@@ -85,9 +85,15 @@ server and client mode operations.

      management-external-key

      management-external-key nopadding

      management-external-key pkcs1

+     management-external-key pss

+

+  or any combination like:

+  ::

+

      management-external-key nopadding pkcs1

+     management-external-key pkcs1 pss

-  The optional parameters :code:`nopadding` and :code:`pkcs1` signal

+  The optional parameters :code:`nopadding` :code:`pkcs1` and :code:`pss` signal

   support for different padding algorithms. See

   :code:`doc/mangement-notes.txt` for a complete description of this

   feature.

@@ -907,10 +907,24 @@ can be indicated in the signing request only if the client version is > 2"

 The currently defined padding algorithms are:

- - RSA_PKCS1_PADDING  -  PKCS1 padding and RSA signature

- - RSA_NO_PADDING     -  No padding may be added for the signature

- - ECDSA              -  EC signature.

-

+ - RSA_PKCS1_PADDING            -  PKCS1 padding and RSA signature

+ - RSA_NO_PADDING               -  No padding may be added for the signature

+ - ECDSA                        -  EC signature.

+ - RSA_PKCS1_PSS_PADDING,params -  RSA signature with PSS padding

+

+   The params for PSS are specified as 'hashalg=name,saltlen=[max|digest]'.

+

+   The hashalg names are short common names such as SHA256, SHA224, etc.

+   PSS saltlen="digest" means use the same size as the hash to sign, while

+   "max" indicates maximum possible saltlen which is

+   '(nbits-1)/8 - hlen - 2'. Here 'nbits' is the number of bits in the

+   key modulus and 'hlen' the size in octets of the hash.

+   (See: RFC 8017 sec 8.1.1 and 9.1.1)

+

+   In the case of PKCS1_PADDING, when the hash algorithm is not legacy

+   MD5-SHA1, the hash is encoded with DigestInfo header before presenting

+   to the management interface. This is identical to CKM_RSA_PKCS in Cryptoki

+   as well as what RSA_private_encrypt() in OpenSSL expects.

 COMMAND -- certificate (OpenVPN 2.4 or higher)

 ----------------------------------------------

@@ -339,6 +339,7 @@ struct management *management_init(void);

 #define MF_QUERY_REMOTE             (1<<13)

 #define MF_QUERY_PROXY              (1<<14)

 #define MF_EXTERNAL_CERT            (1<<15)

+#define MF_EXTERNAL_KEY_PSSPAD      (1<<16)

 bool management_open(struct management *man,

                      const char *addr,

@@ -60,6 +60,7 @@

 #include "forward.h"

 #include "ssl_verify.h"

 #include "platform.h"

+#include "xkey_common.h"

 #include <ctype.h>

 #include "memdbg.h"

@@ -2207,14 +2208,14 @@ options_postprocess_verify_ce(const struct options *options,

 #endif /* ifdef ENABLE_MANAGEMENT */

-#if  defined(ENABLE_MANAGEMENT)

+#if defined(ENABLE_MANAGEMENT) && !defined(HAVE_XKEY_PROVIDER)

     if ((tls_version_max() >= TLS_VER_1_3)

         && (options->management_flags & MF_EXTERNAL_KEY)

         && !(options->management_flags & (MF_EXTERNAL_KEY_NOPADDING))

         )

     {

-        msg(M_ERR, "management-external-key with OpenSSL 1.1.1 requires "

-            "the nopadding argument/support");

+        msg(M_FATAL, "management-external-key with TLS 1.3 or later requires "

+            "nopadding argument/support");

     }

 #endif

     /*

@@ -5520,6 +5521,10 @@ add_option(struct options *options,

             {

                 options->management_flags |= MF_EXTERNAL_KEY_PKCS1PAD;

             }

+            else if (streq(p[j], "pss"))

+            {

+                options->management_flags |= MF_EXTERNAL_KEY_PSSPAD;

+            }

             else

             {

                 msg(msglevel, "Unknown management-external-key flag: %s", p[j]);