RSA 1 2003-07-24 0.9.9-dev OpenSSL
NAME
rsa - RSA key processing tool
LIBRARY
libcrypto, -lcrypto
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.
COMMAND OPTIONS
-
--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 _o_p_e_n_s_s_l(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 _o_p_e_n_s_s_l(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.
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 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.
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
NNEETT format.
There should be an option that automatically handles .key files,
without having to manually edit them.
SEE ALSO
_o_p_e_n_s_s_l___p_k_c_s_8(1), _o_p_e_n_s_s_l___d_s_a(1), _o_p_e_n_s_s_l___g_e_n_r_s_a(1),
_o_p_e_n_s_s_l___g_e_n_d_s_a(1)