openssl/doc/crypto/dh.pod
Matt Caswell 0263b99288 Add documentation for following DH and DH_METHOD opacity
A number of new functions have been added following the DH and DH_METHOD
opacity commits. This commit provides documentation for those functions.

Reviewed-by: Richard Levitte <levitte@openssl.org>
2016-04-09 10:10:55 +01:00

62 lines
1.9 KiB
Plaintext

=pod
=head1 NAME
dh - Diffie-Hellman key agreement
=head1 SYNOPSIS
#include <openssl/dh.h>
#include <openssl/engine.h>
DH * DH_new(void);
void DH_free(DH *dh);
DH * DH_generate_parameters(int prime_len, int generator,
void (*callback)(int, int, void *), void *cb_arg);
int DH_check(const DH *dh, int *codes);
int DH_generate_key(DH *dh);
int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh);
void DH_set_default_method(const DH_METHOD *meth);
const DH_METHOD *DH_get_default_method(void);
int DH_set_method(DH *dh, const DH_METHOD *meth);
DH *DH_new_method(ENGINE *engine);
const DH_METHOD *DH_OpenSSL(void);
DH * d2i_DHparams(DH **a, unsigned char **pp, long length);
int i2d_DHparams(const DH *a, unsigned char **pp);
int DHparams_print_fp(FILE *fp, const DH *x);
int DHparams_print(BIO *bp, const DH *x);
=head1 DESCRIPTION
These functions implement the Diffie-Hellman key agreement protocol.
The generation of shared DH parameters is described in
L<DH_generate_parameters(3)>; L<DH_generate_key(3)> describes how
to perform a key agreement.
The B<DH> structure consists of several BIGNUM components. The prime B<p>, the
generate B<g>, the Private key B<priv_key> and the public key B<pub_key>.
Optionally there may also be an additional parameter B<q>.
Note that DH keys may use non-standard B<DH_METHOD> implementations,
either directly or by the use of B<ENGINE> modules. In some cases (eg. an
ENGINE providing support for hardware-embedded keys), these BIGNUM values
will not be used by the implementation or may be used for alternative data
storage.
=head1 SEE ALSO
L<dhparam(1)>, L<bn(3)>, L<dsa(3)>, L<err(3)>,
L<rand(3)>, L<rsa(3)>, L<engine(3)>,
L<DH_set_method(3)>, L<DH_new(3)>,
L<DH_get_ex_new_index(3)>,
L<DH_generate_parameters(3)>,
L<DH_compute_key(3)>, L<DH_get0_pqg(3)>, L<DH_meth_new(3)>, L<d2i_DHparams(3)>,
L<RSA_print(3)>
=cut