cosmic-lib
Version:
A JavaScript implementation of the CosmicLink protocol for Stellar
279 lines (244 loc) • 7.49 kB
JavaScript
/**
* Sep-0007 protocol utilities.
*
* The methods listed in the documentation are browser-only.
*
* @see https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0007.md
*
* @exports sep7Utils
*/
const sep7Utils = exports
const Buffer = require("@cosmic-plus/base/es5/buffer")
const env = require("@cosmic-plus/jsutils/es5/env")
const StellarSdk = require("@cosmic-plus/base/es5/stellar-sdk")
const { timeout } = require("@cosmic-plus/jsutils/es5/misc")
const check = require("./check")
const convert = require("./convert")
const decode = require("./decode")
const parse = require("./parse")
/* Utils */
/**
* Proposes the user to register **handler** as her default SEP-0007 link
* handler. SEP-0007 requests will hit `{handler}?sep7={sep7Request}`.
*
* Note that this makes use of a non-standard feature. Compatibility can be
* checked using `sep7Utils.isWebHandlerSupported()`.
*
* [List of compatible browsers](https://caniuse.com/#feat=registerprotocolhandler).
*
* @example
* cosmicLib.sep7Utils.registerWebHandler(
* "https://cosmic.link/",
* "Cosmic.link"
* )
*
* @param handler {String} URL of the SEP-0007 web handler.
* @param description {String} A brief description of the service.
*/
sep7Utils.registerWebHandler = function (handler, description) {
if (!env.isBrowser) throw new Error("This is a browser-only function.")
if (navigator.registerProtocolHandler) {
navigator.registerProtocolHandler(
"web+stellar",
`${handler}?sep7=%s`,
description
)
} else {
throw new Error("This browser can't register a SEP-0007 web handler.")
}
}
/**
* Returns whether or not the browser can register a SEP-0007 web handler.
*
* @example
* if (cosmicLib.sep7Utils.isWebHandlerSupported()) {
* registerSep7HandlerButton.show()
* }
*
* @returns {Boolean}
*/
sep7Utils.isWebHandlerSupported = function () {
return env.isBrowser && !!navigator.registerProtocolHandler
}
/* Parsing */
/**
* Initialize cosmicLink using `sep7Request`.
* @private
*/
sep7Utils.parseRequest = function (cosmicLink, sep7Request, options) {
parse.page(cosmicLink, sep7Request)
const query = convert.uriToQuery(cosmicLink, sep7Request)
const sep7 = decodeURIComponent(query.replace(/^\?(req|sep7)=/, ""))
return sep7Utils.parseLink(cosmicLink, sep7, options)
}
/**
* Initialize cosmicLink using `sep7`.
* @private
*/
sep7Utils.parseLink = function (cosmicLink, sep7, options = {}) {
cosmicLink._sep7 = sep7
if (!options.network) options.network = "public"
if (sep7.substr(12, 4) === "pay?") {
cosmicLink.extra.type = "pay"
return sep7Utils.parsePayLink(cosmicLink, sep7, options)
} else if (sep7.substr(12, 3) === "tx?") {
cosmicLink.extra.type = "tx"
return sep7Utils.parseTxLink(cosmicLink, sep7, options)
} else {
throw new Error("Invalid SEP-0007 link.")
}
}
/**
* Initialize cosmicLink using `sep7.xdr`.
* @private
*/
sep7Utils.parseTxLink = function (cosmicLink, sep7, options = {}) {
const query = convert.uriToQuery(cosmicLink, sep7)
const params = query.substr(1).split("&")
let xdr
params.forEach((entry) => {
const field = entry.replace(/=.*$/, "")
const value = entry.substr(field.length + 1)
switch (field) {
case "xdr":
xdr = decodeURIComponent(value)
break
case "pubkey":
check.address(cosmicLink, value)
cosmicLink.extra.pubkey = value
break
default:
sep7Utils.parseLinkCommons(cosmicLink, "xdr", field, value, options)
}
})
if (!xdr) throw new Error("Missing XDR parameter")
options.stripNeutralSequence = true
return { type: "xdr", value: xdr, options }
}
/**
* Initialize cosmicLink using `sep7.pay`.
* @private
*/
sep7Utils.parsePayLink = function (cosmicLink, sep7, options = {}) {
const query = convert.uriToQuery(cosmicLink, sep7)
const params = query.substr(1).split("&")
const odesc = { type: "payment" },
asset = {},
memo = {}
const tdesc = {
network: options.network,
operations: [odesc]
}
// Parse
params.forEach((entry) => {
const field = entry.replace(/=.*$/, "")
const value = entry.substr(field.length + 1)
switch (field) {
case "destination":
case "amount":
odesc[field] = decode.field(cosmicLink, field, value)
break
case "asset_code":
asset.code = decodeURIComponent(value)
break
case "asset_issuer":
asset.issuer = decodeURIComponent(value)
break
case "memo_type":
memo.type = value.split("_")[1].toLowerCase()
break
case "memo":
memo.value = decode.string(cosmicLink, value)
break
default:
sep7Utils.parseLinkCommons(cosmicLink, "pay", field, value, options)
}
})
// Convert
if (memo.type || memo.value) {
if (memo.type === "hash" || memo.type === "return") {
memo.value = Buffer.from(memo.value, "base64").toString("hex")
}
tdesc.memo = memo
}
if (asset.code || asset.issuer) odesc.asset = asset
if (!odesc.destination) throw new Error("Missing parameter: destination")
return { type: "tdesc", value: tdesc, options }
}
sep7Utils.parseLinkCommons = function (
cosmicLink,
mode,
field,
value,
options
) {
switch (field) {
case "network_passphrase":
options.network = decode.network(cosmicLink, value)
break
case "callback":
value = decode.url(cosmicLink, value)
if (value.substr(0, 4) !== "url:") {
throw new Error("Invalid callback: " + value)
}
options.callback = value.substr(4)
break
case "origin_domain":
cosmicLink.extra.originDomain = sep7Utils.verifySignature(
cosmicLink,
value
)
break
case "signature":
cosmicLink.extra.signature = decodeURIComponent(value)
break
case "msg":
cosmicLink.extra.msg = decode.string(cosmicLink, value)
break
default:
throw new Error(`Invalid SEP-0007 ${mode} field: ` + field)
}
}
/* Signing */
sep7Utils.signLink = function (cosmicLink, domain, keypair) {
if (!cosmicLink.locker) throw new Error("cosmicLink is not locked.")
cosmicLink.extra.originDomain = domain
delete cosmicLink.extra.signature
delete cosmicLink._sep7
const link = cosmicLink.sep7
const payload = sep7Utils.makePayload(link)
cosmicLink.extra.signature = keypair.sign(payload).toString("base64")
delete cosmicLink._sep7
}
sep7Utils.verifySignature = async function (cosmicLink, domain) {
const link = cosmicLink.sep7.replace(/&signature=.*/, "")
// Let parser parse signature.
await timeout(1)
const signature = cosmicLink.extra.signature
if (!signature) {
throw new Error(`No signature attached for domain: ${domain}`)
}
const payload = sep7Utils.makePayload(link)
const keypair = await sep7Utils.getDomainKeypair(domain)
if (keypair.verify(payload, Buffer.from(signature, "base64"))) {
return domain
} else {
throw new Error(`Invalid signature for domain: ${domain}`)
}
}
sep7Utils.getDomainKeypair = async function (domain) {
const toml = await StellarSdk.StellarTomlResolver.resolve(domain)
const signingKey = toml.URI_REQUEST_SIGNING_KEY
if (!signingKey) {
throw new Error(`Can't find signing key for domain: ${domain}`)
}
return StellarSdk.Keypair.fromPublicKey(signingKey)
}
sep7Utils.makePayload = function (link) {
return Buffer.concat([
Buffer.alloc(35),
Buffer.alloc(1, 4),
Buffer.from(`stellar.sep.7 - URI Scheme${link}`)
])
}