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DH_generate_key(3)
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
  The DH_generate_key() function 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.

  The DH_generate_key() function 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.

  The DH_compute_key() function 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.  The key must point to DH_size(dh) bytes of memory.

RETURN VALUES
  The DH_generate_key() function returns 1 on success, 0 otherwise.

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

  The error codes can be obtained from ERR_get_error().

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

SEE ALSO
  Functions: dh(3), err(3), rand(3), DH_size(3)

Index for Section 3

Alphabetical listing for D

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