From: Krzysztof Jackiewicz <k.jackiewicz@samsung.com>
Date: Wed, 12 Jul 2023 06:58:38 +0000 (+0200)
Subject: Reserve enough space for GCM tag in TZ backend
X-Git-Tag: accepted/tizen/6.0/unified/20230717.162449~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fchanges%2F78%2F295878%2F1;p=platform%2Fcore%2Fsecurity%2Fkey-manager.git

Reserve enough space for GCM tag in TZ backend

Change-Id: I36f9718cfdc37f7fdac1e47fc056aeaabdeee242
---

diff --git a/src/manager/crypto/tz-backend/tz-context.cpp b/src/manager/crypto/tz-backend/tz-context.cpp
index 1359258..3cf5702 100644
--- a/src/manager/crypto/tz-backend/tz-context.cpp
+++ b/src/manager/crypto/tz-backend/tz-context.cpp
@@ -50,6 +50,9 @@ namespace {
 // whatever TA will return us.
 const uint32_t CIPHER_EXTRA_PADDING_SIZE = 16;
 
+// Maximum size of GCM tag in bytes.
+const size_t MAX_GCM_TAG_SIZE = 16;
+
 // Identifier of our TA
 const TEEC_UUID KEY_MANAGER_TA_UUID = KM_TA_UUID;
 
@@ -547,7 +550,7 @@ RawBuffer TrustZoneContext::finalizeGcmCipher(uint32_t opId,
 	sIn.Serialize(inMemory);
 
 	TZSerializer sOut;
-	sOut.Push(new TZSerializableBinary(data.size()));
+	sOut.Push(new TZSerializableBinary(MAX_GCM_TAG_SIZE, false));
 	TrustZoneMemory outMemory(m_Context, sOut.GetSize(), TEEC_MEM_OUTPUT);
 
 	TEEC_Operation op = makeOp(TEEC_VALUE_INOUT, inMemory, outMemory);