Document the BN library.

1 files changed, 48 insertions, 0 deletions

diff --git a/doc/crypto/BN_CTX_new.pod b/doc/crypto/BN_CTX_new.pod
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+++ b/doc/crypto/BN_CTX_new.pod
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+=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_init(BN_CTX *c);
+
+ void BN_CTX_free(BN_CTX *c);
+
+=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.
+
+BN_CTX_new() allocated 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.
+
+=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
+ERR_get_error(3).
+
+BN_CTX_init() and BN_CTX_free() have no return values.
+
+=head1 SEE ALSO
+
+bn(3), err(3), BN_add(3)
+
+=head1 HISTORY
+
+BN_CTX_new() and BN_CTX_free() are availabe in all versions on SSLeay
+and OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b.
+
+=cut