RSA(1)                      OpenSSL                      RSA(1)





NAME
       rsa - RSA key processing tool

SYNOPSIS
       openssl rsa [-inform PEM|NET|DER] [-outform PEM|NET|DER]
       [-in filename] [-passin arg] [-out filename] [-passout
       arg] [-sgckey] [-des] [-des3] [-idea] [-text] [-noout]
       [-modulus] [-check] [-pubin] [-pubout] [-engine id]

DESCRIPTION
       The rsa command processes RSA keys. They can be con-
       verted between various forms and their components
       printed out. Note this command uses the traditional
       SSLeay compatible format for private key encryption:
       newer applications should use the more secure PKCS#8
       format using the pkcs8 utility.

COMMAND OPTIONS
       -inform DER|NET|PEM
           This specifies the input format. The DER option uses
           an ASN1 DER encoded form compatible with the PKCS#1
           RSAPrivateKey or SubjectPublicKeyInfo format.  The
           PEM form is the default format: it consists of the
           DER format base64 encoded with additional header and
           footer lines. On input PKCS#8 format private keys
           are also accepted. The NET form is a format is
           described in the NOTES section.

       -outform DER|NET|PEM
           This specifies the output format, the options have
           the same meaning as the -inform option.

       -in filename
           This specifies the input filename to read a key from
           or standard input if this option is not specified.
           If the key is encrypted a pass phrase will be
           prompted for.

       -passin arg
           the input file password source. For more information
           about the format of arg see the PASS PHRASE ARGU-
           MENTS section in openssl(1).

       -out filename
           This specifies the output filename to write a key to
           or standard output if this option is not specified.
           If any encryption options are set then a pass phrase
           will be prompted for. The output filename should not
           be the same as the input filename.

       -passout password
           the output file password source. For more informa-
           tion about the format of arg see the PASS PHRASE
           ARGUMENTS section in openssl(1).

       -sgckey
           use the modified NET algorithm used with some ver-
           sions of Microsoft IIS and SGC keys.

       -des|-des3|-idea
           These options encrypt the private key with the DES,
           triple DES, or the IDEA ciphers respectively before
           outputting it. A pass phrase is prompted for.  If
           none of these options is specified the key is
           written in plain text. This means that using the rsa
           utility to read in an encrypted key with no encryp-
           tion option can be used to remove the pass phrase
           from a key, or by setting the encryption options it
           can be use to add or change the pass phrase.  These
           options can only be used with PEM format output
           files.

       -text
           prints out the various public or private key compo-
           nents in plain text in addition to the encoded ver-
           sion.

       -noout
           this option prevents output of the encoded version
           of the key.

       -modulus
           this option prints out the value of the modulus of
           the key.

       -check
           this option checks the consistency of an RSA private
           key.

       -pubin
           by default a private key is read from the input
           file: with this option a public key is read instead.

       -pubout
           by default a private key is output: with this option
           a public key will be output instead. This option is
           automatically set if the input is a public key.

       -engine id
           specifying an engine (by it's unique id string) will
           cause req to attempt to obtain a functional refer-
           ence to the specified engine, thus initialising it
           if needed. The engine will then be set as the
           default for all available algorithms.

NOTES
       The PEM private key format uses the header and footer
       lines:

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

       The PEM public key format uses the header and footer
       lines:

        -----BEGIN PUBLIC KEY-----
        -----END PUBLIC KEY-----

       The NET form is a format compatible with older Netscape
       servers and Microsoft IIS .key files, this uses unsalted
       RC4 for its encryption.  It is not very secure and so
       should only be used when necessary.

       Some newer version of IIS have additional data in the
       exported .key files. To use these with the utility, view
       the file with a binary editor and look for the string
       "private-key", then trace back to the byte sequence
       0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data
       from this point onwards to another file and use that as
       the input to the rsa utility with the -inform NET
       option. If you get an error after entering the password
       try the -sgckey option.

EXAMPLES
       To remove the pass phrase on an RSA private key:

        openssl rsa -in key.pem -out keyout.pem

       To encrypt a private key using triple DES:

        openssl rsa -in key.pem -des3 -out keyout.pem

       To convert a private key from PEM to DER format:

        openssl rsa -in key.pem -outform DER -out keyout.der

       To print out the components of a private key to standard
       output:

        openssl rsa -in key.pem -text -noout

       To just output the public part of a private key:

        openssl rsa -in key.pem -pubout -out pubkey.pem

BUGS
       The command line password arguments don't currently work
       with NET format.

       There should be an option that automatically handles
       .key files, without having to manually edit them.

SEE ALSO
       pkcs8(1), dsa(1), genrsa(1), gendsa(1)



0.9.7c                     2003-01-30                    RSA(1)
