5 rsa - RSA key processing tool
11 [B<-inform PEM|NET|DER>]
12 [B<-outform PEM|NET|DER>]
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|NET|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. The B<NET> form is a format is described in the B<NOTES>
64 =item B<-outform DER|NET|PEM>
66 This specifies the output format, the options have the same meaning as the
71 This specifies the input filename to read a key from or standard input if this
72 option is not specified. If the key is encrypted a pass phrase will be
77 the input file password source. For more information about the format of B<arg>
78 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
80 =item B<-out filename>
82 This specifies the output filename to write a key to or standard output if this
83 option is not specified. If any encryption options are set then a pass phrase
84 will be prompted for. The output filename should B<not> be the same as the input
87 =item B<-passout password>
89 the output file password source. For more information about the format of B<arg>
90 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
92 =item B<-aes128|-aes192|-aes256|-aria128|-aria192|-aria256|-camellia128|-camellia192|-camellia256|-des|-des3|-idea>
94 These options encrypt the private key with the specified
95 cipher before outputting it. A pass phrase is prompted for.
96 If none of these options is specified the key is written in plain text. This
97 means that using the B<rsa> utility to read in an encrypted key with no
98 encryption option can be used to remove the pass phrase from a key, or by
99 setting the encryption options it can be use to add or change the pass phrase.
100 These options can only be used with PEM format output files.
104 prints out the various public or private key components in
105 plain text in addition to the encoded version.
109 this option prevents output of the encoded version of the key.
113 this option prints out the value of the modulus of the key.
117 this option checks the consistency of an RSA private key.
121 by default a private key is read from the input file: with this
122 option a public key is read instead.
126 by default a private key is output: with this option a public
127 key will be output instead. This option is automatically set if
128 the input is a public key.
130 =item B<-RSAPublicKey_in>, B<-RSAPublicKey_out>
132 like B<-pubin> and B<-pubout> except B<RSAPublicKey> format is used instead.
136 specifying an engine (by its unique B<id> string) will cause B<rsa>
137 to attempt to obtain a functional reference to the specified engine,
138 thus initialising it if needed. The engine will then be set as the default
139 for all available algorithms.
145 The PEM private key format uses the header and footer lines:
147 -----BEGIN RSA PRIVATE KEY-----
148 -----END RSA PRIVATE KEY-----
150 The PEM public key format uses the header and footer lines:
152 -----BEGIN PUBLIC KEY-----
153 -----END PUBLIC KEY-----
155 The PEM B<RSAPublicKey> format uses the header and footer lines:
157 -----BEGIN RSA PUBLIC KEY-----
158 -----END RSA PUBLIC KEY-----
160 The B<NET> form is a format compatible with older Netscape servers
161 and Microsoft IIS .key files, this uses unsalted RC4 for its encryption.
162 It is not very secure and so should only be used when necessary.
164 Some newer version of IIS have additional data in the exported .key
165 files. To use these with the utility, view the file with a binary editor
166 and look for the string "private-key", then trace back to the byte
167 sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data
168 from this point onwards to another file and use that as the input
169 to the B<rsa> utility with the B<-inform NET> option.
173 To remove the pass phrase on an RSA private key:
175 openssl rsa -in key.pem -out keyout.pem
177 To encrypt a private key using triple DES:
179 openssl rsa -in key.pem -des3 -out keyout.pem
181 To convert a private key from PEM to DER format:
183 openssl rsa -in key.pem -outform DER -out keyout.der
185 To print out the components of a private key to standard output:
187 openssl rsa -in key.pem -text -noout
189 To just output the public part of a private key:
191 openssl rsa -in key.pem -pubout -out pubkey.pem
193 Output the public part of a private key in B<RSAPublicKey> format:
195 openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem
199 The command line password arguments don't currently work with
202 There should be an option that automatically handles .key files,
203 without having to manually edit them.
207 L<pkcs8(1)>, L<dsa(1)>, L<genrsa(1)>,
212 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
214 Licensed under the OpenSSL license (the "License"). You may not use
215 this file except in compliance with the License. You can obtain a copy
216 in the file LICENSE in the source distribution or at
217 L<https://www.openssl.org/source/license.html>.