Mathematical Mesh: Reference

NB: The reference material in this document is generated from the schema used to derive the source code. The tool used to create this material has not been optimized to produce output for the IETF documentation format at this time. Consequently, the formatting is currently sub-optimal.

This section presents the related specifications and standard, the terms that are used as terms of art within the documents and the terms used as requirements language.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] .

The terms of art used in this document are described in the Mesh Architecture Guide [draft-hallambaker-mesh-architecture] .

The architecture of the Mathematical Mesh is described in the Mesh Architecture Guide [draft-hallambaker-mesh-architecture] . The Mesh documentation set and related specifications are described in this document.

The implementation status of the reference code base is described in the companion document [draft-hallambaker-mesh-developer] .

[Account request does not specify the portal in the request body, only the HTTP package includes this information. This is probably a bug.]

A user interacts with a Mesh service through a Mesh portal provider with which she establishes a portal account. For user convenience, a portal account identifier has the familiar <username>@<domain> format established in [~RFC822]. For example Alice selects example.com as her portal provider and chooses the account name alice. Her portal account identifier is alice. A user MAY establish accounts with multiple portal providers and/or change their portal provider at any time they choose.

The first step in creating a new account is to check to see if the chosen account identifier is available. This allows a client to validate user input and if necessary warn the user that they need to choose a new account identifier when the data is first entered. The ValidateRequest message contains the requested account identifier and an optional language parameter to allow the service to provide informative error messages in a language the user understands. The Language field contains a list of ISO language identifier codes in order of preference, most preferred first.

The ValidateResponse message returns the result of the validation request in the Valid field. Note that even if the value true is returned, a subsequent account creation request MAY still fail.

?|\\@#"}}]]> [Note that for the sake of concise presentation, the HTTP binding information is omitted from future examples.]

The first step in creating a new personal profile is to create a Master Profile object. This contains the long term Master Signing Key that will remain constant for the life of the profile, at least one Online Signature Key to be used for administering the personal profile and (optionally), one or more master escrow keys. For convenience, the descriptions of the Master Signing Key, Online Signing Keys and Escrow Keys typically include PKIX certificates signed by the Master Signing Key. This allows PKIX based applications to make use of PKIX certificate chains to express the same trust relationships described in the Mesh.

The Master Profile is always signed using the Master Signing Key:

Since the device used to create the personal profile is typically connected to the profile, a Device profile entry is created for it. This contains a Device Signing Key, a Device Encryption Key and a Device Authentication Key:

The Device Profile is signed using the Device Signing Key:

A personal profile would typically contain at least one application when first created. For the sake of demonstration, we will do this later. The personal profile thus consists of the master profile and the device profile:

The personal profile is then signed using the Online Signing Key:

Once the signed personal profile is created, the client can finaly make the request for the service to create the account. The request object contains the requested account identifier and profile:

The service reports the success (or failure) of the account creation request:

Connecting a device to a profile requires the client on the new device to interact with a client on a device that has administration capabilities, i.e. it has access to an Online Signing Key. Since clients cannot interact directly with other clients, a service is required to mediate the connection. This service is provided by a Mesh portal provider. All service transactions are initiated by the clients. First the connecting device posts ConnectStart, after which it may poll for the outcome of the connection request using ConnectStatus. Periodically, the Administration Device polls for a list of pending connection requests using ConnectPending. After posting a request, the administration device posts the result using ConnectComplete:

| | | | ConnectPending | | | <---------------------- | | | | | | ConnectComplete | | | <---------------------- | | ConnectStatus | | | ----------------------> | |]]> The first step in the process is for the client to generate a device profile. Ideally the device profile is bound to the device in a read-only fashion such that applications running on the device can make use of the deencryption and authentication keys but these private keys cannot be extracted from the device:

The device profile is then signed:

One of the main architecutral principles of the Mesh is bilateral authentication. Every device that is connected to a Mesh profile MUST authenticate the profile it is connecting to and every Mesh profile administrator MUST authenticate devices that are connected. Having created the necessary profile, the device MUST verify that it is connecting to the correct Mesh profile. The best mechanism for achieving this purpose depends on the capabilities of the device being connected. The administration device obviously requires some means of communicating with the user to serve its function. But the device being connected may have a limited display capability or no user interaction capability at all.

If the device has user input and display capabilities, it can verify that it is connecting to the correct display by first requesting the user enter the portal account of the profile they wish to connect to, retreiving the profile associated with the device and displaying the profile fingerprint. The client requests the profile for the requested account name:

The response contains the requested profile information.

Having received the profile data, the user can then verify that the device is attempting to connect to the correct profile by verifying that the fingerprint shown by the device attempting to connect is correct.

Connection of an Internet of Things 'IoT' device that does not have the ability to accept user input requires a mechanism by which the user can identify the device they wish to connect to their profile and a mechanism to authenticate the profile to the device. If the connecting device has a wired communication capability such as a USB port, this MAY be used to effect the device connection using a standardized interaction profile. But an increasing number of constrained IoT devices are only capable of wireless communication. Configuration of such devices for the purpose of the Mesh requires that we also consider configuration of the wireless networking capabilities at the same time. The precise mechanism by which this is achieved is therefore outside the scope of this particular document. However prototypes have been built and are being considered that make use of some or all of the following communication techniques: Wired serial connection (RS232, RS485). DHCP signalling. Machine readable device identifiers (barcodes, QRCodes). Default device profile installed during manufacture. Optical communication path using camera on administrative device and status light on connecting device to communicate the device identifier, challenge nonce and confirm profile fingerprint. Speech output on audio capable connecting device.

After the user verifies the device fingerprint as correct, the client posts a device connection request to the portal:

The portal verifies that the request is accepable and returns the transaction result:

The client can poll the portal for the status of pending requests at any time (modulo any service throttling restrictions at the service side). But the request status will only change when an update is posted by an administration device. Since the user is typically connecting a device to their profile, the next step in connecting the device is to start the administration client. When started, the client polls for pending connection requests using ConnectPendingRequest.

The service responds with a list of pending requests:

The device profile is added to the Personal profile which is then signed by the online signing key. The administration client publishes the updated profile to the Mesh through the portal:

As usual, the service returns the response code:

Having accepted the device and connected it to the profile, the administration client creates and signs a connection completion result which is posted to the portal using ConnectCompleteRequest:

Again, the service returns the response code:

As stated previously, the connecting device polls the portal periodically to determine the status of the pending request using ConnectStatusRequest:

If the response is that the connection status has not changed, the service MAY return a response that specifies a minimum retry interval. In this case however there is a connection result:

[Should probably unpack further.]

Application profiles are published separately from the personal profile to which they are linked. This allows a device to be given administration capability for a particular application without granting administration capability for the profile itself and the ability to connect additional profiles and devices. Another advantage of this separation is that an application profile might be managed by a separate party. In an enterprise, the application profile for a user's corporate email account could be managed by the corporate IT department. A user MAY have multiple application profiles for the same application. If a user has three email accounts, they would have three email application profiles, one for each account. In this example, the user has requested a PaswordProfile to be created. When populated, this records the usernames and passwords for the various Web sites that the user has created accounts at and has requested the Web browser store in the Mesh. Unlike a traditional password management service, the data stored the Password Profile is encrypted end to end and can only be decrypted by the devices that hold a decryption key.

The application profile is published to the Mesh in the same way as any other profile update, via a a Publish transaction: % Point = Example.Traces.Get (Example.LabelApplicationWeb1); {Point.Messages[0].String()} The service returns a status response. {Point.Messages[1].String()} Note that the degree of verification to be performed by the service when an application profile is published is an open question. Having created the application profile, the administration client adds it to the personal profile and publishes it: {Point.Messages[0].String()} Note that if the publication was to happen in the reverse order, with the personal profile being published before the application profile, the personal profile might be rejected by the portal for inconsistency as it links to a non existent application profile. Though the value of such a check is debatable. It might well be preferable to not make such checks as it permits an application profile to have a degree of anonymity. {Point.Messages[1].String()}

The Mesh invites users to put all their data eggs in one cryptographic basket. If the private keys in their master profile are lost, they could lose all their digital assets. The debate over the desirability of key escrow is a complex one. Not least because voluntary key escrow by the user to protect the user's digital assets is frequently conflated with mechanisms to support 'Lawful Access' through government managed backdoors. Accidents happen and so do disasters. For most users and most applications, data loss is a much more important concern than data disclosure. The option of using a robust key recovery mechanism is therefore essential for use of strong cryptography is to become ubiquitous. There are of course circumstances in which some users may prefer to risk losing some of their data rather than risk disclosure. Since any key recovery infrastructure necessarily introduces the risk of coercion, the choice of whether to use key recovery or not is left to the user to decide. The Mesh permits users to escrow their private keys in the Mesh itself in an OfflineEscrowEntry. Such entries are encrypted using the strongest degree of encryption available under a symmetric key. The symmetric key is then in turn split using Shamir secret sharing using an n of m threshold scheme. The OfflineEscrowEntry identifier is a UDF fingerprint of the symmetric key used to encrypt the data. This guarantees that a party that has the decryption key has the ability to locate the corresponding Escrow entry. The OfflineEscrowEntry is published using the usual Publish transaction: {Point.Messages[0].String()} The response indicates success or failure: {Point.Messages[1].String()}

To recover a profile, the user MUST supply the necessary number of secret shares. These are then used to calculate the UDF fingerprint to use as the locator in a Get transaction: {Point.Messages[0].String()} If the transaction succeeds, GetResponse is returned with the requested data. {Point.Messages[1].String()} The client can now decrypt the OfflineEscrowEntry to recover the private key(s).

The following classes are used as common elements in Mesh profile specifications.a

Most Mesh objects are signed and/or encrypted. For consistency all Mesh classes make use of the cryptographic data classes described in this section.

The PublicKey class is used to describe public key pairs and trust assertions associated with a public key. String (Optional) UDF fingerprint of the public key parameters/ Binary (Optional) List of X.509 Certificates Binary [0..Many] X.509 Certificate chain. Binary (Optional) X.509 Certificate Signing Request.

Container for JOSE signed data and related attributes. Binary (Optional) The signed data

Container for JOSE encrypted data and related attributes. Binary (Optional) The encrypted data

Describes network connection parameters for an application String (Optional) DNS address of the server Integer (Optional) TCP/UDP Port number String (Optional) DNS service prefix as described in [!RFC6335] String [0..Many] Describes the security mode to use. Valid choices are Direct/Upgrade/None String (Optional) Username to present to the service for authentication String (Optional) Password to present to the service for authentication String (Optional) Service connection parameters in URI format String (Optional) List of the supported/acceptable authentication mechanisms, preferred mechanism first. Integer (Optional) Service timeout in seconds. Boolean (Optional) If set, the client should poll the specified service intermittently for updates.

Base class for all Mesh Profile objects. String (Optional) Globally unique identifier that remains constant for the lifetime of the entry.

Entry Contains a signed profile entry JoseWebSignature (Optional) The signed profile. Note that each child of SignedProfile requires that the Payload field of the SignedData object contain an object of a specific type. For example, a SignedDeviceProfile object MUST contain a Payload field that contains a DeviceProfile object. Advice (Optional) Additional data that is not authenticated.

Additional data bound to a signed profile that is not authenticated. DateTime (Optional) If specified, the profile was the default profile at the specified date and time. The current default for that type of profile is the profile with the most recent Default timestamp.

Advice String [0..Many] A portal address at which this profile is registered.

Entry Parent class from which all profile types are derived String [0..Many] Fingerprints of index terms for profile retrieval. The use of the fingerprint of the name rather than the name itself is a precaution against enumeration attacks and other forms of abuse. DateTime (Optional) The time instant the profile was last modified. String (Optional) A Uniform Notary Token providing evidence that a signature was performed after the notary token was created.

SignedProfile Contains a signed device profile [No fields]

Profile Describes a mesh device. String (Optional) Description of the device PublicKey (Optional) Key used to sign certificates for the DAK and DEK. The fingerprint of the DSK is the UniqueID of the Device Profile PublicKey (Optional) Key used to authenticate requests made by the device. PublicKey (Optional) Key used to pass encrypted data to the device such as a DeviceUseEntry

Private portion of device encryption profile. Key (Optional) Private portion of the DeviceSignatureKey Key (Optional) Private portion of the DeviceAuthenticationKey Key (Optional) Private portion of the DeviceEncryptiontionKey

SignedProfile Contains a signed Personal master profile [No fields]

Profile Describes the long term parameters associated with a personal profile. PublicKey (Optional) The root of trust for the Personal PKI, the public key of the PMSK is presented as a self-signed X.509v3 certificate with Certificate Signing use enabled. The PMSK is used to sign certificates for the PMEK, POSK and PKEK keys. PublicKey [0..Many] A Personal Profile MAY contain one or more PMEK keys to enable escrow of private keys used for stored data. PublicKey [0..Many] A Personal profile contains at least one POSK which is used to sign device administration application profiles.

SignedProfile Contains a signed Personal current profile [No fields]

Profile Describes the current applications and devices connected to a personal master profile. SignedMasterProfile (Optional) The corresponding master profile. The profile MUST be signed by the PMSK. SignedDeviceProfile [0..Many] The set of device profiles connected to the profile. The profile MUST be signed by the DSK in the profile. ApplicationProfileEntry [0..Many] Application profiles connected to this profile.

Personal profile entry describing the privileges of specific devices. String (Optional) The unique identifier of the application String (Optional) The application type String (Optional) Optional friendly name identifying the application. String [0..Many] List of devices authorized to sign application profiles String [0..Many] List of devices authorized to read private parts of application profiles.

SignedProfile Contains a signed device profile [No fields]

Profile Parent class from which all application profiles inherit. [No fields]

Entry The base class for all private profiles. [No fields]

Entry Describes the public per device data String (Optional) Description of the device for convenience of the user. String (Optional) Fingerprint of device that this key corresponds to.

Entry Describes the private per device data [No fields]

Entry Contains escrowed data JoseWebEncryption (Optional) The encrypted escrow data

EscrowEntry Contains data escrowed using the offline escrow mechanism. [No fields]

EscrowEntry Contains data escrowed using the online escrow mechanism. [No fields]

A set of escrowed keys. [No fields]

Describes a connection request. String (Optional) UDF of Mesh Profile to which connection is requested. SignedDeviceProfile (Optional) The Device profile to be connected

SignedProfile Contains a ConnectionRequest signed by the corresponding device signature key. [No fields]

Describes the result of a connection request. ConnectionRequest String (Optional) The result of the connection request. Valid responses are: Accepted, Refused, Query.

SignedProfile Contains a signed connection result [No fields]

_mmm._tcp /.well-known/mmm Every Mesh Portal Service transaction consists of exactly one request followed by exactly one response. Mesh Service transactions MAY cause modification of the data stored in the Mesh Portal or the Mesh itself but do not cause changes to the connection state. The protocol itself is thus idempotent. There is no set sequence in which operations are required to be performed. It is not necessary to perform a Hello transaction prior to a ValidateAccount, Publish or any other transaction.

A Mesh Portal Service request consists of a payload object that inherits from the MeshRequest class. When using the HTTP binding, the request MUST specify the portal DNS address in the HTTP Host field.

Base class for all request messages. String (Optional) Name of the Mesh Portal Service to which the request is directed.

A Mesh Portal Service response consists of a payload object that inherits from the MeshResponse class. When using the HTTP binding, the response SHOULD report the Status response code in the HTTP response message. However the response code returned in the payload object MUST always be considered authoritative.

Base class for all response messages. Contains only the status code and status description fields. [No fields]

The Mesh Service protocol makes use of JSON objects defined in the JOSE Signatgure and Encryption specifications.

The following common structures are used in the protocol messages:

Describes a Key/Value structure used to make queries for records matching one or more selection criteria. String (Optional) The data retrieval key. String (Optional) The data value to match.

Specifies constraints to be applied to a search result. These allow a client to limit the number of records returned, the quantity of data returned, the earliest and latest data returned, etc. DateTime (Optional) Only data published on or after the specified time instant is requested. DateTime (Optional) Only data published before the specified time instant is requested. This excludes data published at the specified time instant. Integer (Optional) Maximum number of data entries to return. Integer (Optional) Maximum number of data bytes to return. String (Optional) Specifies a page key returned in a previous search operation in which the number of responses exceeded the specified bounds. When a page key is specified, all the other search parameters except for MaxEntries and MaxBytes are ignored and the service returns the next set of data responding to the earlier query.

HelloRequest HelloResponse Report service and version information. The Hello transaction provides a means of determining which protocol versions, message encodings and transport protocols are supported by the service.

ValidateRequest ValidateResponse Request validation of a proposed name for a new account. For validation of a user's account name during profile creation.

MeshRequest Describes the proposed account properties. Currently, these are limited to the account name but could be extended in future versions of the protocol. String (Optional) Account name requested Boolean (Optional) If true, request a reservation for the specified account name. Note that the service is not obliged to honor reservation requests. String [0..Many] List of ISO language codes in order of preference. For creating explanatory text.

MeshResponse States whether the proposed account properties are acceptable and (optional) returns an indication of what properties are valid. Note that receiving a 'Valid' responseto a Validate Request does not guarantee creation of the account. In addition to the possibility that the account namecould be requested by another user between the Validate and Create transactions, a portal service MAY perform more stringent validation criteria when an account is actually being created. For example, checking with the authoritative list of current accounts rather than a cached copy. Boolean (Optional) If true, the specified account identifier is acceptable. If false, the account identifier is rejected. Integer (Optional) Specifies the minimum length of an account name. Integer (Optional) Specifies the maximum length of an account name. String (Optional) A list of characters that the service does not accept in account names. The list of characters MAY not be exhaustive but SHOULD include any illegal characters in the proposed account name. String (Optional) Text explaining the reason an account name was rejected.

CreateRequest CreateResponse Request creation of a new portal account. Unlike a profile, a mesh account is specific to a particular Mesh portal. A mesh account must be created and accepted before a profile can be published.

Request creation of a new portal account. The request specifies the requested account identifier and the Mesh profile to be associated with the account. MeshRequest String (Optional) Account identifier requested.

MeshResponse Reports the success or failure of a Create transaction. [No fields]

DeleteRequest DeleteResponse Request deletion of a portal account. Deletes a portal account but not the underlying profile. Once registered, profiles are permanent.

Request deletion of a new portal account. The request specifies the requested account identifier. MeshRequest String (Optional) Account identifier to be deleted.

MeshResponse Reports the success or failure of a Delete transaction. [No fields]

GetRequest GetResponse Search for data in the mesh that matches a set of properties described by a sequence of key/value pairs.

Describes the Portal or Mesh data to be retreived. MeshRequest String (Optional) Lookup by profile ID String (Optional) Lookup by Account ID KeyValue [0..Many] List of KeyValue pairs specifying the conditions to be met SearchConstraints (Optional) Constrain the search to a specific time interval and/or limit the number and/or total size of data records returned. Boolean (Optional) If true return multiple responses if available Boolean (Optional) If true, the client requests that the full Mesh data record be returned containing both the Mesh entry itself and the Mesh metadata that allows the date and time of the publication of the Mesh entry to be verified.

Reports the success or failure of a Get transaction. If a Mesh entry matching the specified profile is found, containsthe list of entries matching the request. MeshResponse DataItem [0..Many] List of mesh data records matching the request. String (Optional) If non-null, indicates that the number and/or size of the data records returned exceeds either the SearchConstraints specified in the request or internal server limits.

PublishRequest PublishResponse Publish a profile or key escrow entry to the mesh.

Requests publication of the specified Mesh entry. MeshRequest [No fields]

Reports the success or failure of a Publish transaction. MeshResponse [No fields]

StatusRequest StatusResponse Request the current status of the mesh as seen by the portal to which it is directed. The response to the status request contains the last signed checkpoint and proof chains for each of the peer portals that have been checkpointed. [Not currently implemented]

MeshRequest Initiates a status transaction. [No fields]

Reports the success or failure of a Status transaction. MeshResponse DateTime (Optional) Time that the last write update was made to the Mesh DateTime (Optional) Time that the last Mesh checkpoint was calculated. DateTime (Optional) Time at which the next Mesh checkpoint should be calculated. String (Optional) Last checkpoint value.

ConnectStartRequest ConnectStartResponse Request connection of a new device to a mesh profile

MeshRequest Initial device connection request. SignedConnectionRequest (Optional) Device connection request signed by thesignature key of the device requesting connection. String (Optional) Account identifier of account to which the device is requesting connection.

Reports the success or failure of a ConnectStart transaction. MeshRequest [No fields]

ConnectStatusRequest ConnectStatusResponse Request status of pending connection request of a new device to a mesh profile

MeshRequest Request status information for a pending request posted previously. String (Optional) Account identifier for which pending connection information is requested. String (Optional) Device identifier of device requesting status information.

Reports the success or failure of a ConnectStatus transaction. MeshRequest SignedConnectionResult (Optional) The signed ConnectionResult object.

ConnectPendingRequest ConnectPendingResponse Request a list of pending requests for an administration profile.

MeshRequest Specify the criteria for pending requests. String (Optional) The account identifier of the account for which pending connection requests are requested. SearchConstraints (Optional) Constrain the search to a specific time interval and/or limit the number and/or total size of data records returned.

Reports the success or failure of a ConnectPending transaction. MeshRequest SignedConnectionRequest [0..Many] A list of pending requests satisfying the criteria set out in the request. String (Optional) If non-null, indicates that the number and/or size of the data records returned exceeds either the SearchConstraints specified in the request or internal server limits.

ConnectCompleteRequest ConnectCompleteResponse Post response to a pending connection request.

Reports the success or failure of a ConnectComplete transaction. MeshRequest SignedConnectionResult (Optional) The connection result to be posted to the portal. The result MUST be signed by a valid administration key for the Mesh profile. String (Optional) The account identifier to which the connection result is posted.

MeshRequest Reports the success or failure of a ConnectComplete transaction. [No fields]

TransferRequest TransferResponse Perform a bulk transfer of the log between the specified transaction identifiers. Requires appropriate authorization [Not currently implemented]

Request a bulk transfer of the log between the specified transaction identifiers. Requires appropriate authorization MeshRequest SearchConstraints (Optional) Constrain the search to a specific time interval and/or limit the number and/or total size of data records returned.

MeshResponse Reports the success or failure of a Transfer transaction. If successful, contains the list of Mesh records to be transferred. DataItem [0..Many] List of mesh data records matching the request. String (Optional) If non-null, indicates that the number and/or size of the data records returned exceeds either the SearchConstraints specified in the request or internal server limits.

All the IANA considerations for the Mesh documents are specified in this document