using System; using System.Collections.Generic; using System.Data; using System.Globalization; using System.IO; using System.Linq; using System.Reflection; using System.Security.Cryptography; using System.Security.Cryptography.X509Certificates; using System.Text; using System.Text.Json; using System.Text.RegularExpressions; using System.Threading; using System.Threading.Tasks; using System.Web; using Azure.Storage.Queues; using Azure.Storage.Queues.Models; using Bit.Core.Context; using Bit.Core.Enums; using Bit.Core.Enums.Provider; using Bit.Core.Models.Data; using Bit.Core.Models.Table; using Bit.Core.Settings; using Dapper; using IdentityModel; using Microsoft.AspNetCore.DataProtection; using Microsoft.Azure.Storage; using Microsoft.Azure.Storage.Blob; using MimeKit; using Newtonsoft.Json; namespace Bit.Core.Utilities { public static class CoreHelpers { private static readonly long _baseDateTicks = new DateTime(1900, 1, 1).Ticks; private static readonly DateTime _epoc = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc); private static readonly DateTime _max = new DateTime(9999, 1, 1, 0, 0, 0, DateTimeKind.Utc); private static readonly Random _random = new Random(); private static string _version; private static readonly string _qwertyDvorakMap = "-=qwertyuiop[]asdfghjkl;'zxcvbnm,./_+QWERTYUIO" + "P{}ASDFGHJKL:\"ZXCVBNM<>?"; private static readonly string _dvorakMap = "[]',.pyfgcrl/=aoeuidhtns-;qjkxbmwvz{}\"<>PYFGC" + "RL?+AOEUIDHTNS_:QJKXBMWVZ"; private static readonly string _qwertyColemakMap = "qwertyuiopasdfghjkl;zxcvbnmQWERTYUIOPASDFGHJKL:ZXCVBNM"; private static readonly string _colemakMap = "qwfpgjluy;arstdhneiozxcvbkmQWFPGJLUY:ARSTDHNEIOZXCVBKM"; private static readonly string CloudFlareConnectingIp = "CF-Connecting-IP"; private static readonly string RealIp = "X-Real-IP"; /// /// Generate sequential Guid for Sql Server. /// ref: https://github.com/nhibernate/nhibernate-core/blob/master/src/NHibernate/Id/GuidCombGenerator.cs /// /// A comb Guid. public static Guid GenerateComb() { var guidArray = Guid.NewGuid().ToByteArray(); var now = DateTime.UtcNow; // Get the days and milliseconds which will be used to build the byte string var days = new TimeSpan(now.Ticks - _baseDateTicks); var msecs = now.TimeOfDay; // Convert to a byte array // Note that SQL Server is accurate to 1/300th of a millisecond so we divide by 3.333333 var daysArray = BitConverter.GetBytes(days.Days); var msecsArray = BitConverter.GetBytes((long)(msecs.TotalMilliseconds / 3.333333)); // Reverse the bytes to match SQL Servers ordering Array.Reverse(daysArray); Array.Reverse(msecsArray); // Copy the bytes into the guid Array.Copy(daysArray, daysArray.Length - 2, guidArray, guidArray.Length - 6, 2); Array.Copy(msecsArray, msecsArray.Length - 4, guidArray, guidArray.Length - 4, 4); return new Guid(guidArray); } public static IEnumerable> Batch(this IEnumerable source, int size) { T[] bucket = null; var count = 0; foreach (var item in source) { if (bucket == null) { bucket = new T[size]; } bucket[count++] = item; if (count != size) { continue; } yield return bucket.Select(x => x); bucket = null; count = 0; } // Return the last bucket with all remaining elements if (bucket != null && count > 0) { yield return bucket.Take(count); } } public static DataTable ToGuidIdArrayTVP(this IEnumerable ids) { return ids.ToArrayTVP("GuidId"); } public static DataTable ToArrayTVP(this IEnumerable values, string columnName) { var table = new DataTable(); table.SetTypeName($"[dbo].[{columnName}Array]"); table.Columns.Add(columnName, typeof(T)); if (values != null) { foreach (var value in values) { table.Rows.Add(value); } } return table; } public static DataTable ToArrayTVP(this IEnumerable values) { var table = new DataTable(); table.SetTypeName("[dbo].[SelectionReadOnlyArray]"); var idColumn = new DataColumn("Id", typeof(Guid)); table.Columns.Add(idColumn); var readOnlyColumn = new DataColumn("ReadOnly", typeof(bool)); table.Columns.Add(readOnlyColumn); var hidePasswordsColumn = new DataColumn("HidePasswords", typeof(bool)); table.Columns.Add(hidePasswordsColumn); if (values != null) { foreach (var value in values) { var row = table.NewRow(); row[idColumn] = value.Id; row[readOnlyColumn] = value.ReadOnly; row[hidePasswordsColumn] = value.HidePasswords; table.Rows.Add(row); } } return table; } public static DataTable ToTvp(this IEnumerable orgUsers) { var table = new DataTable(); table.SetTypeName("[dbo].[OrganizationUserType]"); var columnData = new List<(string name, Type type, Func getter)> { (nameof(OrganizationUser.Id), typeof(Guid), ou => ou.Id), (nameof(OrganizationUser.OrganizationId), typeof(Guid), ou => ou.OrganizationId), (nameof(OrganizationUser.UserId), typeof(Guid), ou => ou.UserId), (nameof(OrganizationUser.Email), typeof(string), ou => ou.Email), (nameof(OrganizationUser.Key), typeof(string), ou => ou.Key), (nameof(OrganizationUser.Status), typeof(byte), ou => ou.Status), (nameof(OrganizationUser.Type), typeof(byte), ou => ou.Type), (nameof(OrganizationUser.AccessAll), typeof(bool), ou => ou.AccessAll), (nameof(OrganizationUser.ExternalId), typeof(string), ou => ou.ExternalId), (nameof(OrganizationUser.CreationDate), typeof(DateTime), ou => ou.CreationDate), (nameof(OrganizationUser.RevisionDate), typeof(DateTime), ou => ou.RevisionDate), (nameof(OrganizationUser.Permissions), typeof(string), ou => ou.Permissions), (nameof(OrganizationUser.ResetPasswordKey), typeof(string), ou => ou.ResetPasswordKey), }; foreach (var (name, type, getter) in columnData) { var column = new DataColumn(name, type); table.Columns.Add(column); } foreach (var orgUser in orgUsers ?? new OrganizationUser[] { }) { var row = table.NewRow(); foreach (var (name, type, getter) in columnData) { var val = getter(orgUser); if (val == null) { row[name] = DBNull.Value; } else { row[name] = val; } } table.Rows.Add(row); } return table; } public static string CleanCertificateThumbprint(string thumbprint) { // Clean possible garbage characters from thumbprint copy/paste // ref http://stackoverflow.com/questions/8448147/problems-with-x509store-certificates-find-findbythumbprint return Regex.Replace(thumbprint, @"[^\da-fA-F]", string.Empty).ToUpper(); } public static X509Certificate2 GetCertificate(string thumbprint) { thumbprint = CleanCertificateThumbprint(thumbprint); X509Certificate2 cert = null; var certStore = new X509Store(StoreName.My, StoreLocation.CurrentUser); certStore.Open(OpenFlags.ReadOnly); var certCollection = certStore.Certificates.Find(X509FindType.FindByThumbprint, thumbprint, false); if (certCollection.Count > 0) { cert = certCollection[0]; } certStore.Close(); return cert; } public static X509Certificate2 GetCertificate(string file, string password) { return new X509Certificate2(file, password); } public async static Task GetEmbeddedCertificateAsync(string file, string password) { var assembly = typeof(CoreHelpers).GetTypeInfo().Assembly; using (var s = assembly.GetManifestResourceStream($"Bit.Core.{file}")) using (var ms = new MemoryStream()) { await s.CopyToAsync(ms); return new X509Certificate2(ms.ToArray(), password); } } public static string GetEmbeddedResourceContentsAsync(string file) { var assembly = Assembly.GetCallingAssembly(); var resourceName = assembly.GetManifestResourceNames().Single(n => n.EndsWith(file)); using (var stream = assembly.GetManifestResourceStream(resourceName)) using (var reader = new StreamReader(stream)) { return reader.ReadToEnd(); } } public async static Task GetBlobCertificateAsync(CloudStorageAccount cloudStorageAccount, string container, string file, string password) { var blobClient = cloudStorageAccount.CreateCloudBlobClient(); var containerRef = blobClient.GetContainerReference(container); if (await containerRef.ExistsAsync().ConfigureAwait(false)) { var blobRef = containerRef.GetBlobReference(file); if (await blobRef.ExistsAsync().ConfigureAwait(false)) { var blobBytes = new byte[blobRef.Properties.Length]; await blobRef.DownloadToByteArrayAsync(blobBytes, 0).ConfigureAwait(false); return new X509Certificate2(blobBytes, password); } } return null; } public static long ToEpocMilliseconds(DateTime date) { return (long)Math.Round((date - _epoc).TotalMilliseconds, 0); } public static DateTime FromEpocMilliseconds(long milliseconds) { return _epoc.AddMilliseconds(milliseconds); } public static long ToEpocSeconds(DateTime date) { return (long)Math.Round((date - _epoc).TotalSeconds, 0); } public static DateTime FromEpocSeconds(long seconds) { return _epoc.AddSeconds(seconds); } public static string U2fAppIdUrl(GlobalSettings globalSettings) { return string.Concat(globalSettings.BaseServiceUri.Vault, "/app-id.json"); } public static string RandomString(int length, bool alpha = true, bool upper = true, bool lower = true, bool numeric = true, bool special = false) { return RandomString(length, RandomStringCharacters(alpha, upper, lower, numeric, special)); } public static string RandomString(int length, string characters) { return new string(Enumerable.Repeat(characters, length).Select(s => s[_random.Next(s.Length)]).ToArray()); } public static string SecureRandomString(int length, bool alpha = true, bool upper = true, bool lower = true, bool numeric = true, bool special = false) { return SecureRandomString(length, RandomStringCharacters(alpha, upper, lower, numeric, special)); } // ref https://stackoverflow.com/a/8996788/1090359 with modifications public static string SecureRandomString(int length, string characters) { if (length < 0) { throw new ArgumentOutOfRangeException(nameof(length), "length cannot be less than zero."); } if ((characters?.Length ?? 0) == 0) { throw new ArgumentOutOfRangeException(nameof(characters), "characters invalid."); } const int byteSize = 0x100; if (byteSize < characters.Length) { throw new ArgumentException( string.Format("{0} may contain no more than {1} characters.", nameof(characters), byteSize), nameof(characters)); } var outOfRangeStart = byteSize - (byteSize % characters.Length); using (var rng = RandomNumberGenerator.Create()) { var sb = new StringBuilder(); var buffer = new byte[128]; while (sb.Length < length) { rng.GetBytes(buffer); for (var i = 0; i < buffer.Length && sb.Length < length; ++i) { // Divide the byte into charSet-sized groups. If the random value falls into the last group and the // last group is too small to choose from the entire allowedCharSet, ignore the value in order to // avoid biasing the result. if (outOfRangeStart <= buffer[i]) { continue; } sb.Append(characters[buffer[i] % characters.Length]); } } return sb.ToString(); } } private static string RandomStringCharacters(bool alpha, bool upper, bool lower, bool numeric, bool special) { var characters = string.Empty; if (alpha) { if (upper) { characters += "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; } if (lower) { characters += "abcdefghijklmnopqrstuvwxyz"; } } if (numeric) { characters += "0123456789"; } if (special) { characters += "!@#$%^*&"; } return characters; } // ref: https://stackoverflow.com/a/11124118/1090359 // Returns the human-readable file size for an arbitrary 64-bit file size . // The format is "0.## XB", ex: "4.2 KB" or "1.43 GB" public static string ReadableBytesSize(long size) { // Get absolute value var absoluteSize = (size < 0 ? -size : size); // Determine the suffix and readable value string suffix; double readable; if (absoluteSize >= 0x40000000) // 1 Gigabyte { suffix = "GB"; readable = (size >> 20); } else if (absoluteSize >= 0x100000) // 1 Megabyte { suffix = "MB"; readable = (size >> 10); } else if (absoluteSize >= 0x400) // 1 Kilobyte { suffix = "KB"; readable = size; } else { return size.ToString("0 Bytes"); // Byte } // Divide by 1024 to get fractional value readable = (readable / 1024); // Return formatted number with suffix return readable.ToString("0.## ") + suffix; } /// /// Creates a clone of the given object through serializing to json and deserializing. /// This method is subject to the limitations of Newstonsoft. For example, properties with /// inaccessible setters will not be set. /// public static T CloneObject(T obj) { return JsonConvert.DeserializeObject(JsonConvert.SerializeObject(obj)); } public static bool SettingHasValue(string setting) { var normalizedSetting = setting?.ToLowerInvariant(); return !string.IsNullOrWhiteSpace(normalizedSetting) && !normalizedSetting.Equals("secret") && !normalizedSetting.Equals("replace"); } public static string Base64EncodeString(string input) { return Convert.ToBase64String(Encoding.UTF8.GetBytes(input)); } public static string Base64DecodeString(string input) { return Encoding.UTF8.GetString(Convert.FromBase64String(input)); } public static string Base64UrlEncodeString(string input) { return Base64UrlEncode(Encoding.UTF8.GetBytes(input)); } public static string Base64UrlDecodeString(string input) { return Encoding.UTF8.GetString(Base64UrlDecode(input)); } public static string Base64UrlEncode(byte[] input) { var output = Convert.ToBase64String(input) .Replace('+', '-') .Replace('/', '_') .Replace("=", string.Empty); return output; } public static byte[] Base64UrlDecode(string input) { var output = input; // 62nd char of encoding output = output.Replace('-', '+'); // 63rd char of encoding output = output.Replace('_', '/'); // Pad with trailing '='s switch (output.Length % 4) { case 0: // No pad chars in this case break; case 2: // Two pad chars output += "=="; break; case 3: // One pad char output += "="; break; default: throw new InvalidOperationException("Illegal base64url string!"); } // Standard base64 decoder return Convert.FromBase64String(output); } public static string PunyEncode(string text) { if (text == "") { return ""; } if (text == null) { return null; } if (!text.Contains("@")) { // Assume domain name or non-email address var idn = new IdnMapping(); return idn.GetAscii(text); } else { // Assume email address return MailboxAddress.EncodeAddrspec(text); } } public static string FormatLicenseSignatureValue(object val) { if (val == null) { return string.Empty; } if (val.GetType() == typeof(DateTime)) { return ToEpocSeconds((DateTime)val).ToString(); } if (val.GetType() == typeof(bool)) { return val.ToString().ToLowerInvariant(); } if (val is PlanType planType) { return planType switch { PlanType.Free => "Free", PlanType.FamiliesAnnually2019 => "FamiliesAnnually", PlanType.TeamsMonthly2019 => "TeamsMonthly", PlanType.TeamsAnnually2019 => "TeamsAnnually", PlanType.EnterpriseMonthly2019 => "EnterpriseMonthly", PlanType.EnterpriseAnnually2019 => "EnterpriseAnnually", PlanType.Custom => "Custom", _ => ((byte)planType).ToString(), }; } return val.ToString(); } public static string GetVersion() { if (string.IsNullOrWhiteSpace(_version)) { _version = Assembly.GetEntryAssembly() .GetCustomAttribute() .InformationalVersion; } return _version; } public static string Dvorak2Qwerty(string value) { return Other2Qwerty(value, _dvorakMap, _qwertyDvorakMap); } public static string Colemak2Qwerty(string value) { return Other2Qwerty(value, _colemakMap, _qwertyColemakMap); } private static string Other2Qwerty(string value, string otherMap, string qwertyMap) { var sb = new StringBuilder(); foreach (var c in value) { sb.Append(otherMap.IndexOf(c) > -1 ? qwertyMap[otherMap.IndexOf(c)] : c); } return sb.ToString(); } public static string SanitizeForEmail(string value, bool htmlEncode = true) { var cleanedValue = value.Replace("@", "[at]"); var regexOptions = RegexOptions.CultureInvariant | RegexOptions.Singleline | RegexOptions.IgnoreCase; cleanedValue = Regex.Replace(cleanedValue, @"(\.\w)", m => string.Concat("[dot]", m.ToString().Last()), regexOptions); while (Regex.IsMatch(cleanedValue, @"((^|\b)(\w*)://)", regexOptions)) { cleanedValue = Regex.Replace(cleanedValue, @"((^|\b)(\w*)://)", string.Empty, regexOptions); } return htmlEncode ? HttpUtility.HtmlEncode(cleanedValue) : cleanedValue; } public static string DateTimeToTableStorageKey(DateTime? date = null) { if (date.HasValue) { date = date.Value.ToUniversalTime(); } else { date = DateTime.UtcNow; } return _max.Subtract(date.Value).TotalMilliseconds.ToString(CultureInfo.InvariantCulture); } // ref: https://stackoverflow.com/a/27545010/1090359 public static Uri ExtendQuery(Uri uri, IDictionary values) { var baseUri = uri.ToString(); var queryString = string.Empty; if (baseUri.Contains("?")) { var urlSplit = baseUri.Split('?'); baseUri = urlSplit[0]; queryString = urlSplit.Length > 1 ? urlSplit[1] : string.Empty; } var queryCollection = HttpUtility.ParseQueryString(queryString); foreach (var kvp in values ?? new Dictionary()) { queryCollection[kvp.Key] = kvp.Value; } var uriKind = uri.IsAbsoluteUri ? UriKind.Absolute : UriKind.Relative; if (queryCollection.Count == 0) { return new Uri(baseUri, uriKind); } return new Uri(string.Format("{0}?{1}", baseUri, queryCollection), uriKind); } public static string CustomProviderName(TwoFactorProviderType type) { return string.Concat("Custom_", type.ToString()); } public static bool UserInviteTokenIsValid(IDataProtector protector, string token, string userEmail, Guid orgUserId, IGlobalSettings globalSettings) { return TokenIsValid("OrganizationUserInvite", protector, token, userEmail, orgUserId, globalSettings.OrganizationInviteExpirationHours); } public static bool TokenIsValid(string firstTokenPart, IDataProtector protector, string token, string userEmail, Guid id, double expirationInHours) { var invalid = true; try { var unprotectedData = protector.Unprotect(token); var dataParts = unprotectedData.Split(' '); if (dataParts.Length == 4 && dataParts[0] == firstTokenPart && new Guid(dataParts[1]) == id && dataParts[2].Equals(userEmail, StringComparison.InvariantCultureIgnoreCase)) { var creationTime = FromEpocMilliseconds(Convert.ToInt64(dataParts[3])); var expTime = creationTime.AddHours(expirationInHours); invalid = expTime < DateTime.UtcNow; } } catch { invalid = true; } return !invalid; } public static string GetApplicationCacheServiceBusSubcriptionName(GlobalSettings globalSettings) { var subName = globalSettings.ServiceBus.ApplicationCacheSubscriptionName; if (string.IsNullOrWhiteSpace(subName)) { var websiteInstanceId = Environment.GetEnvironmentVariable("WEBSITE_INSTANCE_ID"); if (string.IsNullOrWhiteSpace(websiteInstanceId)) { throw new Exception("No service bus subscription name available."); } else { subName = $"{globalSettings.ProjectName.ToLower()}_{websiteInstanceId}"; if (subName.Length > 50) { subName = subName.Substring(0, 50); } } } return subName; } public static string GetIpAddress(this Microsoft.AspNetCore.Http.HttpContext httpContext, GlobalSettings globalSettings) { if (httpContext == null) { return null; } if (!globalSettings.SelfHosted && httpContext.Request.Headers.ContainsKey(CloudFlareConnectingIp)) { return httpContext.Request.Headers[CloudFlareConnectingIp].ToString(); } if (globalSettings.SelfHosted && httpContext.Request.Headers.ContainsKey(RealIp)) { return httpContext.Request.Headers[RealIp].ToString(); } return httpContext.Connection?.RemoteIpAddress?.ToString(); } public static bool IsCorsOriginAllowed(string origin, GlobalSettings globalSettings) { return // Web vault origin == globalSettings.BaseServiceUri.Vault || // Safari extension origin origin == "file://" || // Product website (!globalSettings.SelfHosted && origin == "https://bitwarden.com"); } public static X509Certificate2 GetIdentityServerCertificate(GlobalSettings globalSettings) { if (globalSettings.SelfHosted && SettingHasValue(globalSettings.IdentityServer.CertificatePassword) && File.Exists("identity.pfx")) { return GetCertificate("identity.pfx", globalSettings.IdentityServer.CertificatePassword); } else if (SettingHasValue(globalSettings.IdentityServer.CertificateThumbprint)) { return GetCertificate( globalSettings.IdentityServer.CertificateThumbprint); } else if (!globalSettings.SelfHosted && SettingHasValue(globalSettings.Storage?.ConnectionString) && SettingHasValue(globalSettings.IdentityServer.CertificatePassword)) { var storageAccount = CloudStorageAccount.Parse(globalSettings.Storage.ConnectionString); return GetBlobCertificateAsync(storageAccount, "certificates", "identity.pfx", globalSettings.IdentityServer.CertificatePassword).GetAwaiter().GetResult(); } return null; } public static Dictionary AdjustIdentityServerConfig(Dictionary configDict, string publicServiceUri, string internalServiceUri) { var dictReplace = new Dictionary(); foreach (var item in configDict) { if (item.Key == "authorization_endpoint" && item.Value is string val) { var uri = new Uri(val); dictReplace.Add(item.Key, string.Concat(publicServiceUri, uri.LocalPath)); } else if ((item.Key == "jwks_uri" || item.Key.EndsWith("_endpoint")) && item.Value is string val2) { var uri = new Uri(val2); dictReplace.Add(item.Key, string.Concat(internalServiceUri, uri.LocalPath)); } } foreach (var replace in dictReplace) { configDict[replace.Key] = replace.Value; } return configDict; } public static List> BuildIdentityClaims(User user, ICollection orgs, ICollection providers, bool isPremium) { var claims = new List>() { new KeyValuePair("premium", isPremium ? "true" : "false"), new KeyValuePair(JwtClaimTypes.Email, user.Email), new KeyValuePair(JwtClaimTypes.EmailVerified, user.EmailVerified ? "true" : "false"), new KeyValuePair("sstamp", user.SecurityStamp) }; if (!string.IsNullOrWhiteSpace(user.Name)) { claims.Add(new KeyValuePair(JwtClaimTypes.Name, user.Name)); } // Orgs that this user belongs to if (orgs.Any()) { foreach (var group in orgs.GroupBy(o => o.Type)) { switch (group.Key) { case Enums.OrganizationUserType.Owner: foreach (var org in group) { claims.Add(new KeyValuePair("orgowner", org.Id.ToString())); } break; case Enums.OrganizationUserType.Admin: foreach (var org in group) { claims.Add(new KeyValuePair("orgadmin", org.Id.ToString())); } break; case Enums.OrganizationUserType.Manager: foreach (var org in group) { claims.Add(new KeyValuePair("orgmanager", org.Id.ToString())); } break; case Enums.OrganizationUserType.User: foreach (var org in group) { claims.Add(new KeyValuePair("orguser", org.Id.ToString())); } break; case Enums.OrganizationUserType.Custom: foreach (var org in group) { claims.Add(new KeyValuePair("orgcustom", org.Id.ToString())); foreach (var (permission, claimName) in org.Permissions.ClaimsMap) { if (!permission) { continue; } claims.Add(new KeyValuePair(claimName, org.Id.ToString())); } } break; default: break; } } } if (providers.Any()) { foreach (var group in providers.GroupBy(o => o.Type)) { switch (group.Key) { case ProviderUserType.ProviderAdmin: foreach (var provider in group) { claims.Add(new KeyValuePair("providerprovideradmin", provider.Id.ToString())); } break; case ProviderUserType.ServiceUser: foreach (var provider in group) { claims.Add(new KeyValuePair("providerserviceuser", provider.Id.ToString())); } break; } } } return claims; } public static T LoadClassFromJsonData(string jsonData) where T : new() { if (string.IsNullOrWhiteSpace(jsonData)) { return new T(); } var options = new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase, }; return System.Text.Json.JsonSerializer.Deserialize(jsonData, options); } public static string ClassToJsonData(T data) { var options = new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase, }; return System.Text.Json.JsonSerializer.Serialize(data, options); } public static ICollection AddIfNotExists(this ICollection list, T item) { if (list.Contains(item)) { return list; } list.Add(item); return list; } public static string DecodeMessageText(this QueueMessage message) { var text = message?.MessageText; if (string.IsNullOrWhiteSpace(text)) { return text; } try { return Base64DecodeString(text); } catch { return text; } } public static bool FixedTimeEquals(string input1, string input2) { return CryptographicOperations.FixedTimeEquals( Encoding.UTF8.GetBytes(input1), Encoding.UTF8.GetBytes(input2)); } public static string ObfuscateEmail(string email) { if (email == null) { return email; } var emailParts = email.Split('@', StringSplitOptions.RemoveEmptyEntries); if (emailParts.Length != 2) { return email; } var username = emailParts[0]; if (username.Length < 2) { return email; } var sb = new StringBuilder(); sb.Append(emailParts[0][..2]); for (var i = 2; i < emailParts[0].Length; i++) { sb.Append('*'); } return sb.Append('@') .Append(emailParts[1]) .ToString(); } } }