More secure storage of key material.

[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 37a188e3c3d643def02fb846c28dd4b6f275f55a..958e551467574c0bce22d011b1a29470852afe9c 100644 (file)
--- a/doc/crypto/BN_CTX_new.pod
+++ b/doc/crypto/BN_CTX_new.pod
@@ -2,7 +2,7 @@
 
 =head1 NAME
 
-BN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures
+BN_CTX_new, BN_CTX_secure_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures
 
 =head1 SYNOPSIS
 
@@ -10,7 +10,7 @@ BN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures
 
  BN_CTX *BN_CTX_new(void);
 
- void BN_CTX_init(BN_CTX *c);
+ BN_CTX *BN_CTX_secure_new(void);
 
  void BN_CTX_free(BN_CTX *c);
 
@@ -21,28 +21,49 @@ 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_init() initializes an existing uninitialized
-B<BN_CTX>.
+BN_CTX_new() allocates and initializes a B<BN_CTX> structure.
+BN_CTX_secure_new() allocates and initializes a B<BN_CTX> structure
+but uses the secure heap (see L<CRYPTO_secure_malloc(3)>) to hold the
+B<BIGNUM>s.
 
 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().
+If B<c> is NULL, nothing is done.
 
 =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
+BN_CTX_new() and BN_CTX_secure_new() return a pointer to the B<BN_CTX>.
+If the allocation fails,
+they return 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.
+BN_CTX_free() has no return values.
+
+=head1 REMOVED FUNCTIONALITY
+
+ void BN_CTX_init(BN_CTX *c);
+
+BN_CTX_init() is no longer available as of OpenSSL 1.1.0. Applications should
+replace use of BN_CTX_init with BN_CTX_new instead:
+
+ BN_CTX *ctx;
+ ctx = BN_CTX_new();
+ if(!ctx) /* Handle error */
+ ...
+ BN_CTX_free(ctx);
 
 =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_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.
+and OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b and removed in OpenSSL
+1.1.0.
 
 =cut