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			130 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
			
		
		
	
	
			130 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
| =pod
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| 
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| =head1 NAME
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| 
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| BN_rand_ex, BN_rand, BN_priv_rand_ex, BN_priv_rand, BN_pseudo_rand,
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| BN_rand_range_ex, BN_rand_range, BN_priv_rand_range_ex, BN_priv_rand_range,
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| BN_pseudo_rand_range
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| - generate pseudo-random number
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| 
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| =head1 SYNOPSIS
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| 
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|  #include <openssl/bn.h>
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| 
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|  int BN_rand_ex(BIGNUM *rnd, int bits, int top, int bottom,
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|                 unsigned int strength, BN_CTX *ctx);
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|  int BN_rand(BIGNUM *rnd, int bits, int top, int bottom);
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| 
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|  int BN_priv_rand_ex(BIGNUM *rnd, int bits, int top, int bottom,
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|                      unsigned int strength, BN_CTX *ctx);
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|  int BN_priv_rand(BIGNUM *rnd, int bits, int top, int bottom);
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| 
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|  int BN_rand_range_ex(BIGNUM *rnd, const BIGNUM *range, unsigned int strength,
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|                       BN_CTX *ctx);
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|  int BN_rand_range(BIGNUM *rnd, const BIGNUM *range);
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| 
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|  int BN_priv_rand_range_ex(BIGNUM *rnd, const BIGNUM *range, unsigned int strength,
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|                            BN_CTX *ctx);
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|  int BN_priv_rand_range(BIGNUM *rnd, const BIGNUM *range);
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| 
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| The following functions have been deprecated since OpenSSL 3.0, and can be
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| hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
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| see L<openssl_user_macros(7)>:
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| 
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|  int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom);
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|  int BN_pseudo_rand_range(BIGNUM *rnd, const BIGNUM *range);
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| 
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| =head1 DESCRIPTION
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| 
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| BN_rand_ex() generates a cryptographically strong pseudo-random
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| number of I<bits> in length and security strength at least I<strength> bits
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| using the random number generator for the library context associated with
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| I<ctx>. The function stores the generated data in I<rnd>. The parameter I<ctx>
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| may be NULL in which case the default library context is used.
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| If I<bits> is less than zero, or too small to
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| accommodate the requirements specified by the I<top> and I<bottom>
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| parameters, an error is returned.
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| The I<top> parameters specifies
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| requirements on the most significant bit of the generated number.
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| If it is B<BN_RAND_TOP_ANY>, there is no constraint.
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| If it is B<BN_RAND_TOP_ONE>, the top bit must be one.
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| If it is B<BN_RAND_TOP_TWO>, the two most significant bits of
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| the number will be set to 1, so that the product of two such random
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| numbers will always have 2*I<bits> length.
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| If I<bottom> is B<BN_RAND_BOTTOM_ODD>, the number will be odd; if it
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| is B<BN_RAND_BOTTOM_ANY> it can be odd or even.
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| If I<bits> is 1 then I<top> cannot also be B<BN_RAND_TOP_TWO>.
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| 
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| BN_rand() is the same as BN_rand_ex() except that the default library context
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| is always used.
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| 
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| BN_rand_range_ex() generates a cryptographically strong pseudo-random
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| number I<rnd>, of security strength at least I<strength> bits,
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| in the range 0 E<lt>= I<rnd> E<lt> I<range> using the random number
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| generator for the library context associated with I<ctx>. The parameter I<ctx>
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| may be NULL in which case the default library context is used.
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| 
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| BN_rand_range() is the same as BN_rand_range_ex() except that the default
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| library context is always used.
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| 
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| BN_priv_rand_ex(), BN_priv_rand(), BN_priv_rand_rand_ex() and
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| BN_priv_rand_range() have the same semantics as BN_rand_ex(), BN_rand(),
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| BN_rand_range_ex() and BN_rand_range() respectively.  They are intended to be
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| used for generating values that should remain private, and mirror the
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| same difference between L<RAND_bytes(3)> and L<RAND_priv_bytes(3)>.
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| 
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| =head1 NOTES
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| 
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| Always check the error return value of these functions and do not take
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| randomness for granted: an error occurs if the CSPRNG has not been
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| seeded with enough randomness to ensure an unpredictable byte sequence.
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| 
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| =head1 RETURN VALUES
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| 
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| The functions return 1 on success, 0 on error.
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| The error codes can be obtained by L<ERR_get_error(3)>.
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| 
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| =head1 SEE ALSO
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| 
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| L<ERR_get_error(3)>,
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| L<RAND_add(3)>,
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| L<RAND_bytes(3)>,
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| L<RAND_priv_bytes(3)>,
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| L<RAND(7)>,
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| L<EVP_RAND(7)>
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| 
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| =head1 HISTORY
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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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| Starting with OpenSSL release 1.1.0, BN_pseudo_rand() has been identical
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| to BN_rand() and BN_pseudo_rand_range() has been identical to
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| BN_rand_range().
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| The BN_pseudo_rand() and BN_pseudo_rand_range() functions were
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| deprecated in OpenSSL 3.0.
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| 
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| =item *
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| 
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| The BN_priv_rand() and BN_priv_rand_range() functions were added in
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| OpenSSL 1.1.1.
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| 
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| =item *
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| 
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| The BN_rand_ex(), BN_priv_rand_ex(), BN_rand_range_ex() and
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| BN_priv_rand_range_ex() functions were added in OpenSSL 3.0.
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| 
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| =back
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| 
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| =head1 COPYRIGHT
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| 
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| Copyright 2000-2022 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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