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Diffstat (limited to 'openssl/trunk/doc/crypto/DH_set_method.pod')
| -rw-r--r-- | openssl/trunk/doc/crypto/DH_set_method.pod | 129 |
1 files changed, 0 insertions, 129 deletions
diff --git a/openssl/trunk/doc/crypto/DH_set_method.pod b/openssl/trunk/doc/crypto/DH_set_method.pod deleted file mode 100644 index 73261fc4..00000000 --- a/openssl/trunk/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 dependant 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 |