aboutsummaryrefslogtreecommitdiff
path: root/doc/crypto/DH_set_method.pod
diff options
context:
space:
mode:
Diffstat (limited to 'doc/crypto/DH_set_method.pod')
-rw-r--r--doc/crypto/DH_set_method.pod129
1 files changed, 0 insertions, 129 deletions
diff --git a/doc/crypto/DH_set_method.pod b/doc/crypto/DH_set_method.pod
deleted file mode 100644
index d5cdc3be0ce6..000000000000
--- a/doc/crypto/DH_set_method.pod
+++ /dev/null
@@ -1,129 +0,0 @@
-=pod
-
-=head1 NAME
-
-DH_set_default_method, DH_get_default_method,
-DH_set_method, DH_new_method, DH_OpenSSL - select DH method
-
-=head1 SYNOPSIS
-
- #include <openssl/dh.h>
- #include <openssl/engine.h>
-
- 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);
-
-=head1 DESCRIPTION
-
-A B<DH_METHOD> specifies the functions that OpenSSL uses for Diffie-Hellman
-operations. By modifying the method, alternative implementations
-such as hardware accelerators may be used. IMPORTANT: See the NOTES section for
-important information about how these DH API functions are affected by the use
-of B<ENGINE> API calls.
-
-Initially, the default DH_METHOD is the OpenSSL internal implementation, as
-returned by DH_OpenSSL().
-
-DH_set_default_method() makes B<meth> the default method for all DH
-structures created later. B<NB>: This is true only whilst no ENGINE has been set
-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 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>.
-This will replace the DH_METHOD used by the DH key and if the previous method
-was supplied by an ENGINE, the handle to that ENGINE will be released during the
-change. It is possible to have DH keys that only work with certain DH_METHOD
-implementations (eg. from an ENGINE module that supports embedded
-hardware-protected keys), and in such cases attempting to change the DH_METHOD
-for the key can have unexpected results.
-
-DH_new_method() allocates and initializes a DH structure so that B<engine> will
-be used for the DH operations. If B<engine> is NULL, the default ENGINE for 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;
-
-=head1 RETURN VALUES
-
-DH_OpenSSL() and DH_get_default_method() return pointers to the respective
-B<DH_METHOD>s.
-
-DH_set_default_method() returns no value.
-
-DH_set_method() returns non-zero if the provided B<meth> was successfully set as
-the method for B<dh> (including unloading the ENGINE handle if the previous
-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
-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.
-
-=cut