From 549cce375671be7ea7c91d8cd1793a4b27c17281 Mon Sep 17 00:00:00 2001
From: UnicodingUnicorn <7555ic@gmail.com>
Date: Sun, 10 Feb 2019 18:43:02 +0800
Subject: [PATCH] Initial commit

---
 .gitignore | 12 +++++++++++
 README.md  | 26 ++++++++++++++++++++++-
 main.go    | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 97 insertions(+), 1 deletion(-)
 create mode 100644 .gitignore
 create mode 100644 main.go

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..f2dd955
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,12 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
diff --git a/README.md b/README.md
index f187868..b373cbe 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,27 @@
 # backend-login
 
-Beep backend handling login.
\ No newline at end of file
+Beep backend handling login. For now, just a POST endpoint returning a JWT. In the furture, SMS-based perpetual login.
+
+## API (temporary)
+
+```
+POST /login
+```
+
+### Body
+
+| Name | Type | Description | Required |
+| ---- | ---- | ----------- | -------- |
+| user | String | User's ID. | ✓ |
+| device | String | Device's ID. Must be unique to the device. I suggest something based on MAC address. | ✓ |
+
+### Success (200 OK)
+
+JWT token.
+
+### Errors
+
+| Code | Description |
+| ---- | ----------- |
+| 400 | Required fields in body were not supplied |
+| 500 | Error creating the JWT |
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..2a5da04
--- /dev/null
+++ b/main.go
@@ -0,0 +1,60 @@
+package main
+
+import (
+  "encoding/json"
+  "flag"
+  "log"
+  "net/http"
+
+  "github.com/julienschmidt/httprouter"
+  "github.com/dgrijalva/jwt-go"
+)
+
+var listen string
+var secret []byte
+
+func main() {
+  var s string
+  // Parse flags
+	flag.StringVar(&listen, "listen", ":8080", "host and port to listen on")
+  flag.StringVar(&s, "secret", "secret", "JWT secret")
+  flag.Parse()
+
+  secret = []byte(s)
+
+  // Routes
+	router := httprouter.New()
+
+  router.POST("/login", Login);
+
+  // Start server
+  log.Printf("starting server on %s", listen)
+	log.Fatal(http.ListenAndServe(listen, router))
+}
+
+type LoginData struct {
+  ID string `json:"id"`
+  Client string `json:"client"`
+}
+
+func Login(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
+  login := LoginData {}
+  decoder := json.NewDecoder(r.Body)
+  err := decoder.Decode(&login)
+	if err != nil {
+		http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
+		return
+	}
+
+  token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims {
+    "id": login.ID,
+    "client": login.Client,
+  })
+
+  tokenString, err := token.SignedString(secret)
+  if err != nil {
+    http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+  }
+
+  w.Write([]byte(tokenString))
+}