DH_GET0_PQG(3ossl) OpenSSL DH_GET0_PQG(3ossl)
NAME
DH_get0_pqg, DH_set0_pqg, DH_get0_key, DH_set0_key, DH_get0_p,
DH_get0_q, DH_get0_g, DH_get0_priv_key, DH_get0_pub_key,
DH_clear_flags, DH_test_flags, DH_set_flags, DH_get0_engine,
DH_get_length, DH_set_length - Routines for getting and setting data in
a DH object
SYNOPSIS
#include <openssl/dh.h>
The following functions have been deprecated since OpenSSL 3.0, and can
be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
version value, see openssl_user_macros(7):
void DH_get0_pqg(const DH *dh,
const BIGNUM **p, const BIGNUM **q, const BIGNUM **g);
int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g);
void DH_get0_key(const DH *dh,
const BIGNUM **pub_key, const BIGNUM **priv_key);
int DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key);
const BIGNUM *DH_get0_p(const DH *dh);
const BIGNUM *DH_get0_q(const DH *dh);
const BIGNUM *DH_get0_g(const DH *dh);
const BIGNUM *DH_get0_priv_key(const DH *dh);
const BIGNUM *DH_get0_pub_key(const DH *dh);
void DH_clear_flags(DH *dh, int flags);
int DH_test_flags(const DH *dh, int flags);
void DH_set_flags(DH *dh, int flags);
long DH_get_length(const DH *dh);
int DH_set_length(DH *dh, long length);
ENGINE *DH_get0_engine(DH *d);
DESCRIPTION
All of the functions described on this page are deprecated.
Applications should instead use EVP_PKEY_get_bn_param(3) for any
methods that return a BIGNUM. Refer to EVP_PKEY-DH(7) for more
information.
A DH object contains the parameters p, q and g. Note that the q
parameter is optional. It also contains a public key (pub_key) and
(optionally) a private key (priv_key).
The p, q and g parameters can be obtained by calling DH_get0_pqg(3). If
the parameters have not yet been set then *p, *q and *g will be set to
NULL. Otherwise they are set to pointers to their respective values.
These point directly to the internal representations of the values and
therefore should not be freed directly. Any of the out parameters p,
q, and g can be NULL, in which case no value will be returned for that
parameter.
The p, q and g values can be set by calling DH_set0_pqg() and passing
the new values for p, q and g as parameters to the function. Calling
this function transfers the memory management of the values to the DH
object, and therefore the values that have been passed in should not be
freed directly after this function has been called. The q parameter may
be NULL. DH_set0_pqg() also checks if the parameters associated with p
and g and optionally q are associated with known safe prime groups. If
it is a safe prime group then the value of q will be set to q = (p - 1)
/ 2 if q is NULL. The optional length parameter will be set to
BN_num_bits(q) if q is not NULL.
To get the public and private key values use the DH_get0_key()
function. A pointer to the public key will be stored in *pub_key, and a
pointer to the private key will be stored in *priv_key. Either may be
NULL if they have not been set yet, although if the private key has
been set then the public key must be. The values point to the internal
representation of the public key and private key values. This memory
should not be freed directly. Any of the out parameters pub_key and
priv_key can be NULL, in which case no value will be returned for that
parameter.
The public and private key values can be set using DH_set0_key().
Either parameter may be NULL, which means the corresponding DH field is
left untouched. As with DH_set0_pqg() this function transfers the
memory management of the key values to the DH object, and therefore
they should not be freed directly after this function has been called.
Any of the values p, q, g, priv_key, and pub_key can also be retrieved
separately by the corresponding function DH_get0_p(), DH_get0_q(),
DH_get0_g(), DH_get0_priv_key(), and DH_get0_pub_key(), respectively.
DH_set_flags() sets the flags in the flags parameter on the DH object.
Multiple flags can be passed in one go (bitwise ORed together). Any
flags that are already set are left set. DH_test_flags() tests to see
whether the flags passed in the flags parameter are currently set in
the DH object. Multiple flags can be tested in one go. All flags that
are currently set are returned, or zero if none of the flags are set.
DH_clear_flags() clears the specified flags within the DH object.
DH_get0_engine() returns a handle to the ENGINE that has been set for
this DH object, or NULL if no such ENGINE has been set. This function
is deprecated. All engines should be replaced by providers.
The DH_get_length() and DH_set_length() functions get and set the
optional length parameter associated with this DH object. If the length
is nonzero then it is used, otherwise it is ignored. The length
parameter indicates the length of the secret exponent (private key) in
bits. For safe prime groups the optional length parameter length can be
set to a value greater or equal to 2 *
maximum_target_security_strength(BN_num_bits(p)) as listed in
SP800-56Ar3 Table(s) 25 & 26. These functions are deprecated and
should be replaced with EVP_PKEY_CTX_set_params() and
EVP_PKEY_get_int_param() using the parameter key
OSSL_PKEY_PARAM_DH_PRIV_LEN as described in EVP_PKEY-DH(7).
NOTES
Values retrieved with DH_get0_key() are owned by the DH object used in
the call and may therefore not be passed to DH_set0_key(). If needed,
duplicate the received value using BN_dup() and pass the duplicate.
The same applies to DH_get0_pqg(3) and DH_set0_pqg().
RETURN VALUES
DH_set0_pqg() and DH_set0_key() return 1 on success or 0 on failure.
DH_get0_p(), DH_get0_q(), DH_get0_g(), DH_get0_priv_key(), and
DH_get0_pub_key() return the respective value, or NULL if it is unset.
DH_test_flags() returns the current state of the flags in the DH
object.
DH_get0_engine() returns the ENGINE set for the DH object or NULL if no
ENGINE has been set.
DH_get_length() returns the length of the secret exponent (private key)
in bits, or zero if no such length has been explicitly set.
SEE ALSO
DH_new(3), DH_new(3), DH_generate_parameters(3), DH_generate_key(3),
DH_set_method(3), DH_size(3), DH_meth_new(3)
HISTORY
The functions described here were added in OpenSSL 1.1.0.
All of these functions were deprecated in OpenSSL 3.0.
COPYRIGHT
Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
3.3.2 2024-09-04 DH_GET0_PQG(3ossl)
openssl 3.3.2 - Generated Sun Sep 8 18:04:46 CDT 2024