CREATE DATABASE permission denied in database 'master' accessing as SA

I created a small application for test purposes. The problem starts when I try to deploy the app to an Azure VM. When accessing the published app, I get an error

CREATE DATABASE permission denied in database 'master'

The strange thing is that it works fine when I access the same DB, with the same user (sa), from my PC or SSMS. It just doesn't work only when running on the web server. I have no idea what is going wrong.

Here is the stack trace I get:

[SqlException (0x80131904): CREATE DATABASE permission denied in database 'master'.]
   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +3306108
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +736
   System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +4061
   System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async, Int32 timeout, Boolean asyncWrite) +1293
   System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) +421
   System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +380
   System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch(TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed) +104
   System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.NonQuery(DbCommand command, DbCommandInterceptionContext interceptionContext) +499
   System.Data.Entity.SqlServer.<>c__DisplayClass1a.<CreateDatabaseFromScript>b__19(DbConnection conn) +135
   System.Data.Entity.SqlServer.<>c__DisplayClass33.<UsingConnection>b__32() +587
   System.Data.Entity.SqlServer.<>c__DisplayClass1.<Execute>b__0() +18
   System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Func`1 operation) +234
   System.Data.Entity.SqlServer.SqlProviderServices.UsingMasterConnection(DbConnection sqlConnection, Action`1 act) +909
   System.Data.Entity.SqlServer.SqlProviderServices.CreateDatabaseFromScript(Nullable`1 commandTimeout, DbConnection sqlConnection, String createDatabaseScript) +117
   System.Data.Entity.SqlServer.SqlProviderServices.DbCreateDatabase(DbConnection connection, Nullable`1 commandTimeout, StoreItemCollection storeItemCollection) +211
   System.Data.Entity.Migrations.Utilities.DatabaseCreator.Create(DbConnection connection) +125
   System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase) +156
   System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration) +116
   System.Data.Entity.Internal.DatabaseCreator.CreateDatabase(InternalContext internalContext, Func`3 createMigrator, ObjectContext objectContext) +124
   System.Data.Entity.Database.Create(DatabaseExistenceState existenceState) +292
   System.Data.Entity.CreateDatabaseIfNotExists`1.InitializeDatabase(TContext context) +187
   System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action) +75
   System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization() +482
   System.Data.Entity.Internal.RetryAction`1.PerformAction(TInput input) +177
   System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action`1 action) +269
   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +38
   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +69
   System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext() +21
   System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() +59
   System.Linq.Queryable.FirstOrDefault(IQueryable`1 source, Expression`1 predicate) +61
   MajowskiMartinCloud.Models.ADALTokenCache..ctor(String signedInUserId) +539
   MajowskiMartinCloud.Startup.<ConfigureAuth>b__7_0(AuthorizationCodeReceivedNotification context) +149
   Microsoft.Owin.Security.OpenIdConnect.<AuthenticateCoreAsync>d__1a.MoveNext() +5428
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +31
   Microsoft.Owin.Security.OpenIdConnect.<AuthenticateCoreAsync>d__1a.MoveNext() +5937
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +31
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +60
   Microsoft.Owin.Security.Infrastructure.<BaseInitializeAsync>d__0.MoveNext() +817
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +31
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +60
   Microsoft.Owin.Security.Infrastructure.<Invoke>d__0.MoveNext() +329
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +31
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +60
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.<RunApp>d__5.MoveNext() +197
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +31
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +60
   Microsoft.Owin.Security.Infrastructure.<Invoke>d__0.MoveNext() +768
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +31
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +60
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.<RunApp>d__5.MoveNext() +197
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +31
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +60
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.<DoFinalWork>d__2.MoveNext() +184
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +31
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.StageAsyncResult.End(IAsyncResult ar) +117
   System.Web.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +367
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +195
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +128

After 2 days, I finally found out witch was the problem.

When I created the project in VS2015, i created a new MVC project with AzureAD authentication. While creating the solution, VS added to web config this part of code to manage the token cache:

<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />

On my PC I was using the IIS Express server, so I assume that VS was managing all the authorization part. And I just did't care about it, since it was working, so I didn't even know that there was another DB access, other than the one I defined for EF Model.

I'm not sure, but I assume that with this configuration the app try to connect to the local sql server instance (.\SQLEXPRESS) using the IIS user. The IIS user does,'t have any role on my Sql instance, so I think that this is the reason of the error. I resolved changing the part above with this:

<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework">
  <parameters>
    <parameter value="Data Source=.\SQLEXPRESS;Initial Catalog=MyDB;MultipleActiveResultSets=True;User ID=*******;Password=*******" />
  </parameters>
</defaultConnectionFactory>

Now it works