Add Microsoft auth provider

Microsoft uses JSON Web Tokens (JWT) as OAuth tokens. These can run to many thousands of characters which are too long for TTYs. Work around this by base64-encoding the token and chunk it into smaller pieces.

Closes #70 

1 files changed, 20 insertions, 0 deletions

diff --git a/server/web.go b/server/web.go
index e238150..d55aa52 100644
--- a/server/web.go
+++ b/server/web.go
@@ -1,7 +1,9 @@
 package server
 
 import (
+	"bytes"
 	"crypto/rand"
+	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
@@ -189,6 +191,23 @@ func callbackHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int
 	return http.StatusFound, nil
 }
 
+func encodeString(s string) string {
+	var buffer bytes.Buffer
+	chunkSize := 70
+	runes := []rune(base64.StdEncoding.EncodeToString([]byte(s)))
+
+	for i := 0; i < len(runes); i += chunkSize {
+		end := i + chunkSize
+		if end > len(runes) {
+			end = len(runes)
+		}
+		buffer.WriteString(string(runes[i:end]))
+		buffer.WriteString("\n")
+	}
+	buffer.WriteString(".\n")
+	return buffer.String()
+}
+
 // rootHandler starts the auth process. If the client is authenticated it renders the token to the user.
 func rootHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
 	if !a.isLoggedIn(w, r) {
@@ -198,6 +217,7 @@ func rootHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, er
 	page := struct {
 		Token string
 	}{tok.AccessToken}
+	page.Token = encodeString(page.Token)
 
 	tmpl := template.Must(template.New("token.html").Parse(templates.Token))
 	tmpl.Execute(w, page)