mirror of
https://github.com/nillerusr/source-engine.git
synced 2024-12-28 09:03:01 +00:00
74 lines
2.3 KiB
Plaintext
74 lines
2.3 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
DH_generate_parameters, DH_check - generate and check Diffie-Hellman parameters
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/dh.h>
|
|
|
|
DH *DH_generate_parameters(int prime_len, int generator,
|
|
void (*callback)(int, int, void *), void *cb_arg);
|
|
|
|
int DH_check(DH *dh, int *codes);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
DH_generate_parameters() generates Diffie-Hellman parameters that can
|
|
be shared among a group of users, and returns them in a newly
|
|
allocated B<DH> structure. The pseudo-random number generator must be
|
|
seeded prior to calling DH_generate_parameters().
|
|
|
|
B<prime_len> is the length in bits of the safe prime to be generated.
|
|
B<generator> is a small number E<gt> 1, typically 2 or 5.
|
|
|
|
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 described in L<BN_generate_prime(3)|BN_generate_prime(3)> while a random prime
|
|
number is generated, and when a prime has been found, B<callback(3,
|
|
0, cb_arg)> is called.
|
|
|
|
DH_check() validates Diffie-Hellman parameters. It checks that B<p> is
|
|
a safe prime, and that B<g> is a suitable generator. In the case of an
|
|
error, the bit flags DH_CHECK_P_NOT_SAFE_PRIME or
|
|
DH_NOT_SUITABLE_GENERATOR are set in B<*codes>.
|
|
DH_UNABLE_TO_CHECK_GENERATOR is set if the generator cannot be
|
|
checked, i.e. it does not equal 2 or 5.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
DH_generate_parameters() returns a pointer to the DH structure, or
|
|
NULL if the parameter generation fails. The error codes can be
|
|
obtained by L<ERR_get_error(3)|ERR_get_error(3)>.
|
|
|
|
DH_check() returns 1 if the check could be performed, 0 otherwise.
|
|
|
|
=head1 NOTES
|
|
|
|
DH_generate_parameters() may run for several hours before finding a
|
|
suitable prime.
|
|
|
|
The parameters generated by DH_generate_parameters() are not to be
|
|
used in signature schemes.
|
|
|
|
=head1 BUGS
|
|
|
|
If B<generator> is not 2 or 5, B<dh-E<gt>g>=B<generator> is not
|
|
a usable generator.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<dh(3)|dh(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<rand(3)|rand(3)>,
|
|
L<DH_free(3)|DH_free(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
DH_check() is available in all versions of SSLeay and OpenSSL.
|
|
The B<cb_arg> argument to DH_generate_parameters() was added in SSLeay 0.9.0.
|
|
|
|
In versions before OpenSSL 0.9.5, DH_CHECK_P_NOT_STRONG_PRIME is used
|
|
instead of DH_CHECK_P_NOT_SAFE_PRIME.
|
|
|
|
=cut
|