secretive/SecretKit/SmartCard/SmartCardStore.swift

113 lines
3.7 KiB
Swift

import Foundation
import Security
import CryptoTokenKit
// TODO: Might need to split this up into "sub-stores?"
// ie, each token has its own Store.
extension SmartCard {
public class Store: SecretStore {
// TODO: Read actual smart card name, eg "YubiKey 5c"
public let name = NSLocalizedString("Smart Card", comment: "Smart Card")
@Published public fileprivate(set) var secrets: [Secret] = []
fileprivate let watcher = TKTokenWatcher()
fileprivate var id: String?
public init() {
id = watcher.tokenIDs.filter { !$0.contains("setoken") }.first
watcher.setInsertionHandler { string in
guard self.id == nil else { return }
guard !string.contains("setoken") else { return }
self.id = string
self.secrets.removeAll()
self.loadSecrets()
}
loadSecrets()
}
// MARK: Public API
public func create(name: String) throws {
fatalError("Keys must be created on the smart card.")
}
public func delete(secret: Secret) throws {
fatalError("Keys must be deleted on the smart card.")
}
public func sign(data: Data, with secret: SecretType) throws -> Data {
guard let id = id else { fatalError() }
let attributes = [
kSecClass: kSecClassKey,
kSecAttrKeyClass: kSecAttrKeyClassPrivate,
kSecAttrApplicationLabel: secret.id as CFData,
kSecAttrTokenID: id,
kSecReturnRef: true
] as CFDictionary
var untyped: CFTypeRef?
let status = SecItemCopyMatching(attributes, &untyped)
if status != errSecSuccess {
throw KeychainError(statusCode: status)
}
guard let untypedSafe = untyped else {
throw KeychainError(statusCode: errSecSuccess)
}
let key = untypedSafe as! SecKey
var signError: SecurityError?
guard let signature = SecKeyCreateSignature(key, .ecdsaSignatureMessageX962SHA256, data as CFData, &signError) else {
throw SigningError(error: signError)
}
return signature as Data
}
}
}
extension SmartCard.Store {
fileprivate func loadSecrets() {
guard let id = id else { return }
let attributes = [
kSecClass: kSecClassKey,
kSecAttrTokenID: id,
kSecReturnRef: true,
kSecMatchLimit: kSecMatchLimitAll,
kSecReturnAttributes: true
] as CFDictionary
var untyped: CFTypeRef?
SecItemCopyMatching(attributes, &untyped)
guard let typed = untyped as? [[CFString: Any]] else { return }
let wrapped: [SmartCard.Secret] = typed.map {
let name = $0[kSecAttrLabel] as? String ?? "Unnamed"
let id = $0[kSecAttrApplicationLabel] as! Data
let publicKeyRef = $0[kSecValueRef] as! SecKey
let publicKeySecRef = SecKeyCopyPublicKey(publicKeyRef)!
let publicKeyAttributes = SecKeyCopyAttributes(publicKeySecRef) as! [CFString: Any]
let publicKey = publicKeyAttributes[kSecValueData] as! Data
return SmartCard.Secret(id: id, name: name, publicKey: publicKey)
}
secrets.append(contentsOf: wrapped)
}
}
extension SmartCard {
public struct KeychainError: Error {
public let statusCode: OSStatus
}
public struct SigningError: Error {
public let error: SecurityError?
}
}
extension SmartCard {
public typealias SecurityError = Unmanaged<CFError>
}