5 openssl-rsa - RSA key processing tool
11 [B<-inform> B<DER>|B<PEM>]
12 [B<-outform> B<DER>|B<PEM>]
36 [B<-RSAPublicKey_out>]
39 =for openssl ifdef pvk-strong pvk-weak pvk-none engine
43 This command processes RSA keys. They can be converted between
44 various forms and their components printed out. B<Note> this command uses the
45 traditional SSLeay compatible format for private key encryption: newer
46 applications should use the more secure PKCS#8 format using the
47 L<openssl-pkcs8(1)> command.
55 Print out a usage message.
57 =item B<-inform> B<DER>|B<PEM>
59 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
60 form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format.
61 The B<PEM> form is the default format: it consists of the B<DER> format base64
62 encoded with additional header and footer lines. On input PKCS#8 format private
63 keys are also accepted.
65 =item B<-outform> B<DER>|B<PEM>
67 This specifies the output format, the options have the same meaning and default
68 as the B<-inform> option.
70 =item B<-in> I<filename>
72 This specifies the input filename to read a key from or standard input if this
73 option is not specified. If the key is encrypted a pass phrase will be
76 =item B<-passin> I<arg>, B<-passout> I<arg>
78 The password source for the input and output file.
79 For more information about the format of B<arg>
80 see L<openssl(1)/Pass Phrase Options>.
82 =item B<-out> I<filename>
84 This specifies the output filename to write a key to or standard output if this
85 option is not specified. If any encryption options are set then a pass phrase
86 will be prompted for. The output filename should B<not> be the same as the input
89 =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>
91 These options encrypt the private key with the specified
92 cipher before outputting it. A pass phrase is prompted for.
93 If none of these options is specified the key is written in plain text. This
94 means that this command can be used to remove the pass phrase from a key
95 by not giving any encryption option is given, or to add or change the pass
96 phrase by setting them.
97 These options can only be used with PEM format output files.
101 Prints out the various public or private key components in
102 plain text in addition to the encoded version.
106 This option prevents output of the encoded version of the key.
110 This option prints out the value of the modulus of the key.
114 This option checks the consistency of an RSA private key.
118 By default a private key is read from the input file: with this
119 option a public key is read instead.
123 By default a private key is output: with this option a public
124 key will be output instead. This option is automatically set if
125 the input is a public key.
127 =item B<-RSAPublicKey_in>, B<-RSAPublicKey_out>
129 Like B<-pubin> and B<-pubout> except B<RSAPublicKey> format is used instead.
131 =item B<-engine> I<id>
133 Specifying an engine (by its unique I<id> string) will cause this command
134 to attempt to obtain a functional reference to the specified engine,
135 thus initialising it if needed. The engine will then be set as the default
136 for all available algorithms.
142 The PEM private key format uses the header and footer lines:
144 -----BEGIN RSA PRIVATE KEY-----
145 -----END RSA PRIVATE KEY-----
147 The PEM public key format uses the header and footer lines:
149 -----BEGIN PUBLIC KEY-----
150 -----END PUBLIC KEY-----
152 The PEM B<RSAPublicKey> format uses the header and footer lines:
154 -----BEGIN RSA PUBLIC KEY-----
155 -----END RSA PUBLIC KEY-----
159 To remove the pass phrase on an RSA private key:
161 openssl rsa -in key.pem -out keyout.pem
163 To encrypt a private key using triple DES:
165 openssl rsa -in key.pem -des3 -out keyout.pem
167 To convert a private key from PEM to DER format:
169 openssl rsa -in key.pem -outform DER -out keyout.der
171 To print out the components of a private key to standard output:
173 openssl rsa -in key.pem -text -noout
175 To just output the public part of a private key:
177 openssl rsa -in key.pem -pubout -out pubkey.pem
179 Output the public part of a private key in B<RSAPublicKey> format:
181 openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem
185 There should be an option that automatically handles F<.key> files,
186 without having to manually edit them.
193 L<openssl-genrsa(1)>,
198 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
200 Licensed under the Apache License 2.0 (the "License"). You may not use
201 this file except in compliance with the License. You can obtain a copy
202 in the file LICENSE in the source distribution or at
203 L<https://www.openssl.org/source/license.html>.