Found a problem with the no screen reader path that could have a user type password when unnecessary and potentially leak the password via speech if key echo is enabled.

sas.py

@@ -8,9 +8,9 @@ import string
 import subprocess
 import sys
 import tempfile
+import threading
 import time
 import pwd
-import threading
 
 
 stormuxAdmin = ("storm",)
@@ -24,16 +24,41 @@ pingIntervalSeconds = 180
 pingCount = 5
 maxWormholeFailures = 3
 
+sudoRefreshIntervalSeconds = 60
 sudoKeepaliveThread = None
 sudoKeepaliveStop = threading.Event()
+sudoSessionPrepared = False
+sudoAuthenticationError = ""
 
 
-def speak_message(message):
+def speak_message(
+    message,
+    fallbackFile=None,
+    wait=False,
+    applicationName=None,
+    connectionName=None,
+):
+    command = ["spd-say"]
+    if applicationName:
+        command += ["-N", applicationName]
+    if connectionName:
+        command += ["-n", connectionName]
+    if wait:
+        command.append("-w")
+    command.append(message)
     try:
-        subprocess.run(["spd-say", message], check=False)
+        result = subprocess.run(
+            command,
+            check=False,
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+            start_new_session=wait,
+        )
     except FileNotFoundError:
-        print(message, flush=True)
-
+        print(message, file=fallbackFile or sys.stdout, flush=True)
+        return
+    if result.returncode != 0:
+        print(message, file=fallbackFile or sys.stdout, flush=True)
 
 def say_or_print(message, useSpeech):
     if useSpeech:
@@ -53,16 +78,76 @@ def run_command(command, inputText=None, check=False, env=None):
     )
 
 
+def run_terminal_sudo_authentication():
+    speak_message(
+        "Your sudo password will be requested next. Do not type your password yet. "
+        "If your microphone can carry computer speech into the support meeting, mute it "
+        "before continuing and unmute it afterward. Press Enter to continue. After you "
+        "press Enter, wait one second, then type your password and press Enter. If you "
+        "hear any part of your password spoken, stop immediately, do not finish it, and "
+        "tell the support assistant.",
+        wait=True,
+        applicationName="sas",
+        connectionName=f"sudo-password-{os.getpid()}",
+    )
+    input()
+    return run_command(["sudo", "-v"])
+
+
+def authenticate_sudo(useSpeech):
+    global sudoAuthenticationError
+    sudoAuthenticationError = ""
+    command = ["sudo"]
+    if useSpeech:
+        result = run_terminal_sudo_authentication()
+    else:
+        result = run_command(command + ["-v"])
+    if result.returncode != 0:
+        sudoAuthenticationError = concise_command_error(result)
+        return False
+    start_sudo_keepalive()
+    return True
+
+
+def prepare_sudo_session(useSpeech):
+    global sudoAuthenticationError, sudoSessionPrepared
+    if os.geteuid() == 0:
+        sudoSessionPrepared = True
+        return True
+    invalidateResult = run_command(["sudo", "-k"])
+    if invalidateResult.returncode != 0:
+        sudoAuthenticationError = concise_command_error(invalidateResult)
+        return False
+    probeEnv = os.environ.copy()
+    probeEnv["LC_ALL"] = "C"
+    probeEnv["LANG"] = "C"
+    probeResult = run_command(["sudo", "-n", "-v"], env=probeEnv)
+    if probeResult.returncode == 0:
+        start_sudo_keepalive()
+        sudoSessionPrepared = True
+        return True
+    probeError = concise_command_error(probeResult)
+    if "password is required" not in probeError.lower():
+        sudoAuthenticationError = probeError
+        return False
+    if not authenticate_sudo(useSpeech=useSpeech):
+        return False
+    sudoSessionPrepared = True
+    return True
+
+
 def ensure_sudo(useSpeech):
     if os.geteuid() == 0:
         return True
-    if useSpeech:
-        speak_message("Sudo password required. Please enter your password now.")
-    result = run_command(["sudo", "-v"])
-    if result.returncode == 0:
-        start_sudo_keepalive()
-        return True
-    return False
+    if sudoSessionPrepared:
+        return run_command(["sudo", "-n", "-v"]).returncode == 0
+    return authenticate_sudo(useSpeech)
+
+
+def sudo_command_prefix():
+    if sudoSessionPrepared:
+        return ["sudo", "-n"]
+    return ["sudo"]
 
 
 def start_sudo_keepalive():
@@ -71,7 +156,7 @@ def start_sudo_keepalive():
         return
 
     def keepalive_loop():
-        while not sudoKeepaliveStop.wait(240):
+        while not sudoKeepaliveStop.wait(sudoRefreshIntervalSeconds):
             run_command(["sudo", "-n", "-v"])
 
     sudoKeepaliveThread = threading.Thread(target=keepalive_loop, daemon=True)
@@ -84,7 +169,7 @@ def run_privileged(command, useSpeech, inputText=None, check=True):
     else:
         if not ensure_sudo(useSpeech):
             raise RuntimeError("sudo authentication failed")
-        fullCommand = ["sudo"] + command
+        fullCommand = sudo_command_prefix() + command
     return run_command(fullCommand, inputText=inputText, check=check)
 
 
@@ -94,7 +179,7 @@ def run_as_user(userName, command, useSpeech, check=True):
     else:
         if not ensure_sudo(useSpeech):
             raise RuntimeError("sudo authentication failed")
-        fullCommand = ["sudo", "-u", userName, "-H"] + command
+        fullCommand = sudo_command_prefix() + ["-u", userName, "-H"] + command
     return run_command(fullCommand, check=check)
 
 
@@ -102,6 +187,15 @@ def command_error_text(result):
     return (result.stderr or result.stdout or "").strip()
 
 
+def concise_command_error(result):
+    errorText = " ".join(command_error_text(result).split())
+    if not errorText:
+        return "sudo returned no error details"
+    if len(errorText) > 400:
+        return errorText[:400] + "..."
+    return errorText
+
+
 def service_is_active(serviceName):
     result = run_command(["systemctl", "is-active", "--quiet", serviceName])
     return result.returncode == 0
@@ -373,6 +467,15 @@ def main():
     answer = input().strip().lower()
     useSpeech = answer in ("n", "no")
 
+    if useSpeech and not prepare_sudo_session(useSpeech=True):
+        failureMessage = (
+            f"Sudo authentication failed. {sudoAuthenticationError}. "
+            "The support session was not started."
+        )
+        say_or_print(failureMessage, True)
+        print(failureMessage, flush=True)
+        return 1
+
     shouldRemoveUser = False
     cleanupDone = False
     tempDir = tempfile.mkdtemp(prefix="sas-ii-")
@@ -425,7 +528,10 @@ def main():
                         useSpeech,
                     )
             except Exception:
-                pass
+                say_or_print(
+                    "Cleanup warning: failed to remove sas user. Please remove it manually.",
+                    useSpeech,
+                )
 
         sudoKeepaliveStop.set()
         if sudoKeepaliveThread:
@@ -615,7 +721,7 @@ def main():
             privateKeyPath,
             f"{sasUser}@{remoteHost}",
         ]
-        sshCommand = ["sudo", "-u", sasUser, "-H"] + sshCommand
+        sshCommand = sudo_command_prefix() + ["-u", sasUser, "-H"] + sshCommand
         sshProcess = subprocess.Popen(sshCommand)
         sshProcess.wait()
         say_or_print("The support connection ended. Cleaning up.", useSpeech)
@@ -649,5 +755,13 @@ def remove_tree(path):
         pass
 
 
+def command_line_main(arguments=None):
+    arguments = sys.argv[1:] if arguments is None else arguments
+    if arguments:
+        print("Usage: sas", file=sys.stderr)
+        return 2
+    return main()
+
+
 if __name__ == "__main__":
-    sys.exit(main())
+    sys.exit(command_line_main())