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Fix wrong information with respect to CAs listed to the client
(follows from technical discussion with Amit Chopra <amitc@pspl.co.in>).

Lutz Jänicke 23 years ago
parent
commit
638b0d4277
2 changed files with 21 additions and 17 deletions
  1. 7 7
      doc/ssl/SSL_CTX_load_verify_locations.pod
  2. 14 10
      doc/ssl/SSL_CTX_set_client_CA_list.pod

+ 7 - 7
doc/ssl/SSL_CTX_load_verify_locations.pod

@@ -33,10 +33,6 @@ which can be used e.g. for descriptions of the certificates.
 The B<CAfile> is processed on execution of the SSL_CTX_load_verify_locations()
 function.
 
-If on an TLS/SSL server no special setting is performed using *client_CA_list()
-functions, the certificates contained in B<CAfile> are listed to the client
-as available CAs during the TLS/SSL handshake.
-
 If B<CApath> is not NULL, it points to a directory containing CA certificates
 in PEM format. The files each contain one CA certificate. The files are
 looked up by the CA subject name hash value, which must hence be available.
@@ -50,9 +46,6 @@ The certificates in B<CApath> are only looked up when required, e.g. when
 building the certificate chain or when actually performing the verification
 of a peer certificate.
 
-On a server, the certificates in B<CApath> are not listed as available
-CA certificates to a client during a TLS/SSL handshake.
-
 When looking up CA certificates, the OpenSSL library will first search the
 certificates in B<CAfile>, then those in B<CApath>. Certificate matching
 is done based on the subject name, the key identifier (if present), and the
@@ -62,6 +55,13 @@ matching the parameters is found, the verification process will be performed;
 no other certificates for the same parameters will be searched in case of
 failure.
 
+In server mode, when requesting a client certificate, the server must send
+the list of CAs of which it will accept client certificates. This list
+is not influenced by the contents of B<CAfile> or B<CApath> and must
+explicitely be set using the
+L<SSL_CTX_set_client_CA_list(3)|SSL_CTX_set_client_CA_list(3)>
+family of functions.
+
 When building its own certificate chain, an OpenSSL client/server will
 try to fill in missing certificates from B<CAfile>/B<CApath>, if the
 certificate chain was not explicitly specified (see

+ 14 - 10
doc/ssl/SSL_CTX_set_client_CA_list.pod

@@ -36,25 +36,23 @@ the chosen B<ssl>, overriding the setting valid for B<ssl>'s SSL_CTX object.
 
 When a TLS/SSL server requests a client certificate (see
 B<SSL_CTX_set_verify_options()>), it sends a list of CAs, for which
-it will accept certificates, to the client. If no special list is provided,
-the CAs available using the B<CAfile> option in
-L<SSL_CTX_load_verify_locations(3)|SSL_CTX_load_verify_locations(3)>
-are sent.
+it will accept certificates, to the client.
 
-This list can be explicitly set using the SSL_CTX_set_client_CA_list() for
+This list must explicitly be set using SSL_CTX_set_client_CA_list() for
 B<ctx> and SSL_set_client_CA_list() for the specific B<ssl>. The list
 specified overrides the previous setting. The CAs listed do not become
 trusted (B<list> only contains the names, not the complete certificates); use
 L<SSL_CTX_load_verify_locations(3)|SSL_CTX_load_verify_locations(3)> 
 to additionally load them for verification.
 
+If the list of acceptable CAs is compiled in a file, the
+L<SSL_load_client_CA_file(3)|SSL_load_client_CA_file(3)>
+function can be used to help importing the necessary data.
+
 SSL_CTX_add_client_CA() and SSL_add_client_CA() can be used to add additional
 items the list of client CAs. If no list was specified before using
 SSL_CTX_set_client_CA_list() or SSL_set_client_CA_list(), a new client
-CA list for B<ctx> or B<ssl> (as appropriate) is opened. The CAs implicitly
-specified using
-L<SSL_CTX_load_verify_locations(3)|SSL_CTX_load_verify_locations(3)>
-are no longer used automatically.
+CA list for B<ctx> or B<ssl> (as appropriate) is opened.
 
 These functions are only useful for TLS/SSL servers.
 
@@ -80,11 +78,17 @@ to find out the reason.
 
 =back
 
+=head1 EXAMPLES
+
+Scan all certificates in B<CAfile> and list them as acceptable CAs:
+
+  SSL_CTX_set_client_CA_list(ctx,SSL_load_client_CA_file(CAfile));
+
 =head1 SEE ALSO
 
 L<ssl(3)|ssl(3)>,
 L<SSL_get_client_CA_list(3)|SSL_get_client_CA_list(3)>,
-L<SSL_load_client_CA_file(3)|SSL_load_client_CA_file(3)>
+L<SSL_load_client_CA_file(3)|SSL_load_client_CA_file(3)>,
 L<SSL_CTX_load_verify_locations(3)|SSL_CTX_load_verify_locations(3)>
 
 =cut