=head1 SYNOPSIS
#include <openssl/dh.h>
+ #include <openssl/engine.h>
void DH_set_default_method(const DH_METHOD *meth);
int DH_set_method(DH *dh, const DH_METHOD *meth);
- DH *DH_new_method(DH_METHOD *meth);
+ DH *DH_new_method(ENGINE *engine);
const DH_METHOD *DH_OpenSSL(void);
as a default for DH, so this function is no longer recommended.
DH_get_default_method() returns a pointer to the current default DH_METHOD.
-However, the meaningfulness of this result is dependant on whether the ENGINE
+However, the meaningfulness of this result is dependent on whether the ENGINE
API is being used, so this function is no longer recommended.
DH_set_method() selects B<meth> to perform all operations using the key B<dh>.
operations is used, and if no default ENGINE is set, the DH_METHOD controlled by
DH_set_default_method() is used.
-=head1 THE DH_METHOD STRUCTURE
-
- typedef struct dh_meth_st
- {
- /* name of the implementation */
- const char *name;
-
- /* generate private and public DH values for key agreement */
- int (*generate_key)(DH *dh);
-
- /* compute shared secret */
- int (*compute_key)(unsigned char *key, BIGNUM *pub_key, DH *dh);
-
- /* compute r = a ^ p mod m (May be NULL for some implementations) */
- int (*bn_mod_exp)(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
- const BIGNUM *m, BN_CTX *ctx,
- BN_MONT_CTX *m_ctx);
-
- /* called at DH_new */
- int (*init)(DH *dh);
-
- /* called at DH_free */
- int (*finish)(DH *dh);
-
- int flags;
-
- char *app_data; /* ?? */
-
- } DH_METHOD;
+A new DH_METHOD object may be constructed using DH_meth_new() (see
+L<DH_meth_new(3)>).
=head1 RETURN VALUES
method was supplied by an ENGINE).
DH_new_method() returns NULL and sets an error code that can be obtained by
-L<ERR_get_error(3)|ERR_get_error(3)> if the allocation fails. Otherwise it
+L<ERR_get_error(3)> if the allocation fails. Otherwise it
returns a pointer to the newly allocated structure.
-=head1 NOTES
-
-As of version 0.9.7, DH_METHOD implementations are grouped together with other
-algorithmic APIs (eg. RSA_METHOD, EVP_CIPHER, etc) in B<ENGINE> modules. If a
-default ENGINE is specified for DH functionality using an ENGINE API function,
-that will override any DH defaults set using the DH API (ie.
-DH_set_default_method()). For this reason, the ENGINE API is the recommended way
-to control default implementations for use in DH and other cryptographic
-algorithms.
-
=head1 SEE ALSO
-L<dh(3)|dh(3)>, L<DH_new(3)|DH_new(3)>
-
-=head1 HISTORY
-
-DH_set_default_method(), DH_get_default_method(), DH_set_method(),
-DH_new_method() and DH_OpenSSL() were added in OpenSSL 0.9.4.
-
-DH_set_default_openssl_method() and DH_get_default_openssl_method() replaced
-DH_set_default_method() and DH_get_default_method() respectively, and
-DH_set_method() and DH_new_method() were altered to use B<ENGINE>s rather than
-B<DH_METHOD>s during development of the engine version of OpenSSL 0.9.6. For
-0.9.7, the handling of defaults in the ENGINE API was restructured so that this
-change was reversed, and behaviour of the other functions resembled more closely
-the previous behaviour. The behaviour of defaults in the ENGINE API now
-transparently overrides the behaviour of defaults in the DH API without
-requiring changing these function prototypes.
+L<dh(3)>, L<DH_new(3)>, L<DH_meth_new(3)>
=cut