title: Correct way to validate dangerous characters MVC model field after allowing broader range of input
body: <p><strong>Our initial situation</strong>:</p>
  
  <ul>
  <li>We have ClientValidationEnabled =true on our website</li>
  <li>We are using MVC 5 and have a model for the username + password</li>
  <li>We need to allow '&lt;' '>' in the password because the data is sent to another existing system which allows a wider range of characters.</li>
  </ul>
  
  <p>When a password (for instance '&lt; special password >') is submitted a HttpRequestValidationException is thrown.</p>
  
  <p><strong>Problem description:</strong></p>
  
  <p>We would like to allow for additional characters only in the password property of the model.</p>
  
  <p><strong>Current found methods:</strong></p>
  
  <ul>
  <li>disable validation on a level (overall, page or only the specific method).
  Downside: 
  This applies to all fields in the input (or even more depending on the chosen level).</li>
  <li>Not use a model and use form fields directly and use this method: <a href="https://stackoverflow.com/questions/16617423/how-to-bypass-httprequestvalidationexception-for-just-one-request-value-without">other question</a> -> <a href="http://www.asp.net/aspnet/overview/aspnet-and-visual-studio-2012/whats-new#_Toc318097381" rel="nofollow noreferrer">Deferred ("lazy") request validation</a></li>
  <li>Specify [AllowHtml] as suggested by <a href="https://stackoverflow.com/users/3390350/greg">Greg</a></li>
  </ul>
  
  <p><strong>Question:</strong></p>
  
  <p>Both these methods require additional validation of the non validated field. For these validations we could write custom validation, but we'd prefer using a existing well known solution.</p>
  
  <p>Are there any good suggestions to <strong>validate</strong> the field?</p>