299 lines
10 KiB
Swift
299 lines
10 KiB
Swift
import Foundation
|
|
|
|
enum SaslType {
|
|
case sasl1
|
|
case sasl2
|
|
|
|
var xmlns: String {
|
|
switch self {
|
|
case .sasl1: "urn:ietf:params:xml:ns:xmpp-sasl"
|
|
case .sasl2: "urn:xmpp:sasl:2"
|
|
}
|
|
}
|
|
}
|
|
|
|
// TODO: Implement SHA-256/SHA-512, the difference only in hmac/pbkdf2 lenght
|
|
enum AuthorizationMechanismType: String {
|
|
case plain = "PLAIN"
|
|
case scramSha1 = "SCRAM-SHA-1"
|
|
// case scramSha1Plus = "SCRAM-SHA-1-PLUS" // TODO: check whats wrong with cahnnel binding
|
|
|
|
var priority: Int { // less - better
|
|
switch self {
|
|
case .plain: 1000
|
|
// case .scramSha1Plus: 10
|
|
case .scramSha1: 20
|
|
}
|
|
}
|
|
|
|
var isPlus: Bool {
|
|
switch self {
|
|
// case .scramSha1Plus: return true
|
|
default: return false
|
|
}
|
|
}
|
|
}
|
|
|
|
protocol AuthorizationMechanism {
|
|
var initRequest: XMLElement? { get }
|
|
func challenge(xml: XMLElement) async -> Event
|
|
}
|
|
|
|
final class AuthorizationMechanismImpl: AuthorizationMechanism {
|
|
private let type: AuthorizationMechanismType
|
|
private let jid: JID
|
|
private let credentials: Credentials?
|
|
private let userAgent: UserAgent
|
|
private let saslType: SaslType
|
|
private let channelBind: String?
|
|
private let inlines: XMLElement? // TODO: Implement inlines
|
|
|
|
private let alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
|
|
private var clientNonce = ""
|
|
private var serverSignature = ""
|
|
|
|
init(type: AuthorizationMechanismType, jid: JID, credentials: Credentials?, saslType: SaslType, userAgent: UserAgent, channelBind: String?, inlines: XMLElement?) {
|
|
self.type = type
|
|
self.jid = jid
|
|
self.credentials = credentials
|
|
self.userAgent = userAgent
|
|
self.saslType = saslType
|
|
self.channelBind = channelBind
|
|
self.inlines = inlines
|
|
}
|
|
|
|
var initRequest: XMLElement? {
|
|
switch type {
|
|
case .plain:
|
|
return plainRequest
|
|
|
|
case .scramSha1: // .scramSha1Plus:
|
|
return scramSha1Request
|
|
}
|
|
}
|
|
|
|
func challenge(xml: XMLElement) async -> Event {
|
|
switch type {
|
|
case .plain:
|
|
return await plainChallenge(xml: xml)
|
|
|
|
case .scramSha1: // .scramSha1Plus:
|
|
return await scramSha1Challenge(xml: xml)
|
|
}
|
|
}
|
|
}
|
|
|
|
// MARK: PLAIN
|
|
private extension AuthorizationMechanismImpl {
|
|
var plainRequest: XMLElement? {
|
|
guard let pass = credentials?["password"], !pass.isEmpty else {
|
|
print("no credentials...")
|
|
return nil
|
|
}
|
|
let lreq = "\0\(jid.localPart)\0\(pass)"
|
|
let utf8str = lreq.data(using: .utf8)
|
|
let base64 = utf8str?.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
|
|
let str = base64 ?? ""
|
|
switch saslType {
|
|
case .sasl1:
|
|
return XMLElement(
|
|
name: "auth",
|
|
xmlns: saslType.xmlns,
|
|
attributes: ["mechanism": "PLAIN"],
|
|
content: str,
|
|
nodes: []
|
|
)
|
|
|
|
case .sasl2:
|
|
return XMLElement(
|
|
name: "authenticate",
|
|
xmlns: saslType.xmlns,
|
|
attributes: ["mechanism": "PLAIN"],
|
|
content: nil,
|
|
nodes: [
|
|
XMLElement(name: "initial-response", xmlns: nil, attributes: [:], content: str, nodes: []),
|
|
userAgentXml
|
|
]
|
|
)
|
|
}
|
|
}
|
|
|
|
func plainChallenge(xml: XMLElement) async -> Event {
|
|
if xml.name == "success" {
|
|
return succesEvent(xml: xml)
|
|
} else {
|
|
let error = xml.nodes.first?.name ?? "unknown"
|
|
let text = xml.nodes.first(where: { $0.name == "text" })?.content ?? ""
|
|
return .gotAuthError(.mechanismError("\(error) \(text)"))
|
|
}
|
|
}
|
|
}
|
|
|
|
// MARK: SCRAM-SHA-1
|
|
private extension AuthorizationMechanismImpl {
|
|
var scramSha1Request: XMLElement? {
|
|
guard let pass = credentials?["password"], !pass.isEmpty else {
|
|
print("no credentials...")
|
|
return nil
|
|
}
|
|
|
|
let (requestStr, clientNonce) = scramSha1InitRequestString()
|
|
self.clientNonce = clientNonce
|
|
switch saslType {
|
|
case .sasl1:
|
|
return XMLElement(
|
|
name: "auth",
|
|
xmlns: saslType.xmlns,
|
|
attributes: ["mechanism": type.rawValue],
|
|
content: requestStr,
|
|
nodes: []
|
|
)
|
|
|
|
case .sasl2:
|
|
return XMLElement(
|
|
name: "authenticate",
|
|
xmlns: saslType.xmlns,
|
|
attributes: ["mechanism": type.rawValue],
|
|
content: nil,
|
|
nodes: [
|
|
XMLElement(name: "initial-response", xmlns: nil, attributes: [:], content: requestStr, nodes: []),
|
|
userAgentXml
|
|
]
|
|
)
|
|
}
|
|
}
|
|
|
|
func scramSha1Challenge(xml: XMLElement) async -> Event {
|
|
switch xml.name {
|
|
case "challenge":
|
|
guard let pass = credentials?["password"], !pass.isEmpty else {
|
|
return .gotAuthError(.mechanismError("No password"))
|
|
}
|
|
// decode base64 challenge with options
|
|
guard let content = xml.content else { return .gotAuthError(.mechanismError("Wrong challenge string")) }
|
|
guard let msgBytes = Foundation.Data(base64Encoded: content, options: NSData.Base64DecodingOptions(rawValue: 0)) else {
|
|
return .gotAuthError(.mechanismError("Wrong challenge string"))
|
|
}
|
|
let msg = String(decoding: msgBytes, as: UTF8.self)
|
|
|
|
// get payload
|
|
let dict = msg.split(separator: ",")
|
|
.compactMap { part -> (String, String)? in
|
|
guard part.count > 2 else { return nil }
|
|
let line1 = part.prefix(1)
|
|
let line2 = part.dropFirst(2)
|
|
return (String(line1), String(line2))
|
|
}
|
|
.reduce(into: [String: String]()) {
|
|
$0[$1.0] = $1.1
|
|
}
|
|
|
|
guard
|
|
let serverNonce = dict["r"],
|
|
let salt = dict["s"],
|
|
let itrs = dict["i"],
|
|
let iterations = Int(itrs)
|
|
else {
|
|
return .gotAuthError(.mechanismError("Wrong challenge string"))
|
|
}
|
|
|
|
guard serverNonce.hasPrefix(clientNonce) else {
|
|
return .gotAuthError(.mechanismError("Server nonce incorrect"))
|
|
}
|
|
|
|
guard let saltData = Data(base64Encoded: salt, options: Data.Base64DecodingOptions(rawValue: 0)) else {
|
|
return .gotAuthError(.mechanismError("Error forming challenge response"))
|
|
}
|
|
|
|
let saltedPass = Data(pass.utf8).pbkdf2(salt: saltData, rounds: iterations)
|
|
let clientFinalMessageBare = "c=biws,r=\(serverNonce)"
|
|
let clientKeyData = Data("Client Key".utf8)
|
|
let serverKeyData = Data("Server Key".utf8)
|
|
let clientKey = clientKeyData.hmac(key: saltedPass)
|
|
let storedKey = clientKey.sha1()
|
|
let authMessage = "n=\(jid.localPart),r=\(clientNonce),\(msg),\(clientFinalMessageBare)"
|
|
let clientSignature = authMessage.data(using: .utf8)?.hmac(key: storedKey) ?? Data()
|
|
let clientProof = clientKey.xor(other: clientSignature)
|
|
let serverKey = serverKeyData.hmac(key: saltedPass)
|
|
serverSignature = authMessage.data(using: .utf8)?.hmac(key: serverKey).base64EncodedString() ?? ""
|
|
let clientFinalMessage = "\(clientFinalMessageBare),p=\(clientProof.base64EncodedString())"
|
|
|
|
// make challenge response
|
|
let req = XMLElement(
|
|
name: "response",
|
|
xmlns: saslType.xmlns,
|
|
attributes: [:],
|
|
content: clientFinalMessage.base64Encoded,
|
|
nodes: []
|
|
)
|
|
return .xmlOutbound(req)
|
|
|
|
case "success":
|
|
// get server signature
|
|
let signature: String?
|
|
switch saslType {
|
|
case .sasl1:
|
|
signature = xml.content?.base64Decoded
|
|
|
|
case .sasl2:
|
|
signature = xml.nodes.first(where: { $0.name == "additional-data" })?.content?.base64Decoded
|
|
}
|
|
|
|
// check signature
|
|
if let signature, signature == "v=\(serverSignature)" {
|
|
return succesEvent(xml: xml)
|
|
} else {
|
|
return .gotAuthError(.mechanismError("Wrong server signature"))
|
|
}
|
|
|
|
case "failure":
|
|
let error = xml.nodes.first?.name ?? "unknown"
|
|
let text = xml.nodes.first(where: { $0.name == "text" })?.content ?? ""
|
|
return .gotAuthError(.mechanismError("\(error) \(text)"))
|
|
|
|
default:
|
|
return .gotAuthError(.mechanismError("Unknown server challenge \(xml.name) \(xml.content ?? "")"))
|
|
}
|
|
}
|
|
|
|
func scramSha1InitRequestString() -> (String, String) {
|
|
let gssHeader = "n,,"
|
|
let randString = randomString(length: 20)
|
|
let lreq = "\(gssHeader)n=\(jid.localPart),r=\(randString)"
|
|
let utf8str = lreq.data(using: .utf8)
|
|
let base64 = utf8str?.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
|
|
return (base64 ?? "", randString)
|
|
}
|
|
|
|
func randomString(length: Int) -> String {
|
|
String((0 ..< length).map { _ in alphabet.randomElement() ?? "A" })
|
|
}
|
|
|
|
var userAgentXml: XMLElement {
|
|
XMLElement(
|
|
name: "user-agent",
|
|
xmlns: nil,
|
|
attributes: ["id": userAgent.uuid],
|
|
content: nil,
|
|
nodes: [
|
|
XMLElement(name: "device", xmlns: nil, attributes: [:], content: userAgent.device, nodes: []),
|
|
XMLElement(name: "software", xmlns: nil, attributes: [:], content: userAgent.software, nodes: [])
|
|
]
|
|
)
|
|
}
|
|
|
|
func succesEvent(xml: XMLElement) -> Event {
|
|
var args: [String: String] = [:]
|
|
switch saslType {
|
|
case .sasl1:
|
|
break
|
|
|
|
case .sasl2:
|
|
if let authId = xml.nodes.first(where: { $0.name == "authorization-identifier" })?.content {
|
|
args["authorization-identifier"] = authId
|
|
}
|
|
}
|
|
return .authDone(sasl: saslType, args: args)
|
|
}
|
|
}
|