Document the BN library.

1 files changed, 53 insertions, 0 deletions

diff --git a/doc/crypto/BN_new.pod b/doc/crypto/BN_new.pod
new file mode 100644
index 0000000000..ee95645751
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+++ b/doc/crypto/BN_new.pod
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+=pod
+
+=head1 NAME
+
+BN_new, BN_init, BN_clear, BN_free, BN_clear_free - allocate and free BIGNUMs
+
+=head1 SYNOPSIS
+
+ #include <openssl/bn.h>
+
+ BIGNUM *BN_new(void);
+
+ void BN_init(BIGNUM *);
+
+ void BN_clear(BIGNUM *a);
+
+ void BN_free(BIGNUM *a);
+
+ void BN_clear_free(BIGNUM *a);
+
+=head1 DESCRIPTION
+
+BN_new() allocated and initializes a B<BIGNUM> structure. BN_init()
+initializes an existing uninitialized B<BIGNUM>.
+
+BN_clear() is used to destroy sensitive data such as keys when they
+are no longer needed. It erases the memory used by B<a> and sets it
+to the value 0.
+
+BN_free() frees the components of the B<BIGNUM>, and if it was created
+by BN_new(), also the structure itself. BN_clear_free() additionally
+overwrites the data before the memory is returned to the system.
+
+=head1 RETURN VALUES
+
+BN_new() returns a pointer to the B<BIGNUM>. If the allocation fails,
+it returns B<NULL> and sets an error code that can be obtained
+by ERR_get_error(3).
+
+BN_init(), BN_clear(), BN_free() and BN_clear_free() have no return
+values.
+
+=head1 SEE ALSO
+
+bn(3), err(3)
+
+=head1 HISTORY
+
+BN_new(), BN_clear(), BN_free() and BN_clear_free() are availabe in
+all versions on SSLeay and OpenSSL.  BN_init() was added in SSLeay
+0.9.1b.
+
+=cut