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

1 files changed, 389 insertions, 0 deletions

diff --git a/node/Capability.hpp b/node/Capability.hpp
new file mode 100644
index 00000000..6de4e0a1
--- /dev/null
+++ b/node/Capability.hpp
@@ -0,0 +1,389 @@
+/*
+ * 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_CAPABILITY_HPP
+#define ZT_CAPABILITY_HPP
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "Constants.hpp"
+#include "Address.hpp"
+#include "C25519.hpp"
+#include "Utils.hpp"
+#include "Buffer.hpp"
+#include "Identity.hpp"
+#include "../include/ZeroTierOne.h"
+
+namespace ZeroTier {
+
+class RuntimeEnvironment;
+
+/**
+ * A set of grouped and signed network flow rules
+ *
+ * The use of capabilities implements capability-based security on ZeroTIer
+ * virtual networks for efficient and manageable network micro-segmentation.
+ *
+ * On the sending side the sender does the following for each packet:
+ *
+ * (1) Evaluates its capabilities in ascending order of ID to determine
+ *     which capability allows it to transmit this packet.
+ * (2) If it has not done so lately, it then sends this capability to the
+ *     receving peer ("presents" it).
+ * (3) The sender then sends the packet.
+ *
+ * On the receiving side the receiver does the following for each packet:
+ *
+ * (1) Evaluates the capabilities of the sender (that the sender has
+ *     presented) to determine if the sender was allowed to send this.
+ * (2) Evaluates its own capabilities to determine if it should receive
+ *     and process this packet.
+ * (3) If both check out, it receives the packet.
+ *
+ * Note that rules in capabilities can do other things as well such as TEE
+ * or REDIRECT packets. See Filter and ZT_VirtualNetworkRule.
+ */
+class Capability
+{
+public:
+	Capability()
+	{
+		memset(this,0,sizeof(Capability));
+	}
+
+	/**
+	 * @param id Capability ID
+	 * @param nwid Network ID
+	 * @param expiration Expiration relative to network config timestamp
+	 * @param name Capability short name (max strlen == ZT_MAX_CAPABILITY_NAME_LENGTH, overflow ignored)
+	 * @param mccl Maximum custody chain length (1 to create non-transferrable capability)
+	 * @param rules Network flow rules for this capability
+	 * @param ruleCount Number of flow rules
+	 */
+	Capability(uint32_t id,uint64_t nwid,uint64_t expiration,const char *name,unsigned int mccl,const ZT_VirtualNetworkRule *rules,unsigned int ruleCount)
+	{
+		memset(this,0,sizeof(Capability));
+		_nwid = nwid;
+		_expiration = expiration;
+		_id = id;
+		_maxCustodyChainLength = (mccl > 0) ? ((mccl < ZT_MAX_CAPABILITY_CUSTODY_CHAIN_LENGTH) ? mccl : (unsigned int)ZT_MAX_CAPABILITY_CUSTODY_CHAIN_LENGTH) : 1;
+		_ruleCount = (ruleCount < ZT_MAX_CAPABILITY_RULES) ? ruleCount : ZT_MAX_CAPABILITY_RULES;
+		if (_ruleCount)
+			memcpy(_rules,rules,sizeof(ZT_VirtualNetworkRule) * _ruleCount);
+	}
+
+	/**
+	 * @return Rules -- see ruleCount() for size of array
+	 */
+	inline const ZT_VirtualNetworkRule *rules() const { return _rules; }
+
+	/**
+	 * @return Number of rules in rules()
+	 */
+	inline unsigned int ruleCount() const { return _ruleCount; }
+
+	/**
+	 * @return ID and evaluation order of this capability in network
+	 */
+	inline uint32_t id() const { return _id; }
+
+	/**
+	 * @return Network ID for which this capability was issued
+	 */
+	inline uint64_t networkId() const { return _nwid; }
+
+	/**
+	 * Sign this capability and add signature to its chain of custody
+	 *
+	 * If this returns false, this object should be considered to be
+	 * in an undefined state and should be discarded. False can be returned
+	 * if there is no more room for signatures (max chain length reached)
+	 * or if the 'from' identity does not include a secret key to allow
+	 * it to sign anything.
+	 *
+	 * @param from Signing identity (must have secret)
+	 * @param to Recipient of this signature
+	 * @return True if signature successful and chain of custody appended
+	 */
+	inline bool sign(const Identity &from,const Address &to)
+	{
+		try {
+			Buffer<(sizeof(Capability) * 2)> tmp;
+			for(unsigned int i=0;((i<_maxCustodyChainLength)&&(i<ZT_MAX_CAPABILITY_CUSTODY_CHAIN_LENGTH));++i) {
+				if (!(_custody[i].to)) {
+					_custody[i].to = to;
+					_custody[i].from = from.address();
+					this->serialize(tmp,true);
+					_custody[i].signature = from.sign(tmp.data(),tmp.size());
+					return true;
+				}
+			}
+		} catch ( ... ) {}
+		return false;
+	}
+
+	/**
+	 * Verify this capability's chain of custody
+	 *
+	 * This returns a tri-state result. A return value of zero indicates that
+	 * the chain of custody is valid and all signatures are okay. A positive
+	 * return value means at least one WHOIS was issued for a missing signing
+	 * identity and we should retry later. A negative return value means that
+	 * this chain or one of its signature is BAD and this capability should
+	 * be discarded.
+	 *
+	 * Note that the entire chain is checked regardless of verifyInChain.
+	 *
+	 * @param RR Runtime environment to provide for peer lookup, etc.
+	 * @param verifyInChain Also check to ensure that this capability was at some point properly issued to this peer (if non-null)
+	 * @return 0 == OK, 1 == waiting for WHOIS, -1 == BAD signature or chain
+	 */
+	int verify(const RuntimeEnvironment *RR,const Address &verifyInChain) const;
+
+	template<unsigned int C>
+	inline void serialize(Buffer<C> &b,const bool forSign = false) const
+	{
+		if (forSign) b.append((uint64_t)0x7f7f7f7f7f7f7f7fULL);
+
+		b.append(_id);
+		b.append(_nwid);
+		b.append(_expiration);
+
+		b.append((uint16_t)_ruleCount);
+		for(unsigned int i=0;i<_ruleCount;++i) {
+			// Each rule consists of its 8-bit type followed by the size of that type's
+			// field followed by field data. The inclusion of the size will allow non-supported
+			// rules to be ignored but still parsed.
+			b.append((uint8_t)_rules[i].t);
+			switch((ZT_VirtualNetworkRuleType)(_rules[i].t & 0x7f)) {
+				//case ZT_NETWORK_RULE_ACTION_DROP:
+				//case ZT_NETWORK_RULE_ACTION_ACCEPT:
+				default:
+					b.append((uint8_t)0);
+					break;
+				case ZT_NETWORK_RULE_ACTION_TEE:
+				case ZT_NETWORK_RULE_ACTION_REDIRECT:
+				case ZT_NETWORK_RULE_MATCH_SOURCE_ZEROTIER_ADDRESS:
+				case ZT_NETWORK_RULE_MATCH_DEST_ZEROTIER_ADDRESS:
+					b.append((uint8_t)5);
+					Address(_rules[i].v.zt).appendTo(b);
+					break;
+				case ZT_NETWORK_RULE_MATCH_VLAN_ID:
+					b.append((uint8_t)2);
+					b.append((uint16_t)_rules[i].v.vlanId);
+					break;
+				case ZT_NETWORK_RULE_MATCH_VLAN_PCP:
+					b.append((uint8_t)1);
+					b.append((uint8_t)_rules[i].v.vlanPcp);
+					break;
+				case ZT_NETWORK_RULE_MATCH_VLAN_DEI:
+					b.append((uint8_t)1);
+					b.append((uint8_t)_rules[i].v.vlanDei);
+					break;
+				case ZT_NETWORK_RULE_MATCH_ETHERTYPE:
+					b.append((uint8_t)2);
+					b.append((uint16_t)_rules[i].v.etherType);
+					break;
+				case ZT_NETWORK_RULE_MATCH_MAC_SOURCE:
+				case ZT_NETWORK_RULE_MATCH_MAC_DEST:
+					b.append((uint8_t)6);
+					b.append(_rules[i].v.mac,6);
+					break;
+				case ZT_NETWORK_RULE_MATCH_IPV4_SOURCE:
+				case ZT_NETWORK_RULE_MATCH_IPV4_DEST:
+					b.append((uint8_t)5);
+					b.append(&(_rules[i].v.ipv4.ip),4);
+					b.append((uint8_t)_rules[i].v.ipv4.mask);
+					break;
+				case ZT_NETWORK_RULE_MATCH_IPV6_SOURCE:
+				case ZT_NETWORK_RULE_MATCH_IPV6_DEST:
+					b.append((uint8_t)17);
+					b.append(_rules[i].v.ipv6.ip,16);
+					b.append((uint8_t)_rules[i].v.ipv6.mask);
+					break;
+				case ZT_NETWORK_RULE_MATCH_IP_TOS:
+					b.append((uint8_t)1);
+					b.append((uint8_t)_rules[i].v.ipTos);
+					break;
+				case ZT_NETWORK_RULE_MATCH_IP_PROTOCOL:
+					b.append((uint8_t)1);
+					b.append((uint8_t)_rules[i].v.ipProtocol);
+					break;
+				case ZT_NETWORK_RULE_MATCH_IP_SOURCE_PORT_RANGE:
+				case ZT_NETWORK_RULE_MATCH_IP_DEST_PORT_RANGE:
+					b.append((uint8_t)4);
+					b.append((uint16_t)_rules[i].v.port[0]);
+					b.append((uint16_t)_rules[i].v.port[1]);
+					break;
+				case ZT_NETWORK_RULE_MATCH_CHARACTERISTICS:
+					b.append((uint8_t)16);
+					b.append((uint64_t)_rules[i].v.characteristics[0]);
+					b.append((uint64_t)_rules[i].v.characteristics[1]);
+					break;
+				case ZT_NETWORK_RULE_MATCH_FRAME_SIZE_RANGE:
+					b.append((uint8_t)4);
+					b.append((uint16_t)_rules[i].v.frameSize[0]);
+					b.append((uint16_t)_rules[i].v.frameSize[1]);
+					break;
+			}
+		}
+
+		b.append((uint8_t)_maxCustodyChainLength);
+		for(unsigned int i=0;;++i) {
+			if ((i < _maxCustodyChainLength)&&(i < ZT_MAX_CAPABILITY_CUSTODY_CHAIN_LENGTH)&&(_custody[i].to)) {
+				_custody[i].to.appendTo(b);
+				_custody[i].from.appendTo(b);
+				if (!forSign) {
+					b.append((uint8_t)1); // 1 == Ed25519 signature
+					b.append((uint16_t)ZT_C25519_SIGNATURE_LEN); // length of signature
+					b.append(_custody[i].signature.data,ZT_C25519_SIGNATURE_LEN);
+				}
+			} else {
+				b.append((unsigned char)0,ZT_ADDRESS_LENGTH); // zero 'to' terminates chain
+				break;
+			}
+		}
+
+		// This is the size of any additional fields. If it is nonzero,
+		// the last 2 bytes of the next field will be another size field.
+		b.append((uint16_t)0);
+
+		if (forSign) b.append((uint64_t)0x7f7f7f7f7f7f7f7fULL);
+	}
+
+	template<unsigned int C>
+	inline unsigned int deserialize(const Buffer<C> &b,unsigned int startAt = 0)
+	{
+		memset(this,0,sizeof(Capability));
+
+		unsigned int p = startAt;
+
+		_id = b.template at<uint32_t>(p); p += 4;
+		_nwid = b.template at<uint64_t>(p); p += 8;
+		_expiration = b.template at<uint64_t>(p); p += 8;
+
+		_ruleCount = b.template at<uint16_t>(p); p += 2;
+		if (_ruleCount > ZT_MAX_CAPABILITY_RULES)
+			throw std::runtime_error("rule count overflow");
+		for(unsigned int i=0;i<_ruleCount;++i) {
+			_rules[i].t = (uint8_t)b[p++];
+			const unsigned int fieldLen = (unsigned int)b[p++];
+			switch((ZT_VirtualNetworkRuleType)(_rules[i].t & 0x7f)) {
+				default:
+					break;
+				case ZT_NETWORK_RULE_ACTION_TEE:
+				case ZT_NETWORK_RULE_ACTION_REDIRECT:
+				case ZT_NETWORK_RULE_MATCH_SOURCE_ZEROTIER_ADDRESS:
+				case ZT_NETWORK_RULE_MATCH_DEST_ZEROTIER_ADDRESS:
+					_rules[i].v.zt = Address(b.field(p,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH).toInt();
+					break;
+				case ZT_NETWORK_RULE_MATCH_VLAN_ID:
+					_rules[i].v.vlanId = b.template at<uint16_t>(p);
+					break;
+				case ZT_NETWORK_RULE_MATCH_VLAN_PCP:
+					_rules[i].v.vlanPcp = (uint8_t)b[p];
+					break;
+				case ZT_NETWORK_RULE_MATCH_VLAN_DEI:
+					_rules[i].v.vlanDei = (uint8_t)b[p];
+					break;
+				case ZT_NETWORK_RULE_MATCH_ETHERTYPE:
+					_rules[i].v.etherType = b.template at<uint16_t>(p);
+					break;
+				case ZT_NETWORK_RULE_MATCH_MAC_SOURCE:
+				case ZT_NETWORK_RULE_MATCH_MAC_DEST:
+					memcpy(_rules[i].v.mac,b.field(p,6),6);
+					break;
+				case ZT_NETWORK_RULE_MATCH_IPV4_SOURCE:
+				case ZT_NETWORK_RULE_MATCH_IPV4_DEST:
+					memcpy(&(_rules[i].v.ipv4.ip),b.field(p,4),4);
+					_rules[i].v.ipv4.mask = (uint8_t)b[p + 4];
+					break;
+				case ZT_NETWORK_RULE_MATCH_IPV6_SOURCE:
+				case ZT_NETWORK_RULE_MATCH_IPV6_DEST:
+					memcpy(_rules[i].v.ipv6.ip,b.field(p,16),16);
+					_rules[i].v.ipv6.mask = (uint8_t)b[p + 16];
+					break;
+				case ZT_NETWORK_RULE_MATCH_IP_TOS:
+					_rules[i].v.ipTos = (uint8_t)b[p];
+					break;
+				case ZT_NETWORK_RULE_MATCH_IP_PROTOCOL:
+					_rules[i].v.ipProtocol = (uint8_t)b[p];
+					break;
+				case ZT_NETWORK_RULE_MATCH_IP_SOURCE_PORT_RANGE:
+				case ZT_NETWORK_RULE_MATCH_IP_DEST_PORT_RANGE:
+					_rules[i].v.port[0] = b.template at<uint16_t>(p);
+					_rules[i].v.port[1] = b.template at<uint16_t>(p + 2);
+					break;
+				case ZT_NETWORK_RULE_MATCH_CHARACTERISTICS:
+					_rules[i].v.characteristics[0] = b.template at<uint64_t>(p);
+					_rules[i].v.characteristics[1] = b.template at<uint64_t>(p + 8);
+					break;
+				case ZT_NETWORK_RULE_MATCH_FRAME_SIZE_RANGE:
+					_rules[i].v.frameSize[0] = b.template at<uint16_t>(p);
+					_rules[i].v.frameSize[0] = b.template at<uint16_t>(p + 2);
+					break;
+			}
+			p += fieldLen;
+		}
+
+		_maxCustodyChainLength = (unsigned int)b[p++];
+		if ((_maxCustodyChainLength < 1)||(_maxCustodyChainLength > ZT_MAX_CAPABILITY_CUSTODY_CHAIN_LENGTH))
+			throw std::runtime_error("invalid max custody chain length");
+		for(unsigned int i;;++i) {
+			const Address to(b.field(p,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); p += ZT_ADDRESS_LENGTH;
+			if (!to)
+				break;
+			if ((i >= _maxCustodyChainLength)||(i >= ZT_MAX_CAPABILITY_CUSTODY_CHAIN_LENGTH))
+				throw std::runtime_error("unterminated custody chain");
+			_custody[i].to = to;
+			_custody[i].from.setTo(b.field(p,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); p += ZT_ADDRESS_LENGTH;
+			memcpy(_custody[i].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);
+	}
+
+	// Provides natural sort order by ID
+	inline bool operator<(const Capability &c) const { return (_id < c._id); }
+
+private:
+	uint64_t _nwid;
+	uint64_t _expiration;
+	uint32_t _id;
+
+	unsigned int _maxCustodyChainLength;
+
+	unsigned int _ruleCount;
+	ZT_VirtualNetworkRule _rules[ZT_MAX_CAPABILITY_RULES];
+
+	struct {
+		Address to;
+		Address from;
+		C25519::Signature signature;
+	} _custody[ZT_MAX_CAPABILITY_CUSTODY_CHAIN_LENGTH];
+};
+
+} // namespace ZeroTier
+
+#endif