1BN_zero(3)                          OpenSSL                         BN_zero(3)
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NAME

6       BN_zero, BN_one, BN_value_one, BN_set_word, BN_get_word - BIGNUM
7       assignment operations
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SYNOPSIS

10        #include <openssl/bn.h>
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12        int BN_zero(BIGNUM *a);
13        int BN_one(BIGNUM *a);
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15        const BIGNUM *BN_value_one(void);
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17        int BN_set_word(BIGNUM *a, BN_ULONG w);
18        BN_ULONG BN_get_word(BIGNUM *a);
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DESCRIPTION

21       BN_ULONG is a macro that will be an unsigned integral type optimied for
22       the most efficient implementation on the local platform.
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24       BN_zero(), BN_one() and BN_set_word() set a to the values 0, 1 and w
25       respectively.  BN_zero() and BN_one() are macros.
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27       BN_value_one() returns a BIGNUM constant of value 1. This constant is
28       useful for use in comparisons and assignment.
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30       BN_get_word() returns a, if it can be represented as a BN_ULONG.
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RETURN VALUES

33       BN_get_word() returns the value a, or all-bits-set if a cannot be
34       represented as a BN_ULONG.
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36       BN_zero(), BN_one() and BN_set_word() return 1 on success, 0 otherwise.
37       BN_value_one() returns the constant.
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BUGS

40       If a BIGNUM is equal to the value of all-bits-set, it will collide with
41       the error condition returned by BN_get_word() which uses that as an
42       error value.
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44       BN_ULONG should probably be a typedef.
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SEE ALSO

47       bn(3), BN_bn2bin(3)
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HISTORY

50       BN_zero(), BN_one() and BN_set_word() are available in all versions of
51       SSLeay and OpenSSL. BN_value_one() and BN_get_word() were added in
52       SSLeay 0.8.
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54       BN_value_one() was changed to return a true const BIGNUM * in OpenSSL
55       0.9.7.
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591.0.2o                            2020-01-28                        BN_zero(3)