Create BN_CTX_new_ex() and BN_CTX_secure_new_ex()

[openssl.git] / doc / man3 / BN_CTX_new.pod

diff --git a/doc/man3/BN_CTX_new.pod b/doc/man3/BN_CTX_new.pod
index 84c23e0484584bd1376c17697c118dc6353e9264..17c53ec79d6ced60524ba6339d506327c50b15c4 100644 (file)
--- a/doc/man3/BN_CTX_new.pod
+++ b/doc/man3/BN_CTX_new.pod
@@ -2,14 +2,17 @@
 
 =head1 NAME
 
-BN_CTX_new, BN_CTX_secure_new, BN_CTX_free - allocate and free BN_CTX structures
+BN_CTX_new_ex, BN_CTX_new, BN_CTX_secure_new_ex, BN_CTX_secure_new, BN_CTX_free
+- allocate and free BN_CTX structures
 
 =head1 SYNOPSIS
 
  #include <openssl/bn.h>
 
+ BN_CTX *BN_CTX_new_ex(OPENSSL_CTX *ctx);
  BN_CTX *BN_CTX_new(void);
 
+ BN_CTX *BN_CTX_secure_new_ex(OPENSSL_CTX *ctx);
  BN_CTX *BN_CTX_secure_new(void);
 
  void BN_CTX_free(BN_CTX *c);
@@ -21,17 +24,26 @@ 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_secure_new() allocates and initializes a B<BN_CTX> structure
+BN_CTX_new_ex() allocates and initializes a B<BN_CTX> structure for the given
+library context B<ctx>. The <ctx> value may be NULL in which case the default
+library context will be used. BN_CTX_new() is the same as BN_CTX_new_ex() except
+that the default library context is always used.
+
+BN_CTX_secure_new_ex() 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.
+B<BIGNUM>s for the given library context B<ctx>. The <ctx> value may be NULL in
+which case the default library context will be used. BN_CTX_secure_new() is the
+same as BN_CTX_secure_new_ex() except that the default library context is always
+used.
+
+BN_CTX_free() frees the components of the B<BN_CTX> and the structure itself.
+Since BN_CTX_start() is required in order to obtain B<BIGNUM>s from the
+B<BN_CTX>, in most cases BN_CTX_end() must be called before the B<BN_CTX> may
+be freed by BN_CTX_free().  If B<c> is NULL, nothing is done.
 
-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)> has been used on the B<BN_CTX>,
-L<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.
+A given B<BN_CTX> must only be used by a single thread of execution.  No
+locking is performed, and the internal pool allocator will not properly handle
+multiple threads of execution.
 
 =head1 RETURN VALUES
 
@@ -51,13 +63,14 @@ replace use of BN_CTX_init with BN_CTX_new instead:
 
  BN_CTX *ctx;
  ctx = BN_CTX_new();
- if(!ctx) /* Handle error */
+ if (!ctx)
+     /* error */
  ...
  BN_CTX_free(ctx);
 
 =head1 SEE ALSO
 
-L<bn(7)>, L<ERR_get_error(3)>, L<BN_add(3)>,
+L<ERR_get_error(3)>, L<BN_add(3)>,
 L<BN_CTX_start(3)>
 
 =head1 HISTORY
@@ -66,9 +79,9 @@ BN_CTX_init() was removed in OpenSSL 1.1.0.
 
 =head1 COPYRIGHT
 
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
 
-Licensed under the OpenSSL license (the "License").  You may not use
+Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy
 in the file LICENSE in the source distribution or at
 L<https://www.openssl.org/source/license.html>.