fix: Search for ECDSA and Ed25519 keys in default SSH key locations (#26954)

Search for ECDSA and Ed25519 keys in default SSH key locations

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

cli/src/main/java/hudson/cli/PrivateKeyProvider.java

@@ -75,7 +75,7 @@ public class PrivateKeyProvider {
     /**
      * Read keys from default keyFiles
      *
-     * {@code .ssh/id_rsa}, {@code .ssh/id_dsa} and {@code .ssh/identity}.
+     * {@code .ssh/id_rsa}, {@code .ssh/id_ecdsa}, {@code .ssh/id_ed25519}, {@code .ssh/id_dsa} and {@code .ssh/identity}.
      *
      * @return true if some key was read successfully.
      */
@@ -83,7 +83,7 @@ public class PrivateKeyProvider {
         final File home = new File(System.getProperty("user.home"));
 
         boolean read = false;
-        for (String path : new String[] {".ssh/id_rsa", ".ssh/id_dsa", ".ssh/identity"}) {
+        for (String path : new String[] {".ssh/id_rsa", ".ssh/id_ecdsa", ".ssh/id_ed25519", ".ssh/id_dsa", ".ssh/identity"}) {
             final File key = new File(home, path);
             if (!key.exists()) continue;
 

cli/src/test/java/hudson/cli/PrivateKeyProviderTest.java

@@ -142,4 +142,22 @@ class PrivateKeyProviderTest {
         String password = "password";
         assertThrows(IllegalArgumentException.class, () -> PrivateKeyProvider.loadKey(file, password));
     }
+
+    /**
+    key command: ssh-keygen -t ecdsa -b 256 -N "" -C "" -f ecdsa
+    */
+    @Test
+    void loadKeyECDSA() throws IOException, GeneralSecurityException {
+        File file = resourceAsFile("ecdsa");
+        assertKeyPairNotNull(file, null);
+    }
+
+    /**
+    key command: ssh-keygen -t ed25519 -N "" -C "" -f ed25519
+    */
+    @Test
+    void loadKeyED25519() throws IOException, GeneralSecurityException {
+        File file = resourceAsFile("ed25519");
+        assertKeyPairNotNull(file, null);
+    }
 }

cli/src/test/resources/hudson/cli/ecdsa

@@ -0,0 +1,8 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAaAAAABNlY2RzYS
+1zaGEyLW5pc3RwMjU2AAAACG5pc3RwMjU2AAAAQQSmYgxT7E9XwGYmr8cd++EvpaNX3e1/
+T5w30hcO7xNk4n7xDsfZk8jOvg1ZbsfItBB5yjwRy7QTyXt/2ankp/E7AAAAoG6/A51uvw
+OdAAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBKZiDFPsT1fAZiav
+xx374S+lo1fd7X9PnDfSFw7vE2TifvEOx9mTyM6+DVlux8i0EHnKPBHLtBPJe3/ZqeSn8T
+sAAAAhAJgBcc/Ez07nhpmLlsHhySD5zFeW/mHizkk/CIrvjkqSAAAAAAECAwQFBgc=
+-----END OPENSSH PRIVATE KEY-----

cli/src/test/resources/hudson/cli/ed25519

@@ -0,0 +1,7 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW
+QyNTUxOQAAACD6KfM1gIePqB5IPHvD0vjniUUYE6hb6c6GsxVrPZg4ngAAAIiLNylbizcp
+WwAAAAtzc2gtZWQyNTUxOQAAACD6KfM1gIePqB5IPHvD0vjniUUYE6hb6c6GsxVrPZg4ng
+AAAEAA/Q+bSWkxT9WZacetaaN/KBJvrDRlHOuxKQghG49hKvop8zWAh4+oHkg8e8PS+OeJ
+RRgTqFvpzoazFWs9mDieAAAAAAECAwQF
+-----END OPENSSH PRIVATE KEY-----