From 6b1eeb4004156f41fafd4a6bc87e61ec193dff8b Mon Sep 17 00:00:00 2001
From: Pol Henarejos <pol.henarejos@cttc.es>
Date: Thu, 12 Oct 2023 17:42:31 +0200
Subject: [PATCH] Fix DKEK import when no logged.

DKEK shall accept import even if it is not logged in. However, to store the DKEK, the PIN is used for MKEK, which is not available if it is nog logged in. I added a queueing system to store a pending DKEK after login.

Therefore, to import a DKEK, the user must import it AND call VERIFY command if it is not already logged in.

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
---
 src/hsm/cmd_key_domain.c | 14 ++++++++++----
 src/hsm/kek.c            |  1 +
 src/hsm/kek.h            |  2 ++
 src/hsm/sc_hsm.c         |  4 ++++
 4 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/hsm/cmd_key_domain.c b/src/hsm/cmd_key_domain.c
index 06b329c..aeecb31 100644
--- a/src/hsm/cmd_key_domain.c
+++ b/src/hsm/cmd_key_domain.c
@@ -68,10 +68,16 @@ int cmd_key_domain() {
             }
             import_dkek_share(p2, apdu.data);
             if (++current_dkeks >= dkeks) {
-                if (save_dkek_key(p2, NULL) != CCID_OK) {
-                    /* On fail, it will return to previous dkek state. */
-                    import_dkek_share(p2, apdu.data);
-                    return SW_FILE_NOT_FOUND();
+                int r = save_dkek_key(p2, NULL);
+                if (r != CCID_OK) {
+                    if (r == CCID_NO_LOGIN) {
+                        pending_save_dkek = p2;
+                    }
+                    else {
+                        /* On fail, it will return to previous dkek state. */
+                        import_dkek_share(p2, apdu.data);
+                        return SW_FILE_NOT_FOUND();
+                    }
                 }
             }
             uint8_t t[MAX_KEY_DOMAINS * 2];
diff --git a/src/hsm/kek.c b/src/hsm/kek.c
index 8b797ed..54cb5c3 100644
--- a/src/hsm/kek.c
+++ b/src/hsm/kek.c
@@ -36,6 +36,7 @@ extern bool has_session_pin, has_session_sopin;
 extern uint8_t session_pin[32], session_sopin[32];
 uint8_t mkek_mask[MKEK_KEY_SIZE];
 bool has_mkek_mask = false;
+uint8_t pending_save_dkek = 0xff;
 
 #define POLY 0xedb88320
 
diff --git a/src/hsm/kek.h b/src/hsm/kek.h
index e6b5ade..5c85c2f 100644
--- a/src/hsm/kek.h
+++ b/src/hsm/kek.h
@@ -74,4 +74,6 @@ extern mse_t mse;
 
 extern int mse_decrypt_ct(uint8_t *, size_t);
 
+extern uint8_t pending_save_dkek;
+
 #endif
diff --git a/src/hsm/sc_hsm.c b/src/hsm/sc_hsm.c
index a7bfcf2..2fd0fd6 100644
--- a/src/hsm/sc_hsm.c
+++ b/src/hsm/sc_hsm.c
@@ -407,6 +407,10 @@ int check_pin(const file_t *pin, const uint8_t *data, size_t len) {
         hash_multi(data, len, session_sopin);
         has_session_sopin = true;
     }
+    if (pending_save_dkek != 0xff) {
+        save_dkek_key(pending_save_dkek, NULL);
+        pending_save_dkek = 0xff;
+    }
     return SW_OK();
 }