wg: windows: enforce named pipe ownership and use protected prefix
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
		
							parent
							
								
									4154476d89
								
							
						
					
					
						commit
						959937672a
					
				
							
								
								
									
										32
									
								
								src/ipc.c
									
									
									
									
									
								
							
							
						
						
									
										32
									
								
								src/ipc.c
									
									
									
									
									
								
							@ -96,7 +96,7 @@ static int add_next_to_inflatable_buffer(struct inflatable_buffer *buffer)
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
#ifndef WINCOMPAT
 | 
			
		||||
static FILE *userspace_interface_file(const char *interface)
 | 
			
		||||
static FILE *userspace_interface_file(const char *iface)
 | 
			
		||||
{
 | 
			
		||||
	struct stat sbuf;
 | 
			
		||||
	struct sockaddr_un addr = { .sun_family = AF_UNIX };
 | 
			
		||||
@ -104,9 +104,9 @@ static FILE *userspace_interface_file(const char *interface)
 | 
			
		||||
	FILE *f = NULL;
 | 
			
		||||
 | 
			
		||||
	errno = EINVAL;
 | 
			
		||||
	if (strchr(interface, '/'))
 | 
			
		||||
	if (strchr(iface, '/'))
 | 
			
		||||
		goto out;
 | 
			
		||||
	ret = snprintf(addr.sun_path, sizeof(addr.sun_path), SOCK_PATH "%s" SOCK_SUFFIX, interface);
 | 
			
		||||
	ret = snprintf(addr.sun_path, sizeof(addr.sun_path), SOCK_PATH "%s" SOCK_SUFFIX, iface);
 | 
			
		||||
	if (ret < 0)
 | 
			
		||||
		goto out;
 | 
			
		||||
	ret = stat(addr.sun_path, &sbuf);
 | 
			
		||||
@ -140,15 +140,15 @@ out:
 | 
			
		||||
	return f;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static bool userspace_has_wireguard_interface(const char *interface)
 | 
			
		||||
static bool userspace_has_wireguard_interface(const char *iface)
 | 
			
		||||
{
 | 
			
		||||
	struct stat sbuf;
 | 
			
		||||
	struct sockaddr_un addr = { .sun_family = AF_UNIX };
 | 
			
		||||
	int fd, ret;
 | 
			
		||||
 | 
			
		||||
	if (strchr(interface, '/'))
 | 
			
		||||
	if (strchr(iface, '/'))
 | 
			
		||||
		return false;
 | 
			
		||||
	if (snprintf(addr.sun_path, sizeof(addr.sun_path), SOCK_PATH "%s" SOCK_SUFFIX, interface) < 0)
 | 
			
		||||
	if (snprintf(addr.sun_path, sizeof(addr.sun_path), SOCK_PATH "%s" SOCK_SUFFIX, iface) < 0)
 | 
			
		||||
		return false;
 | 
			
		||||
	if (stat(addr.sun_path, &sbuf) < 0)
 | 
			
		||||
		return false;
 | 
			
		||||
@ -288,7 +288,7 @@ static int userspace_set_device(struct wgdevice *dev)
 | 
			
		||||
	num; \
 | 
			
		||||
})
 | 
			
		||||
 | 
			
		||||
static int userspace_get_device(struct wgdevice **out, const char *interface)
 | 
			
		||||
static int userspace_get_device(struct wgdevice **out, const char *iface)
 | 
			
		||||
{
 | 
			
		||||
	struct wgdevice *dev;
 | 
			
		||||
	struct wgpeer *peer = NULL;
 | 
			
		||||
@ -302,14 +302,14 @@ static int userspace_get_device(struct wgdevice **out, const char *interface)
 | 
			
		||||
	if (!dev)
 | 
			
		||||
		return -errno;
 | 
			
		||||
 | 
			
		||||
	f = userspace_interface_file(interface);
 | 
			
		||||
	f = userspace_interface_file(iface);
 | 
			
		||||
	if (!f)
 | 
			
		||||
		return -errno;
 | 
			
		||||
 | 
			
		||||
	fprintf(f, "get=1\n\n");
 | 
			
		||||
	fflush(f);
 | 
			
		||||
 | 
			
		||||
	strncpy(dev->name, interface, IFNAMSIZ - 1);
 | 
			
		||||
	strncpy(dev->name, iface, IFNAMSIZ - 1);
 | 
			
		||||
	dev->name[IFNAMSIZ - 1] = '\0';
 | 
			
		||||
 | 
			
		||||
	while (getline(&key, &line_buffer_len, f) > 0) {
 | 
			
		||||
@ -889,7 +889,7 @@ static void coalesce_peers(struct wgdevice *device)
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static int kernel_get_device(struct wgdevice **device, const char *interface)
 | 
			
		||||
static int kernel_get_device(struct wgdevice **device, const char *iface)
 | 
			
		||||
{
 | 
			
		||||
	int ret = 0;
 | 
			
		||||
	struct nlmsghdr *nlh;
 | 
			
		||||
@ -908,7 +908,7 @@ try_again:
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	nlh = mnlg_msg_prepare(nlg, WG_CMD_GET_DEVICE, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP);
 | 
			
		||||
	mnl_attr_put_strz(nlh, WGDEVICE_A_IFNAME, interface);
 | 
			
		||||
	mnl_attr_put_strz(nlh, WGDEVICE_A_IFNAME, iface);
 | 
			
		||||
	if (mnlg_socket_send(nlg, nlh) < 0) {
 | 
			
		||||
		ret = -errno;
 | 
			
		||||
		goto out;
 | 
			
		||||
@ -963,14 +963,14 @@ cleanup:
 | 
			
		||||
	return buffer.buffer;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
int ipc_get_device(struct wgdevice **dev, const char *interface)
 | 
			
		||||
int ipc_get_device(struct wgdevice **dev, const char *iface)
 | 
			
		||||
{
 | 
			
		||||
#ifdef __linux__
 | 
			
		||||
	if (userspace_has_wireguard_interface(interface))
 | 
			
		||||
		return userspace_get_device(dev, interface);
 | 
			
		||||
	return kernel_get_device(dev, interface);
 | 
			
		||||
	if (userspace_has_wireguard_interface(iface))
 | 
			
		||||
		return userspace_get_device(dev, iface);
 | 
			
		||||
	return kernel_get_device(dev, iface);
 | 
			
		||||
#else
 | 
			
		||||
	return userspace_get_device(dev, interface);
 | 
			
		||||
	return userspace_get_device(dev, iface);
 | 
			
		||||
#endif
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
@ -5,18 +5,23 @@
 | 
			
		||||
 | 
			
		||||
#include <windows.h>
 | 
			
		||||
#include <tlhelp32.h>
 | 
			
		||||
#include <accctrl.h>
 | 
			
		||||
#include <aclapi.h>
 | 
			
		||||
#include <stdio.h>
 | 
			
		||||
#include <stdbool.h>
 | 
			
		||||
#include <fcntl.h>
 | 
			
		||||
 | 
			
		||||
static FILE *userspace_interface_file(const char *interface)
 | 
			
		||||
static FILE *userspace_interface_file(const char *iface)
 | 
			
		||||
{
 | 
			
		||||
	char fname[MAX_PATH], error_message[1024 * 128] = { 0 };
 | 
			
		||||
	HANDLE thread_token, process_snapshot, winlogon_process, winlogon_token, duplicated_token, pipe_handle = INVALID_HANDLE_VALUE;
 | 
			
		||||
	PROCESSENTRY32 entry = { .dwSize = sizeof(PROCESSENTRY32) };
 | 
			
		||||
	PSECURITY_DESCRIPTOR pipe_sd;
 | 
			
		||||
	PSID pipe_sid;
 | 
			
		||||
	SID expected_sid;
 | 
			
		||||
	BOOL ret;
 | 
			
		||||
	int fd;
 | 
			
		||||
	DWORD last_error = ERROR_SUCCESS;
 | 
			
		||||
	DWORD last_error = ERROR_SUCCESS, bytes = sizeof(expected_sid);
 | 
			
		||||
	TOKEN_PRIVILEGES privileges = {
 | 
			
		||||
		.PrivilegeCount = 1,
 | 
			
		||||
		.Privileges = {{ .Attributes = SE_PRIVILEGE_ENABLED }}
 | 
			
		||||
@ -24,6 +29,8 @@ static FILE *userspace_interface_file(const char *interface)
 | 
			
		||||
 | 
			
		||||
	if (!LookupPrivilegeValue(NULL, SE_DEBUG_NAME, &privileges.Privileges[0].Luid))
 | 
			
		||||
		goto err;
 | 
			
		||||
	if (!CreateWellKnownSid(WinLocalSystemSid, NULL, &expected_sid, &bytes))
 | 
			
		||||
		goto err;
 | 
			
		||||
 | 
			
		||||
	process_snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
 | 
			
		||||
	if (process_snapshot == INVALID_HANDLE_VALUE)
 | 
			
		||||
@ -63,13 +70,24 @@ static FILE *userspace_interface_file(const char *interface)
 | 
			
		||||
		}
 | 
			
		||||
		CloseHandle(duplicated_token);
 | 
			
		||||
 | 
			
		||||
		snprintf(fname, sizeof(fname), "\\\\.\\pipe\\WireGuard\\%s", interface);
 | 
			
		||||
		snprintf(fname, sizeof(fname), "\\\\.\\pipe\\ProtectedPrefix\\Administrators\\WireGuard\\%s", iface);
 | 
			
		||||
		pipe_handle = CreateFile(fname, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
 | 
			
		||||
		last_error = GetLastError();
 | 
			
		||||
		if (pipe_handle != INVALID_HANDLE_VALUE) {
 | 
			
		||||
			last_error = ERROR_SUCCESS;
 | 
			
		||||
			break;
 | 
			
		||||
		if (pipe_handle == INVALID_HANDLE_VALUE)
 | 
			
		||||
			continue;
 | 
			
		||||
		last_error = GetSecurityInfo(pipe_handle, SE_FILE_OBJECT, OWNER_SECURITY_INFORMATION, &pipe_sid, NULL, NULL, NULL, &pipe_sd);
 | 
			
		||||
		if (last_error != ERROR_SUCCESS) {
 | 
			
		||||
			CloseHandle(pipe_handle);
 | 
			
		||||
			continue;
 | 
			
		||||
		}
 | 
			
		||||
		last_error = EqualSid(&expected_sid, pipe_sid) ? ERROR_SUCCESS : ERROR_ACCESS_DENIED;
 | 
			
		||||
		LocalFree(pipe_sd);
 | 
			
		||||
		if (last_error != ERROR_SUCCESS) {
 | 
			
		||||
			CloseHandle(pipe_handle);
 | 
			
		||||
			continue;
 | 
			
		||||
		}
 | 
			
		||||
		last_error = ERROR_SUCCESS;
 | 
			
		||||
		break;
 | 
			
		||||
	}
 | 
			
		||||
	RevertToSelf();
 | 
			
		||||
	CloseHandle(process_snapshot);
 | 
			
		||||
 | 
			
		||||
		Reference in New Issue
	
	Block a user