Added JWK and JWKS support

Sources/JWT/JWK+KeyOperation.swift

@@ -0,0 +1,22 @@
+import Foundation
+
+public extension JWK {
+    public enum KeyOperation: String, Codable {
+        /// Compute digital signature or MAC.
+        case sign
+        /// Verify digital signature or MAC.
+        case verify
+        /// Encrypt content.
+        case encrypt
+        /// Decrypt content and validate decryption, if applicable.
+        case decrypt
+        /// Encrypt key.
+        case wrapKey
+        /// Decrypt key and validate decryption, if applicable.
+        case unwrapKey
+        /// Derive key.
+        case deriveKey
+        /// Derive bits not to be used as a key.
+        case deriveBits
+    }
+}

Sources/JWT/JWK+PublicKeyUse.swift

@@ -0,0 +1,42 @@
+import Foundation
+
+public extension JWK {
+    public enum PublicKeyUse: RawRepresentable, Codable {
+        case signature
+        case encryption
+        case other(String)
+
+        public var rawValue: String {
+            switch self {
+            case .signature:
+                return "sig"
+            case .encryption:
+                return "enc"
+            case .other(let value):
+                return value
+            }
+        }
+
+        public init(rawValue: String) {
+            switch rawValue {
+            case "sig":
+                self = .signature
+            case "enc":
+                self = .encryption
+            default:
+                self = .other(rawValue)
+            }
+        }
+
+        public init(from decoder: Decoder) throws {
+            let container = try decoder.singleValueContainer()
+            let rawValue = try container.decode(String.self)
+            self.init(rawValue: rawValue)
+        }
+
+        public func encode(to encoder: Encoder) throws {
+            var container = encoder.singleValueContainer()
+            try container.encode(self.rawValue)
+        }
+    }
+}

Sources/JWT/JWK.swift

@@ -0,0 +1,191 @@
+import Foundation
+import Crypto
+
+/// A JSON Web Key.
+///
+/// Read specification (RFC 7517) https://tools.ietf.org/html/rfc7517.
+public struct JWK: Codable {
+    /// The `kty` (key type) parameter identifies the cryptographic algorithm family used with the key, such as `RSA` or `EC`. The `kty` value is a case-sensitive string.
+    public var kty: String
+
+    /// The `use` (public key use) parameter identifies the intended use of the public key. The `use` parameter is employed to indicate whether a public key is used for encrypting data or verifying the signature on data.
+    public var use: PublicKeyUse?
+
+    /// The `key_ops` (key operations) parameter identifies the operation(s) for which the key is intended to be used. The `key_ops` parameter is intended for use cases in which public, private, or symmetric keys may be present.
+    public var keyOps: [KeyOperation]?
+
+    /// The `alg` (algorithm) parameter identifies the algorithm intended for use with the key. The `alg` value is a case-sensitive ASCII string.
+    public var alg: String?
+
+    /**
+     The `kid` (key ID) parameter is used to match a specific key. This is used, for instance, to choose among a set of keys within a JWK Set during key rollover.
+
+     The structure of the `kid` value is unspecified. When `kid` values are used within a JWK Set, different keys within the JWK Set SHOULD use distinct `kid` values.
+
+     (One example in which different keys might use the same `kid` value is if they have different `kty` (key type) values but are considered to be equivalent alternatives by the application using them.)
+
+     The `kid` value is a case-sensitive string.
+     */
+    public var kid: String?
+
+    /// The `x5u` (X.509 URL) parameter is a URI [RFC3986] that refers to a resource for an X.509 public key certificate or certificate chain [RFC5280].
+    public var x5u: String?
+
+    /// The `x5c` (X.509 certificate chain) parameter contains a chain of one or more PKIX certificates [RFC5280].
+    public var x5c: [String]?
+
+    /// The `x5t` (X.509 certificate SHA-1 thumbprint) parameter is a base64url-encoded SHA-1 thumbprint (a.k.a. digest) of the DER encoding of an X.509 certificate [RFC5280].  Note that certificate thumbprints are also sometimes known as certificate fingerprints.
+    public var x5t: String?
+
+    /// The `x5t#S256` (X.509 certificate SHA-256 thumbprint) parameter is a base64url-encoded SHA-256 thumbprint (a.k.a. digest) of the DER encoding of an X.509 certificate [RFC5280].
+    public var x5tS256: String?
+
+    // RSA keys
+    // Represented as the base64url encoding of the value’s unsigned big endian representation as an octet sequence.
+
+    /// Modulus.
+    public var n: String?
+
+    /// Exponent.
+    public var e: String?
+
+    /// Private exponent.
+    public var d: String?
+
+    /// First prime factor.
+    public var p: String?
+
+    /// Second prime factor.
+    public var q: String?
+
+    /// First factor CRT exponent.
+    public var dp: String?
+
+    /// Second factor CRT exponent.
+    public var dq: String?
+
+    /// First CRT coefficient.
+    public var qi: String?
+
+    /// Other primes info.
+    public var oth: OthType?
+
+    // EC DSS keys
+
+    public var crv: String?
+
+    public var x: String?
+
+    public var y: String?
+
+    public enum OthType: String, Codable {
+        case r
+        case d
+        case t
+    }
+
+    private enum CodingKeys: String, CodingKey {
+        case kty
+        case use
+        case keyOps = "key_ops"
+        case alg
+        case kid
+        case x5u
+        case x5c
+        case x5t
+        case x5tS256 = "x5t#S256"
+        case n
+        case e
+        case d
+        case p
+        case q
+        case dp
+        case dq
+        case qi
+        case oth
+        case crv
+        case x
+        case y
+    }
+
+    public init(
+        kty: String,
+        use: PublicKeyUse? = nil,
+        keyOps: [KeyOperation]? = nil,
+        alg: String? = nil,
+        kid: String? = nil,
+        x5u: String? = nil,
+        x5c: [String]? = nil,
+        x5t: String? = nil,
+        x5tS256: String? = nil,
+        n: String? = nil,
+        e: String? = nil,
+        d: String? = nil,
+        p: String? = nil,
+        q: String? = nil,
+        dp: String? = nil,
+        dq: String? = nil,
+        qi: String? = nil,
+        oth: OthType? = nil,
+        crv: String? = nil,
+        x: String? = nil,
+        y: String? = nil
+    ) {
+        self.kty = kty
+        self.use = use
+        self.keyOps = keyOps
+        self.alg = alg
+        self.kid = kid
+        self.x5u = x5u
+        self.x5c = x5c
+        self.x5t = x5t
+        self.x5tS256 = x5tS256
+        self.n = n
+        self.e = e
+        self.d = d
+        self.p = p
+        self.q = q
+        self.dp = dp
+        self.dq = dq
+        self.qi = qi
+        self.oth = oth
+        self.crv = crv
+        self.x = x
+        self.y = y
+    }
+}
+
+public extension JWTSigner {
+
+    /// Creates a JWT signer with the supplied JWK
+    public static func jwk(key: JWK) throws -> JWTSigner {
+        switch key.kty.lowercased() {
+        case "rsa":
+            guard let n = key.n else {
+                throw JWTError(identifier: "missingModulus", reason: "Modulus not specified for JWK RSA key.")
+            }
+            guard let e = key.e else {
+                throw JWTError(identifier: "missingExponent", reason: "Exponent not specified for JWK RSA key.")
+            }
+
+            guard let algorithm = key.alg?.lowercased() else {
+                throw JWTError(identifier: "missingAlgorithm", reason: "Algorithm missing for JWK RSA key.")
+            }
+
+            let rsaKey = try RSAKey.components(n: n, e: e, d: key.d)
+
+            switch algorithm {
+            case "rs256":
+                return JWTSigner.rs256(key: rsaKey)
+            case "rs384":
+                return JWTSigner.rs384(key: rsaKey)
+            case "rs512":
+                return JWTSigner.rs512(key: rsaKey)
+            default:
+                throw JWTError(identifier: "invalidAlgorithm", reason: "Algorithm \(String(describing: key.alg)) not supported for JWK RSA key.")
+            }
+        default:
+            throw JWTError(identifier: "invalidKeyType", reason: "Key type \(String(describing: key.kty)) not supported.")
+        }
+    }
+}

Sources/JWT/JWKS.swift

@@ -0,0 +1,32 @@
+import Foundation
+
+/// A JSON Web Key Set.
+///
+/// A JSON object that represents a set of JWKs.
+/// Read specification (RFC 7517) https://tools.ietf.org/html/rfc7517.
+public struct JWKS: Codable {
+
+    public var keys: [JWK]
+
+    public init(keys: [JWK]) {
+        self.keys = keys
+    }
+}
+
+public extension JWTSigners {
+
+    public convenience init(jwks: JWKS, skipAnonymousKeys: Bool = true) throws  {
+        self.init()
+        for jwk in jwks.keys {
+            guard let kid = jwk.kid else {
+                if skipAnonymousKeys {
+                    continue
+                } else {
+                    throw JWTError(identifier: "missingKID", reason: "At least a JSON Web Key in the JSON Web Key Set is missing a `kid`.")
+                }
+            }
+
+            try self.use(JWTSigner.jwk(key: jwk), kid: kid)
+        }
+    }
+}

Sources/JWT/JWTSigner.swift

@@ -14,7 +14,7 @@ public final class JWTSigner {
     ///
     /// Can be transformed into a String like so:
     ///
-    ///     let signature = try jws.sign()
+    ///     let signature = try jwt.sign()
     ///     guard let string = String(bytes: signed, encoding: .utf8) else {
     ///         throw ...
     ///     }

Tests/JWTTests/JWKTests.swift

@@ -0,0 +1,36 @@
+import XCTest
+@testable import JWT
+
+class JWKTests: XCTestCase {
+
+    static let allTests = [
+        ("testJWKSigner", testJWKSigner)
+    ]
+
+    func testJWKSigner() throws {
+
+        let jsonDecoder = JSONDecoder()
+
+        let privateJWK = try jsonDecoder.decode(JWK.self, from: "{\"kty\":\"RSA\",\"d\":\"L4z0tz7QWE0aGuOA32YqCSnrSYKdBTPFDILCdfHonzfP7WMPibz4jWxu_FzNk9s4Dh-uN2lV3NGW10pAsnqffD89LtYanRjaIdHnLW_PFo5fEL2yltK7qMB9hO1JegppKCfoc79W4-dr-4qy1Op0B3npOP-DaUYlNamfDmIbQW32UKeJzdGIn-_ryrBT7hQW6_uHLS2VFPPk0rNkPPKZYoNaqGnJ0eaFFF-dFwiThXIpPz--dxTAL8xYf275rjG8C9lh6awOfJSIdXMVuQITWf62E0mSQPR2-219bShMKriDYcYLbT3BJEgOkRBBHGuHo9R5TN298anxZqV1u5jtUQ\",\"e\":\"AQAB\",\"use\":\"sig\",\"kid\":\"1234\",\"alg\":\"RS256\",\"n\":\"gWu7yhI35FScdKARYboJoAm-T7yJfJ9JTvAok_RKOJYcL8oLIRSeLqQX83PPZiWdKTdXaiGWntpDu6vW7VAb-HWPF6tNYSLKDSmR3sEu2488ibWijZtNTCKOSb_1iAKAI5BJ80LTqyQtqaKzT0XUBtMsde8vX1nKI05UxujfTX3kqUtkZgLv1Yk1ZDpUoLOWUTtCm68zpjtBrPiN8bU2jqCGFyMyyXys31xFRzz4MyJ5tREHkQCzx0g7AvW0ge_sBTPQ2U6NSkcZvQyDbfDv27cMUHij1Sjx16SY9a2naTuOgamjtUzyClPLVpchX-McNyS0tjdxWY_yRL9MYuw4AQ\"}".convertToData())
+
+        let publicJWK = try jsonDecoder.decode(JWK.self, from: "{\"kty\":\"RSA\",\"e\":\"AQAB\",\"use\":\"sig\",\"kid\":\"1234\",\"alg\":\"RS256\",\"n\":\"gWu7yhI35FScdKARYboJoAm-T7yJfJ9JTvAok_RKOJYcL8oLIRSeLqQX83PPZiWdKTdXaiGWntpDu6vW7VAb-HWPF6tNYSLKDSmR3sEu2488ibWijZtNTCKOSb_1iAKAI5BJ80LTqyQtqaKzT0XUBtMsde8vX1nKI05UxujfTX3kqUtkZgLv1Yk1ZDpUoLOWUTtCm68zpjtBrPiN8bU2jqCGFyMyyXys31xFRzz4MyJ5tREHkQCzx0g7AvW0ge_sBTPQ2U6NSkcZvQyDbfDv27cMUHij1Sjx16SY9a2naTuOgamjtUzyClPLVpchX-McNyS0tjdxWY_yRL9MYuw4AQ\"}".convertToData())
+
+        let privateSigner = try JWTSigner.jwk(key: privateJWK)
+        let publicSigner = try JWTSigner.jwk(key: publicJWK)
+
+        let jwt = JWT(payload: TestPayload(
+            sub: "vapor",
+            name: "Foo",
+            admin: false,
+            exp: .init(value: .init(timeIntervalSince1970: 2_000_000_000))
+        ))
+
+        let signature = try privateSigner.sign(jwt)
+
+        let publicVerified = try JWT<TestPayload>(from: signature, verifiedUsing: publicSigner)
+        let privateVerified = try JWT<TestPayload>(from: signature, verifiedUsing: privateSigner)
+
+        XCTAssertEqual(publicVerified.payload.name, "Foo")
+        XCTAssertEqual(privateVerified.payload.name, "Foo")
+    }
+}

Tests/LinuxMain.swift

@@ -3,4 +3,5 @@ import XCTest
 
 XCTMain([
     testCase(JWTTests.allTests),
+    testCase(JWKTests.allTests)    
 ])