doc/man1/openssl-rsa.pod

   1 =pod
   2
   3 =head1 NAME
   4
   5 openssl-rsa - RSA key processing tool
   6
   7 =head1 SYNOPSIS
   8
   9 B<openssl> B<rsa>
  10 [B<-help>]
  11 [B<-inform PEM|DER>]
  12 [B<-outform PEM|DER>]
  13 [B<-in filename>]
  14 [B<-passin arg>]
  15 [B<-out filename>]
  16 [B<-passout arg>]
  17 [B<-aes128>]
  18 [B<-aes192>]
  19 [B<-aes256>]
  20 [B<-aria128>]
  21 [B<-aria192>]
  22 [B<-aria256>]
  23 [B<-camellia128>]
  24 [B<-camellia192>]
  25 [B<-camellia256>]
  26 [B<-des>]
  27 [B<-des3>]
  28 [B<-idea>]
  29 [B<-text>]
  30 [B<-noout>]
  31 [B<-modulus>]
  32 [B<-check>]
  33 [B<-pubin>]
  34 [B<-pubout>]
  35 [B<-RSAPublicKey_in>]
  36 [B<-RSAPublicKey_out>]
  37 [B<-engine id>]
  38
  39 =head1 DESCRIPTION
  40
  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>
  45 utility.
  46
  47 =head1 OPTIONS
  48
  49 =over 4
  50
  51 =item B<-help>
  52
  53 Print out a usage message.
  54
  55 =item B<-inform DER|PEM>
  56
  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.
  62
  63 =item B<-outform DER|PEM>
  64
  65 This specifies the output format, the options have the same meaning and default
  66 as the B<-inform> option.
  67
  68 =item B<-in filename>
  69
  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
  72 prompted for.
  73
  74 =item B<-passin arg>
  75
  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)>.
  78
  79 =item B<-out filename>
  80
  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
  84 filename.
  85
  86 =item B<-passout password>
  87
  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)>.
  90
  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>
  92
  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.
 100
 101 =item B<-text>
 102
 103 Prints out the various public or private key components in
 104 plain text in addition to the encoded version.
 105
 106 =item B<-noout>
 107
 108 This option prevents output of the encoded version of the key.
 109
 110 =item B<-modulus>
 111
 112 This option prints out the value of the modulus of the key.
 113
 114 =item B<-check>
 115
 116 This option checks the consistency of an RSA private key.
 117
 118 =item B<-pubin>
 119
 120 By default a private key is read from the input file: with this
 121 option a public key is read instead.
 122
 123 =item B<-pubout>
 124
 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.
 128
 129 =item B<-RSAPublicKey_in>, B<-RSAPublicKey_out>
 130
 131 Like B<-pubin> and B<-pubout> except B<RSAPublicKey> format is used instead.
 132
 133 =item B<-engine id>
 134
 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.
 139
 140 =back
 141
 142 =head1 NOTES
 143
 144 The PEM private key format uses the header and footer lines:
 145
 146  -----BEGIN RSA PRIVATE KEY-----
 147  -----END RSA PRIVATE KEY-----
 148
 149 The PEM public key format uses the header and footer lines:
 150
 151  -----BEGIN PUBLIC KEY-----
 152  -----END PUBLIC KEY-----
 153
 154 The PEM B<RSAPublicKey> format uses the header and footer lines:
 155
 156  -----BEGIN RSA PUBLIC KEY-----
 157  -----END RSA PUBLIC KEY-----
 158
 159 =head1 EXAMPLES
 160
 161 To remove the pass phrase on an RSA private key:
 162
 163  openssl rsa -in key.pem -out keyout.pem
 164
 165 To encrypt a private key using triple DES:
 166
 167  openssl rsa -in key.pem -des3 -out keyout.pem
 168
 169 To convert a private key from PEM to DER format:
 170
 171  openssl rsa -in key.pem -outform DER -out keyout.der
 172
 173 To print out the components of a private key to standard output:
 174
 175  openssl rsa -in key.pem -text -noout
 176
 177 To just output the public part of a private key:
 178
 179  openssl rsa -in key.pem -pubout -out pubkey.pem
 180
 181 Output the public part of a private key in B<RSAPublicKey> format:
 182
 183  openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem
 184
 185 =head1 BUGS
 186
 187 There should be an option that automatically handles .key files,
 188 without having to manually edit them.
 189
 190 =head1 SEE ALSO
 191
 192 L<openssl(1)>,
 193 L<openssl-pkcs8(1)>,
 194 L<openssl-dsa(1)>,
 195 L<openssl-genrsa(1)>,
 196 L<openssl-gendsa(1)>
 197
 198 =head1 COPYRIGHT
 199
 200 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
 201
 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>.
 206
 207 =cut