Add export command

Sources/XcodeSimulatorKit/Command line parsing/CommandLineOptions.swift

@@ -34,6 +34,7 @@ struct CommandLineOptions {
     private static let allCommands: [Command] = [
         ListDevicesCommand(),
         InstallCACommand(),
+        ExportCACommand(),
         RemoveCACommand()
     ]
 

Sources/XcodeSimulatorKit/Commands/ExportCACommand.swift

@@ -0,0 +1,103 @@
+//
+//  Copyright © 2019 Simon Kågedal Reimer. See LICENSE.
+//
+
+import Foundation
+import Basic
+import SPMUtility
+
+class ExportCACommand: Command {
+    private struct Options {
+    }
+    let name = "export-ca"
+    let overview = "Export Certificate Authorities"
+
+    private let binder = ArgumentBinder<Options>()
+    private var options = Options()
+
+    private let filteringBinder = ArgumentBinder<FilteringOptions>()
+    private var filteringOptions = FilteringOptions()
+
+    private var exportedCertificates: Set<Data> = []
+
+    func addOptions(to parser: ArgumentParser) {
+        filteringBinder.bind(to: &filteringOptions, parser: parser)
+    }
+
+    func fillParseResult(_ parseResult: ArgumentParser.Result) throws {
+        try binder.fill(parseResult: parseResult, into: &options)
+        try filteringBinder.fill(parseResult: parseResult, into: &filteringOptions)
+    }
+
+    func run() throws {
+        exportedCertificates = []
+        for device in try Simctl.flatListDevices().filter(using: filteringOptions) {
+            exportCertificates(for: device)
+        }
+    }
+
+    private func exportCertificates(for device: Simctl.Device) {
+        do {
+            let store = try TrustStore(uuid: device.udid).open()
+            for row in try store.rows() where !exportedCertificates.contains(row.sha1) {
+                guard let data = row.data else { continue }
+                do {
+                    let path = try exportCertificate(from: data)
+                    print("Exported PEM to \(localFileSystem.printable(path))")
+                    exportedCertificates.insert(row.sha1)
+                } catch {
+                    print("Found invalid certificate: \(error)")
+                }
+            }
+        } catch {
+        }
+    }
+
+    private func exportCertificate(from certificateData: Data) throws -> AbsolutePath {
+        let certificate = try Certificate(certificateData)
+        let fileName = certificate.subjectSummary?.clean() ?? "unknown-certificate"
+        let path = try localFileSystem.uniquePath(base: fileName, ext: "crt")
+        let data = try certificate.exportPEM()
+        try data.write(to: path.asURL)
+        return path
+    }
+}
+
+private extension String {
+    func clean() -> String {
+        return String(map { $0.isWhitespace || $0 == "/" ? "-" : $0 })
+    }
+}
+
+enum FileSystemError: LocalizedError {
+    case couldNotGetCurrentyWorkingDirectory
+
+    var errorDescription: String? {
+        switch self {
+        case .couldNotGetCurrentyWorkingDirectory:
+            return "Unable to get current working directory"
+        }
+    }
+}
+
+private extension FileSystem {
+    /// Returns "base.ext" unless that already exists, in which case it appends a serial number until a unique path has
+    /// been found: "base.ext" -> "base-1.ext" -> "base-2.ext" etc.
+    func uniquePath(base: String, ext: String, count: Int? = nil) throws -> AbsolutePath {
+        guard let directory = currentWorkingDirectory else {
+            throw FileSystemError.couldNotGetCurrentyWorkingDirectory
+        }
+        let path = directory.appending(component: base + (count.map { "-\($0)" } ?? "") + "." + ext)
+        if exists(path) {
+            return try uniquePath(base: base, ext: ext, count: count.map { $0 + 1 } ?? 1)
+        }
+        return path
+    }
+
+    func printable(_ path: AbsolutePath) -> String {
+        if let directory = currentWorkingDirectory {
+            return path.relative(to: directory).description
+        }
+        return path.description
+    }
+}

Sources/XcodeSimulatorKit/Trust Store/Certificate.swift

@@ -9,6 +9,8 @@ struct Certificate {
     enum Error: LocalizedError {
         case invalidDERX509
         case importError(OSStatus)
+        case exportError(OSStatus)
+        case exportNoData
         case notACertficate
         case unknown
 
@@ -18,6 +20,10 @@ struct Certificate {
                 return "Given data was not a valid DER encoded X.509 certificate"
             case .importError(let status):
                 return "Error from SecItemImport: \(status)"
+            case .exportError(let status):
+                return "Error from SecItemExport: \(status)"
+            case .exportNoData:
+                return "No data returned from SecItemExport"
             case .notACertficate:
                 return "SecItemImport gave something else than a certificate"
             case .unknown:
@@ -93,4 +99,17 @@ struct Certificate {
         return try Certificate(certData)
     }
 
+    func exportPEM() throws -> Data {
+        var cfData: CFData?
+        let status = withUnsafeMutablePointer(to: &cfData) { pointer in
+            SecItemExport(certificate, .formatX509Cert, .pemArmour, nil, pointer)
+        }
+        guard status == errSecSuccess else {
+            throw Error.exportError(status)
+        }
+        guard let data = cfData else {
+            throw Error.exportNoData
+        }
+        return data as Data
+    }
 }