5 openssl-rsa - RSA key processing tool
36 [B<-RSAPublicKey_out>]
41 The B<rsa> command processes RSA keys. They can be converted between various
42 forms and their components printed out. B<Note> this command uses the
43 traditional SSLeay compatible format for private key encryption: newer
44 applications should use the more secure PKCS#8 format using the B<pkcs8>
53 Print out a usage message.
55 =item B<-inform DER|PEM>
57 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
58 form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format.
59 The B<PEM> form is the default format: it consists of the B<DER> format base64
60 encoded with additional header and footer lines. On input PKCS#8 format private
61 keys are also accepted.
63 =item B<-outform DER|PEM>
65 This specifies the output format, the options have the same meaning and default
66 as the B<-inform> option.
70 This specifies the input filename to read a key from or standard input if this
71 option is not specified. If the key is encrypted a pass phrase will be
76 The input file password source. For more information about the format of B<arg>
77 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
79 =item B<-out filename>
81 This specifies the output filename to write a key to or standard output if this
82 option is not specified. If any encryption options are set then a pass phrase
83 will be prompted for. The output filename should B<not> be the same as the input
86 =item B<-passout password>
88 The output file password source. For more information about the format of B<arg>
89 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
91 =item B<-aes128>, B<-aes192>, B<-aes256>, B<-aria128>, B<-aria192>, B<-aria256>, B<-camellia128>, B<-camellia192>, B<-camellia256>, B<-des>, B<-des3>, B<-idea>
93 These options encrypt the private key with the specified
94 cipher before outputting it. A pass phrase is prompted for.
95 If none of these options is specified the key is written in plain text. This
96 means that using the B<rsa> utility to read in an encrypted key with no
97 encryption option can be used to remove the pass phrase from a key, or by
98 setting the encryption options it can be use to add or change the pass phrase.
99 These options can only be used with PEM format output files.
103 Prints out the various public or private key components in
104 plain text in addition to the encoded version.
108 This option prevents output of the encoded version of the key.
112 This option prints out the value of the modulus of the key.
116 This option checks the consistency of an RSA private key.
120 By default a private key is read from the input file: with this
121 option a public key is read instead.
125 By default a private key is output: with this option a public
126 key will be output instead. This option is automatically set if
127 the input is a public key.
129 =item B<-RSAPublicKey_in>, B<-RSAPublicKey_out>
131 Like B<-pubin> and B<-pubout> except B<RSAPublicKey> format is used instead.
135 Specifying an engine (by its unique B<id> string) will cause B<rsa>
136 to attempt to obtain a functional reference to the specified engine,
137 thus initialising it if needed. The engine will then be set as the default
138 for all available algorithms.
144 The PEM private key format uses the header and footer lines:
146 -----BEGIN RSA PRIVATE KEY-----
147 -----END RSA PRIVATE KEY-----
149 The PEM public key format uses the header and footer lines:
151 -----BEGIN PUBLIC KEY-----
152 -----END PUBLIC KEY-----
154 The PEM B<RSAPublicKey> format uses the header and footer lines:
156 -----BEGIN RSA PUBLIC KEY-----
157 -----END RSA PUBLIC KEY-----
161 To remove the pass phrase on an RSA private key:
163 openssl rsa -in key.pem -out keyout.pem
165 To encrypt a private key using triple DES:
167 openssl rsa -in key.pem -des3 -out keyout.pem
169 To convert a private key from PEM to DER format:
171 openssl rsa -in key.pem -outform DER -out keyout.der
173 To print out the components of a private key to standard output:
175 openssl rsa -in key.pem -text -noout
177 To just output the public part of a private key:
179 openssl rsa -in key.pem -pubout -out pubkey.pem
181 Output the public part of a private key in B<RSAPublicKey> format:
183 openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem
187 There should be an option that automatically handles .key files,
188 without having to manually edit them.
195 L<openssl-genrsa(1)>,
200 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
202 Licensed under the Apache License 2.0 (the "License"). You may not use
203 this file except in compliance with the License. You can obtain a copy
204 in the file LICENSE in the source distribution or at
205 L<https://www.openssl.org/source/license.html>.