From 48efec10b28ce6970fb4016f9e2f2be981d75e7d Mon Sep 17 00:00:00 2001
From: nsAstro <102520074+nsAstro@users.noreply.github.com>
Date: Mon, 9 May 2022 18:49:22 -0400
Subject: [PATCH] Add exception to catch single line private keys (#23043)

(cherry picked from commit e63dbdc431c2fa973e9a4c0b48ec6230731c38d1)
---
 airflow/providers/ssh/hooks/ssh.py    |  3 +++
 tests/providers/ssh/hooks/test_ssh.py | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/airflow/providers/ssh/hooks/ssh.py b/airflow/providers/ssh/hooks/ssh.py
index 50ea15f276493..88673ae371c76 100644
--- a/airflow/providers/ssh/hooks/ssh.py
+++ b/airflow/providers/ssh/hooks/ssh.py
@@ -415,6 +415,9 @@ def _pkey_from_private_key(self, private_key: str, passphrase: Optional[str] = N
         :return: ``paramiko.PKey`` appropriate for given key
         :raises AirflowException: if key cannot be read
         """
+        if len(private_key.split("\n", 2)) < 2:
+            raise AirflowException('Key must have BEGIN and END header/footer on separate lines.')
+
         for pkey_class in self._pkey_loaders:
             try:
                 key = pkey_class.from_private_key(StringIO(private_key), password=passphrase)
diff --git a/tests/providers/ssh/hooks/test_ssh.py b/tests/providers/ssh/hooks/test_ssh.py
index 0230588c47c45..b17e3170a8007 100644
--- a/tests/providers/ssh/hooks/test_ssh.py
+++ b/tests/providers/ssh/hooks/test_ssh.py
@@ -740,6 +740,24 @@ def test_openssh_private_key(self):
             session.delete(conn)
             session.commit()
 
+    def test_oneline_key(self):
+        with pytest.raises(Exception):
+            TEST_ONELINE_KEY = "-----BEGIN OPENSSH" + "PRIVATE KEY-----asdfg-----END OPENSSH PRIVATE KEY-----"
+            session = settings.Session()
+            try:
+                conn = Connection(
+                    conn_id='openssh_pkey',
+                    host='localhost',
+                    conn_type='ssh',
+                    extra={"private_key": TEST_ONELINE_KEY},
+                )
+                session.add(conn)
+                session.flush()
+                SSHHook(ssh_conn_id=conn.conn_id)
+            finally:
+                session.delete(conn)
+                session.commit()
+
     @pytest.mark.flaky(max_runs=5, min_passes=1)
     def test_exec_ssh_client_command(self):
         hook = SSHHook(