wg: windows: enforce named pipe ownership and use protected prefix

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2019-08-30 13:51:27 -06:00
parent 4154476d89
commit 959937672a
2 changed files with 40 additions and 22 deletions

View file

@ -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
}

View file

@ -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)
@ -63,14 +70,25 @@ 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) {
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);