irtimmer / tpm2-pk11

[DEPRECATED] PKCS#11 Module for TPM 2.0
BSD 2-Clause "Simplified" License
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Is it possible to add PKCS 11 shared library support for ssh-add / ssh-agent? #38

Closed liuqun closed 6 years ago

liuqun commented 6 years ago
man 1 ssh-add

says that:

 ssh-add -e pkcs11
         Remove keys provided by the PKCS#11 shared library pkcs11.
 ssh-add -s pkcs11
         Add keys provided by the PKCS#11 shared library pkcs11.

Perhaps we could add private key identities to the authentication agent using ssh-add -s libtpm2-pk11.so

For example:

  1. Start ssh agent daemon, and show it's PID

    $ eval "$(ssh-agent -s)"
    Agent pid 59566
  2. List existing identities:

    $ ssh-add -L
    The agent has no identities.
  3. add one private key identity from hard disk

    
    $ ssh-add ~/.ssh/id_rsa
    Enter passphrase for /home/$USER/.ssh/id_rsa: ******
    Identity added: /home/$USER/.ssh/id_rsa

$ ssh-add -L ssh-rsa AAAAB3.../home/.../.ssh/id_rsa



4. add TPM2.0 key identities to authentication agent
    ssh-add -s libtpm2-pk11.so
    (Not supported yet)
liuqun commented 6 years ago

Some related articles:

SSH-ADD(1)                BSD General Commands Manual               SSH-ADD(1)

NAME
     ssh-add — adds private key identities to the authentication agent

SYNOPSIS
     ssh-add [-cDdkLlXx] [-E fingerprint_hash] [-t life] [file ...]
     ssh-add -s pkcs11
     ssh-add -e pkcs11

DESCRIPTION
     ssh-add adds private key identities to the authentication agent,
     ssh-agent(1).  When run without arguments, it adds the files
     ~/.ssh/id_rsa, ~/.ssh/id_dsa, ~/.ssh/id_ecdsa, ~/.ssh/id_ed25519 and
     ~/.ssh/identity.  After loading a private key, ssh-add will try to load
     corresponding certificate information from the filename obtained by
     appending -cert.pub to the name of the private key file.  Alternative
     file names can be given on the command line.

     If any file requires a passphrase, ssh-add asks for the passphrase from
     the user.  The passphrase is read from the user's tty.  ssh-add retries
     the last passphrase if multiple identity files are given.

     The authentication agent must be running and the SSH_AUTH_SOCK environ‐
     ment variable must contain the name of its socket for ssh-add to work.

     The options are as follows:

     -c      Indicates that added identities should be subject to confirmation
             before being used for authentication.  Confirmation is performed
             by ssh-askpass(1).  Successful confirmation is signaled by a zero
             exit status from ssh-askpass(1), rather than text entered into
             the requester.

     -D      Deletes all identities from the agent.

     -d      Instead of adding identities, removes identities from the agent.
             If ssh-add has been run without arguments, the keys for the
             default identities and their corresponding certificates will be
             removed.  Otherwise, the argument list will be interpreted as a
             list of paths to public key files to specify keys and certifi‐
             cates to be removed from the agent.  If no public key is found at
             a given path, ssh-add will append .pub and retry.

     -E fingerprint_hash
             Specifies the hash algorithm used when displaying key finger‐
             prints.  Valid options are: “md5” and “sha256”.  The default is
             “sha256”.

     -e pkcs11
             Remove keys provided by the PKCS#11 shared library pkcs11.

     -k      When loading keys into or deleting keys from the agent, process
             plain private keys only and skip certificates.

     -L      Lists public key parameters of all identities currently repre‐
             sented by the agent.

     -l      Lists fingerprints of all identities currently represented by the
             agent.

     -s pkcs11
             Add keys provided by the PKCS#11 shared library pkcs11.

     -t life
             Set a maximum lifetime when adding identities to an agent.  The
             lifetime may be specified in seconds or in a time format speci‐
             fied in sshd_config(5).

     -X      Unlock the agent.

     -x      Lock the agent with a password.

ENVIRONMENT
     DISPLAY and SSH_ASKPASS
             If ssh-add needs a passphrase, it will read the passphrase from
             the current terminal if it was run from a terminal.  If ssh-add
             does not have a terminal associated with it but DISPLAY and
             SSH_ASKPASS are set, it will execute the program specified by
             SSH_ASKPASS (by default “ssh-askpass”) and open an X11 window to
             read the passphrase.  This is particularly useful when calling
             ssh-add from a .xsession or related script.  (Note that on some
             machines it may be necessary to redirect the input from /dev/null
             to make this work.)

     SSH_AUTH_SOCK
             Identifies the path of a UNIX-domain socket used to communicate
             with the agent.

FILES
     ~/.ssh/identity
             Contains the protocol version 1 RSA authentication identity of
             the user.

     ~/.ssh/id_dsa
             Contains the protocol version 2 DSA authentication identity of
             the user.

     ~/.ssh/id_ecdsa
             Contains the protocol version 2 ECDSA authentication identity of
             the user.

     ~/.ssh/id_ed25519
             Contains the protocol version 2 Ed25519 authentication identity
             of the user.

     ~/.ssh/id_rsa
             Contains the protocol version 2 RSA authentication identity of
             the user.

     Identity files should not be readable by anyone but the user.  Note that
     ssh-add ignores identity files if they are accessible by others.

EXIT STATUS
     Exit status is 0 on success, 1 if the specified command fails, and 2 if
     ssh-add is unable to contact the authentication agent.

SEE ALSO
     ssh(1), ssh-agent(1), ssh-askpass(1), ssh-keygen(1), sshd(8)

AUTHORS
     OpenSSH is a derivative of the original and free ssh 1.2.12 release by
     Tatu Ylonen.  Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
     de Raadt and Dug Song removed many bugs, re-added newer features and cre‐
     ated OpenSSH.  Markus Friedl contributed the support for SSH protocol
     versions 1.5 and 2.0.

BSD                             March 30, 2015                             BSD
irtimmer commented 6 years ago

This should now have been fixed with the merge of #75, although you have to enable login-required in the config file