| =pod |
| |
| =head1 NAME |
| |
| RSA_generate_key - generate RSA key pair |
| |
| =head1 SYNOPSIS |
| |
| #include <openssl/rsa.h> |
| |
| RSA *RSA_generate_key(int num, unsigned long e, |
| void (*callback)(int,int,void *), void *cb_arg); |
| |
| =head1 DESCRIPTION |
| |
| RSA_generate_key() generates a key pair and returns it in a newly |
| allocated B<RSA> structure. The pseudo-random number generator must |
| be seeded prior to calling RSA_generate_key(). |
| |
| The modulus size will be B<num> bits, and the public exponent will be |
| B<e>. Key sizes with B<num> E<lt> 1024 should be considered insecure. |
| The exponent is an odd number, typically 3, 17 or 65537. |
| |
| A callback function may be used to provide feedback about the |
| progress of the key generation. If B<callback> is not B<NULL>, it |
| will be called as follows: |
| |
| =over 4 |
| |
| =item * |
| |
| While a random prime number is generated, it is called as |
| described in L<BN_generate_prime(3)|BN_generate_prime(3)>. |
| |
| =item * |
| |
| When the n-th randomly generated prime is rejected as not |
| suitable for the key, B<callback(2, n, cb_arg)> is called. |
| |
| =item * |
| |
| When a random p has been found with p-1 relatively prime to B<e>, |
| it is called as B<callback(3, 0, cb_arg)>. |
| |
| =back |
| |
| The process is then repeated for prime q with B<callback(3, 1, cb_arg)>. |
| |
| =head1 RETURN VALUE |
| |
| If key generation fails, RSA_generate_key() returns B<NULL>; the |
| error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>. |
| |
| =head1 BUGS |
| |
| B<callback(2, x, cb_arg)> is used with two different meanings. |
| |
| RSA_generate_key() goes into an infinite loop for illegal input values. |
| |
| =head1 SEE ALSO |
| |
| L<ERR_get_error(3)|ERR_get_error(3)>, L<rand(3)|rand(3)>, L<rsa(3)|rsa(3)>, |
| L<RSA_free(3)|RSA_free(3)> |
| |
| =head1 HISTORY |
| |
| The B<cb_arg> argument was added in SSLeay 0.9.0. |
| |
| =cut |
