Refactor listing of certificates

Sources/XcodeSimulatorKit/CommandLineOptions.swift

@@ -64,7 +64,7 @@ struct CommandLineOptions {
         binder.bind(
             parser: parser,
             to: { _, subcommand in
-                print("Parsed subcommand: \(subcommand)")
+//                print("Parsed subcommand: \(subcommand)")
             }
         )
 

Sources/XcodeSimulatorKit/Commands/ListDevicesCommand.swift

@@ -34,15 +34,27 @@ struct ListDevicesCommand: Command {
                 print(" - \(device.name)")
                 let trustStore = TrustStore(uuid: device.udid)
                 if trustStore.exists {
-                    if let store = try? trustStore.open(), store.isValid() {
-                        try? store.listCertificates()
-                    } else {
-                        print("   - Invalid trust store exists at \(trustStore.path)")
-                    }
+                    try listCertificates(in: trustStore)
                 }
             }
         }
     }
+
+    private func listCertificates(in trustStore: TrustStore) throws {
+        let store = try trustStore.open()
+        guard store.isValid() else {
+            return print("   Invalid trust store at \(trustStore.path)")
+        }
+
+        var didPrintHeader = false
+        for certificate in try store.certificates() {
+            if !didPrintHeader {
+                print("   Certificates:")
+                didPrintHeader = true
+            }
+            print("    - \(certificate.subjectSummary ?? "<unknown certificate>")")
+        }
+    }
 }
 
 extension FilteringOptions.Availability {

Sources/XcodeSimulatorKit/Trust Store/Security+Convenience.swift

@@ -5,37 +5,39 @@
 import Foundation
 import Security
 
-enum SecurityError: LocalizedError {
-    case invalidDERX509
-    case unknown
+struct Certificate {
+    enum Error: LocalizedError {
+        case invalidDERX509
+        case unknown
 
-    var errorDescription: String? {
-        switch self {
-        case .invalidDERX509:
-            return "Given data was not a valid DER encoded X.509 certificate"
-        case .unknown:
-            return "Operation completed with an unknown error from the Security framework"
+        var errorDescription: String? {
+            switch self {
+            case .invalidDERX509:
+                return "Given data was not a valid DER encoded X.509 certificate"
+            case .unknown:
+                return "Operation completed with an unknown error from the Security framework"
+            }
         }
     }
-}
 
-extension SecCertificate {
-    static func read(data: Data) throws -> SecCertificate {
+    private let certificate: SecCertificate
+
+    init(_ data: Data) throws {
         guard let certificate = SecCertificateCreateWithData(nil, data as CFData) else {
-            throw SecurityError.invalidDERX509
+            throw Error.invalidDERX509
         }
-        return certificate
+        self.certificate = certificate
     }
 
     var subjectSummary: String? {
-        return SecCertificateCopySubjectSummary(self) as String?
+        return SecCertificateCopySubjectSummary(certificate) as String?
     }
 
     func normalizedSubjectSequence() throws -> Data {
         var error: Unmanaged<CFError>?
-        guard let data = SecCertificateCopyNormalizedSubjectContent(self, &error) else {
+        guard let data = SecCertificateCopyNormalizedSubjectContent(certificate, &error) else {
             guard let error = error else {
-                throw SecurityError.unknown
+                throw Error.unknown
             }
             throw error.takeRetainedValue()
         }

Sources/XcodeSimulatorKit/Trust Store/TrustStore.swift

@@ -42,17 +42,11 @@ struct TrustStore {
             }
         }
 
-        func listCertificates() throws {
-            for certificate in try connection.prepare(tsettings) {
-                guard let blob = certificate[dataColumn] else {
-                    print("Couldn't get data blob from row...")
-                    continue
+        func certificates() throws -> [Certificate] {
+            return try connection.prepare(tsettings).compactMap { row in
+                try row[dataColumn].map { blob in
+                    try Certificate(Data(blob.bytes))
                 }
-                let data = Data(blob.bytes)
-                let cert = try SecCertificate.read(data: data)
-                cert.printInfo()
-                let count = blob.bytes.count
-                print(" - \(count) bytes")
             }
         }
     }