From 7fb72ccf7bf3ca2ff3979b7ffbb690eed41ddb5f Mon Sep 17 00:00:00 2001
From: Frank Morgner <frankmorgner@gmail.com>
Date: Fri, 14 Jun 2019 07:54:39 +0200
Subject: [PATCH] pkcs11: fixed slotIDs when a new slot list is requested

fixes https://github.com/OpenSC/OpenSC/issues/1706

regression of 24b7507a69704f69e371834953cf78cffec104b0
---
 src/pkcs11/pkcs11-global.c | 22 +++++++++++++++++++++-
 src/pkcs11/slot.c          |  2 +-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/pkcs11/pkcs11-global.c b/src/pkcs11/pkcs11-global.c
index c3cf2591..d8c0df5f 100644
--- a/src/pkcs11/pkcs11-global.c
+++ b/src/pkcs11/pkcs11-global.c
@@ -451,8 +451,13 @@ CK_RV C_GetSlotList(CK_BBOOL       tokenPresent,  /* only slots with token prese
 			pSlotList==NULL_PTR? "plug-n-play":"refresh");
 
 	/* Slot list can only change in v2.20 */
-	if (pSlotList == NULL_PTR)
+	if (pSlotList == NULL_PTR) {
 		sc_ctx_detect_readers(context);
+		for (i=0; i<list_size(&virtual_slots); i++) {
+			slot = (sc_pkcs11_slot_t *) list_get_at(&virtual_slots, i);
+			slot->flags &= ~SC_PKCS11_SLOT_FLAG_SEEN;
+		}
+	}
 
 	card_detect_all();
 
@@ -483,6 +488,21 @@ CK_RV C_GetSlotList(CK_BBOOL       tokenPresent,  /* only slots with token prese
 		prev_reader = slot->reader;
 	}
 
+	/* Slot list can only change in v2.20 */
+	if (pSlotList == NULL_PTR) {
+		/* slot->id is derived from its location in the list virtual_slots.
+		 * When the slot list changes, so does slot->id, so we reindex the
+		 * slots here the same way it is done in `create_slot()`
+		 *
+		 * TODO use a persistent CK_SLOT_ID, e.g. by using something like
+		 * `slot->id = sc_crc32(slot, sizeof *slot);` (this example, however,
+		 * is currently not thread safe).  */
+		for (i=0; i<list_size(&virtual_slots); i++) {
+			slot = (sc_pkcs11_slot_t *) list_get_at(&virtual_slots, i);
+			slot->id = (CK_SLOT_ID) list_locate(&virtual_slots, slot);
+		}
+	}
+
 	if (pSlotList == NULL_PTR) {
 		sc_log(context, "was only a size inquiry (%lu)\n", numMatches);
 		*pulCount = numMatches;
diff --git a/src/pkcs11/slot.c b/src/pkcs11/slot.c
index 44b041ee..c74f2c0a 100644
--- a/src/pkcs11/slot.c
+++ b/src/pkcs11/slot.c
@@ -115,7 +115,6 @@ CK_RV create_slot(sc_reader_t *reader)
 	}
 
 	slot->login_user = -1;
-	slot->id = (CK_SLOT_ID) list_locate(&virtual_slots, slot);
 	init_slot_info(&slot->slot_info, reader);
 	sc_log(context, "Initializing slot with id 0x%lx", slot->id);
 
@@ -126,6 +125,7 @@ CK_RV create_slot(sc_reader_t *reader)
 		slot->slot_info.hardwareVersion.major = reader->version_major;
 		slot->slot_info.hardwareVersion.minor = reader->version_minor;
 	}
+	slot->id = (CK_SLOT_ID) list_locate(&virtual_slots, slot);
 
 	return CKR_OK;
 }