For these purposes, will work well [RsaCtfTool](https://github.com/sourcekris/RsaCtfTool)
```cd /opt/RsaCtfTool./RsaCtfTool.py --publickey /media/DATA/CTF/yubitsec/RSA_I/RSA/Part1/PublicKey1.pem --private --uncipher /media/DATA/CTF/yubitsec/RSA_I/RSA/Part1/ciphertext1./RsaCtfTool.py --publickey /media/DATA/CTF/yubitsec/RSA_I/RSA/Part2/PublicKey2.pem --private --uncipher /media/DATA/CTF/yubitsec/RSA_I/RSA/Part2/ciphertext2./RsaCtfTool.py --publickey /media/DATA/CTF/yubitsec/RSA_I/RSA/Part3/PublicKey3.pem --private --uncipher /media/DATA/CTF/yubitsec/RSA_I/RSA/Part3/ciphertext3```After the launch it only remains to collect the flag:```gh0st3rs@leacher-pc:RSA_I$ ./solver.sh -----BEGIN RSA PRIVATE KEY-----MG4CAQACExqs08kNGr393d4YNfWKiPA2i58CAwEAAQITAQtEmrjVlBwMg4SswXPAD6tZMQIKA15X18VLlSZm6QIKB+s+al7J1uFZRwIKAJ2AqdZNQcar0QIKAJDL53sXvZJg9wIKAuJxXfZGtKRLsg==-----END RSA PRIVATE KEY-----[+] Clear text : ?�ԗ��tA?3�YUBITS-----BEGIN RSA PRIVATE KEY-----MG8CAQACFAOK8x5ZjiQrX88bMG/f8OLWbvI5AgMBAAECEyglbOF/9j/pRMn/kooJwOtYVoUCCh1itmCUgFlKT/8CCh7dHr/XqtdlPccCCgt2f0hLhYnPSEcCChb4x+lMUZlOfoMCCg0EYHu6Sip/N/s=-----END RSA PRIVATE KEY-----[+] Clear text : ?�6x?A�KΡEC{S4V3-----BEGIN RSA PRIVATE KEY-----MG4CAQACE2V6kIQmEBr6JVHPyibjmvVkUycCAwEAAQITQyZ6kOe7Co7yqrRYsOVcBFCU0QIKBs3zoRJ7rHVf6QIKDunZ8G691p3AjwIKA6M+x7F15HCrYQIKBBzmJ/LClB+pbQIKA1rNqY0KXkCtvg==-----END RSA PRIVATE KEY-----[+] Clear text : ?�"?Ꙍ���_FL46}```
Flag: YUBITSEC{S4V3_FL46}