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			127 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
			
		
		
	
	
			127 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
| =pod
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| 
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| =head1 NAME
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| 
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| DSA_generate_parameters_ex, DSA_generate_parameters - generate DSA parameters
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| 
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| =head1 SYNOPSIS
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| 
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|  #include <openssl/dsa.h>
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| 
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|  int DSA_generate_parameters_ex(DSA *dsa, int bits,
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|                                 const unsigned char *seed, int seed_len,
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|                                 int *counter_ret, unsigned long *h_ret,
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|                                 BN_GENCB *cb);
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| 
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| Deprecated since OpenSSL 0.9.8, can be hidden entirely by defining
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| B<OPENSSL_API_COMPAT> with a suitable version value, see
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| L<openssl_user_macros(7)>:
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| 
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|  DSA *DSA_generate_parameters(int bits, unsigned char *seed, int seed_len,
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|                               int *counter_ret, unsigned long *h_ret,
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|                               void (*callback)(int, int, void *), void *cb_arg);
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| 
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| =head1 DESCRIPTION
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| 
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| DSA_generate_parameters_ex() generates primes p and q and a generator g
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| for use in the DSA and stores the result in B<dsa>.
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| 
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| B<bits> is the length of the prime p to be generated.
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| For lengths under 2048 bits, the length of q is 160 bits; for lengths
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| greater than or equal to 2048 bits, the length of q is set to 256 bits.
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| 
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| If B<seed> is NULL, the primes will be generated at random.
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| If B<seed_len> is less than the length of q, an error is returned.
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| 
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| DSA_generate_parameters_ex() places the iteration count in
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| *B<counter_ret> and a counter used for finding a generator in
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| *B<h_ret>, unless these are B<NULL>.
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| 
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| A callback function may be used to provide feedback about the progress
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| of the key generation. If B<cb> is not B<NULL>, it will be
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| called as shown below. For information on the BN_GENCB structure and the
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| BN_GENCB_call function discussed below, refer to
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| L<BN_generate_prime(3)>.
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| 
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| DSA_generate_prime() is similar to DSA_generate_prime_ex() but
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| expects an old-style callback function; see
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| L<BN_generate_prime(3)> for information on the old-style callback.
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| 
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| =over 2
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| 
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| =item *
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| 
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| When a candidate for q is generated, B<BN_GENCB_call(cb, 0, m++)> is called
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| (m is 0 for the first candidate).
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| 
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| =item *
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| 
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| When a candidate for q has passed a test by trial division,
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| B<BN_GENCB_call(cb, 1, -1)> is called.
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| While a candidate for q is tested by Miller-Rabin primality tests,
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| B<BN_GENCB_call(cb, 1, i)> is called in the outer loop
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| (once for each witness that confirms that the candidate may be prime);
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| i is the loop counter (starting at 0).
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| 
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| =item *
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| 
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| When a prime q has been found, B<BN_GENCB_call(cb, 2, 0)> and
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| B<BN_GENCB_call(cb, 3, 0)> are called.
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| 
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| =item *
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| 
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| Before a candidate for p (other than the first) is generated and tested,
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| B<BN_GENCB_call(cb, 0, counter)> is called.
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| 
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| =item *
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| 
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| When a candidate for p has passed the test by trial division,
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| B<BN_GENCB_call(cb, 1, -1)> is called.
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| While it is tested by the Miller-Rabin primality test,
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| B<BN_GENCB_call(cb, 1, i)> is called in the outer loop
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| (once for each witness that confirms that the candidate may be prime).
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| i is the loop counter (starting at 0).
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| 
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| =item *
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| 
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| When p has been found, B<BN_GENCB_call(cb, 2, 1)> is called.
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| 
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| =item *
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| 
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| When the generator has been found, B<BN_GENCB_call(cb, 3, 1)> is called.
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| 
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| =back
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| 
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| =head1 RETURN VALUES
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| 
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| DSA_generate_parameters_ex() returns a 1 on success, or 0 otherwise.
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| The error codes can be obtained by L<ERR_get_error(3)>.
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| 
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| DSA_generate_parameters() returns a pointer to the DSA structure or
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| B<NULL> if the parameter generation fails.
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| 
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| =head1 BUGS
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| 
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| Seed lengths greater than 20 are not supported.
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| 
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| =head1 SEE ALSO
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| 
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| L<DSA_new(3)>, L<ERR_get_error(3)>, L<RAND_bytes(3)>,
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| L<DSA_free(3)>, L<BN_generate_prime(3)>
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| 
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| =head1 HISTORY
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| 
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| DSA_generate_parameters() was deprecated in OpenSSL 0.9.8; use
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| DSA_generate_parameters_ex() instead.
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| 
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| =head1 COPYRIGHT
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| 
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| Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
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| 
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| Licensed under the Apache License 2.0 (the "License").  You may not use
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| this file except in compliance with the License.  You can obtain a copy
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| in the file LICENSE in the source distribution or at
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| L<https://www.openssl.org/source/license.html>.
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| 
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| =cut
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