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      1 =pod
      2 {- OpenSSL::safe::output_do_not_edit_headers(); -}
      3 
      4 =head1 NAME
      5 
      6 openssl-genrsa - generate an RSA private key
      7 
      8 =head1 SYNOPSIS
      9 
     10 B<openssl> B<genrsa>
     11 [B<-help>]
     12 [B<-out> I<filename>]
     13 [B<-passout> I<arg>]
     14 [B<-aes128>]
     15 [B<-aes192>]
     16 [B<-aes256>]
     17 [B<-aria128>]
     18 [B<-aria192>]
     19 [B<-aria256>]
     20 [B<-camellia128>]
     21 [B<-camellia192>]
     22 [B<-camellia256>]
     23 [B<-des>]
     24 [B<-des3>]
     25 [B<-idea>]
     26 [B<-F4>]
     27 [B<-f4>]
     28 [B<-3>]
     29 [B<-primes> I<num>]
     30 [B<-verbose>]
     31 [B<-traditional>]
     32 {- $OpenSSL::safe::opt_r_synopsis -}
     33 {- $OpenSSL::safe::opt_engine_synopsis -}{- $OpenSSL::safe::opt_provider_synopsis -}
     34 [B<numbits>]
     35 
     36 =head1 DESCRIPTION
     37 
     38 This command generates an RSA private key.
     39 
     40 =head1 OPTIONS
     41 
     42 =over 4
     43 
     44 =item B<-help>
     45 
     46 Print out a usage message.
     47 
     48 =item B<-out> I<filename>
     49 
     50 Output the key to the specified file. If this argument is not specified then
     51 standard output is used.
     52 
     53 =item B<-passout> I<arg>
     54 
     55 The output file password source. For more information about the format
     56 see L<openssl-passphrase-options(1)>.
     57 
     58 =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>
     59 
     60 These options encrypt the private key with specified
     61 cipher before outputting it. If none of these options is
     62 specified no encryption is used. If encryption is used a pass phrase is prompted
     63 for if it is not supplied via the B<-passout> argument.
     64 
     65 =item B<-F4>, B<-f4>, B<-3>
     66 
     67 The public exponent to use, either 65537 or 3. The default is 65537.
     68 The B<-3> option has been deprecated.
     69 
     70 =item B<-primes> I<num>
     71 
     72 Specify the number of primes to use while generating the RSA key. The I<num>
     73 parameter must be a positive integer that is greater than 1 and less than 16.
     74 If I<num> is greater than 2, then the generated key is called a 'multi-prime'
     75 RSA key, which is defined in RFC 8017.
     76 
     77 =item B<-verbose>
     78 
     79 Print extra details about the operations being performed.
     80 
     81 =item B<-traditional>
     82 
     83 Write the key using the traditional PKCS#1 format instead of the PKCS#8 format.
     84 
     85 {- $OpenSSL::safe::opt_r_item -}
     86 
     87 {- $OpenSSL::safe::opt_engine_item -}
     88 
     89 {- $OpenSSL::safe::opt_provider_item -}
     90 
     91 =item B<numbits>
     92 
     93 The size of the private key to generate in bits. This must be the last option
     94 specified. The default is 2048 and values less than 512 are not allowed.
     95 
     96 =back
     97 
     98 =head1 NOTES
     99 
    100 RSA private key generation essentially involves the generation of two or more
    101 prime numbers. When generating a private key various symbols will be output to
    102 indicate the progress of the generation. A B<.> represents each number which
    103 has passed an initial sieve test, B<+> means a number has passed a single
    104 round of the Miller-Rabin primality test, B<*> means the current prime starts
    105 a regenerating progress due to some failed tests. A newline means that the number
    106 has passed all the prime tests (the actual number depends on the key size).
    107 
    108 Because key generation is a random process the time taken to generate a key
    109 may vary somewhat. But in general, more primes lead to less generation time
    110 of a key.
    111 
    112 =head1 SEE ALSO
    113 
    114 L<openssl(1)>,
    115 L<openssl-genpkey(1)>,
    116 L<openssl-gendsa(1)>
    117 
    118 =head1 COPYRIGHT
    119 
    120 Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved.
    121 
    122 Licensed under the Apache License 2.0 (the "License").  You may not use
    123 this file except in compliance with the License.  You can obtain a copy
    124 in the file LICENSE in the source distribution or at
    125 L<https://www.openssl.org/source/license.html>.
    126 
    127 =cut
    128