genrsa.pod revision 59191 
1=pod
2
3=head1 NAME
4
5genrsa - generate an RSA private key
6
7=head1 SYNOPSIS
8
9B<openssl> B<genrsa>
10[B<-out filename>]
11[B<-passout arg>]
12[B<-des>]
13[B<-des3>]
14[B<-idea>]
15[B<-f4>]
16[B<-3>]
17[B<-rand file(s)>]
18[B<numbits>]
19
20=head1 DESCRIPTION
21
22The B<genrsa> command generates an RSA private key.
23
24=head1 OPTIONS
25
26=over 4
27
28=item B<-out filename>
29
30the output filename. If this argument is not specified then standard output is
31used.  
32
33=item B<-passout arg>
34
35the output file password source. For more information about the format of B<arg>
36see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
37
38=item B<-des|-des3|-idea>
39
40These options encrypt the private key with the DES, triple DES, or the 
41IDEA ciphers respectively before outputting it. If none of these options is
42specified no encryption is used. If encryption is used a pass phrase is prompted
43for if it is not supplied via the B<-passout> argument.
44
45=item B<-F4|-3>
46
47the public exponent to use, either 65537 or 3. The default is 65537.
48
49=item B<-rand file(s)>
50
51a file or files containing random data used to seed the random number
52generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
53Multiple files can be specified separated by a OS-dependent character.
54The separator is B<;> for MS-Windows, B<,> for OpenVSM, and B<:> for
55all others.
56
57=item B<numbits>
58
59the size of the private key to generate in bits. This must be the last option
60specified. The default is 512.
61
62=back
63
64=head1 NOTES
65
66RSA private key generation essentially involves the generation of two prime
67numbers. When generating a private key various symbols will be output to
68indicate the progress of the generation. A B<.> represents each number which
69has passed an initial sieve test, B<+> means a number has passed a single
70round of the Miller-Rabin primality test. A newline means that the number has
71passed all the prime tests (the actual number depends on the key size).
72
73Because key generation is a random process the time taken to generate a key
74may vary somewhat.
75
76=head1 BUGS
77
78A quirk of the prime generation algorithm is that it cannot generate small
79primes. Therefore the number of bits should not be less that 64. For typical
80private keys this will not matter because for security reasons they will
81be much larger (typically 1024 bits).
82
83=head1 SEE ALSO
84
85L<gendsa(1)|gendsa(1)>
86
87=cut
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