[117] Allow JWK parameters of type [String]

JOSESwift/Sources/ECKeyCodable.swift

@@ -33,8 +33,14 @@ extension ECPublicKey: Encodable {
         // Other common parameters are optional.
         for parameter in parameters {
             // Only encode known parameters.
-            if let key = JWKParameter(rawValue: parameter.key) {
-                try commonParameters.encode(parameter.value, forKey: key)
+            guard let key = JWKParameter(rawValue: parameter.key) else {
+                continue
+            }
+
+            if let value = parameter.value as? String {
+                try commonParameters.encode(value, forKey: key)
+            } else if let value = parameter.value as? [String] {
+                try commonParameters.encode(value, forKey: key)
             }
         }
 
@@ -62,9 +68,17 @@ extension ECPublicKey: Decodable {
         }
 
         // Other common parameters are optional.
-        var parameters: [String: String] = [:]
-        for key in commonParameters.allKeys where !JWKParameter.nonStringParameters.contains(key) {
-            parameters[key.rawValue] = try commonParameters.decode(String.self, forKey: key)
+        var parameters: [String: JWKParameterType] = [:]
+
+        for key in commonParameters.allKeys {
+            switch key.type {
+            case is String.Type:
+                parameters[key.rawValue] = try commonParameters.decode(String.self, forKey: key)
+            case is [String].Type:
+                parameters[key.rawValue] = try commonParameters.decode([String].self, forKey: key)
+            default:
+                break
+            }
         }
 
         // EC public key specific parameters.
@@ -92,8 +106,14 @@ extension ECPrivateKey: Encodable {
         // Other common parameters are optional.
         for parameter in parameters {
             // Only encode known parameters.
-            if let key = JWKParameter(rawValue: parameter.key) {
-                try commonParameters.encode(parameter.value, forKey: key)
+            guard let key = JWKParameter(rawValue: parameter.key) else {
+                continue
+            }
+
+            if let value = parameter.value as? String {
+                try commonParameters.encode(value, forKey: key)
+            } else if let value = parameter.value as? [String] {
+                try commonParameters.encode(value, forKey: key)
             }
         }
 
@@ -122,9 +142,17 @@ extension ECPrivateKey: Decodable {
         }
 
         // Other common parameters are optional.
-        var parameters: [String: String] = [:]
-        for key in commonParameters.allKeys where !JWKParameter.nonStringParameters.contains(key) {
-            parameters[key.rawValue] = try commonParameters.decode(String.self, forKey: key)
+        var parameters: [String: JWKParameterType] = [:]
+
+        for key in commonParameters.allKeys {
+            switch key.type {
+            case is String.Type:
+                parameters[key.rawValue] = try commonParameters.decode(String.self, forKey: key)
+            case is [String].Type:
+                parameters[key.rawValue] = try commonParameters.decode([String].self, forKey: key)
+            default:
+                break
+            }
         }
 
         // EC private key specific parameters.

JOSESwift/Sources/ECKeys.swift

@@ -96,7 +96,7 @@ public struct ECPublicKey: JWK {
     public let keyType: JWKKeyType
 
     /// The JWK parameters.
-    public let parameters: [String: String]
+    public let parameters: [String: JWKParameterType]
 
     /// The curve value for the EC public key.
     public let crv: ECCurveType
@@ -120,7 +120,10 @@ public struct ECPublicKey: JWK {
     ///   - y: The y coordinate for the EC public key in `base64urlUInt` encoding
     ///        as specified in [RFC-7518, Section 2](https://tools.ietf.org/html/rfc7518#section-2).
     ///   - parameters: Additional JWK parameters.
-    public init(crv: ECCurveType, x: String, y: String, additionalParameters parameters: [String: String] = [:]) {
+    public init(crv: ECCurveType,
+                x: String,
+                y: String,
+                additionalParameters parameters: [String: JWKParameterType] = [:]) {
         self.keyType = .EC
         self.crv = crv
         self.x = x
@@ -143,7 +146,8 @@ public struct ECPublicKey: JWK {
     ///   - publicKey: The public key that the resulting JWK should represent.
     ///   - parameters: Any additional parameters to be contained in the JWK.
     /// - Throws: A `JOSESwiftError` indicating any errors.
-    public init(publicKey: ExpressibleAsECPublicKeyComponents, additionalParameters parameters: [String: String] = [:]) throws {
+    public init(publicKey: ExpressibleAsECPublicKeyComponents,
+                additionalParameters parameters: [String: JWKParameterType] = [:]) throws {
         guard let components = try? publicKey.ecPublicKeyComponents() else {
             throw JOSESwiftError.couldNotConstructJWK
         }
@@ -197,7 +201,7 @@ public struct ECPrivateKey: JWK {
     public let keyType: JWKKeyType
 
     /// The JWK parameters.
-    public let parameters: [String: String]
+    public let parameters: [String: JWKParameterType]
 
     /// The curve value for the EC public key.
     public let crv: ECCurveType
@@ -226,7 +230,11 @@ public struct ECPrivateKey: JWK {
     ///   - privateKey: The private key component for the EC public key in `base64urlUInt` encoding
     ///                 as specified in [RFC-7518, Section 2](https://tools.ietf.org/html/rfc7518#section-2).
     ///   - parameters: Additional JWK parameters.
-    public init(crv: String, x: String, y: String, privateKey: String, additionalParameters parameters: [String: String] = [:]) throws {
+    public init(crv: String,
+                x: String,
+                y: String,
+                privateKey: String,
+                additionalParameters parameters: [String: JWKParameterType] = [:]) throws {
         self.keyType = .EC
 
         guard let curve = ECCurveType(rawValue: crv) else {
@@ -256,7 +264,8 @@ public struct ECPrivateKey: JWK {
     ///   - privateKey: The private key that the resulting JWK should represent.
     ///   - parameters: Any additional parameters to be contained in the JWK.
     /// - Throws: A `JOSESwiftError` indicating any errors.
-    public init(privateKey: ExpressibleAsECPrivateKeyComponents, additionalParameters parameters: [String: String] = [:]) throws {
+    public init(privateKey: ExpressibleAsECPrivateKeyComponents,
+                additionalParameters parameters: [String: JWKParameterType] = [:]) throws {
         guard let (crv, x, y, privateKey) = try? privateKey.ecPrivateKeyComponents() else {
             throw JOSESwiftError.couldNotConstructJWK
         }

JOSESwift/Sources/JWK.swift

@@ -55,15 +55,15 @@ public protocol JWK: Codable {
     /// The parameters of the JWK representing the properties of the key(s), including the value(s).
     /// Check [RFC 7517, Section 4](https://tools.ietf.org/html/rfc7517#section-4) and
     /// [RFC 7518, Section 6](https://tools.ietf.org/html/rfc7518#section-6) for possible parameters.
-    var parameters: [String: String] { get }
+    var parameters: [String: JWKParameterType] { get }
 
     /// Accesses the specified parameter.
     /// The parameters of the JWK representing the properties of the key(s), including the value(s).
     /// Check [RFC 7517, Section 4](https://tools.ietf.org/html/rfc7517#section-4) and
     /// [RFC 7518, Section 6](https://tools.ietf.org/html/rfc7518#section-6) for possible parameters.
     ///
     /// - Parameter parameter: The desired parameter.
-    subscript(parameter: String) -> String? { get }
+    subscript(parameter: String) -> JWKParameterType? { get }
 
     /// Initializes a JWK from given JSON data.
     ///

JOSESwift/Sources/JWKExtensions.swift

@@ -26,7 +26,7 @@ import Foundation
 // MARK: Subscript
 
 public extension JWK {
-    subscript(parameter: String) -> String? {
+    subscript(parameter: String) -> JWKParameterType? {
         return parameters[parameter]
     }
 }
@@ -46,3 +46,59 @@ public extension JWK {
         return try? JSONEncoder().encode(self)
     }
 }
+
+// MARK: Parameter getters
+
+extension JWK {
+    /// The public key use parameter identifies the intended use of a public key.
+    /// See [RFC-7517](https://tools.ietf.org/html/rfc7517#section-4.2).
+    var keyUse: String? {
+        return parameters[JWKParameter.keyUse.rawValue] as? String
+    }
+
+    /// The key operations parameter identifies the operation(s) for which the key is intended to be used.
+    /// See [RFC-7517](https://tools.ietf.org/html/rfc7517#section-4.3).
+    var keyOperations: [String]? {
+        return parameters[JWKParameter.keyOperations.rawValue] as? [String]
+    }
+
+    /// The algorithm parameter identifies the algorithm intended for use with the key.
+    /// See [RFC-7517](https://tools.ietf.org/html/rfc7517#section-4.4).
+    var algorithm: String? {
+        return parameters[JWKParameter.algorithm.rawValue] as? String
+    }
+
+    /// The key identifier parameter is used to match a specific key.
+    /// See [RFC-7517](https://tools.ietf.org/html/rfc7517#section-4.5).
+    var keyIdentifier: String? {
+        return parameters[JWKParameter.keyIdentifier.rawValue] as? String
+    }
+
+    /// The X.509 URL parameter is a URI that refers to a resource for an X.509 public key certificate
+    /// or certificate chain.
+    /// See [RFC-7517](https://tools.ietf.org/html/rfc7517#section-4.6).
+    var X509URL: String? {
+        return parameters[JWKParameter.X509URL.rawValue] as? String
+    }
+
+    /// The X.509 certificate chain parameter contains a chain of one or more PKIX certificates.
+    /// See [RFC-7517](https://tools.ietf.org/html/rfc7517#section-4.7).
+    var X509CertificateChain: [String]? {
+        return parameters[JWKParameter.X509CertificateChain.rawValue] as? [String]
+    }
+
+    /// The 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.
+    /// See [RFC-7517](https://tools.ietf.org/html/rfc7517#section-4.8).
+    var X509CertificateSHA1Thumbprint: String? {
+        return parameters[JWKParameter.X509CertificateSHA1Thumbprint.rawValue] as? String
+    }
+
+    /// The 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.
+    /// See [RFC-7517](https://tools.ietf.org/html/rfc7517#section-4.9).
+    var X509CertificateSHA256Thumbprint: String? {
+        return parameters[JWKParameter.X509CertificateSHA256Thumbprint.rawValue] as? String
+    }
+}
+

JOSESwift/Sources/JWKParameters.swift

@@ -24,6 +24,12 @@
 
 import Foundation
 
+// Common protocol for all types that can be used as JWK parameters.
+public protocol JWKParameterType: Codable { }
+
+extension String: JWKParameterType { }
+extension Array: JWKParameterType where Element == String { }
+
 /// Possible common JWK parameters.
 /// See [RFC-7517, Section 4](https://tools.ietf.org/html/rfc7517#section-4) for details.
 public enum JWKParameter: String, CodingKey {
@@ -37,10 +43,15 @@ public enum JWKParameter: String, CodingKey {
     case X509CertificateSHA1Thumbprint = "x5t"
     case X509CertificateSHA256Thumbprint = "x5t#S256"
 
-    static let nonStringParameters: [JWKParameter] = [
-        .keyOperations,
-        .X509CertificateChain
-    ]
+    var type: Codable.Type {
+        switch self {
+        case .keyType, .keyUse, .algorithm, .keyIdentifier,
+             .X509URL, .X509CertificateSHA1Thumbprint, .X509CertificateSHA256Thumbprint:
+            return String.self
+        case .keyOperations, .X509CertificateChain:
+            return [String].self
+        }
+    }
 }
 
 /// RSA specific JWK parameters.

JOSESwift/Sources/RSAKeyCodable.swift

@@ -33,8 +33,14 @@ extension RSAPublicKey: Encodable {
         // Other common parameters are optional.
         for parameter in parameters {
             // Only encode known parameters.
-            if let key = JWKParameter(rawValue: parameter.key) {
-                try commonParameters.encode(parameter.value, forKey: key)
+            guard let key = JWKParameter(rawValue: parameter.key) else {
+                continue
+            }
+
+            if let value = parameter.value as? String {
+                try commonParameters.encode(value, forKey: key)
+            } else if let value = parameter.value as? [String] {
+                try commonParameters.encode(value, forKey: key)
             }
         }
 
@@ -61,9 +67,17 @@ extension RSAPublicKey: Decodable {
         }
 
         // Other common parameters are optional.
-        var parameters: [String: String] = [:]
-        for key in commonParameters.allKeys where !JWKParameter.nonStringParameters.contains(key) {
-            parameters[key.rawValue] = try commonParameters.decode(String.self, forKey: key)
+        var parameters: [String: JWKParameterType] = [:]
+
+        for key in commonParameters.allKeys {
+            switch key.type {
+            case is String.Type:
+                parameters[key.rawValue] = try commonParameters.decode(String.self, forKey: key)
+            case is [String].Type:
+                parameters[key.rawValue] = try commonParameters.decode([String].self, forKey: key)
+            default:
+                break
+            }
         }
 
         // RSA public key specific parameters.
@@ -89,8 +103,14 @@ extension RSAPrivateKey: Encodable {
         // Other common parameters are optional.
         for parameter in parameters {
             // Only encode known parameters.
-            if let key = JWKParameter(rawValue: parameter.key) {
-                try commonParameters.encode(parameter.value, forKey: key)
+            guard let key = JWKParameter(rawValue: parameter.key) else {
+                continue
+            }
+
+            if let value = parameter.value as? String {
+                try commonParameters.encode(value, forKey: key)
+            } else if let value = parameter.value as? [String] {
+                try commonParameters.encode(value, forKey: key)
             }
         }
 
@@ -118,9 +138,17 @@ extension RSAPrivateKey: Decodable {
         }
 
         // Other common parameters are optional.
-        var parameters: [String: String] = [:]
-        for key in commonParameters.allKeys where !JWKParameter.nonStringParameters.contains(key) {
-            parameters[key.rawValue] = try commonParameters.decode(String.self, forKey: key)
+        var parameters: [String: JWKParameterType] = [:]
+
+        for key in commonParameters.allKeys {
+            switch key.type {
+            case is String.Type:
+                parameters[key.rawValue] = try commonParameters.decode(String.self, forKey: key)
+            case is [String].Type:
+                parameters[key.rawValue] = try commonParameters.decode([String].self, forKey: key)
+            default:
+                break
+            }
         }
 
         // RSA private key specific parameters.

JOSESwift/Sources/RSAKeys.swift

@@ -94,7 +94,7 @@ public struct RSAPublicKey: JWK {
     public let keyType: JWKKeyType
 
     /// The JWK parameters.
-    public let parameters: [String: String]
+    public let parameters: [String: JWKParameterType]
 
     /// The modulus value for the RSA public key.
     public let modulus: String
@@ -113,7 +113,7 @@ public struct RSAPublicKey: JWK {
     ///   - exponent: The public exponent value for the RSA public key in `base64urlUInt` encoding
     ///               as specified in [RFC-7518, Section 2](https://tools.ietf.org/html/rfc7518#section-2).
     ///   - parameters: Additional JWK parameters.
-    public init(modulus: String, exponent: String, additionalParameters parameters: [String: String] = [:]) {
+    public init(modulus: String, exponent: String, additionalParameters parameters: [String: JWKParameterType] = [:]) {
         self.keyType = .RSA
         self.modulus = modulus
         self.exponent = exponent
@@ -134,7 +134,8 @@ public struct RSAPublicKey: JWK {
     ///   - publicKey: The public key that the resulting JWK should represent.
     ///   - parameters: Any additional parameters to be contained in the JWK.
     /// - Throws: A `JOSESwiftError` indicating any errors.
-    public init(publicKey: ExpressibleAsRSAPublicKeyComponents, additionalParameters parameters: [String: String] = [:]) throws {
+    public init(publicKey: ExpressibleAsRSAPublicKeyComponents,
+                additionalParameters parameters: [String: JWKParameterType] = [:]) throws {
         guard let components = try? publicKey.rsaPublicKeyComponents() else {
             throw JOSESwiftError.couldNotConstructJWK
         }
@@ -184,7 +185,7 @@ public struct RSAPrivateKey: JWK {
     public let keyType: JWKKeyType
 
     /// The JWK parameters.
-    public let parameters: [String: String]
+    public let parameters: [String: JWKParameterType]
 
     /// The modulus value for the RSA private key.
     public let modulus: String
@@ -205,7 +206,7 @@ public struct RSAPrivateKey: JWK {
     //    - privateExponent: The private exponent value for the RSA private key in `base64urlUInt` encoding
     ///               as specified in [RFC-7518, Section 2](https://tools.ietf.org/html/rfc7518#section-2).
     ///   - parameters: Additional JWK parameters.
-    public init(modulus: String, exponent: String, privateExponent: String, additionalParameters parameters: [String: String] = [:]) {
+    public init(modulus: String, exponent: String, privateExponent: String, additionalParameters parameters: [String: JWKParameterType] = [:]) {
         self.keyType = .RSA
         self.modulus = modulus
         self.exponent = exponent
@@ -228,7 +229,8 @@ public struct RSAPrivateKey: JWK {
     ///   - privateKey: The private key that the resulting JWK should represent.
     ///   - parameters: Any additional parameters to be contained in the JWK.
     /// - Throws: A `JOSESwiftError` indicating any errors.
-    public init(privateKey: ExpressibleAsRSAPrivateKeyComponents, additionalParameters parameters: [String: String] = [:]) throws {
+    public init(privateKey: ExpressibleAsRSAPrivateKeyComponents,
+                additionalParameters parameters: [String: JWKParameterType] = [:]) throws {
         guard let (modulus, exponent, privateExponent) = try? privateKey.rsaPrivateKeyComponents() else {
             throw JOSESwiftError.couldNotConstructJWK
         }