204 lines
9.7 KiB
Plaintext
204 lines
9.7 KiB
Plaintext
SSH-ADD(1) General Commands Manual SSH-ADD(1)
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NAME
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ssh-add M-bM-^@M-^S adds private key identities to the OpenSSH authentication agent
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SYNOPSIS
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ssh-add [-cDdKkLlqvXx] [-E fingerprint_hash] [-H hostkey_file]
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[-h destination_constraint] [-S provider] [-t life] [file ...]
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ssh-add -s pkcs11
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ssh-add -e pkcs11
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ssh-add -T pubkey ...
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DESCRIPTION
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ssh-add adds private key identities to the authentication agent,
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ssh-agent(1). When run without arguments, it adds the files
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~/.ssh/id_rsa, ~/.ssh/id_ecdsa, ~/.ssh/id_ecdsa_sk, ~/.ssh/id_ed25519,
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~/.ssh/id_ed25519_sk, and ~/.ssh/id_dsa. After loading a private key,
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ssh-add will try to load corresponding certificate information from the
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filename obtained by appending -cert.pub to the name of the private key
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file. Alternative file names can be given on the command line.
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If any file requires a passphrase, ssh-add asks for the passphrase from
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the user. The passphrase is read from the user's tty. ssh-add retries
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the last passphrase if multiple identity files are given.
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The authentication agent must be running and the SSH_AUTH_SOCK
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environment variable must contain the name of its socket for ssh-add to
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work.
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The options are as follows:
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-c Indicates that added identities should be subject to confirmation
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before being used for authentication. Confirmation is performed
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by ssh-askpass(1). Successful confirmation is signaled by a zero
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exit status from ssh-askpass(1), rather than text entered into
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the requester.
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-D Deletes all identities from the agent.
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-d Instead of adding identities, removes identities from the agent.
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If ssh-add has been run without arguments, the keys for the
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default identities and their corresponding certificates will be
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removed. Otherwise, the argument list will be interpreted as a
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list of paths to public key files to specify keys and
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certificates to be removed from the agent. If no public key is
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found at a given path, ssh-add will append .pub and retry. If
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the argument list consists of M-bM-^@M-^\-M-bM-^@M-^] then ssh-add will read public
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keys to be removed from standard input.
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-E fingerprint_hash
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Specifies the hash algorithm used when displaying key
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fingerprints. Valid options are: M-bM-^@M-^\md5M-bM-^@M-^] and M-bM-^@M-^\sha256M-bM-^@M-^]. The
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default is M-bM-^@M-^\sha256M-bM-^@M-^].
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-e pkcs11
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Remove keys provided by the PKCS#11 shared library pkcs11.
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-H hostkey_file
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Specifies a known hosts file to look up hostkeys when using
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destination-constrained keys via the -h flag. This option may be
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specified multiple times to allow multiple files to be searched.
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If no files are specified, ssh-add will use the default
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ssh_config(5) known hosts files: ~/.ssh/known_hosts,
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~/.ssh/known_hosts2, /etc/ssh/ssh_known_hosts, and
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/etc/ssh/ssh_known_hosts2.
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-h destination_constraint
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When adding keys, constrain them to be usable only through
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specific hosts or to specific destinations.
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Destination constraints of the form M-bM-^@M-^X[user@]dest-hostnameM-bM-^@M-^Y permit
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use of the key only from the origin host (the one running
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ssh-agent(1)) to the listed destination host, with optional user
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name.
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Constraints of the form M-bM-^@M-^Xsrc-hostname>[user@]dst-hostnameM-bM-^@M-^Y allow
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a key available on a forwarded ssh-agent(1) to be used through a
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particular host (as specified by M-bM-^@M-^Xsrc-hostnameM-bM-^@M-^Y) to authenticate
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to a further host, specified by M-bM-^@M-^Xdst-hostnameM-bM-^@M-^Y.
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Multiple destination constraints may be added when loading keys.
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When attempting authentication with a key that has destination
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constraints, the whole connection path, including ssh-agent(1)
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forwarding, is tested against those constraints and each hop must
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be permitted for the attempt to succeed. For example, if key is
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forwarded to a remote host, M-bM-^@M-^Xhost-bM-bM-^@M-^Y, and is attempting
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authentication to another host, M-bM-^@M-^Xhost-cM-bM-^@M-^Y, then the operation will
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be successful only if M-bM-^@M-^Xhost-bM-bM-^@M-^Y was permitted from the origin host
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and the subsequent M-bM-^@M-^Xhost-b>host-cM-bM-^@M-^Y hop is also permitted by
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destination constraints.
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Hosts are identified by their host keys, and are looked up from
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known hosts files by ssh-add. Wildcards patterns may be used for
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hostnames and certificate host keys are supported. By default,
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keys added by ssh-add are not destination constrained.
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Destination constraints were added in OpenSSH release 8.9.
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Support in both the remote SSH client and server is required when
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using destination-constrained keys over a forwarded ssh-agent(1)
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channel.
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It is also important to note that destination constraints can
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only be enforced by ssh-agent(1) when a key is used, or when it
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is forwarded by a cooperating ssh(1). Specifically, it does not
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prevent an attacker with access to a remote SSH_AUTH_SOCK from
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forwarding it again and using it on a different host (but only to
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a permitted destination).
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-K Load resident keys from a FIDO authenticator.
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-k When loading keys into or deleting keys from the agent, process
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plain private keys only and skip certificates.
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-L Lists public key parameters of all identities currently
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represented by the agent.
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-l Lists fingerprints of all identities currently represented by the
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agent.
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-q Be quiet after a successful operation.
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-S provider
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Specifies a path to a library that will be used when adding FIDO
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authenticator-hosted keys, overriding the default of using the
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internal USB HID support.
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-s pkcs11
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Add keys provided by the PKCS#11 shared library pkcs11.
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-T pubkey ...
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Tests whether the private keys that correspond to the specified
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pubkey files are usable by performing sign and verify operations
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on each.
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-t life
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Set a maximum lifetime when adding identities to an agent. The
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lifetime may be specified in seconds or in a time format
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specified in sshd_config(5).
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-v Verbose mode. Causes ssh-add to print debugging messages about
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its progress. This is helpful in debugging problems. Multiple
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-v options increase the verbosity. The maximum is 3.
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-X Unlock the agent.
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-x Lock the agent with a password.
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ENVIRONMENT
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DISPLAY, SSH_ASKPASS and SSH_ASKPASS_REQUIRE
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If ssh-add needs a passphrase, it will read the passphrase from
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the current terminal if it was run from a terminal. If ssh-add
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does not have a terminal associated with it but DISPLAY and
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SSH_ASKPASS are set, it will execute the program specified by
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SSH_ASKPASS (by default M-bM-^@M-^\ssh-askpassM-bM-^@M-^]) and open an X11 window to
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read the passphrase. This is particularly useful when calling
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ssh-add from a .xsession or related script.
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SSH_ASKPASS_REQUIRE allows further control over the use of an
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askpass program. If this variable is set to M-bM-^@M-^\neverM-bM-^@M-^] then ssh-add
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will never attempt to use one. If it is set to M-bM-^@M-^\preferM-bM-^@M-^], then
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ssh-add will prefer to use the askpass program instead of the TTY
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when requesting passwords. Finally, if the variable is set to
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M-bM-^@M-^\forceM-bM-^@M-^], then the askpass program will be used for all passphrase
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input regardless of whether DISPLAY is set.
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SSH_AUTH_SOCK
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Identifies the path of a UNIX-domain socket used to communicate
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with the agent.
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SSH_SK_PROVIDER
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Specifies a path to a library that will be used when loading any
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FIDO authenticator-hosted keys, overriding the default of using
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the built-in USB HID support.
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FILES
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~/.ssh/id_dsa
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~/.ssh/id_ecdsa
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~/.ssh/id_ecdsa_sk
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~/.ssh/id_ed25519
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~/.ssh/id_ed25519_sk
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~/.ssh/id_rsa
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Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519,
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authenticator-hosted Ed25519 or RSA authentication identity of
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the user.
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Identity files should not be readable by anyone but the user. Note that
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ssh-add ignores identity files if they are accessible by others.
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EXIT STATUS
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Exit status is 0 on success, 1 if the specified command fails, and 2 if
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ssh-add is unable to contact the authentication agent.
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SEE ALSO
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ssh(1), ssh-agent(1), ssh-askpass(1), ssh-keygen(1), sshd(8)
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AUTHORS
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OpenSSH is a derivative of the original and free ssh 1.2.12 release by
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Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
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de Raadt and Dug Song removed many bugs, re-added newer features and
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created OpenSSH. Markus Friedl contributed the support for SSH protocol
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versions 1.5 and 2.0.
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OpenBSD 7.2 February 4, 2022 OpenBSD 7.2
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