> For the complete documentation index, see [llms.txt](https://davids-tutorials.gitbook.io/robotics/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://davids-tutorials.gitbook.io/robotics/ignore-extra/cyber.md). # Cyber > First complete Lab, then Project > [wget](https://www.gnu.org/software/wget/) (short for "web-get") ### Tree Command (Alternative to ls) ``` sudo apt-get install tree ``` ``` tree ``` ``` ############# # OUTPUT: # ############# /home └── folder ├── unit2 ├── unit3 │ ├── cp_leak.txt │ └── crackfiles.zip └── unit6 ├── attrib.txt ├── cat.jpg ├── dog.jpg ``` PRE-REQ * [ ] [CYB101 Setup Scripts zip](https://github.com/codepath/cyb101-vm-setup/archive/refs/heads/main.zip) into the `~` directory on your VM so that `~/Scripts` and `~/Files` are valid paths. * [ ] From the `~` directory, run `./Scripts/setup.sh` * If you run into issues, try looking through the Scripts and only run the ones you need for the unit you're trying to complete (e.g., `Scripts/unit3_lab.sh`) * More guidance can be found on the repo [README](https://github.com/codepath/cyb101-vm-setup). * [ ] [CYB101 Setup Scripts zip](https://github.com/codepath/cyb101-vm-setup/archive/refs/heads/main.zip) into the `~` directory on your VM so that `~/Scripts` and `~/Files` are valid paths. * [ ] From the `~` directory, run `./Scripts/setup.sh` * If you run into issues, try looking through the Scripts and only run the ones you need for the unit you're trying to complete (e.g., `Scripts/unit3_lab.sh`) * More guidance can be found on the repo [README](https://github.com/codepath/cyb101-vm-setup) * Once you get the `"All scripts executed successfully."` message, you're ready to start the course! ## Project Part: SSH Keys ``` ssh-keygen -t rsa -b 4096 -C "CYB Ubuntu Key" ``` * 4096-bit SSH RSA public and private keys. * **Commands breakdown:** * `ssh-keygen` = the utility used to generate the key pair * `-t rsa` = specifies the **t**ype of key to create (e.g., rsa) * `-C "CYB Ubuntu Key"` = provides custom key comment (which will be appended at the end of the public key). * Usually an email address is used as a comment, but this time we're labeling it with the machine we'll use it on. * Think of it like a label for your key, so you don't mix it up with other keys! ``` Enter file in which to save the key (/home/codepath/.ssh/id_rsa): /home/codepath/.ssh/id_rsa_cyb ## No Passphrase ``` * Public key is .pub * Private key is no extension or .pem #### View keys ``` cat ~/.ssh/id_rsa_cyb101 #### OUTPUT #### b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAACFwAAAAdzc2gtcn cat ~/.ssh/id_rsa_cyb101.pub #### OUTPUT #### ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAACAQC5OSa7cKQQg4rWohWVYobfVUhilcojgydrxTOtzRDrYm/W+K1QrndFjxL6CH9JTFPapqkZDk92lDXvrn+qQKNaBkzNDjTyTKJp2cLd5eGIax2CWdSqgZhtjo+kAeB2wnEPU6C2rPqw5EVveATYoPfUBVTtfZt2PsxZGAVp #### OUTPUT #### QbFREW0tL05V8T2YHBtvoCeoSlQ1NjMLWvKQ== CYB101 Ubuntu Key ``` > 3 main uses of keys: authentication, encryption integrity #### Using ssh to connect to remote server ``` ## Example: ssh -p XXXX -i ~/.ssh/id_rsa_cyb101 codepath@lab-xxxxx.eastus.cloudapp.azure.com ``` #### Stuck on this part (might not need): ``` ssh-copy-id codepath@localhost ``` * ``` Their user@domanin: codepath@lab000001 ``` ## Part 3: Encryption with SSH Keys Assymetric encryption:\ \- Public key: encrypt\ \- Private key: decrypt ``` openssl genrsa -out ~/.ssh/privatekey.pem 2048 ``` \- creates private.pem file (longer file) ``` openssl rsa -in ~/.ssh/privatekey.pem -out ~/.ssh/publickey.pem -pubout -outform PEM ``` \- creates publickey.pem file (shorter file) ``` echo "MY SECRET MESSAGE" > secret.txt cat secret.txt ``` \- creates file & display, this is final step to setup ``` openssl pkeyutl -encrypt -pubin -inkey ~/.ssh/publickey.pem -in secret.txt -out secret.txt.encrypted ``` \- this encrypts our secret msg with public ``` cat secret.txt.encrypted ``` \- to view file ``` openssl pkeyutl -decrypt -inkey ~/.ssh/privatekey.pem -in secret.txt.encrypted -out secret.txt.decrypted ``` \- generate decrypted file ``` cat secret.txt.decrypted ```