{"error":"invalid_grant","error_description":"authentication failure"}

local.http = new Http(url='https://test.salesforce.com/services/oauth2/token',method='post');

      local.http.addParam(type='header',name='content-type',   value='application/x-www-form-urlencoded');
      local.http.addParam(type='formField',name='grant_type',   value='password');
      local.http.addParam(type='formField',name='client_id',    value='client_id');
      local.http.addParam(type='formField',name='client_secret',  value='client_password_string');
      local.http.addParam(type='formField',name='username',   value='user@email.com');
      local.http.addParam(type='formField',name='password',   value='userspassword');
      local.http.addParam(type='formField',name='format',     value='json');

      local.httpSendResult = local.http.send();
      rc.httpResult = httpSendResult.getPrefix();

<cfhttp url="https://test.salesforce.com/services/oauth2/token" method="POST">
         <cfhttpparam type="header" name="Content-Type" value="application/x-www-form-urlencoded" />
         <cfhttpparam type="formField" name="grant_type" value="password" />

         <cfhttpparam type="formField" name="client_id" value="client_id" />
         <cfhttpparam type="formField" name="client_secret" value="client_password_string" />
         <cfhttpparam type="formField" name="username" value="user@email.com" />
         <cfhttpparam type="formField" name="password" value="userspassword" />

        </cfhttp>
        <cfset rc.result = cfhttp.fileContent />

curl -d "grant_type=password"
   -d "client_id=client_id"
   -d "client_secret=client_secret_string"
   -d "username=user@email.com.dev"
   -d "password=userpassword" https://test.salesforce.com/services/oauth2/token