Basic And Form Authentication

The Ktor authentication plugin allows you to create multiple authorizations and give them different names. Let's create two form authentications as follows:

install(Authentication) {
    form("myFormAuth") {
        userParamName = "username"
        passwordParamName = "password"
        validate { credentials ->
            if (credentials.name == "Admin" && credentials.password == "2425") {
                UserIdPrincipal(credentials.name)
            } else {
                null
            }
        }
        challenge {
            call.respondRedirect("/auth")
        }
    }
    form("myFormAuth2") {
        userParamName = "username"
        passwordParamName = "password"
        validate { credentials ->
            if (credentials.name == "Admin2" && credentials.password == "1213") {
                UserIdPrincipal(credentials.name)
            } else {
                null
            }
        }
        challenge {
            call.respondRedirect("/auth")
        }
    }
}

What happens if we apply these authorizations to one page?

authenticate("myFormAuth") {
    authenticate("myFormAuth2") {
        post("/page") {
            call.respondText("Protected content! Name: ${call.principal<UserIdPrincipal>()?.name}")
        }
    }
}
get("/page") {
    call.respondRedirect("/auth")
}
get("/auth") {
    val formHtml = """
    <form action="/page" method="post">
        <input type="text" name="username">
        <input type="password" name="password">
        <input type="submit" value="Auth">
    </form>
""".trimIndent()
    call.respondText(formHtml, ContentType.Text.Html)
}

Open the IDE and check the result yourself.