NAME

       sshpk-conv - convert between key formats

SYNOPSYS

       sshpk-conv -t FORMAT [FILENAME] [OPTIONS...]

       sshpk-conv -i [FILENAME] [OPTIONS...]

DESCRIPTION

       Reads  in  a public or private key and converts it between different formats, particularly
       formats used in the SSH protocol and the well-known PEM PKCS#1/7 formats.

       In the second form, with the -i option given,  identifies  a  key  and  prints  to  stderr
       information about its nature, size and fingerprint.

EXAMPLES

       Assume the following SSH-format public key in id_ecdsa.pub:

         ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTI...9M/4c4= user@host

       Identify it with -i:

         $ sshpk-conv -i id_ecdsa.pub
         id_ecdsa: a 256 bit ECDSA public key
         ECDSA curve: nistp256
         Comment: user@host
         Fingerprint:
           SHA256:vCNX7eUkdvqqW0m4PoxQAZRv+CM4P4fS8+CbliAvS4k
           81:ad:d5:57:e5:6f:7d:a2:93:79:56:af:d7:c0:38:51

       Convert it to pkcs8 format, for use with e.g. OpenSSL:

         $ sshpk-conv -t pkcs8 id_ecdsa
         -----BEGIN PUBLIC KEY-----
         MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEAsA4R6N6AS3gzaPBeLjG2ObSgUsR
         zOt+kWJoijLnw3ZMYUKmAx+lD0I5XUxdrPcs1vH5f3cn9TvRvO9L0z/hzg==

         -----END PUBLIC KEY-----
       Retrieve the public half of a private key:

         $ openssl genrsa 2048 | sshpk-conv -t ssh -c foo@bar
         ssh-rsa AAAAB3NzaC1yc2EAAA...koK7 foo@bar

       Convert  a private key to PKCS#1 (OpenSSL) format from a new-style OpenSSH key format (the
       ssh-keygen -o format):

         $ ssh-keygen -o -f foobar
         ...
         $ sshpk-conv -p -t pkcs1 foobar
         -----BEGIN RSA PRIVATE KEY-----
         MIIDpAIBAAKCAQEA6T/GYJndb1TRH3+NL....

         -----END RSA PRIVATE KEY-----

OPTIONS

       -i, --identify
         Instead of converting the key, output identifying information about it to
         stderr, including its type, size and fingerprints.

       -p, --private
         Treat the key as a private key instead of a public key (the default). If you
         supply sshpk-conv with a private key and do not give this option, it will
         extract only the public half of the key from it and work with that.

       -f PATH, --file=PATH
         Input file to take the key from instead of stdin. If a filename is supplied
         as a positional argument, it is equivalent to using this option.

       -o PATH, --out=PATH
         Output file name to use instead of stdout.

       -T FORMAT, --informat=FORMAT

       -t FORMAT, --outformat=FORMAT
         Selects the input and output formats to be used (see FORMATS, below).

       -c TEXT, --comment=TEXT
         Sets the key comment for the output file, if supported.

FORMATS

       Currently supported formats:

       pem, pkcs1
         The standard PEM format used by older OpenSSH and most TLS libraries such as
         OpenSSL. The classic id_rsa file is usually in this format. It is an ASN.1
         encoded structure, base64-encoded and placed between PEM headers.

       ssh
         The SSH public key text format (the format of an id_rsa.pub file). A single
         line, containing 3 space separated parts: the key type, key body and optional
         key comment.

       pkcs8
         A newer PEM format, usually used only for public keys by TLS libraries such
         as OpenSSL. The ASN.1 structure is more generic than that of pkcs1.

       openssh
         The new ssh-keygen -o format from OpenSSH. This can be mistaken for a PEM
         encoding but is actually an OpenSSH internal format.

       rfc4253
         The internal binary format of keys when sent over the wire in the SSH
         protocol. This is also the format that the ssh-agent uses in its protocol.

SEE ALSO

       ssh-keygen(1), openssl(1)

BUGS

       Encrypted (password-protected) keys are not supported.

       Report bugs at Github https://github.com/arekinath/node-sshpk/issues

                                             May 2022                                SSHPK-CONV()