| DH_GENERATE_KEY(3) | Library Functions Manual | DH_GENERATE_KEY(3) |
DH_generate_key,
DH_compute_key — perform
Diffie-Hellman key exchange
#include
<openssl/dh.h>
int
DH_generate_key(DH *dh);
int
DH_compute_key(unsigned char
*key, BIGNUM *pub_key, DH
*dh);
DH_generate_key() performs the first step
of a Diffie-Hellman key exchange by generating private and public DH values.
By calling DH_compute_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.
DH_generate_key() returns 1 on success, or
0 otherwise.
DH_compute_key() returns the size of the
shared secret on success, or -1 on error.
The error codes can be obtained by ERR_get_error(3).
DH_generate_key() and
DH_compute_key() first appeared in SSLeay 0.5.1 and
have been available since OpenBSD 2.4.
| August 19, 2019 | OpenBSD-current |