OPENSSL-RSA(1SSL) OpenSSL OPENSSL-RSA(1SSL)
NAME
openssl-rsa - RSA key processing command
SYNOPSIS
openssl rsa [-help] [-inform DER|PEM|P12|ENGINE] [-outform DER|PEM] [-in
filename|uri] [-passin arg] [-out filename] [-passout arg] [-aes128]
[-aes192] [-aes256] [-aria128] [-aria192] [-aria256] [-camellia128]
[-camellia192] [-camellia256] [-des] [-des3] [-idea] [-text] [-noout]
[-modulus] [-traditional] [-check] [-pubin] [-pubout] [-RSAPublicKey_in]
[-RSAPublicKey_out] [-pvk-strong] [-pvk-weak] [-pvk-none] [-engine id]
[-provider name] [-provider-path path] [-provparam [name:]key=value]
[-propquery propq]
DESCRIPTION
This command processes RSA keys. They can be converted between various
forms and their components printed out.
OPTIONS
-help
Print out a usage message.
-inform DER|PEM|P12|ENGINE
The key input format; unspecified by default. See
openssl-format-options(1) for details.
-outform DER|PEM
The key output format; the default is PEM. See
openssl-format-options(1) for details.
-traditional
When writing a private key, use the traditional PKCS#1 format
instead of the PKCS#8 format.
-in filename|uri
This specifies the input 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, -passout arg
The password source for the input and output file. For more
information about the format of arg see
openssl-passphrase-options(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.
-aes128, -aes192, -aes256, -aria128, -aria192, -aria256, -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 this command can be used to remove the pass phrase from a
key by not giving any encryption option is given, or to add or
change the pass phrase by setting them. 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. With this option a
public key is read instead. If the input contains no public key but
a private key, its public part is used.
-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.
-pvk-strong
Enable 'Strong' PVK encoding level (default).
-pvk-weak
Enable 'Weak' PVK encoding level.
-pvk-none
Don't enforce PVK encoding.
-engine id
See "Engine Options" in openssl(1). This option is deprecated.
-provider name
-provider-path path
-provparam [name:]key=value
-propquery propq
See "Provider Options" in openssl(1), provider(7), and property(7).
NOTES
The openssl-pkey(1) command is capable of performing all the operations
this command can, as well as supporting other public key types.
EXAMPLES
The documentation for the openssl-pkey(1) command contains examples
equivalent to the ones listed here.
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
There should be an option that automatically handles .key files, without
having to manually edit them.
SEE ALSO
openssl(1), openssl-pkey(1), openssl-pkcs8(1), openssl-dsa(1),
openssl-genrsa(1), openssl-gendsa(1)
HISTORY
The -engine option was deprecated in OpenSSL 3.0.
COPYRIGHT
Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
3.5.4 2025-09-30 OPENSSL-RSA(1SSL)
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