595999523426901
e = 65537
Use RSA tool to get private key

Decode the base64 code in file flag.b64 and save it as a file name flag then use the private key file (private.pem) to decrypt it.

The flag is ALEXCTF{SMALL_PRIMES_ARE_BAD}