Linux/FreeBSD: Fix regression causing admin password to be requested too many times in some cases

This commit is contained in:
Mounir IDRASSI 2019-11-03 15:35:53 +01:00
parent bd7200e2b5
commit 80cc18f667
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GPG Key ID: 02C30AE90FAE4A6F

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@ -289,43 +289,51 @@ namespace VeraCrypt
request.FastElevation = !ElevatedServiceAvailable;
request.ApplicationExecutablePath = Core->GetApplicationExecutablePath();
// Test if the user has an active "sudo" session.
// This is only done under Linux / FreeBSD by executing the command 'sudo -n uptime'.
// In case a "sudo" session is active, the result of the command contains the string 'load average'.
// Otherwise, the result contains "sudo: a password is required".
// This may not work on all OSX versions because of a bug in sudo in its version 1.7.10,
// therefore we keep the old behaviour of sending a 'dummy' password under OSX.
// See : https://superuser.com/questions/902826/why-does-sudo-n-on-mac-os-x-always-return-0
#if defined(TC_LINUX ) || defined (TC_FREEBSD)
// Set to false to force the 'WarningEvent' to be raised in case of and elevation exception.
request.FastElevation = false;
std::vector<char> buffer(128, 0);
std::string result;
FILE* pipe = popen("sudo -n uptime 2>&1 | grep 'load average' | wc -l", "r"); // We redirect stderr to stdout (2>&1) to be able to catch the result of the command
if (pipe)
{
while (!feof(pipe))
{
if (fgets(buffer.data(), 128, pipe) != nullptr)
result += buffer.data();
}
fflush(pipe);
pclose(pipe);
pipe = NULL;
if (!result.empty() && strlen(result.c_str()) != 0 && !memcmp(result.c_str(), "0", 1))
{
(*AdminPasswordCallback) (request.AdminPassword);
}
}
#endif
while (!ElevatedServiceAvailable)
{
// Test if the user has an active "sudo" session.
// This is only done under Linux / FreeBSD by executing the command 'sudo -n uptime'.
// In case a "sudo" session is active, the result of the command contains the string 'load average'.
// Otherwise, the result contains "sudo: a password is required".
// This may not work on all OSX versions because of a bug in sudo in its version 1.7.10,
// therefore we keep the old behaviour of sending a 'dummy' password under OSX.
// See : https://superuser.com/questions/902826/why-does-sudo-n-on-mac-os-x-always-return-0
//
// If for some reason we are getting empty output from pipe, we revert to old behavior
#if defined(TC_LINUX ) || defined (TC_FREEBSD)
std::vector<char> buffer(128, 0);
std::string result;
bool authCheckDone = false;
FILE* pipe = popen("sudo -n uptime 2>&1 | grep 'load average' | wc -l", "r"); // We redirect stderr to stdout (2>&1) to be able to catch the result of the command
if (pipe)
{
while (!feof(pipe))
{
if (fgets(buffer.data(), 128, pipe) != nullptr)
result += buffer.data();
}
fflush(pipe);
pclose(pipe);
pipe = NULL;
if (!result.empty() && strlen(result.c_str()) != 0)
{
authCheckDone = true;
if (result[0] == '0') // no line found with "load average" text, rerquest admin password
(*AdminPasswordCallback) (request.AdminPassword);
}
}
if (authCheckDone)
{
// Set to false to force the 'WarningEvent' to be raised in case of and elevation exception.
request.FastElevation = false;
}
#endif
try
{
request.Serialize (ServiceInputStream);
@ -432,7 +440,7 @@ namespace VeraCrypt
vector <char> adminPassword (request.AdminPassword.size() + 1);
int timeout = 6000;
// 'request.FastElevation' is always false under Linux / FreeBSD
// 'request.FastElevation' is always false under Linux / FreeBSD when "sudo -n" works properly
if (request.FastElevation)
{
string dummyPassword = "dummy\n";