Keyring REST API ================ [Serval Project][], December 2017 Introduction ------------ The [Serval Mesh network][] is based on [cryptographic identities][] that can easily be created by any node at any time. Each [Serval DNA][] daemon that runs on a node in the network stores its own identities in the [Keyring][], an encrypted store protected by passwords, and gives applications access to the Keyring via the **Keyring REST API** described in this document. Using this API, client applications can add, remove, unlock, lock, query, and modify identities in the keyring. Basic concepts -------------- ### Serval ID Every identity in the [Serval mesh network][] is represented by its **Serval ID**, (usually abbreviated to [SID][], and formerly known as “Subscriber ID”), which is a unique 256-bit public key in the [Curve25519][] *crypto-box* key space. The SID is used: * as the network address in the [Serval Mesh network][] * to encrypt [MDP][] messages * to identify the senders, recipients and authors of [Rhizome bundles][] * to identify the parties in a [MeshMS conversation][] The Serval ID public key is derived from the *Serval ID secret key*, which is generated when the identity is first created, and stored in the keyring. The original implementation of [Serval DNA][] generated the *Serval ID secret key* at random, but since the introduction of [combined IDs](#combined-ids), the secret key is derived from the [Serval Signing ID](#serval-signing-id) secret key. ### Serval Signing ID Every identity in the [Serval mesh network][] has a **Serval Signing ID**, which is a unique 256-bit public key in the [Curve25519][] *crypto-sign* key space that is generated by choosing a *secret signing key* at random when the the identity is first created. The Signing ID is used: * to prevent forgery of [Serval Mesh network][] routing messages * to authenticate non-encrypted [MDP][] messages The large size of the key space means that, as long as the secret key choice is truly random, the [probability of two identities having the same ID][birthday paradox] is negligible, even if billions of identities are generated. ### Combined IDs Since July 2016, [Serval DNA][] generates [Serval ID](#serval-id)s by deriving them from the [Serval Signing ID](#serval-signing-id), so when creating a new identity, only a single secret key is generated at random instead of two. This change was made possible by replacing the [NaCl][] cryptographic library with [libsodium][], which provides a primitive to map keys from the *crypto-sign* key space to the *crypto-box* key space (but not vice versa, which is mathematically impossible). These related keys are called *combined IDs*. Eventually, the [Serval ID](#serval-id) will be replaced by the [Serval Signing ID](#serval-signing-id) throughout the Serval software and protocols, but will still be called “Serval ID”. The encryption key (in the *crypto-box* key space) will be derived from the signing key on the fly whenever needed, so there will only be one kind of Serval ID, which will be a great simplification. ### DID The **DID** ([Dialled Identity][]) is a telephone number, represented as a string of between 5 and 31 ASCII characters from the set `123456789#0*`. It is used by the [DNA][] protocol to allow [Serval mesh network][] users to discover each other by telephone number; the first step in establishing a mesh voice call. ### Name The **Name** is a short, unstructured string between 1 and 63 bytes in length, assigned by a human user to an identity. It is used to represent the identity to human users, as it is more recognisable than a hexadecimal [SID](#serval-id) or a [DID](#did) (telephone number). Serval DNA does not interpret the name, merely stores it, so the name may use any encoding on which all clients agree, such as ASCII or [UTF-8][]. Since it is intended for human consumption, it is recommended that it contain only printable characters, that it contain no carriage-motion characters (eg, TAB U+0009 or LF U+0010), and that it not start or end with white space, but Serval DNA does not enforce any such rules. The only restriction enforced by Serval DNA is that it contain no zero bytes. ### Rhizome Secret The *Rhizome Secret* is a secret key, separate from the [SID](#serval-id) secret, that is generated randomly for each new identity, and stored in the keyring as part of the identity. The Rhizome Secret is used to securely encode the [Bundle Secret][] of a bundle into its [manifest][], in the form of the [Bundle Key][], thus relieving [Rhizome][] applications of the burden of having to store and protect Bundle Secrets themselves. ### PIN When an identity is created, it can optionally be given a PIN (passphrase). If the PIN is *empty* then the identity is permanently unlocked (visible). Identities with a non-empty PIN are stored encrypted in the keyring file. Inspection of the keyring file will not reveal their presence unless the correct PIN is supplied, because all unused entries in the keyring file are filled with pseudo-random content that is indistinguishable from encrypted identities. If a PIN is lost and forgotten, then the identity (identities) it unlocks will remain locked and unusable forever. There is no “master PIN” or back-door. ### Identity unlocking All Keyring requests can supply a passphrase using the optional **pin** parameter, which unlocks all keyring identities protected by that passphrase, prior to performing the request. Serval DNA caches every PIN it receives until the PIN is revoked using the [lock request](#get-restful-keyring-lock), so once an identity is unlocked, it remains visible until explicitly locked. Keyring REST API common features -------------------------------- ### Keyring JSON result All Keyring requests relating to a single identity that do not produce a special response content for the outcome, return the following augmented [JSON result][] object as the HTTP response content: { "http_status_code": ..., "http_status_message": "...", "identity": { "sid": "", "identity": "", "did": "...", "name": "..." } } * the `sid` field is the [SID](#serval-id); a string containing 64 uppercase hexadecimal digits * the `identity` field is the [Signing Id](#serval-signing-id); a string containing 64 uppercase hexadecimal digits * the `did` field is the string [DID](#did); omitted if the identity has no DID * the `name` field is the string [Name](#name); omitted if the identity has no name Keyring REST API operations --------------------------- ### GET /restful/keyring/identities.json Returns a list of all currently unlocked identities, one identity per row in [JSON table][] format. The following parameters are recognised: * **pin** (optional) = a passphrase to unlock identities prior to listing; see [identity unlocking](#identity-unlocking) The table columns are: | heading | content | |:---------- |:------------------------------------------------------------------------- | | `sid` | the [SID](#serval-id), a string of 64 uppercase hex digits | | `identity` | the [Signing ID](#serval-signing-id), a string of 64 uppercase hex digits | | `did` | the optional [DID](#did) (telephone number); `null` if none is assigned | | `name` | the optional string [Name](#name); `null` if none is assigned | ### POST /restful/keyring/add Creates a new identity with a random [SID](#serval-id). This request does not accept parameters in the request body (eg, using a [Content-Type][] of [multipart/form-data][]), but does accept the following [query parameters][] in the *path*: * **pin** (optional) = the passphrase for the new identity; if present, then the new identity is protected by the given passphrase; see [identity unlocking](#identity-unlocking) -- note that the newly created identity is already unlocked when this request returns, because the passphrase has been added to the PIN cache * **did** (optional) = the [DID](#did) of the new identity; empty or absent to indicate no DID, otherwise must be valid * **name** (optional) = the [Name](#name) of the new identity; empty or absent to specify no name, otherwise must be valid If any parameter contains an invalid value then the request returns [400 Bad Request][400]. Returns [201 Created][201] if an identity is created; the [JSON result](#keyring-json-result) describes the identity that was created. ### GET /restful/keyring/SID Return the details of an existing unlocked identity with a given [SID](#serval-id). The following [query parameters][] are recognised: * **pin** (optional) = a passphrase to unlock the identity prior to querying it; see [identity unlocking](#identity-unlocking) If there is no unlocked identity with the given SID, this request returns [404 Not Found][404]. Otherwise it returns [200 OK][200] and the [JSON result](#keyring-json-result) describes the identity. ### DELETE /restful/keyring/SID Removes an existing unlocked identity with a given [SID](#serval-id). The following [query parameters][] are recognised: * **pin** (optional) = a passphrase to unlock the identity prior to deleting it; see [identity unlocking](#identity-unlocking) If there is no unlocked identity with the given SID, this request returns [404 Not Found][404]. Otherwise it returns [200 OK][200] and the [JSON result](#keyring-json-result) describes the identity that was removed. ### PATCH /restful/keyring/SID Sets and/or clears the [DID](#did) and/or [Name](#name) of the unlocked identity that has the given [SID](#serval-id). The following [query parameters][] are recognised: * **pin** (optional) = a passphrase to unlock the identity prior to deleting it; see [identity unlocking](#identity-unlocking) * **did** (optional) = the [DID](#did) to assign to the identity; empty to clear the DID, otherwise must be valid * **name** (optional) = the [Name](#name) to assign to the identity; empty to clear the name, otherwise must be valid If a parameter is missing, then the corresponding field of the identity is left unchanged. If a parameter is set to an empty string, then the corresponding field of the identity is erased. If any parameter contains an invalid value then the request returns [400 Bad Request][400]. If there is no unlocked identity with the given SID, this request returns [404 Not Found][404]. ### PUT /restful/keyring/SID/lock Locks an existing identity with a given [SID](#serval-id). If there is no unlocked identity with the given SID, this request returns [404 Not Found][404]. Otherwise it returns [200 OK][200] and the [JSON result](#keyring-json-result) describes the identity that was locked. ----- **Copyright 2015 Serval Project Inc.** **Copyright 2016-2018 Flinders University** ![CC-BY-4.0](./cc-by-4.0.png) Available under the [Creative Commons Attribution 4.0 International licence][CC BY 4.0]. [Serval Project]: http://www.servalproject.org/ [CC BY 4.0]: ../LICENSE-DOCUMENTATION.md [Serval Mesh network]: http://developer.servalproject.org/dokuwiki/doku.php?id=content:tech:mesh_network [Serval DNA]: ../README.md [REST-API]: ./REST-API.md [Keyring]: http://developer.servalproject.org/dokuwiki/doku.php?id=content:tech:keyring [cryptographic identities]: http://developer.servalproject.org/dokuwiki/doku.php?id=content:tech:security_framework [Curve25519]: https://en.wikipedia.org/wiki/Curve25519 [libsodium]: https://libsodium.org/ [NaCl]: https://nacl.cr.yp.to/ [SID]: http://developer.servalproject.org/dokuwiki/doku.php?id=content:tech:sid [birthday paradox]: http://en.wikipedia.org/wiki/Birthday_problem [Dialled Identity]: http://developer.servalproject.org/dokuwiki/doku.php?id=content:tech:did [DNA]: http://developer.servalproject.org/dokuwiki/doku.php?id=content:tech:dna [MDP]: ./Mesh-Datagram-Protocol.md [Rhizome]: ./REST-API-Rhizome.md [Rhizome bundles]: ./REST-API-Rhizome.md#bundle [manifest]: ./REST-API-Rhizome.md#manifest [Bundle Secret]: ./REST-API-Rhizome.md#bundle-secret [Bundle Key]: ./REST-API-Rhizome.md#bundle-key [MeshMS conversation]: ./REST-API-MeshMS.md#conversation [JSON result]: ./REST-API.md#json-result [JSON table]: ./REST-API.md#json-table [UTF-8]: https://en.wikipedia.org/wiki/UTF-8 [200]: ./REST-API.md#200-ok [201]: ./REST-API.md#201-created [202]: ./REST-API.md#202-accepted [400]: ./REST-API.md#400-bad-request [404]: ./REST-API.md#404-not-found [419]: ./REST-API.md#419-authentication-timeout [422]: ./REST-API.md#422-unprocessable-entity [423]: ./REST-API.md#423-locked [500]: ./REST-API.md#500-server-error