50 lines
1.4 KiB
Text
50 lines
1.4 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
DH_generate_key, DH_compute_key - perform Diffie-Hellman key exchange
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/dh.h>
|
|
|
|
int DH_generate_key(DH *dh);
|
|
|
|
int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
DH_generate_key() performs the first step of a Diffie-Hellman key
|
|
exchange by generating private and public DH values. By calling
|
|
DH_compute_key(), these are combined with the other party's public
|
|
value to compute the shared key.
|
|
|
|
DH_generate_key() expects B<dh> to contain the shared parameters
|
|
B<dh-E<gt>p> and B<dh-E<gt>g>. It generates a random private DH value
|
|
unless B<dh-E<gt>priv_key> is already set, and computes the
|
|
corresponding public value B<dh-E<gt>pub_key>, which can then be
|
|
published.
|
|
|
|
DH_compute_key() computes the shared secret from the private DH value
|
|
in B<dh> and the other party's public value in B<pub_key> and stores
|
|
it in B<key>. B<key> must point to B<DH_size(dh)> bytes of memory.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
DH_generate_key() returns 1 on success, 0 otherwise.
|
|
|
|
DH_compute_key() returns the size of the shared secret on success, -1
|
|
on error.
|
|
|
|
The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<dh(3)|dh(3)>, L<err(3)|err(3)>, L<rand(3)|rand(3)>, L<DH_size(3)|DH_size(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
DH_generate_key() and DH_compute_key() are available in all versions
|
|
of SSLeay and OpenSSL.
|
|
|
|
=cut
|