Allow for higher granularity of entropy estimates by using 'double'

[openssl.git] / doc / crypto / BN_CTX_new.pod

diff --git a/doc/crypto/BN_CTX_new.pod b/doc/crypto/BN_CTX_new.pod
index 45c70fd4079e987a3d91815ecdbbeb88f088f975..c94d8c610da5804de25a73d5b40327721cde09fb 100644 (file)
--- a/doc/crypto/BN_CTX_new.pod
+++ b/doc/crypto/BN_CTX_new.pod
@@ -16,17 +16,21 @@ BN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures
 
 =head1 DESCRIPTION
 
-A B<BN_CTX> is a structure that holds temporary variables used by
-library functions. Thus, it can be avoided to create and destroy
-the temporary B<BIGNUM> objects whenever a library function is
-called.
+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() allocated and initializes a B<BN_CTX>
+BN_CTX_new() allocates and initializes a B<BN_CTX>
 structure. BN_CTX_init() initializes an existing uninitialized
 B<BN_CTX>.
 
 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().
+
 
 =head1 RETURN VALUES
 
@@ -38,7 +42,8 @@ BN_CTX_init() and BN_CTX_free() have no return values.
 
 =head1 SEE ALSO
 
-L<bn(3)|bn(3)>, L<err(3)|err(3)>, L<BN_add(3)|BN_add(3)>
+L<bn(3)|bn(3)>, L<err(3)|err(3)>, L<BN_add(3)|BN_add(3)>,
+L<BN_CTX_start(3)|BN_CTX_start(3)>
 
 =head1 HISTORY