init: 1.0.0

pkg/oauth/telegram/computations.go

@@ -0,0 +1,42 @@
+package telegram
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"reflect"
+	"sort"
+	"strings"
+)
+
+// getAuthDataCheckString returns a string ready to calculate validation hash.
+// Ref: https://core.telegram.org/widgets/login#checking-authorization
+func getAuthDataCheckString(data *AuthData) string {
+	t := reflect.TypeOf(data).Elem()
+	v := reflect.ValueOf(data).Elem()
+	fields := make([]string, 0)
+	for i := 0; i < t.NumField(); i++ {
+		tag, _, _ := strings.Cut(t.Field(i).Tag.Get("json"), ",")
+		if v.Field(i).IsNil() || tag == "hash" {
+			continue
+		}
+		val := v.Field(i).Elem().Interface()
+		if val == nil || val == "null" {
+			continue
+		}
+		fields = append(fields, fmt.Sprintf("%s=%v", tag, val))
+	}
+	sort.Strings(fields)
+	return strings.Join(fields, "\n")
+}
+
+// computeHash returns a hash calculated for AuthData
+// Ref: https://core.telegram.org/widgets/login#checking-authorization
+func computeHash(data *AuthData, botToken []byte) string {
+	checkString := getAuthDataCheckString(data)
+	key := sha256.Sum256(botToken)
+	h := hmac.New(sha256.New, key[:])
+	h.Write([]byte(checkString))
+	return hex.EncodeToString(h.Sum(nil))
+}