1=pod 2 3=head1 NAME 4 5BN_new, BN_init, BN_clear, BN_free, BN_clear_free - allocate and free BIGNUMs 6 7=head1 SYNOPSIS 8 9 #include <openssl/bn.h> 10 11 BIGNUM *BN_new(void); 12 13 void BN_init(BIGNUM *); 14 15 void BN_clear(BIGNUM *a); 16 17 void BN_free(BIGNUM *a); 18 19 void BN_clear_free(BIGNUM *a); 20 21=head1 DESCRIPTION 22 23BN_new() allocates and initializes a B<BIGNUM> structure. BN_init() 24initializes an existing uninitialized B<BIGNUM>. 25 26BN_clear() is used to destroy sensitive data such as keys when they 27are no longer needed. It erases the memory used by B<a> and sets it 28to the value 0. 29 30BN_free() frees the components of the B<BIGNUM>, and if it was created 31by BN_new(), also the structure itself. BN_clear_free() additionally 32overwrites the data before the memory is returned to the system. 33 34=head1 RETURN VALUES 35 36BN_new() returns a pointer to the B<BIGNUM>. If the allocation fails, 37it returns B<NULL> and sets an error code that can be obtained 38by L<ERR_get_error(3)|ERR_get_error(3)>. 39 40BN_init(), BN_clear(), BN_free() and BN_clear_free() have no return 41values. 42 43=head1 SEE ALSO 44 45L<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)> 46 47=head1 HISTORY 48 49BN_new(), BN_clear(), BN_free() and BN_clear_free() are available in 50all versions on SSLeay and OpenSSL. BN_init() was added in SSLeay 510.9.1b. 52 53=cut 54