From df9071c93efff2e648257314198268c7c1d79980 Mon Sep 17 00:00:00 2001
From: Olaf Bergmann <bergmann@tzi.org>
Date: Thu, 21 Oct 2021 09:57:29 +0200
Subject: [PATCH] coap_session.[hc]: Added function to retrieve PSK identity
 from session

The new function coap_session_get_psk_identity() returns the given
session's psk_identity as provided during the handhake (for CoAP server)
or a session setup (for CoAP client).
---
 include/coap3/coap_session.h |  9 +++++++++
 libcoap-3.map                |  1 +
 libcoap-3.sym                |  1 +
 src/coap_session.c           | 12 ++++++++++++
 4 files changed, 23 insertions(+)

diff --git a/include/coap3/coap_session.h b/include/coap3/coap_session.h
index cf250bcfdd..5dc03d4072 100644
--- a/include/coap3/coap_session.h
+++ b/include/coap3/coap_session.h
@@ -287,6 +287,15 @@ coap_session_t *coap_new_client_session_psk2(
 const coap_bin_const_t * coap_session_get_psk_hint(
                                                const coap_session_t *session);
 
+/**
+ * Get the server session's current PSK identity (PSK).
+ *
+ * @param session  The current coap_session_t object.
+ *
+ * @return PSK identity if successful, else @c NULL.
+ */
+const coap_bin_const_t *coap_session_get_psk_identity(
+                                               const coap_session_t *session);
 /**
  * Get the session's current pre-shared key (PSK).
  *
diff --git a/libcoap-3.map b/libcoap-3.map
index 92a37b5f6e..8cbdadf9a7 100644
--- a/libcoap-3.map
+++ b/libcoap-3.map
@@ -188,6 +188,7 @@ global:
   coap_session_get_max_retransmit;
   coap_session_get_proto;
   coap_session_get_psk_hint;
+  coap_session_get_psk_identity;
   coap_session_get_psk_key;
   coap_session_get_state;
   coap_session_get_tls;
diff --git a/libcoap-3.sym b/libcoap-3.sym
index 43adfcb1d2..42eb8c0142 100644
--- a/libcoap-3.sym
+++ b/libcoap-3.sym
@@ -186,6 +186,7 @@ coap_session_get_ifindex
 coap_session_get_max_retransmit
 coap_session_get_proto
 coap_session_get_psk_hint
+coap_session_get_psk_identity
 coap_session_get_psk_key
 coap_session_get_state
 coap_session_get_tls
diff --git a/src/coap_session.c b/src/coap_session.c
index 4b20774f3b..891e3a8d31 100644
--- a/src/coap_session.c
+++ b/src/coap_session.c
@@ -1131,6 +1131,18 @@ coap_session_get_psk_hint(const coap_session_t *session) {
 }
 #endif /* COAP_SERVER_SUPPORT */
 
+const coap_bin_const_t *
+coap_session_get_psk_identity(const coap_session_t *session) {
+  const coap_bin_const_t *psk_identity = NULL;
+  if (session) {
+    psk_identity = session->psk_identity;
+    if (psk_identity == NULL) {
+      psk_identity = &session->cpsk_setup_data.psk_info.identity;
+    }
+  }
+  return psk_identity;
+}
+
 const coap_bin_const_t *
 coap_session_get_psk_key(const coap_session_t *session) {
   if (session)