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DH_NEW(3) Library Functions Manual DH_NEW(3)

DH_new, DH_up_ref, DH_freeallocate and free DH objects

#include <openssl/dh.h>


DH_up_ref(DH *dh);

DH_free(DH *dh);

The DH functions implement the Diffie-Hellman key agreement protocol.

() allocates and initializes a DH structure, setting the reference count to 1. It is equivalent to DH_new_method(3) with a NULL argument.

() increments the reference count by 1.

() decrements the reference count by 1. If it reaches 0, it frees the DH structure and its components. The values are erased before the memory is returned to the system. If dh is a NULL pointer, no action occurs.

If the allocation fails, DH_new() returns NULL and sets an error code that can be obtained by ERR_get_error(3). Otherwise it returns a pointer to the newly allocated structure.

DH_up_ref() returns 1 for success or 0 for failure.

BN_new(3), crypto(3), d2i_DHparams(3), DH_generate_key(3), DH_generate_parameters(3), DH_get0_pqg(3), DH_get_ex_new_index(3), DH_set_method(3), DH_size(3), DHparams_print(3), DSA_dup_DH(3), EVP_PKEY_CTX_set_dh_paramgen_prime_len(3), EVP_PKEY_set1_DH(3)

DH_new() and DH_free() first appeared in SSLeay 0.5.1 and have been available since OpenBSD 2.4.

DH_up_ref() first appeared in OpenSSL 0.9.7 and has been available since OpenBSD 3.2.

June 10, 2019 OpenBSD-6.7