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 comment 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>
78 The input file password source. For more information about the format of I<arg>
79 see L<openssl(1)/Pass phrase options>.
81 =item B<-out> I<filename>
83 This specifies the output filename to write a key to or standard output if this
84 option is not specified. If any encryption options are set then a pass phrase
85 will be prompted for. The output filename should B<not> be the same as the input
88 =item B<-passout> I<arg>
90 The output file password source. For more information about the format of I<arg>
91 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
93 =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>
95 These options encrypt the private key with the specified
96 cipher before outputting it. A pass phrase is prompted for.
97 If none of these options is specified the key is written in plain text. This
98 means that this command can be used to remove the pass phrase from a key
99 by not giving any encryption option is given, or to add or change the pass
100 phrase by setting them.
101 These options can only be used with PEM format output files.
105 Prints out the various public or private key components in
106 plain text in addition to the encoded version.
110 This option prevents output of the encoded version of the key.
114 This option prints out the value of the modulus of the key.
118 This option checks the consistency of an RSA private key.
122 By default a private key is read from the input file: with this
123 option a public key is read instead.
127 By default a private key is output: with this option a public
128 key will be output instead. This option is automatically set if
129 the input is a public key.
131 =item B<-RSAPublicKey_in>, B<-RSAPublicKey_out>
133 Like B<-pubin> and B<-pubout> except B<RSAPublicKey> format is used instead.
135 =item B<-engine> I<id>
137 Specifying an engine (by its unique I<id> string) will cause this command
138 to attempt to obtain a functional reference to the specified engine,
139 thus initialising it if needed. The engine will then be set as the default
140 for all available algorithms.
146 The PEM private key format uses the header and footer lines:
148 -----BEGIN RSA PRIVATE KEY-----
149 -----END RSA PRIVATE KEY-----
151 The PEM public key format uses the header and footer lines:
153 -----BEGIN PUBLIC KEY-----
154 -----END PUBLIC KEY-----
156 The PEM B<RSAPublicKey> format uses the header and footer lines:
158 -----BEGIN RSA PUBLIC KEY-----
159 -----END RSA PUBLIC KEY-----
163 To remove the pass phrase on an RSA private key:
165 openssl rsa -in key.pem -out keyout.pem
167 To encrypt a private key using triple DES:
169 openssl rsa -in key.pem -des3 -out keyout.pem
171 To convert a private key from PEM to DER format:
173 openssl rsa -in key.pem -outform DER -out keyout.der
175 To print out the components of a private key to standard output:
177 openssl rsa -in key.pem -text -noout
179 To just output the public part of a private key:
181 openssl rsa -in key.pem -pubout -out pubkey.pem
183 Output the public part of a private key in B<RSAPublicKey> format:
185 openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem
189 There should be an option that automatically handles .key files,
190 without having to manually edit them.
197 L<openssl-genrsa(1)>,
202 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
204 Licensed under the Apache License 2.0 (the "License"). You may not use
205 this file except in compliance with the License. You can obtain a copy
206 in the file LICENSE in the source distribution or at
207 L<https://www.openssl.org/source/license.html>.