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man pages section 3: Extended Library Functions, Volume 1

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Updated: Wednesday, July 27, 2022
 
 

DH_generate_key (3openssl)

Name

DH_generate_key - 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(3openssl)           OpenSSL          DH_generate_key(3openssl)



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_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.

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).


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+--------------------------+
       |ATTRIBUTE TYPE |     ATTRIBUTE VALUE      |
       +---------------+--------------------------+
       |Availability   | library/security/openssl |
       +---------------+--------------------------+
       |Stability      | Pass-through uncommitted |
       +---------------+--------------------------+

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.



NOTES
       Source code for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from
       https://www.openssl.org/source/openssl-1.0.2ze.tar.gz.

       Further information about this software can be found on the open source
       community website at https://www.openssl.org/.



1.0.2ze                           2022-05-03         DH_generate_key(3openssl)