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DSA_GENERATE_PARAMETERS(3)	    OpenSSL	    DSA_GENERATE_PARAMETERS(3)

NAME
       DSA_generate_parameters_ex, DSA_generate_parameters - generate DSA
       parameters

SYNOPSIS
	#include <openssl/dsa.h>

	int DSA_generate_parameters_ex(DSA *dsa, int bits,
				       const unsigned char *seed, int seed_len,
				       int *counter_ret, unsigned long *h_ret,
				       BN_GENCB	*cb);

       Deprecated:

	#if OPENSSL_API_COMPAT < 0x00908000L
	DSA *DSA_generate_parameters(int bits, unsigned	char *seed, int	seed_len,
				     int *counter_ret, unsigned	long *h_ret,
				     void (*callback)(int, int,	void *), void *cb_arg);
	#endif

DESCRIPTION
       DSA_generate_parameters_ex() generates primes p and q and a generator g
       for use in the DSA and stores the result	in dsa.

       bits is the length of the prime p to be generated.  For lengths under
       2048 bits, the length of	q is 160 bits; for lengths greater than	or
       equal to	2048 bits, the length of q is set to 256 bits.

       If seed is NULL,	the primes will	be generated at	random.	 If seed_len
       is less than the	length of q, an	error is returned.

       DSA_generate_parameters_ex() places the iteration count in *counter_ret
       and a counter used for finding a	generator in *h_ret, unless these are
       NULL.

       A callback function may be used to provide feedback about the progress
       of the key generation. If cb is not NULL, it will be called as shown
       below. For information on the BN_GENCB structure	and the	BN_GENCB_call
       function	discussed below, refer to BN_generate_prime(3).

       DSA_generate_prime() is similar to DSA_generate_prime_ex() but expects
       an old-style callback function; see BN_generate_prime(3)	for
       information on the old-style callback.

       o When a	candidate for q	is generated, BN_GENCB_call(cb,	0, m++)	is
	 called	(m is 0	for the	first candidate).

       o When a	candidate for q	has passed a test by trial division,
	 BN_GENCB_call(cb, 1, -1) is called.  While a candidate	for q is
	 tested	by Miller-Rabin	primality tests, BN_GENCB_call(cb, 1, i) is
	 called	in the outer loop (once	for each witness that confirms that
	 the candidate may be prime); i	is the loop counter (starting at 0).

       o When a	prime q	has been found,	BN_GENCB_call(cb, 2, 0)	and
	 BN_GENCB_call(cb, 3, 0) are called.

       o Before	a candidate for	p (other than the first) is generated and
	 tested, BN_GENCB_call(cb, 0, counter) is called.

       o When a	candidate for p	has passed the test by trial division,
	 BN_GENCB_call(cb, 1, -1) is called.  While it is tested by the
	 Miller-Rabin primality	test, BN_GENCB_call(cb,	1, i) is called	in the
	 outer loop (once for each witness that	confirms that the candidate
	 may be	prime).	 i is the loop counter (starting at 0).

       o When p	has been found,	BN_GENCB_call(cb, 2, 1)	is called.

       o When the generator has	been found, BN_GENCB_call(cb, 3, 1) is called.

RETURN VALUES
       DSA_generate_parameters_ex() returns a 1	on success, or 0 otherwise.
       The error codes can be obtained by ERR_get_error(3).

       DSA_generate_parameters() returns a pointer to the DSA structure	or
       NULL if the parameter generation	fails.

BUGS
       Seed lengths greater than 20 are	not supported.

SEE ALSO
       DSA_new(3), ERR_get_error(3), RAND_bytes(3), DSA_free(3),
       BN_generate_prime(3)

HISTORY
       DSA_generate_parameters() was deprecated	in OpenSSL 0.9.8; use
       DSA_generate_parameters_ex() instead.

COPYRIGHT
       Copyright 2000-2018 The OpenSSL Project Authors.	All Rights Reserved.

       Licensed	under the OpenSSL license (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>.

1.1.1a				  2018-11-20	    DSA_GENERATE_PARAMETERS(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | BUGS | SEE ALSO | HISTORY | COPYRIGHT

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