RSA(1) OpenSSL RSA(1)

NAME
       rsa - RSA key processing tool

SYNOPSIS
       ooppeennssssll rrssaa [-iinnffoorrmm PPEEMM||NNEETT||DDEERR] [-oouuttffoorrmm PPEEMM||NNEETT||DDEERR] [-iinn ffiilleennaammee]
       [-ppaassssiinn aarrgg] [-oouutt ffiilleennaammee] [-ppaassssoouutt aarrgg] [-ssggcckkeeyy] [-ddeess] [-ddeess33]
       [-iiddeeaa] [-tteexxtt] [-nnoooouutt] [-mmoodduulluuss] [-cchheecckk] [-ppuubbiinn] [-ppuubboouutt]
       [-eennggiinnee iidd]

DESCRIPTION
       The rrssaa command processes RSA keys. They can be converted between
       various forms and their components printed out. NNoottee this command uses
       the traditional SSLeay compatible format for private key encryption:
       newer applications should use the more secure PKCS#8 format using the
       ppkkccss88 utility.

CCOOMMMMAANNDD OOPPTTIIOONNSS
       -iinnffoorrmm DDEERR||NNEETT||PPEEMM
           This specifies the input format. The DDEERR option uses an ASN1 DER
           encoded form compatible with the PKCS#1 RSAPrivateKey or
           SubjectPublicKeyInfo format.  The PPEEMM form is the default format:
           it consists of the DDEERR format base64 encoded with additional header
           and footer lines. On input PKCS#8 format private keys are also
           accepted. The NNEETT form is a format is described in the NNOOTTEESS
           section.

       -oouuttffoorrmm DDEERR||NNEETT||PPEEMM
           This specifies the output format, the options have the same meaning
           as the -iinnffoorrmm option.

       -iinn ffiilleennaammee
           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.

       -ppaassssiinn aarrgg
           the input file password source. For more information about the
           format of aarrgg see the PPAASSSS PPHHRRAASSEE AARRGGUUMMEENNTTSS section in openssl(1).

       -oouutt ffiilleennaammee
           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 nnoott be the same as the input filename.

       -ppaassssoouutt ppaasssswwoorrdd
           the output file password source. For more information about the
           format of aarrgg see the PPAASSSS PPHHRRAASSEE AARRGGUUMMEENNTTSS section in openssl(1).

       -ssggcckkeeyy
           use the modified NET algorithm used with some versions of Microsoft
           IIS and SGC keys.

       -ddeess||-ddeess33||-iiddeeaa
           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 rrssaa 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.

       -tteexxtt
           prints out the various public or private key components in plain
           text in addition to the encoded version.

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

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

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

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

       -ppuubboouutt
           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.

       -eennggiinnee iidd
           specifying an engine (by it's unique iidd string) will cause rreeqq 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.

NNOOTTEESS
       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 NNEETT 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 rrssaa utility with the -iinnffoorrmm NNEETT option. If you get an error after
       entering the password try the -ssggcckkeeyy option.

EEXXAAMMPPLLEESS
       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 NNEETT
       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)



0.9.7l                            2003-01-30                            RSA(1)