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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 converted 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
           ARGUMENTS 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 information about the format of arg see the PASS PHRASE
           ARGUMENTS section in openssl(1).

       -sgckey
           use the modified NET algorithm used with some versions 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 encryption 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 components in plain text in addition to the encoded
           version.

       -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
           reference 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 KEY---------END
        -----END RSA PRIVATE KEY-----The KEY----The

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

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

       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)



50                                               2013-03-05                                           RSA(1)

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