logout: add support of logout flow

internal/web/templates/login.tmpl

@@ -0,0 +1,45 @@
+{{ define "title" }}
+	Login Provider Werther
+{{ end }}
+
+{{ define "style" }}
+	<link rel="stylesheet" href="static/style.css">
+{{ end }}
+
+{{ define "js" }}
+	<script type="text/javascript" src="static/script.js"></script>
+{{ end }}
+
+{{ define "content" }}
+	<div class="login-page">
+		<div class="form">
+			<p class="message">
+			{{ if .IsInvalidCredentials }}
+				Invalid username or password
+			{{ else if .IsInternalError }}
+				Internal server error
+			{{ else }}
+				&nbsp;
+			{{ end }}
+			</p>
+			<form class="login-form" action="{{ .LoginURL }}" method="POST">
+				<input type="hidden" name="csrf_token" value={{ .CSRFToken }}>
+				<input type="hidden" name="login_challenge" value={{ .Challenge }}>
+
+				<input type="text" placeholder="username" name="username"/>
+				<input type="password" placeholder="password" name="password"/>
+
+				<div class="checkbox remember-container">
+					<div class="checkbox-overlay">
+						<input type="checkbox" name="remember" />
+						<div class="checkbox-container">
+							<div class="checkbox-checkmark"></div>
+						</div>
+						<label for="remember">Remember me</label>
+					</div>
+				</div>
+				<button type="submit">login</button>
+			</form>
+		</div>
+	</div>
+{{ end }}