initial commit

src/iOS/Services/KeyChainStorageService.cs

@@ -0,0 +1,91 @@
+using System;
+using System.Runtime.CompilerServices;
+using Bit.App.Abstractions;
+using Foundation;
+using Security;
+
+namespace Bit.iOS.Services
+{
+    public class KeyChainStorageService : ISecureStorageService
+    {
+        public void Store(string key, byte[] dataBytes)
+        {
+            using(var data = NSData.FromArray(dataBytes))
+            using(var newRecord = GetKeyRecord(key, data))
+            {
+                Delete(key);
+                CheckError(SecKeyChain.Add(newRecord));
+            }
+        }
+
+        public byte[] Retrieve(string key)
+        {
+            SecStatusCode resultCode;
+
+            using(var existingRecord = GetKeyRecord(key))
+            using(var record = SecKeyChain.QueryAsRecord(existingRecord, out resultCode))
+            {
+                if(resultCode == SecStatusCode.ItemNotFound)
+                {
+                    return null;
+                }
+
+                CheckError(resultCode);
+                return record.Generic.ToArray();
+            }
+        }
+
+        public void Delete(string key)
+        {
+            using(var record = GetExistingRecord(key))
+            {
+                if(record != null)
+                {
+                    CheckError(SecKeyChain.Remove(record));
+                }
+            }
+        }
+
+        public bool Contains(string key)
+        {
+            using(var existingRecord = GetExistingRecord(key))
+            {
+                return existingRecord != null;
+            }
+        }
+
+        private static void CheckError(SecStatusCode resultCode, [CallerMemberName] string caller = null)
+        {
+            if(resultCode != SecStatusCode.Success)
+            {
+                throw new Exception(string.Format("Failed to execute {0}. Result code: {1}", caller, resultCode));
+            }
+        }
+
+        private static SecRecord GetKeyRecord(string key, NSData data = null)
+        {
+            var record = new SecRecord(SecKind.GenericPassword)
+            {
+                Service = NSBundle.MainBundle.BundleIdentifier,
+                Account = key
+            };
+
+            if(data != null)
+            {
+                record.Generic = data;
+            }
+
+            return record;
+        }
+
+        private static SecRecord GetExistingRecord(string key)
+        {
+            var existingRecord = GetKeyRecord(key);
+
+            SecStatusCode resultCode;
+            SecKeyChain.QueryAsRecord(existingRecord, out resultCode);
+
+            return resultCode == SecStatusCode.Success ? existingRecord : null;
+        }
+    }
+}