doc/man3/DH_generate_parameters.pod - third_party/openssl - Git at Google

 =pod

 =head1 NAME

 DH_generate_parameters_ex, DH_generate_parameters,
 DH_check, DH_check_params,
 DH_check_ex, DH_check_params_ex, DH_check_pub_key_ex
 - generate and check Diffie-Hellman
 parameters

 =head1 SYNOPSIS

  #include <openssl/dh.h>

 The following functions have been deprecated since OpenSSL 3.0, and can be
 hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
 see L<openssl_user_macros(7)>:

  int DH_generate_parameters_ex(DH *dh, int prime_len, int generator, BN_GENCB *cb);

  int DH_check(DH *dh, int *codes);
  int DH_check_params(DH *dh, int *codes);

  int DH_check_ex(const DH *dh);
  int DH_check_params_ex(const DH *dh);
  int DH_check_pub_key_ex(const DH *dh, const BIGNUM *pub_key);

 The following functions have been deprecated since OpenSSL 0.9.8, and can be
 hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
 see L<openssl_user_macros(7)>:

  DH *DH_generate_parameters(int prime_len, int generator,
                             void (*callback)(int, int, void *), void *cb_arg);

 =head1 DESCRIPTION

 All of the functions described on this page are deprecated.
 Applications should instead use L<EVP_PKEY_check(3)>,
 L<EVP_PKEY_public_check(3)>, L<EVP_PKEY_private_check(3)> and
 L<EVP_PKEY_param_check(3)>.

 DH_generate_parameters_ex() generates Diffie-Hellman parameters that can
 be shared among a group of users, and stores them in the provided B<DH>
 structure. The pseudo-random number generator must be
 seeded before calling it.
 The parameters generated by DH_generate_parameters_ex() should not be used in
 signature schemes.

 B<prime_len> is the length in bits of the safe prime to be generated.
 B<generator> is a small number E<gt> 1, typically 2 or 5.

 A callback function may be used to provide feedback about the progress
 of the key generation. If B<cb> is not B<NULL>, it will be
 called as described in L<BN_generate_prime(3)> while a random prime
 number is generated, and when a prime has been found, B<BN_GENCB_call(cb, 3, 0)>
 is called. See L<BN_generate_prime_ex(3)> for information on
 the BN_GENCB_call() function.

 DH_generate_parameters() is similar to DH_generate_prime_ex() but
 expects an old-style callback function; see
 L<BN_generate_prime(3)> for information on the old-style callback.

 DH_check_params() confirms that the B<p> and B<g> are likely enough to
 be valid.
 This is a lightweight check, if a more thorough check is needed, use
 DH_check().
 The value of B<*codes> is updated with any problems found.
 If B<*codes> is zero then no problems were found, otherwise the
 following bits may be set:

 =over 4

 =item DH_CHECK_P_NOT_PRIME

 The parameter B<p> has been determined to not being an odd prime.
 Note that the lack of this bit doesn't guarantee that B<p> is a
 prime.

 =item DH_NOT_SUITABLE_GENERATOR

 The generator B<g> is not suitable.
 Note that the lack of this bit doesn't guarantee that B<g> is
 suitable, unless B<p> is known to be a strong prime.

 =item DH_MODULUS_TOO_SMALL

 The modulus is too small.

 =item DH_MODULUS_TOO_LARGE

 The modulus is too large.

 =back

 DH_check() confirms that the Diffie-Hellman parameters B<dh> are valid. The
 value of B<*codes> is updated with any problems found. If B<*codes> is zero then
 no problems were found, otherwise the following bits may be set:

 =over 4

 =item DH_CHECK_P_NOT_PRIME

 The parameter B<p> is not prime.

 =item DH_CHECK_P_NOT_SAFE_PRIME

 The parameter B<p> is not a safe prime and no B<q> value is present.

 =item DH_UNABLE_TO_CHECK_GENERATOR

 The generator B<g> cannot be checked for suitability.

 =item DH_NOT_SUITABLE_GENERATOR

 The generator B<g> is not suitable.

 =item DH_CHECK_Q_NOT_PRIME

 The parameter B<q> is not prime.

 =item DH_CHECK_INVALID_Q_VALUE

 The parameter B<q> is invalid.

 =item DH_CHECK_INVALID_J_VALUE

 The parameter B<j> is invalid.

 =back

 DH_check_ex(), DH_check_params() and DH_check_pub_key_ex() are similar to
 DH_check() and DH_check_params() respectively, but the error reasons are added
 to the thread's error queue instead of provided as return values from the
 function.

 =head1 RETURN VALUES

 DH_generate_parameters_ex(), DH_check() and DH_check_params() return 1
 if the check could be performed, 0 otherwise.

 DH_generate_parameters() returns a pointer to the DH structure or NULL if
 the parameter generation fails.

 DH_check_ex(), DH_check_params() and DH_check_pub_key_ex() return 1 if the
 check is successful, 0 for failed.

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

 =head1 SEE ALSO

 L<DH_new(3)>, L<ERR_get_error(3)>, L<RAND_bytes(3)>,
 L<DH_free(3)>

 =head1 HISTORY

 All of these functions were deprecated in OpenSSL 3.0.

 DH_generate_parameters() was deprecated in OpenSSL 0.9.8; use
 DH_generate_parameters_ex() instead.

 =head1 COPYRIGHT

 Copyright 2000-2020 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
 L<https://www.openssl.org/source/license.html>.

 =cut
	=pod

	=head1 NAME

	DH_generate_parameters_ex, DH_generate_parameters,
	DH_check, DH_check_params,
	DH_check_ex, DH_check_params_ex, DH_check_pub_key_ex
	- generate and check Diffie-Hellman
	parameters

	=head1 SYNOPSIS

	#include <openssl/dh.h>

	The following functions have been deprecated since OpenSSL 3.0, and can be
	hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
	see L<openssl_user_macros(7)>:

	int DH_generate_parameters_ex(DH dh, int prime_len, int generator, BN_GENCB cb);

	int DH_check(DH dh, int codes);
	int DH_check_params(DH dh, int codes);

	int DH_check_ex(const DH *dh);
	int DH_check_params_ex(const DH *dh);
	int DH_check_pub_key_ex(const DH dh, const BIGNUM pub_key);

	The following functions have been deprecated since OpenSSL 0.9.8, and can be
	hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
	see L<openssl_user_macros(7)>:

	DH *DH_generate_parameters(int prime_len, int generator,
	void (callback)(int, int, void ), void *cb_arg);

	=head1 DESCRIPTION

	All of the functions described on this page are deprecated.
	Applications should instead use L<EVP_PKEY_check(3)>,
	L<EVP_PKEY_public_check(3)>, L<EVP_PKEY_private_check(3)> and
	L<EVP_PKEY_param_check(3)>.

	DH_generate_parameters_ex() generates Diffie-Hellman parameters that can
	be shared among a group of users, and stores them in the provided B<DH>
	structure. The pseudo-random number generator must be
	seeded before calling it.
	The parameters generated by DH_generate_parameters_ex() should not be used in
	signature schemes.

	B<prime_len> is the length in bits of the safe prime to be generated.
	B<generator> is a small number E<gt> 1, typically 2 or 5.

	A callback function may be used to provide feedback about the progress
	of the key generation. If B<cb> is not B<NULL>, it will be
	called as described in L<BN_generate_prime(3)> while a random prime
	number is generated, and when a prime has been found, B<BN_GENCB_call(cb, 3, 0)>
	is called. See L<BN_generate_prime_ex(3)> for information on
	the BN_GENCB_call() function.

	DH_generate_parameters() is similar to DH_generate_prime_ex() but
	expects an old-style callback function; see
	L<BN_generate_prime(3)> for information on the old-style callback.

	DH_check_params() confirms that the B<p> and B<g> are likely enough to
	be valid.
	This is a lightweight check, if a more thorough check is needed, use
	DH_check().
	The value of B<*codes> is updated with any problems found.
	If B<*codes> is zero then no problems were found, otherwise the
	following bits may be set:

	=over 4

	=item DH_CHECK_P_NOT_PRIME

	The parameter B<p> has been determined to not being an odd prime.
	Note that the lack of this bit doesn't guarantee that B<p> is a
	prime.

	=item DH_NOT_SUITABLE_GENERATOR

	The generator B<g> is not suitable.
	Note that the lack of this bit doesn't guarantee that B<g> is
	suitable, unless B<p> is known to be a strong prime.

	=item DH_MODULUS_TOO_SMALL

	The modulus is too small.

	=item DH_MODULUS_TOO_LARGE

	The modulus is too large.

	=back

	DH_check() confirms that the Diffie-Hellman parameters B<dh> are valid. The
	value of B<codes> is updated with any problems found. If B<codes> is zero then
	no problems were found, otherwise the following bits may be set:

	=over 4

	=item DH_CHECK_P_NOT_PRIME

	The parameter B<p> is not prime.

	=item DH_CHECK_P_NOT_SAFE_PRIME

	The parameter B<p> is not a safe prime and no B<q> value is present.

	=item DH_UNABLE_TO_CHECK_GENERATOR

	The generator B<g> cannot be checked for suitability.

	=item DH_NOT_SUITABLE_GENERATOR

	The generator B<g> is not suitable.

	=item DH_CHECK_Q_NOT_PRIME

	The parameter B<q> is not prime.

	=item DH_CHECK_INVALID_Q_VALUE

	The parameter B<q> is invalid.

	=item DH_CHECK_INVALID_J_VALUE

	The parameter B<j> is invalid.

	=back

	DH_check_ex(), DH_check_params() and DH_check_pub_key_ex() are similar to
	DH_check() and DH_check_params() respectively, but the error reasons are added
	to the thread's error queue instead of provided as return values from the
	function.

	=head1 RETURN VALUES

	DH_generate_parameters_ex(), DH_check() and DH_check_params() return 1
	if the check could be performed, 0 otherwise.

	DH_generate_parameters() returns a pointer to the DH structure or NULL if
	the parameter generation fails.

	DH_check_ex(), DH_check_params() and DH_check_pub_key_ex() return 1 if the
	check is successful, 0 for failed.

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

	=head1 SEE ALSO

	L<DH_new(3)>, L<ERR_get_error(3)>, L<RAND_bytes(3)>,
	L<DH_free(3)>

	=head1 HISTORY

	All of these functions were deprecated in OpenSSL 3.0.

	DH_generate_parameters() was deprecated in OpenSSL 0.9.8; use
	DH_generate_parameters_ex() instead.

	=head1 COPYRIGHT

	Copyright 2000-2020 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
	L<https://www.openssl.org/source/license.html>.

	=cut