BN_SET_NEGATIVE(3) | Library Functions Manual | BN_SET_NEGATIVE(3)

# NAME

`BN_set_negative`, `BN_is_negative` — change and inspect the sign of a BIGNUM

# SYNOPSIS

library “libcrypto”
`#include <openssl/bn.h>`

void
`BN_set_negative`(BIGNUM *b, int n);

int
`BN_is_negative`(const BIGNUM *b);

# DESCRIPTION

`BN_set_negative`() sets b to negative if both b and n are non-zero, otherwise it sets it to positive.

`BN_is_negative`() tests the sign of b.

# RETURN VALUES

`BN_is_negative`() returns 1 if b is negative or 0 otherwise.

# SEE ALSO

BN_add(3), BN_new(3), BN_set_bit(3), BN_zero(3)

# HISTORY

`BN_set_negative`() and `BN_is_negative`() first appeared in OpenSSL 0.9.8 and have been available since OpenBSD 4.5.

June 8, 2025 | Debian