Rules engine work: capability based security model with tags and capabilities, and some cleanup across other places.

node/Tag.hpp

@@ -0,0 +1,171 @@
+/*
+ * ZeroTier One - Network Virtualization Everywhere
+ * Copyright (C) 2011-2016  ZeroTier, Inc.  https://www.zerotier.com/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef ZT_TAG_HPP
+#define ZT_TAG_HPP
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "Constants.hpp"
+#include "C25519.hpp"
+#include "Address.hpp"
+#include "Identity.hpp"
+#include "Buffer.hpp"
+
+namespace ZeroTier {
+
+class RuntimeEnvironment;
+
+/**
+ * A tag that can be associated with members and matched in rules
+ *
+ * Capabilities group rules, while tags group members subject to those
+ * rules. Tag values can be matched in rules, and tags relevant to a
+ * capability are presented along with it.
+ *
+ * E.g. a capability might be "can speak Samba/CIFS within your
+ * department." This cap might have a rule to allow TCP/137 but
+ * only if a given tag ID's value matches between two peers. The
+ * capability is what members can do, while the tag is who they are.
+ * Different departments might have tags with the same ID but different
+ * values.
+ *
+ * Unlike capabilities tags are signed only by the issuer and are never
+ * transferrable.
+ */
+class Tag
+{
+public:
+	Tag()
+	{
+		memset(this,0,sizeof(Tag));
+	}
+
+	/**
+	 * @param nwid Network ID
+	 * @param expiration Tag expiration relative to network config timestamp
+	 * @param issuedTo Address to which this tag was issued
+	 * @param id Tag ID
+	 * @param value Tag value
+	 */
+	Tag(const uint64_t nwid,const uint64_t expiration,const Address &issuedTo,const uint32_t id,const uint32_t value) :
+		_nwid(nwid),
+		_expiration(expiration),
+		_id(id),
+		_value(value),
+		_issuedTo(issuedTo),
+		_signedBy()
+	{
+	}
+
+
+	inline uint64_t networkId() const { return _nwid; }
+	inline uint64_t expiration() const { return _expiration; }
+	inline uint32_t id() const { return _id; }
+	inline uint32_t value() const { return _value; }
+	inline const Address &issuedTo() const { return _issuedTo; }
+	inline const Address &signedBy() const { return _signedBy; }
+
+	/**
+	 * Sign this tag
+	 *
+	 * @param signer Signing identity, must have private key
+	 * @return True if signature was successful
+	 */
+	inline bool sign(const Identity &signer)
+	{
+		try {
+			Buffer<(sizeof(Tag) * 2)> tmp;
+			_signedBy = signer.address();
+			this->serialize(tmp,true);
+			_signature = signer.sign(tmp.data(),tmp.size());
+			return true;
+		} catch ( ... ) {}
+		return false;
+	}
+
+	/**
+	 * Check this tag's signature
+	 *
+	 * @param RR Runtime environment to allow identity lookup for signedBy
+	 * @return True if signature is present and valid
+	 */
+	bool verify(const RuntimeEnvironment *RR);
+
+	template<unsigned int C>
+	inline void serialize(Buffer<C> &b,const bool forSign = false) const
+	{
+		if (forSign) b.append((uint64_t)0x7f7f7f7f7f7f7f7fULL);
+
+		b.append(_nwid);
+		b.append(_expiration);
+		b.append(_id);
+		b.append(_value);
+		_issuedTo.appendTo(b);
+		_signedBy.appendTo(b);
+		if (!forSign) {
+			b.append((uint8_t)1); // 1 == Ed25519
+			b.append((uint16_t)ZT_C25519_SIGNATURE_LEN); // length of signature
+			b.append(_signature.data,ZT_C25519_SIGNATURE_LEN);
+		}
+		b.append((uint16_t)0); // length of additional fields, currently 0
+
+		if (forSign) b.append((uint64_t)0x7f7f7f7f7f7f7f7fULL);
+	}
+
+	template<unsigned int C>
+	inline unsigned int deserialize(const Buffer<C> &b,unsigned int startAt = 0)
+	{
+		unsigned int p = startAt;
+
+		_nwid = b.template at<uint64_t>(p); p += 8;
+		_expiration = b.template at<uint64_t>(p); p += 8;
+		_id = b.template at<uint32_t>(p); p += 4;
+		_value = b.template at<uint32_t>(p); p += 4;
+		_issuedTo.setTo(b.field(p,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); p += ZT_ADDRESS_LENGTH;
+		_signedBy.setTo(b.field(p,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); p += ZT_ADDRESS_LENGTH;
+		if (b[p++] != 1)
+			throw std::runtime_error("unrecognized signature type");
+		if (b.template at<uint16_t>(p) != ZT_C25519_SIGNATURE_LEN)
+			throw std::runtime_error("invalid signature length");
+		p += 2;
+		memcpy(_signature.data,b.field(p,ZT_C25519_SIGNATURE_LEN),ZT_C25519_SIGNATURE_LEN); p += ZT_C25519_SIGNATURE_LEN;
+
+		p += 2 + b.template at<uint16_t>(p);
+		if (p > b.size())
+			throw std::runtime_error("extended field overflow");
+
+		return (p - startAt);
+	}
+
+private:
+	uint64_t _nwid;
+	uint64_t _expiration;
+	uint32_t _id;
+	uint32_t _value;
+	Address _issuedTo;
+	Address _signedBy;
+	C25519::Signature _signature;
+};
+
+} // namespace ZeroTier
+
+#endif