DragonFly On-Line Manual Pages

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] [-aes128]
       [-aes192] [-aes256] [-camellia128] [-camellia192] [-camellia256] [-des]
       [-des3] [-idea] [-text] [-noout] [-modulus] [-check] [-pubin] [-pubout]
       [-RSAPublicKey_in] [-RSAPublicKey_out] [-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.

       -aes128|-aes192|-aes256|-camellia128|-camellia192|-camellia256|-des|-des3|-idea
	   These options encrypt the private key with the specified cipher
	   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.

       -RSAPublicKey_in, -RSAPublicKey_out
	   like -pubin and -pubout except RSAPublicKey format is used instead.

       -engine id
	   specifying an engine (by its unique id string) will cause rsa 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 RSA PRIVATE KEY-----

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

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

       The PEM RSAPublicKey format uses the header and footer lines:

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

       Output the public part of a private key in RSAPublicKey format:

	openssl rsa -in key.pem -RSAPublicKey_out -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)

1.0.2h				  2016-05-03				RSA(1)