Add documentation for SSL_add_file_cert_subjects_to_stack(3) and

SSL_add_dir_cert_subjects_to_stack(3), written from scratch.
Both functions are listed in ssl(3) and <openssl/ssl.h> and recommended
for the use by browsers in source code comments, so they are clearly
public interfaces.

Mention deduplication.
Purge some duplicate text and improve some wording while here.
Two additional cross references instead of the useless ssl(3).
Add HISTORY, AUTHORS, and BUGS.

It is depressing that BUGS (purely from code inspection) became
longer than the DESCRIPTION.

1 files changed, 103 insertions, 25 deletions

diff --git a/lib/libssl/man/SSL_load_client_CA_file.3 b/lib/libssl/man/SSL_load_client_CA_file.3
index ba08dff77fd..4eab59ff6ee 100644
--- a/lib/libssl/man/SSL_load_client_CA_file.3
+++ b/lib/libssl/man/SSL_load_client_CA_file.3
@@ -1,7 +1,24 @@
-.\"	$OpenBSD: SSL_load_client_CA_file.3,v 1.2 2016/12/04 12:20:54 schwarze Exp $
+.\"	$OpenBSD: SSL_load_client_CA_file.3,v 1.3 2016/12/07 14:38:43 schwarze Exp $
 .\"	OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100
 .\"
-.\" This file was written by Lutz Jaenicke <jaenicke@openssl.org>.
+.\" This file is a derived work.
+.\" The changes are covered by the following Copyright and license:
+.\"
+.\" Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.\" The original file was written by Lutz Jaenicke <jaenicke@openssl.org>.
 .\" Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
@@ -48,42 +65,69 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 .\" OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: December 4 2016 $
+.Dd $Mdocdate: December 7 2016 $
 .Dt SSL_LOAD_CLIENT_CA_FILE 3
 .Os
 .Sh NAME
-.Nm SSL_load_client_CA_file
-.Nd load certificate names from file
+.Nm SSL_load_client_CA_file ,
+.Nm SSL_add_file_cert_subjects_to_stack ,
+.Nm SSL_add_dir_cert_subjects_to_stack
+.Nd load certificate names from files
 .Sh SYNOPSIS
 .In openssl/ssl.h
 .Ft STACK_OF(X509_NAME) *
 .Fn SSL_load_client_CA_file "const char *file"
+.Ft int
+.Fo SSL_add_file_cert_subjects_to_stack
+.Fa "STACK_OF(X509_NAME) *stack"
+.Fa "const char *file"
+.Fc
+.Ft int
+.Fo SSL_add_dir_cert_subjects_to_stack
+.Fa "STACK_OF(X509_NAME) *stack"
+.Fa "const char *dir"
+.Fc
 .Sh DESCRIPTION
 .Fn SSL_load_client_CA_file
-reads certificates from
+reads PEM formatted certificates from
 .Fa file
-and returns a
-.Dv STACK_OF Ns
-.Pq Vt X509_NAME
+and returns a new
+.Vt STACK_OF(X509_NAME)
 with the subject names found.
-.Pp
-.Fn SSL_load_client_CA_file
-reads a file of PEM formatted certificates and extracts the
-.Vt X509_NAME Ns s
-of the certificates found.
-While the name suggests the specific usage as support function for
+While the name suggests the specific usage as a support function for
 .Xr SSL_CTX_set_client_CA_list 3 ,
 it is not limited to CA certificates.
+.Pp
+.Fn SSL_add_file_cert_subjects_to_stack
+is similar except that the names are added to the existing
+.Fa stack .
+.Pp
+.Fn SSL_add_dir_cert_subjects_to_stack
+calls
+.Fn SSL_add_file_cert_subjects_to_stack
+on every file in the directory
+.Fa dir .
+.Pp
+If a name is already on the stack, all these functions skip it and
+do not add it again.
 .Sh RETURN VALUES
-The following return values can occur:
-.Bl -tag -width Ds
-.It Dv NULL
-The operation failed, check out the error stack for the reason.
-.It Pointer to Dv STACK_OF Ns Po Vt X509_NAME Pc
-Pointer to the subject names of the successfully read certificates.
-.El
+.Fn SSL_load_client_CA_file
+returns a pointer to the new
+.Vt STACK_OF(X509_NAME)
+or
+.Dv NULL on failure.
+.Pp
+.Fn SSL_add_file_cert_subjects_to_stack
+and
+.Fn SSL_add_dir_cert_subjects_to_stack
+return 1 for success or 0 for failure.
+.Pp
+All these functions treat empty files and directories as failures.
+.Pp
+In some cases of failure, the reason can be determined with
+.Xr ERR_get_error 3 .
 .Sh EXAMPLES
-Load names of CAs from file and use it as a client CA list:
+Load names of CAs from a file and use it as a client CA list:
 .Bd -literal
 SSL_CTX *ctx;
 STACK_OF(X509_NAME) *cert_names;
@@ -96,5 +140,39 @@ else
 \&...
 .Ed
 .Sh SEE ALSO
-.Xr ssl 3 ,
-.Xr SSL_CTX_set_client_CA_list 3
+.Xr PEM_read_bio_X509 3 ,
+.Xr SSL_CTX_set_client_CA_list 3 ,
+.Xr X509_get_subject_name 3
+.Sh HISTORY
+.Fn SSL_add_file_cert_subjects_to_stack
+and
+.Fn SSL_add_dir_cert_subjects_to_stack
+first appeared in OpenSSL 0.9.2b.
+.Sh AUTHORS
+.Fn SSL_add_file_cert_subjects_to_stack
+and
+.Fn SSL_add_dir_cert_subjects_to_stack
+were written by
+.An Ben Laurie Aq Mt ben@openssl.org
+in 1999.
+.Sh BUGS
+In some cases of failure, for example for empty files and directories,
+these functions fail to report an error, in the sense that
+.Xr ERR_get_error 3
+does not work.
+.Pp
+Even in case of failure, for example when parsing one of the
+files or certificates fails,
+.Fn SSL_add_file_cert_subjects_to_stack
+and
+.Fn SSL_add_dir_cert_subjects_to_stack
+may still have added some certificates to the stack.
+.Pp
+The behaviour of
+.Fn SSL_add_dir_cert_subjects_to_stack
+is non-deterministic.
+If parsing one file fails, parsing of the whole directory is aborted.
+Files in the directory are not parsed in any specific order.
+For example, adding an empty file to
+.Fa dir
+may or may not cause some of the other files to be ignored.