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DH_set_default_method, DH_get_default_method, DH_set_method, DH_new_method, DH_OpenSSL ? select DH method |
#include <openssl/dh.h> void DH_set_default_method(DH_METHOD *meth); DH_METHOD *DH_get_default_method(void); DH_METHOD *DH_set_method(DH *dh, DH_METHOD *meth); DH *DH_new_method(DH_METHOD *meth); DH_METHOD *DH_OpenSSL(void); |
A 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. Initially, the default is to use the OpenSSL internal implementation. DH_OpenSSL() returns a pointer to that method. DH_set_default_method() makes meth the default method for all DH structures created later. DH_get_default_method() returns a pointer to the current default method. DH_set_method() selects meth for all operations using the structure dh. DH_get_method() returns a pointer to the method currently selected for dh. DH_new_method() allocates and initializes a DH structure so that method will be used for the DH operations. If method is NULL, the default method is used. |
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; |
DH_OpenSSL(), DH_get_default_method() and DH_get_method() return pointers to the respective DH_METHODs. DH_set_default_method() returns no value. DH_set_method() returns a pointer to the DH_METHOD previously associated with dh. DH_new_method() returns NULL and sets an error code that can be obtained by ERR_get_error(3) if the allocation fails. Otherwise it returns a pointer to the newly allocated structure. |
dh(3), DH_new(3) |
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_new_method, DH_OpenSSL - select DH method" |