<rewrite>
    <rules>
        <rule name="Append Basic Authentication" patternSyntax="Wildcard" stopProcessing="true">
                    <match url="*" />
                    <conditions>
                        <add input="{REQUEST_METHOD}" pattern="PUT" />
                    </conditions>
                    <serverVariables>
                        <set name="HTTP_Authorization" value="Basic Z3JlZ29yeTpncmVnb3J5" replace="false" />
                    </serverVariables>
                    <action type="None" />
        </rule>
    </rules>
</rewrite>