genrsa.pod revision 68651
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 OpenVMS, 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 88 89