Fix ENCAP_CAP checks to accommodate SPDM 1.2

Fix #2959.

Signed-off-by: Steven Bellock <[email protected]>

Author: steven-bellock

library/spdm_requester_lib/libspdm_req_key_exchange.c

@@ -1,6 +1,6 @@
 /**
  *  Copyright Notice:
- *  Copyright 2021-2024 DMTF. All rights reserved.
+ *  Copyright 2021-2025 DMTF. All rights reserved.
  *  License: BSD 3-Clause License. For full text see link: https://github.com/DMTF/libspdm/blob/main/LICENSE.md
  **/
 
@@ -538,10 +538,6 @@ static libspdm_return_t libspdm_try_send_receive_key_exchange(
             spdm_context, true,
             SPDM_GET_CAPABILITIES_REQUEST_FLAGS_MUT_AUTH_CAP,
             SPDM_GET_CAPABILITIES_RESPONSE_FLAGS_MUT_AUTH_CAP);
-        const bool encap_cap_both = libspdm_is_capabilities_flag_supported(
-            spdm_context, true,
-            SPDM_GET_CAPABILITIES_REQUEST_FLAGS_ENCAP_CAP,
-            SPDM_GET_CAPABILITIES_RESPONSE_FLAGS_ENCAP_CAP);
         const bool cert_cap = libspdm_is_capabilities_flag_supported(
             spdm_context, true,
             SPDM_GET_CAPABILITIES_REQUEST_FLAGS_CERT_CAP,
@@ -600,8 +596,8 @@ static libspdm_return_t libspdm_try_send_receive_key_exchange(
                 status = LIBSPDM_STATUS_INVALID_MSG_FIELD;
                 goto receive_done;
             }
-            /* Encapsulated flow requires ENCAP_CAP for both endpoints. */
-            if (!encap_cap_both) {
+            /* Encapsulated flow requires support for encapsulated messages by both endpoints. */
+            if (!libspdm_is_encap_supported(spdm_context)) {
                 libspdm_secured_message_dhe_free(
                     spdm_context->connection_info.algorithm.dhe_named_group, dhe_context);
                 status = LIBSPDM_STATUS_INVALID_MSG_FIELD;

library/spdm_responder_lib/libspdm_rsp_encap_response.c

@@ -1,6 +1,6 @@
 /**
  *  Copyright Notice:
- *  Copyright 2021-2024 DMTF. All rights reserved.
+ *  Copyright 2021-2025 DMTF. All rights reserved.
  *  License: BSD 3-Clause License. For full text see link: https://github.com/DMTF/libspdm/blob/main/LICENSE.md
  **/
 
@@ -297,10 +297,7 @@ libspdm_return_t libspdm_get_response_encapsulated_response_ack(
                                                response_size, response);
     }
 
-    if (!libspdm_is_capabilities_flag_supported(
-            spdm_context, false,
-            SPDM_GET_CAPABILITIES_REQUEST_FLAGS_ENCAP_CAP,
-            SPDM_GET_CAPABILITIES_RESPONSE_FLAGS_ENCAP_CAP)) {
+    if (!libspdm_is_encap_supported(spdm_context)) {
         return libspdm_generate_error_response(
             spdm_context, SPDM_ERROR_CODE_UNSUPPORTED_REQUEST,
             SPDM_DELIVER_ENCAPSULATED_RESPONSE, response_size, response);