rsa(1)

     RSA(1)                 0.9.6h (2000-06-15)                 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]

     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).

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          -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.

     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-----

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     RSA(1)                 0.9.6h (2000-06-15)                 RSA(1)

          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 thse 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)

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