Initial Commit

openssl-1.0.2f/doc/crypto/BN_CTX_new.pod

@@ -0,0 +1,57 @@
+=pod
+
+=head1 NAME
+
+BN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures
+
+=head1 SYNOPSIS
+
+ #include <openssl/bn.h>
+
+ BN_CTX *BN_CTX_new(void);
+
+ void BN_CTX_free(BN_CTX *c);
+
+Deprecated:
+
+ void BN_CTX_init(BN_CTX *c);
+
+
+=head1 DESCRIPTION
+
+A B<BN_CTX> is a structure that holds B<BIGNUM> temporary variables used by
+library functions. Since dynamic memory allocation to create B<BIGNUM>s
+is rather expensive when used in conjunction with repeated subroutine
+calls, the B<BN_CTX> structure is used.
+
+BN_CTX_new() allocates and initializes a B<BN_CTX>
+structure. 
+
+BN_CTX_free() frees the components of the B<BN_CTX>, and if it was
+created by BN_CTX_new(), also the structure itself.
+If L<BN_CTX_start(3)|BN_CTX_start(3)> has been used on the B<BN_CTX>,
+L<BN_CTX_end(3)|BN_CTX_end(3)> must be called before the B<BN_CTX>
+may be freed by BN_CTX_free().
+
+BN_CTX_init() (deprecated) initializes an existing uninitialized B<BN_CTX>.
+This should not be used for new programs. Use BN_CTX_new() instead.
+
+=head1 RETURN VALUES
+
+BN_CTX_new() returns a pointer to the B<BN_CTX>. If the allocation fails,
+it returns B<NULL> and sets an error code that can be obtained by
+L<ERR_get_error(3)|ERR_get_error(3)>.
+
+BN_CTX_init() and BN_CTX_free() have no return values.
+
+=head1 SEE ALSO
+
+L<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<BN_add(3)|BN_add(3)>,
+L<BN_CTX_start(3)|BN_CTX_start(3)>
+
+=head1 HISTORY
+
+BN_CTX_new() and BN_CTX_free() are available in all versions on SSLeay
+and OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b.
+
+=cut