First Commit

node/Capability.cpp

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+/*
+ * Copyright (c)2019 ZeroTier, Inc.
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file in the project's root directory.
+ *
+ * Change Date: 2026-01-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2.0 of the Apache License.
+ */
+/****/
+
+#include "Capability.hpp"
+#include "RuntimeEnvironment.hpp"
+#include "Identity.hpp"
+#include "Topology.hpp"
+#include "Switch.hpp"
+#include "Network.hpp"
+#include "Node.hpp"
+
+namespace ZeroTier {
+
+int Capability::verify(const RuntimeEnvironment *RR,void *tPtr) const
+{
+	try {
+		// There must be at least one entry, and sanity check for bad chain max length
+		if ((_maxCustodyChainLength < 1)||(_maxCustodyChainLength > ZT_MAX_CAPABILITY_CUSTODY_CHAIN_LENGTH)) {
+			return -1;
+		}
+
+		// Validate all entries in chain of custody
+		Buffer<(sizeof(Capability) * 2)> tmp;
+		this->serialize(tmp,true);
+		for(unsigned int c=0;c<_maxCustodyChainLength;++c) {
+			if (c == 0) {
+				if ((!_custody[c].to)||(!_custody[c].from)||(_custody[c].from != Network::controllerFor(_nwid))) {
+					return -1; // the first entry must be present and from the network's controller
+				}
+			} else {
+				if (!_custody[c].to) {
+					return 0; // all previous entries were valid, so we are valid
+				} else if ((!_custody[c].from)||(_custody[c].from != _custody[c-1].to)) {
+					return -1; // otherwise if we have another entry it must be from the previous holder in the chain
+				}
+			}
+
+			const Identity id(RR->topology->getIdentity(tPtr,_custody[c].from));
+			if (id) {
+				if (!id.verify(tmp.data(),tmp.size(),_custody[c].signature)) {
+					return -1;
+				}
+			} else {
+				RR->sw->requestWhois(tPtr,RR->node->now(),_custody[c].from);
+				return 1;
+			}
+		}
+
+		// We reached max custody chain length and everything was valid
+		return 0;
+	} catch ( ... ) {}
+	return -1;
+}
+
+} // namespace ZeroTier