commit 6dc2e074fb3f0e9ade1a468600a8a62b626e6b05
Author: bel <squeaky2x3@blapointe.com>
Date:   Sun Oct 20 12:59:50 2019 -0600

    Wannabe oauth implementation

diff --git a/const.go b/const.go
new file mode 100644
index 0000000..dd1c1bc
--- /dev/null
+++ b/const.go
@@ -0,0 +1,6 @@
+package oauth2
+
+const (
+	COOKIE   = "BOAuthZ"
+	REDIRECT = "BOAuthZ-Redirect"
+)
diff --git a/oauth2client/client.go b/oauth2client/client.go
new file mode 100644
index 0000000..433fa17
--- /dev/null
+++ b/oauth2client/client.go
@@ -0,0 +1,63 @@
+package oauth2client
+
+import (
+	"errors"
+	"local/oauth2"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func Authenticate(server string, w http.ResponseWriter, r *http.Request) error {
+	oauth2server, err := url.Parse(server)
+	if err != nil {
+		return err
+	}
+	access, err := r.Cookie(oauth2.COOKIE)
+	if err == http.ErrNoCookie {
+		return login(oauth2server, w, r)
+	}
+	return verify(access.Value, oauth2server, w, r)
+}
+
+func login(oauth2server *url.URL, w http.ResponseWriter, r *http.Request) error {
+	oauth2server.Path = "/users/log"
+	url := *r.URL
+	url.Host = r.Host
+	if url.Scheme == "" {
+		url.Scheme = "http"
+	}
+	cookie := &http.Cookie{
+		Name:  oauth2.REDIRECT,
+		Value: url.String(),
+	}
+	http.SetCookie(w, cookie)
+	http.Redirect(w, r, oauth2server.String(), http.StatusSeeOther)
+	return errors.New("logging in")
+}
+
+func verify(access string, oauth2server *url.URL, w http.ResponseWriter, r *http.Request) error {
+	oauth2server.Path = "/verify"
+	data := url.Values{}
+	data.Set("access", access)
+	req, err := http.NewRequest("POST", oauth2server.String(), strings.NewReader(data.Encode()))
+	if err != nil {
+		return err
+	}
+	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Add("Content-Length", strconv.Itoa(len(data.Encode())))
+	c := &http.Client{
+		Timeout: 5 * time.Second,
+	}
+	resp, err := c.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return login(oauth2server, w, r)
+	}
+	return nil
+}
diff --git a/oauth2server/config/config.go b/oauth2server/config/config.go
new file mode 100644
index 0000000..a99cdbd
--- /dev/null
+++ b/oauth2server/config/config.go
@@ -0,0 +1,53 @@
+package config
+
+import (
+	"fmt"
+	"local/args"
+	"os"
+	"strings"
+)
+
+var (
+	Port      string
+	Store     string
+	StoreAddr string
+	StoreUser string
+	StorePass string
+	SecretA   string
+	SecretB   string
+)
+
+func init() {
+	Refresh()
+}
+
+func Refresh() {
+	if strings.Contains(fmt.Sprint(os.Args), "-test") {
+		return
+	}
+	defer func() {
+		if err := recover(); err != nil {
+			panic(err)
+		}
+	}()
+
+	as := args.NewArgSet()
+	as.Append(args.STRING, "port", "port to listen on", "23456")
+	as.Append(args.STRING, "secretA", "secret A", "secret")
+	as.Append(args.STRING, "secretB", "secret B", "secret")
+	as.Append(args.STRING, "store", "type of DB", "map")
+	as.Append(args.STRING, "storeAddr", "addr of DB", "/tmp/oauth2server.db")
+	as.Append(args.STRING, "storeUser", "user of DB", "")
+	as.Append(args.STRING, "storePass", "pass of DB", "")
+	if err := as.Parse(); err != nil {
+		panic(err)
+	}
+
+	Port = ":" + strings.TrimPrefix(as.Get("port").GetString(), ":")
+	Store = as.Get("store").GetString()
+	StoreAddr = as.Get("storeaddr").GetString()
+	StoreUser = as.Get("storeuser").GetString()
+	StorePass = as.Get("storepass").GetString()
+	SecretA = as.Get("secreta").GetString()
+	SecretB = as.Get("secretb").GetString()
+}
diff --git a/oauth2server/main.go b/oauth2server/main.go
new file mode 100644
index 0000000..6a95b2d
--- /dev/null
+++ b/oauth2server/main.go
@@ -0,0 +1,19 @@
+package main
+
+import (
+	"local/oauth2/oauth2server/config"
+	"local/oauth2/oauth2server/server"
+	"log"
+	"net/http"
+)
+
+func main() {
+	s := server.New()
+	if err := s.Routes(); err != nil {
+		panic(err)
+	}
+	log.Println("listening on", config.Port)
+	if err := http.ListenAndServe(config.Port, s); err != nil {
+		panic(err)
+	}
+}
diff --git a/oauth2server/oauth2server b/oauth2server/oauth2server
new file mode 100755
index 0000000..6412a51
Binary files /dev/null and b/oauth2server/oauth2server differ
diff --git a/oauth2server/server/authorize.go b/oauth2server/server/authorize.go
new file mode 100644
index 0000000..a416dde
--- /dev/null
+++ b/oauth2server/server/authorize.go
@@ -0,0 +1,59 @@
+package server
+
+import (
+	"local/oauth2"
+	"local/storage"
+	"net/http"
+
+	"github.com/google/uuid"
+)
+
+func (s *Server) authorize(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "POST" {
+		http.NotFound(w, r)
+		return
+	}
+	id := r.FormValue("username")
+	user, ok := s.getUser(id)
+	if !ok {
+		http.Error(w, "unknown user", http.StatusForbidden)
+		return
+	}
+	access, ok := s.getAccess(user)
+	if !ok {
+		http.Error(w, "no oauth for user", http.StatusForbidden)
+		return
+	}
+	cookie := &http.Cookie{
+		Name:     oauth2.COOKIE,
+		Value:    access,
+		SameSite: http.SameSiteLaxMode,
+	}
+	http.SetCookie(w, cookie)
+	redirectCookie, err := r.Cookie(oauth2.REDIRECT)
+	if err != nil {
+		return
+	}
+	http.Redirect(w, r, redirectCookie.Value, http.StatusSeeOther)
+}
+
+func (s *Server) genAuth(user string) {
+	access := uuid.New().String()
+	token := uuid.New().String()
+	s.store.Set(user, []byte(access), ACCESS)
+	s.store.Set(access, []byte(token), TOKEN)
+}
+
+func (s *Server) getAccess(user string) (string, bool) {
+	access, err := s.store.Get(user, ACCESS)
+	if err == storage.ErrNotFound {
+		s.genAuth(user)
+		access, err = s.store.Get(user, ACCESS)
+	}
+	return string(access), err == nil
+}
+
+func (s *Server) getToken(access string) (string, bool) {
+	token, err := s.store.Get(access, TOKEN)
+	return string(token), err == nil
+}
diff --git a/oauth2server/server/routes.go b/oauth2server/server/routes.go
new file mode 100644
index 0000000..9187d31
--- /dev/null
+++ b/oauth2server/server/routes.go
@@ -0,0 +1,41 @@
+package server
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func (s *Server) Routes() error {
+	endpoints := []struct {
+		path    string
+		handler http.HandlerFunc
+	}{
+		{
+			path:    fmt.Sprintf("authorize"),
+			handler: s.authorize,
+		},
+		{
+			path:    fmt.Sprintf("verify"),
+			handler: s.verify,
+		},
+		{
+			path:    fmt.Sprintf("users/log"),
+			handler: s.usersLog,
+		},
+		{
+			path:    fmt.Sprintf("users/register"),
+			handler: s.usersRegister,
+		},
+		{
+			path:    fmt.Sprintf("users/submit"),
+			handler: s.usersSubmit,
+		},
+	}
+
+	for _, endpoint := range endpoints {
+		if err := s.Add(endpoint.path, endpoint.handler); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/oauth2server/server/server.go b/oauth2server/server/server.go
new file mode 100644
index 0000000..d064ab9
--- /dev/null
+++ b/oauth2server/server/server.go
@@ -0,0 +1,44 @@
+package server
+
+import (
+	"local/oauth2/oauth2server/config"
+	"local/router"
+	"local/storage"
+)
+
+var wildcard = router.Wildcard
+
+const (
+	USERS  = "users"
+	ACCESS = "access"
+	TOKEN  = "token"
+	SALT   = "salt"
+)
+
+type Server struct {
+	*router.Router
+	store storage.DB
+}
+
+func New() *Server {
+	store, err := storage.New(storage.TypeFromString(config.Store), config.StoreAddr, config.StoreUser, config.StorePass)
+	if err != nil {
+		panic(err)
+	}
+	purgeIssuedCredentials(store)
+	return &Server{
+		Router: router.New(),
+		store:  store,
+	}
+}
+
+func purgeIssuedCredentials(store storage.DB) {
+	accesses, _ := store.List([]string{ACCESS})
+	for _, access := range accesses {
+		store.Set(access, nil, ACCESS)
+	}
+	tokens, _ := store.List([]string{TOKEN})
+	for _, token := range tokens {
+		store.Set(token, nil, TOKEN)
+	}
+}
diff --git a/oauth2server/server/users.go b/oauth2server/server/users.go
new file mode 100644
index 0000000..19397b2
--- /dev/null
+++ b/oauth2server/server/users.go
@@ -0,0 +1,82 @@
+package server
+
+import (
+	"crypto/hmac"
+	"crypto/md5"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"local/oauth2/oauth2server/config"
+	"net/http"
+
+	"github.com/google/uuid"
+)
+
+func (s *Server) usersLog(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintln(w, `
+      <html>
+         <body>
+            <form method="post" action="/authorize">
+               <input type="text" name="username"></input>
+               <input type="submit"></input>
+            </form>
+         </body>
+      </html>
+   `)
+}
+
+func (s *Server) usersRegister(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintln(w, `
+      <html>
+         <body>
+            <form method="post" action="/users/submit">
+               <input type="text" name="username"></input>
+               <input type="submit"></input>
+            </form>
+         </body>
+      </html>
+   `)
+}
+
+func (s *Server) usersSubmit(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "POST" {
+		http.NotFound(w, r)
+		return
+	}
+	id := r.FormValue("username")
+	if _, ok := s.getUser(id); ok {
+		http.Error(w, "user already exists", http.StatusConflict)
+		return
+	}
+	s.genUser(id)
+}
+
+func (s *Server) genUser(id string) {
+	user := uuid.New().String()
+	salt := uuid.New().String()
+	s.store.Set(id, []byte(salt), SALT)
+	obscured := s.obscureID(id)
+	s.store.Set(obscured, []byte(user), USERS)
+}
+
+func (s *Server) getUser(id string) (string, bool) {
+	obscured := s.obscureID(id)
+	user, err := s.store.Get(obscured, USERS)
+	return string(user), err == nil
+}
+
+func (s *Server) obscureID(id string) string {
+	salt, _ := s.store.Get(id, SALT)
+	a := s.obscure(string(salt)+id, config.SecretA)
+	b := s.obscure(string(salt)+id, config.SecretB)
+	return a + b
+}
+
+func (s *Server) obscure(payload, secret string) string {
+	hash := md5.New()
+	hash.Write([]byte(secret))
+	key := hash.Sum(nil)
+	sig := hmac.New(sha256.New, key)
+	sig.Write([]byte(payload))
+	return hex.EncodeToString(sig.Sum(nil))
+}
diff --git a/oauth2server/server/verify.go b/oauth2server/server/verify.go
new file mode 100644
index 0000000..5946a7e
--- /dev/null
+++ b/oauth2server/server/verify.go
@@ -0,0 +1,19 @@
+package server
+
+import (
+	"net/http"
+)
+
+func (s *Server) verify(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "POST" {
+		http.NotFound(w, r)
+		return
+	}
+	access := r.FormValue("access")
+	token, ok := s.getToken(access)
+	if !ok {
+		http.Error(w, "unknown access", http.StatusUnauthorized)
+		return
+	}
+	w.Write([]byte(token))
+}
diff --git a/oauth2test/package_test.go b/oauth2test/package_test.go
new file mode 100644
index 0000000..bb85b3e
--- /dev/null
+++ b/oauth2test/package_test.go
@@ -0,0 +1,162 @@
+package oauth2
+
+import (
+	"errors"
+	"fmt"
+	"local/oauth2/oauth2client"
+	"local/oauth2/oauth2server/config"
+	"local/oauth2/oauth2server/server"
+	"net/http"
+	"net/http/cookiejar"
+	"net/http/httptest"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+func TestAll(t *testing.T) {
+	oauth2server, err := launchServer()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer oauth2server.Close()
+
+	s := dummyServer(oauth2server.URL)
+	defer s.Close()
+
+	if err := createUser(oauth2server.URL); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := logUser(oauth2server.URL); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := shouldRedir(s.URL); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := testAuth(oauth2server.URL, s.URL); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func launchServer() (*httptest.Server, error) {
+	config.Store = "map"
+
+	oauth2server := server.New()
+	err := oauth2server.Routes()
+	if err != nil {
+		return nil, err
+	}
+	s := httptest.NewServer(oauth2server)
+
+	re := regexp.MustCompile(":[0-9]*")
+	port := re.FindString(s.URL)
+	config.Port = port
+
+	return s, err
+}
+
+func dummyServer(oauth2server string) *httptest.Server {
+	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		err := oauth2client.Authenticate(oauth2server, w, r)
+		if err != nil {
+			return
+		}
+		fmt.Fprintln(w, "dummy server serving authenticated")
+	}))
+}
+
+func createUser(oauth2server string) error {
+	resp, err := http.Post(oauth2server+"/users/submit", "application/x-www-form-urlencoded", strings.NewReader("username=abc"))
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return errors.New("bad status " + resp.Status)
+	}
+	return nil
+}
+
+func logUser(oauth2server string) error {
+	resp, err := http.Post(oauth2server+"/authorize", "application/x-www-form-urlencoded", strings.NewReader("username=abc"))
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return errors.New("bad status " + resp.Status)
+	}
+	return nil
+}
+
+func shouldRedir(dummy string) error {
+	c := makeClient()
+	return clientShouldRedir(c, dummy)
+}
+
+func clientShouldRedir(c *http.Client, dummy string) error {
+	req, _ := http.NewRequest("GET", dummy, nil)
+	resp, err := c.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.Request.URL.Path != "/users/log" {
+		return fmt.Errorf("did not need redir without auth: %v", resp.Request.URL)
+	}
+	return nil
+}
+
+func clientShouldNotRedir(c *http.Client, dummy string) error {
+	req, _ := http.NewRequest("GET", dummy, nil)
+	resp, err := c.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.Request.URL.Path == "/users/log" {
+		return fmt.Errorf("did redir with auth: %v", resp.Request.URL.Path)
+	}
+	return nil
+}
+
+func testAuth(oauth2server, dummy string) error {
+	c := makeClient()
+	if err := clientShouldRedir(c, dummy); err != nil {
+		return err
+	}
+	if err := clientLogin(c, oauth2server); err != nil {
+		return err
+	}
+	if err := clientShouldNotRedir(c, dummy); err != nil {
+		return err
+	}
+	return nil
+}
+
+func clientLogin(c *http.Client, oauth2server string) error {
+	req, _ := http.NewRequest("POST", oauth2server+"/authorize", strings.NewReader("username=abc"))
+	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+	resp, err := c.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("bad status; %v", resp.StatusCode)
+	}
+	if resp.Request.URL.Path != "/" {
+		return fmt.Errorf("login response path wrong: %v", resp.Request.URL)
+	}
+	return nil
+}
+
+func makeClient() *http.Client {
+	jar, _ := cookiejar.New(&cookiejar.Options{})
+	return &http.Client{
+		Jar: jar,
+	}
+}