/usr/man2/cat.3/DH_compute_key.3.Z(/usr/man2/cat.3/DH_compute_key.3.Z)

NAME

       DH_generate_key, DH_compute_key - perform Diffie-Hellman key exchange

SYNOPSIS

        #include <openssl/dh.h>

        int DH_generate_key(DH *dh);

        int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh);

DESCRIPTION

       DH_generate_key() performs the first step of a Diffie-Hellman key
       exchange by generating private and public DH values. By calling DH_com-
       pute_key(), these are combined with the other party's public value to
       compute the shared key.

       DH_generate_key() expects dh to contain the shared parameters dh->p and
       dh->g. It generates a random private DH value unless dh->priv_key is
       already set, and computes the corresponding public value dh->pub_key,
       which can then be published.

       DH_compute_key() computes the shared secret from the private DH value
       in dh and the other party's public value in pub_key and stores it in
       key. key must point to DH_size(dh) bytes of memory.

RETURN VALUES

       DH_generate_key() returns 1 on success, 0 otherwise.

       DH_compute_key() returns the size of the shared secret on success, -1
       on error.

       The error codes can be obtained by ERR_get_error(3).

SEE ALSO

       dh(3), ERR_get_error(3), rand(3), DH_size(3)

HISTORY

       DH_generate_key() and DH_compute_key() are available in all versions of
       SSLeay and OpenSSL.

1.0.2t                            2019-09-10                DH_generate_key(3)
See also DH_generate_key(3)