passwordless sign in for admin

src/Core/Identity/ReadOnlyEnvIdentityUserStore.cs

@@ -0,0 +1,53 @@
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.Extensions.Configuration;
+
+namespace Bit.Core.Identity
+{
+    public class ReadOnlyEnvIdentityUserStore : ReadOnlyIdentityUserStore
+    {
+        private readonly IConfiguration _configuration;
+
+        public ReadOnlyEnvIdentityUserStore(IConfiguration configuration)
+        {
+            _configuration = configuration;
+        }
+
+        public override Task<IdentityUser> FindByEmailAsync(string normalizedEmail,
+            CancellationToken cancellationToken = default(CancellationToken))
+        {
+            var usersCsv = _configuration["adminSettings:admins"];
+            if(string.IsNullOrWhiteSpace(usersCsv))
+            {
+                return Task.FromResult<IdentityUser>(null);
+            }
+
+            var users = usersCsv.ToLowerInvariant().Split(',');
+            var user = users.Where(a => a.Trim() == normalizedEmail).FirstOrDefault();
+            if(user == null || !user.Contains("@"))
+            {
+                return Task.FromResult<IdentityUser>(null);
+            }
+
+            user = user.Trim();
+            return Task.FromResult(new IdentityUser
+            {
+                Id = user,
+                Email = user,
+                NormalizedEmail = user,
+                EmailConfirmed = true,
+                UserName = user,
+                NormalizedUserName = user,
+                SecurityStamp = user
+            });
+        }
+
+        public override Task<IdentityUser> FindByIdAsync(string userId,
+            CancellationToken cancellationToken = default(CancellationToken))
+        {
+            return FindByEmailAsync(userId, cancellationToken);
+        }
+    }
+}