Log on is OK but this field (rich text) is impossible to edit on the iPad. 

Writing this on Safari on Mac. Is the Safari browser on iPad different from on the Mac? 

iPads can not use any rich text field, as rich text fields are actually a iframe, and you can get focus on an iframe via touch.  I dont know of any mobile touch browser that can do this, but maybe someday soon.

 

The fix is to detect the browser and present a text field instead to mobile browsers and set the richtext source to that on save 

Chrome is currently not supported.

 

However, client side login is working for us, from client js.

var oData = {};
    dojo.xhrGet({
        url: _sClearSessionURL,
        load: function (data) {
        },
        error: function (error) {
        }
    });
    var oData = new Array();
    oData['username']= document.getElementById(_sUsernNameField).value;
    oData['password']= document.getElementById(_sPasswordField).value;
    oData['redirectto']= '\/icons\/view.gif';
    dojo.xhrPost({
        url: _sServerLoginURL,
        content: oData,
        handleAs: "text",
        load: function (data) {
            if( String(data).substring(0,3) == "GIF") {
              ....
            } else {
                if ( String(data).indexOf(_sInvalidReply) != -1) {
                  ...
                } else if ( String(data).indexOf(_sEmptyReply) != -1) {
                    ...
                } else {
                    ...
                };
            };
        },
        error: function (error) {
         ...
        }
    });