Génération de clefs SSH


Les clefs sont de simple fichier texte consultable avec un éditeur de texte.
Pour générer une paire suivre la procédure suivante :

    ssh-keygen -t rsa -b 4096 -C "alan.turing@cambridge.org"  
    # Creates a new ssh key, using the provided email as a label  
    Generating public/private rsa key pair.
  Enter a file in which to save the key (/Users/you/.ssh/id_rsa): [Press enter]
  Enter passphrase (empty for no passphrase): [Type a passphrase]
  Enter same passphrase again: [Type passphrase again]


Il existe plusieurs client SSH pour windows, nous présentons la génération de clefs avec l’un d’eux PuTTY.
Pour une installation minimal vous avez besoin des exécutables suivant: putty.exe et puttygen.exe.

Ils sont disponibles à cette adresse: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html


To generate a set of RSA keys with PuTTYgen:

  1. Start the PuTTYgen utility, by double-clicking on its .exe file;
  2. For Type of key to generate, select SSH-2 RSA;
  3. In the Number of bits in a generated key field, specify 4096 (increasing the bits makes it harder to crack the key by brute-force methods);
  4. Click the Generate button;
  5. Move your mouse pointer around in the blank area of the Key section, below the progress bar (to generate some randomness) until the progress bar is full;
  6. A private/ public key pair has now been generated;
  7. In the Key comment field, enter any comment you’d like, to help you identify this key pair, later (e.g. your e-mail address; home; office; etc.)
  8. Optional but highly recommended:
    Type a passphrase in the Key passphrase field & re-type the same passphrase in the Confirm passphrase field (if you would like to use your keys for automated processes, however, you should not create a passphrase);
  9. Click the Save public key button & choose whatever filename you’d like (some users create a folder in their computer named my_keys);
  10. Click the Save private key button & choose whatever filename you’d like (you can save it in the same location as the public key, but it should be a location that only you can access and that you will NOT lose! If you lose your keys and have disabled username/password logins, you will no longer be able log in!);
  11. Right-click in the text field labeled Public key for pasting into OpenSSH authorized_keys file and choose Select All. This is the text we need in the registration form.
  12. Right-click again in the same text field and choose Copy; then paste it in the field “SSH public key” of the registration form.