Add support for UTF-16 encoded kubeconfig files (#1654)

* support for utf16 files

Signed-off-by: goenning <me@goenning.net>

* add test cases for utf16

Signed-off-by: goenning <me@goenning.net>

---------

Signed-off-by: goenning <me@goenning.net>

kube-client/src/config/file_config.rs

@@ -1,6 +1,6 @@
 use std::{
     collections::HashMap,
-    fs,
+    fs, io,
     path::{Path, PathBuf},
 };
 
@@ -351,8 +351,8 @@ const KUBECONFIG: &str = "KUBECONFIG";
 impl Kubeconfig {
     /// Read a Config from an arbitrary location
     pub fn read_from<P: AsRef<Path>>(path: P) -> Result<Kubeconfig, KubeconfigError> {
-        let data = fs::read_to_string(&path)
-            .map_err(|source| KubeconfigError::ReadConfig(source, path.as_ref().into()))?;
+        let data =
+            read_path(&path).map_err(|source| KubeconfigError::ReadConfig(source, path.as_ref().into()))?;
 
         // Remap all files we read to absolute paths.
         let mut merged_docs = None;
@@ -497,6 +497,33 @@ where
     });
 }
 
+fn read_path<P: AsRef<Path>>(path: P) -> io::Result<String> {
+    let bytes = fs::read(&path)?;
+    match bytes.as_slice() {
+        [0xFF, 0xFE, ..] => {
+            let utf16_data: Vec<u16> = bytes[2..]
+                .chunks(2)
+                .map(|chunk| u16::from_le_bytes([chunk[0], chunk[1]]))
+                .collect();
+            String::from_utf16(&utf16_data)
+                .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid UTF-16 LE"))
+        }
+        [0xFE, 0xFF, ..] => {
+            let utf16_data: Vec<u16> = bytes[2..]
+                .chunks(2)
+                .map(|chunk| u16::from_be_bytes([chunk[0], chunk[1]]))
+                .collect();
+            String::from_utf16(&utf16_data)
+                .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid UTF-16 BE"))
+        }
+        [0xEF, 0xBB, 0xBF, ..] => String::from_utf8(bytes[3..].to_vec())
+            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid UTF-8 BOM")),
+        _ => {
+            String::from_utf8(bytes).map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "Invalid UTF-8"))
+        }
+    }
+}
+
 fn to_absolute(dir: &Path, file: &str) -> Option<String> {
     let path = Path::new(&file);
     if path.is_relative() {
@@ -969,4 +996,21 @@ users:
             json!({"audience": "foo", "other": "bar"})
         );
     }
+
+    #[tokio::test]
+    async fn parse_kubeconfig_encodings() {
+        let files = vec![
+            "kubeconfig_utf8.yaml",
+            "kubeconfig_utf16le.yaml",
+            "kubeconfig_utf16be.yaml",
+        ];
+
+        for file_name in files {
+            let path = PathBuf::from(format!("{}/src/config/test_data/{}", env!("CARGO_MANIFEST_DIR"), file_name));
+            let cfg = Kubeconfig::read_from(path).unwrap();
+            assert_eq!(cfg.clusters[0].name, "k3d-promstack");
+            assert_eq!(cfg.contexts[0].name, "k3d-promstack");
+            assert_eq!(cfg.auth_infos[0].name, "admin@k3d-k3s-default");
+        }
+    }
 }

kube-client/src/config/test_data/kubeconfig_utf8.yaml

@@ -0,0 +1,19 @@
+apiVersion: v1
+clusters:
+- cluster:
+    certificate-authority-data: aGVsbG8K
+    server: https://0.0.0.0:6443
+  name: k3d-promstack
+contexts:
+- context:
+    cluster: k3d-promstack
+    user: admin@k3d-promstack
+  name: k3d-promstack
+users:
+- name: admin@k3d-k3s-default
+  user:
+    client-certificate-data: aGVsbG8K
+    client-key-data: aGVsbG8K
+current-context: k3d-promstack
+kind: Config
+preferences: {}