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Linux in a Nutshell, 6th Edition by Robert Love, Stephen Figgins, Ellen Siever, Arnold Robbins

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Name

ssh-keygen

Synopsis

ssh-keygen [options]

Generate, manage, and convert authentication keys for ssh. When using ssh-keygen to create a key, the -t option must be specified to identify the type of key to create.

Options

-b bits

Specify the number of bits in the key. For RSA keys, the minimum is 512, and the default is 2048. DSA keys must be exactly 1024 bits.

-B

Show the bubblebabble digest (a digest represented as a string that looks like real words) for the private or public keyfile specified with -f.

-c

Change the comment in the private and public keyfiles (for RSA1 keys only).

-C comment

Specify a new comment.

-D reader

Download the RSA public key from the smartcard in reader.

-e

Read an OpenSSH private or public keyfile and write it in SECSH Public Key File Format to standard output for exporting to a commercial SSH.

-f file

Specify the filename of the keyfile.

-F hostname

List occurrences of the specified hostname found in a known_hosts file. Useful with -H to print keys that were found in a hashed format.

-H

Hash a known_hosts file.

-i

Read an SSH2-compatible unencrypted private or public keyfile and write an OpenSSH-compatible key to standard output. Used to import keys from a commercial SSH.

-l

Show fingerprint of public or private RSA1 keyfile specified with -f. With -v, also displays an ASCII art representation of the key.

-N passphrase

Specify the new passphrase.

-p

Change the passphrase for a private keyfile. Prompt for the file, the old passphrase, and twice for the new passphrase.

-P passphrase ...

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