1 files changed, 53 insertions, 0 deletions

diff --git a/src/WixToolset.Data/Common.cs b/src/WixToolset.Data/Common.cs
new file mode 100644
index 00000000..f01b4591
--- /dev/null
+++ b/src/WixToolset.Data/Common.cs
@@ -0,0 +1,53 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Data
+{
+    using System;
+    using System.IO;
+    using System.Security.Cryptography;
+    using System.Text;
+    using System.Text.RegularExpressions;
+    using System.Xml.Linq;
+
+    internal static class Common
+    {
+        public const int IntegerNotSet = int.MinValue;
+
+        internal static readonly XNamespace W3SchemaPrefix = "http://www.w3.org/";
+
+        private static readonly Regex LegalIdentifierCharacters = new Regex(@"^[_A-Za-z][0-9A-Za-z_\.]*$", RegexOptions.Compiled);
+
+        internal static string GetFileHash(FileInfo fileInfo)
+        {
+            byte[] hashBytes;
+            using (SHA1Managed managed = new SHA1Managed())
+            {
+                using (FileStream stream = fileInfo.OpenRead())
+                {
+                    hashBytes = managed.ComputeHash(stream);
+                }
+            }
+
+            StringBuilder sb = new StringBuilder();
+            for (int i = 0; i < hashBytes.Length; i++)
+            {
+                sb.AppendFormat("{0:X2}", hashBytes[i]);
+            }
+
+            return sb.ToString();
+        }
+
+        public static bool IsIdentifier(string value)
+        {
+            if (!String.IsNullOrEmpty(value))
+            {
+                if (LegalIdentifierCharacters.IsMatch(value))
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+    }
+}