tests: Simplify Michael MIC test file writing

Since run-tests.py is now required to run as root, there is no need to
use the somewhat awkward "sudo tee" construction; instead, just write
directly to the file.

Signed-off-by: Jouni Malinen <j@w1.fi>

tests/hwsim/test_ap_ciphers.py

@@ -5,7 +5,6 @@
 # See README for more details.
 
 import time
-import subprocess
 import logging
 logger = logging.getLogger()
 import os.path
@@ -47,22 +46,14 @@ def test_ap_cipher_tkip_countermeasures_ap(dev, apdev):
                    pairwise="TKIP", group="TKIP", scan_freq="2412")
 
     dev[0].dump_monitor()
-    cmd = subprocess.Popen(["sudo", "tee", testfile],
-                           stdin=subprocess.PIPE, stdout=subprocess.PIPE)
-    cmd.stdin.write(apdev[0]['bssid'])
-    cmd.stdin.close()
-    cmd.stdout.read()
-    cmd.stdout.close()
+    with open(testfile, "w") as f:
+        f.write(apdev[0]['bssid'])
     ev = dev[0].wait_event(["CTRL-EVENT-DISCONNECTED"], timeout=1)
     if ev is not None:
         raise Exception("Unexpected disconnection on first Michael MIC failure")
 
-    cmd = subprocess.Popen(["sudo", "tee", testfile],
-                           stdin=subprocess.PIPE, stdout=subprocess.PIPE)
-    cmd.stdin.write("ff:ff:ff:ff:ff:ff")
-    cmd.stdin.close()
-    cmd.stdout.read()
-    cmd.stdout.close()
+    with open(testfile, "w") as f:
+        f.write("ff:ff:ff:ff:ff:ff")
     ev = dev[0].wait_event(["CTRL-EVENT-DISCONNECTED"], timeout=10)
     if ev is None:
         raise Exception("No disconnection after two Michael MIC failures")
@@ -89,22 +80,14 @@ def test_ap_cipher_tkip_countermeasures_sta(dev, apdev):
                    pairwise="TKIP", group="TKIP", scan_freq="2412")
 
     dev[0].dump_monitor()
-    cmd = subprocess.Popen(["sudo", "tee", testfile],
-                           stdin=subprocess.PIPE, stdout=subprocess.PIPE)
-    cmd.stdin.write(dev[0].p2p_dev_addr())
-    cmd.stdin.close()
-    cmd.stdout.read()
-    cmd.stdout.close()
+    with open(testfile, "w") as f:
+        f.write(dev[0].p2p_dev_addr())
     ev = dev[0].wait_event(["CTRL-EVENT-DISCONNECTED"], timeout=1)
     if ev is not None:
         raise Exception("Unexpected disconnection on first Michael MIC failure")
 
-    cmd = subprocess.Popen(["sudo", "tee", testfile],
-                           stdin=subprocess.PIPE, stdout=subprocess.PIPE)
-    cmd.stdin.write("ff:ff:ff:ff:ff:ff")
-    cmd.stdin.close()
-    cmd.stdout.read()
-    cmd.stdout.close()
+    with open(testfile, "w") as f:
+        f.write("ff:ff:ff:ff:ff:ff")
     ev = dev[0].wait_event(["CTRL-EVENT-DISCONNECTED"], timeout=10)
     if ev is None:
         raise Exception("No disconnection after two Michael MIC failures")