* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/.
*
* (c) ZeroTier, Inc.
* https://www.zerotier.com/
*/
#ifndef ZT_CERTIFICATEOFMEMBERSHIP_HPP
#define ZT_CERTIFICATEOFMEMBERSHIP_HPP
#include "Address.hpp"
#include "Buffer.hpp"
#include "Constants.hpp"
#include "Credential.hpp"
#include "ECC.hpp"
#include "Identity.hpp"
#include "Utils.hpp"
#include <algorithm>
#include <stdexcept>
#include <stdint.h>
#include <string.h>
#include <string>
* Maximum number of qualifiers allowed in a COM (absolute max: 65535)
*/
#define ZT_NETWORK_COM_MAX_QUALIFIERS 8
namespace ZeroTier {
class RuntimeEnvironment;
* Certificate of network membership
*
* The COM contains a sorted set of three-element tuples called qualifiers.
* These contain an id, a value, and a maximum delta.
*
* The ID is arbitrary and should be assigned using a scheme that makes
* every ID globally unique. IDs beneath 65536 are reserved for global
* assignment by ZeroTier Networks.
*
* The value's meaning is ID-specific and isn't important here. What's
* important is the value and the third member of the tuple: the maximum
* delta. The maximum delta is the maximum difference permitted between
* values for a given ID between certificates for the two certificates to
* themselves agree.
*
* Network membership is checked by checking whether a peer's certificate
* agrees with your own. The timestamp provides the fundamental criterion--
* each member of a private network must constantly obtain new certificates
* often enough to stay within the max delta for this qualifier. But other
* criteria could be added in the future for very special behaviors, things
* like latitude and longitude for instance.
*
* This is a memcpy()'able structure and is safe (in a crash sense) to modify
* without locks.
*/
class CertificateOfMembership : public Credential {
public:
static inline Credential::Type credentialType()
{
return Credential::CREDENTIAL_TYPE_COM;
}
* Reserved qualifier IDs
*
* IDs below 1024 are reserved for use as standard IDs. Others are available
* for user-defined use.
*
* Addition of new required fields requires that code in hasRequiredFields
* be updated as well.
*/
enum ReservedId {
* Timestamp of certificate
*/
COM_RESERVED_ID_TIMESTAMP = 0,
* Network ID for which certificate was issued
*/
COM_RESERVED_ID_NETWORK_ID = 1,
* ZeroTier address to whom certificate was issued
*/
COM_RESERVED_ID_ISSUED_TO = 2
};
* Create an empty certificate of membership
*/
CertificateOfMembership() : _qualifierCount(0)
{
}
* Create from required fields common to all networks
*
* @param timestamp Timestamp of certificate
* @param timestampMaxDelta Maximum variation between timestamps on this net
* @param nwid Network ID
* @param issuedTo Certificate recipient
*/
CertificateOfMembership(uint64_t timestamp, uint64_t timestampMaxDelta, uint64_t nwid, const Identity& issuedTo);
* Create from binary-serialized COM in buffer
*
* @param b Buffer to deserialize from
* @param startAt Position to start in buffer
*/
template <unsigned int C> CertificateOfMembership(const Buffer<C>& b, unsigned int startAt = 0)
{
deserialize(b, startAt);
}
* @return True if there's something here
*/
inline operator bool() const
{
return (_qualifierCount != 0);
}
* @return Credential ID, always 0 for COMs
*/
inline uint32_t id() const
{
return 0;
}
* @return Timestamp for this cert and maximum delta for timestamp
*/
inline int64_t timestamp() const
{
for (unsigned int i = 0; i < _qualifierCount; ++i) {
if (_qualifiers[i].id == COM_RESERVED_ID_TIMESTAMP) {
return _qualifiers[i].value;
}
}
return 0;
}
* @return Address to which this cert was issued
*/
inline Address issuedTo() const
{
for (unsigned int i = 0; i < _qualifierCount; ++i) {
if (_qualifiers[i].id == COM_RESERVED_ID_ISSUED_TO) {
return Address(_qualifiers[i].value);
}
}
return Address();
}
* @return Network ID for which this cert was issued
*/
inline uint64_t networkId() const
{
for (unsigned int i = 0; i < _qualifierCount; ++i) {
if (_qualifiers[i].id == COM_RESERVED_ID_NETWORK_ID) {
return _qualifiers[i].value;
}
}
return 0ULL;
}
* Compare two certificates for parameter agreement
*
* This compares this certificate with the other and returns true if all
* parameters in this cert are present in the other and if they agree to
* within this cert's max delta value for each given parameter.
*
* Tuples present in other but not in this cert are ignored, but any
* tuples present in this cert but not in other result in 'false'.
*
* @param other Cert to compare with
* @param otherIdentity Identity of other node
* @return True if certs agree and 'other' may be communicated with
*/
bool agreesWith(const CertificateOfMembership& other, const Identity& otherIdentity) const;
* Sign this certificate
*
* @param with Identity to sign with, must include private key
* @return True if signature was successful
*/
bool sign(const Identity& with);
* Verify this COM and its signature
*
* @param RR Runtime environment for looking up peers
* @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
* @return 0 == OK, 1 == waiting for WHOIS, -1 == BAD signature or credential
*/
int verify(const RuntimeEnvironment* RR, void* tPtr) const;
* @return True if signed
*/
inline bool isSigned() const
{
return (_signedBy);
}
* @return Address that signed this certificate or null address if none
*/
inline const Address& signedBy() const
{
return _signedBy;
}
template <unsigned int C> inline void serialize(Buffer<C>& b) const
{
b.append((uint8_t)1);
b.append((uint16_t)_qualifierCount);
for (unsigned int i = 0; i < _qualifierCount; ++i) {
b.append(_qualifiers[i].id);
b.append(_qualifiers[i].value);
b.append(_qualifiers[i].maxDelta);
}
_signedBy.appendTo(b);
if (_signedBy) {
b.append(_signature.data, ZT_ECC_SIGNATURE_LEN);
}
}
template <unsigned int C> inline unsigned int deserialize(const Buffer<C>& b, unsigned int startAt = 0)
{
unsigned int p = startAt;
_qualifierCount = 0;
_signedBy.zero();
if (b[p++] != 1) {
throw ZT_EXCEPTION_INVALID_SERIALIZED_DATA_INVALID_TYPE;
}
unsigned int numq = b.template at<uint16_t>(p);
p += sizeof(uint16_t);
uint64_t lastId = 0;
for (unsigned int i = 0; i < numq; ++i) {
const uint64_t qid = b.template at<uint64_t>(p);
if (qid < lastId) {
throw ZT_EXCEPTION_INVALID_SERIALIZED_DATA_BAD_ENCODING;
}
else {
lastId = qid;
}
if (_qualifierCount < ZT_NETWORK_COM_MAX_QUALIFIERS) {
_qualifiers[_qualifierCount].id = qid;
_qualifiers[_qualifierCount].value = b.template at<uint64_t>(p + 8);
_qualifiers[_qualifierCount].maxDelta = b.template at<uint64_t>(p + 16);
p += 24;
++_qualifierCount;
}
else {
throw ZT_EXCEPTION_INVALID_SERIALIZED_DATA_OVERFLOW;
}
}
_signedBy.setTo(b.field(p, ZT_ADDRESS_LENGTH), ZT_ADDRESS_LENGTH);
p += ZT_ADDRESS_LENGTH;
if (_signedBy) {
memcpy(_signature.data, b.field(p, ZT_ECC_SIGNATURE_LEN), ZT_ECC_SIGNATURE_LEN);
p += ZT_ECC_SIGNATURE_LEN;
}
return (p - startAt);
}
inline bool operator==(const CertificateOfMembership& c) const
{
if (_signedBy != c._signedBy) {
return false;
}
if (_qualifierCount != c._qualifierCount) {
return false;
}
for (unsigned int i = 0; i < _qualifierCount; ++i) {
const _Qualifier& a = _qualifiers[i];
const _Qualifier& b = c._qualifiers[i];
if ((a.id != b.id) || (a.value != b.value) || (a.maxDelta != b.maxDelta)) {
return false;
}
}
return (memcmp(_signature.data, c._signature.data, ZT_ECC_SIGNATURE_LEN) == 0);
}
inline bool operator!=(const CertificateOfMembership& c) const
{
return (! (*this == c));
}
private:
struct _Qualifier {
_Qualifier() : id(0), value(0), maxDelta(0)
{
}
uint64_t id;
uint64_t value;
uint64_t maxDelta;
inline bool operator<(const _Qualifier& q) const
{
return (id < q.id);
}
};
Address _signedBy;
_Qualifier _qualifiers[ZT_NETWORK_COM_MAX_QUALIFIERS];
unsigned int _qualifierCount;
ECC::Signature _signature;
};
}
#endif