Add some of the missing CMS API documentation

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11884)

1 files changed, 55 insertions, 0 deletions

diff --git a/doc/man3/CMS_data_create.pod b/doc/man3/CMS_data_create.pod
new file mode 100644
index 0000000000..b64a7a1d46
--- /dev/null
+++ b/doc/man3/CMS_data_create.pod
@@ -0,0 +1,55 @@
+=pod
+
+=head1 NAME
+
+CMS_data_create_with_libctx, CMS_data_create
+- Create CMS Data object
+
+=head1 SYNOPSIS
+
+ #include <openssl/cms.h>
+
+ CMS_ContentInfo *CMS_data_create_with_libctx(BIO *in, unsigned int flags,
+                                              OPENSSL_CTX *libctx,
+                                              const char *propq);
+ CMS_ContentInfo *CMS_data_create(BIO *in, unsigned int flags);
+
+=head1 DESCRIPTION
+
+CMS_data_create_with_libctx() creates a B<CMS_ContentInfo> structure
+with a type B<NID_pkcs7_data>. The data is supplied via the I<in> BIO.
+The library context I<libctx> and the property query I<propq> are used when
+retrieving algorithms from providers. The I<flags> field supports the
+B<CMS_STREAM> flag. Internally CMS_final() is called unless B<CMS_STREAM> is
+specified.
+
+The B<CMS_ContentInfo> structure can be freed using L<CMS_ContentInfo_free(3)>.
+
+CMS_data_create() is similar to CMS_data_create_with_libctx()
+but uses default values of NULL for the library context I<libctx> and the
+property query I<propq>.
+
+=head1 RETURN VALUES
+
+If the allocation fails, CMS_data_create_with_libctx() and CMS_data_create()
+return NULL and set an error code that can be obtained by L<ERR_get_error(3)>.
+Otherwise they return a pointer to the newly allocated structure.
+
+=head1 SEE ALSO
+
+L<ERR_get_error(3)>, L<CMS_final(3)>
+
+head1 HISTORY
+
+The CMS_data_create_with_libctx() method was added in OpenSSL 3.0.
+
+=head1 COPYRIGHT
+
+Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
+
+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>.
+
+=cut