Vendor after merging mtrmac/image:openpgp, + other updates

Primarily vendor after merging mtrmac/image:openpgp.

Then update for the SigningMechanism API change.

Also skip signing tests if the GPG mechanism does not support signing.

Also abort some of the tests early instead of trying to use invalid (or
nil) values.

The current master of image-tools does not build with Go 1.6, so keep
using an older release.

Also requires adding a few more dependencies of our updated
dependencies.
This commit is contained in:
Miloslav Trmač
2017-03-20 15:29:26 +01:00
parent d2d41ebc33
commit 0caee746fb
98 changed files with 34047 additions and 1455 deletions

View File

@@ -0,0 +1,84 @@
// +build !selinux !linux
package label
// InitLabels returns the process label and file labels to be used within
// the container. A list of options can be passed into this function to alter
// the labels.
func InitLabels(options []string) (string, string, error) {
return "", "", nil
}
func GetROMountLabel() string {
return ""
}
func GenLabels(options string) (string, string, error) {
return "", "", nil
}
func FormatMountLabel(src string, mountLabel string) string {
return src
}
func SetProcessLabel(processLabel string) error {
return nil
}
func GetFileLabel(path string) (string, error) {
return "", nil
}
func SetFileLabel(path string, fileLabel string) error {
return nil
}
func SetFileCreateLabel(fileLabel string) error {
return nil
}
func Relabel(path string, fileLabel string, shared bool) error {
return nil
}
func GetPidLabel(pid int) (string, error) {
return "", nil
}
func Init() {
}
func ReserveLabel(label string) error {
return nil
}
func ReleaseLabel(label string) error {
return nil
}
// DupSecOpt takes a process label and returns security options that
// can be used to set duplicate labels on future container processes
func DupSecOpt(src string) []string {
return nil
}
// DisableSecOpt returns a security opt that can disable labeling
// support for future container processes
func DisableSecOpt() []string {
return nil
}
// Validate checks that the label does not include unexpected options
func Validate(label string) error {
return nil
}
// RelabelNeeded checks whether the user requested a relabel
func RelabelNeeded(label string) bool {
return false
}
// IsShared checks that the label includes a "shared" mark
func IsShared(label string) bool {
return false
}

View File

@@ -0,0 +1,204 @@
// +build selinux,linux
package label
import (
"fmt"
"strings"
"github.com/opencontainers/selinux/go-selinux"
)
// Valid Label Options
var validOptions = map[string]bool{
"disable": true,
"type": true,
"user": true,
"role": true,
"level": true,
}
var ErrIncompatibleLabel = fmt.Errorf("Bad SELinux option z and Z can not be used together")
// InitLabels returns the process label and file labels to be used within
// the container. A list of options can be passed into this function to alter
// the labels. The labels returned will include a random MCS String, that is
// guaranteed to be unique.
func InitLabels(options []string) (string, string, error) {
if !selinux.GetEnabled() {
return "", "", nil
}
processLabel, mountLabel := selinux.ContainerLabels()
if processLabel != "" {
pcon := selinux.NewContext(processLabel)
mcon := selinux.NewContext(mountLabel)
for _, opt := range options {
if opt == "disable" {
return "", "", nil
}
if i := strings.Index(opt, ":"); i == -1 {
return "", "", fmt.Errorf("Bad label option %q, valid options 'disable' or \n'user, role, level, type' followed by ':' and a value", opt)
}
con := strings.SplitN(opt, ":", 2)
if !validOptions[con[0]] {
return "", "", fmt.Errorf("Bad label option %q, valid options 'disable, user, role, level, type'", con[0])
}
pcon[con[0]] = con[1]
if con[0] == "level" || con[0] == "user" {
mcon[con[0]] = con[1]
}
}
processLabel = pcon.Get()
mountLabel = mcon.Get()
}
return processLabel, mountLabel, nil
}
func ROMountLabel() string {
return selinux.ROFileLabel()
}
// DEPRECATED: The GenLabels function is only to be used during the transition to the official API.
func GenLabels(options string) (string, string, error) {
return InitLabels(strings.Fields(options))
}
// FormatMountLabel returns a string to be used by the mount command.
// The format of this string will be used to alter the labeling of the mountpoint.
// The string returned is suitable to be used as the options field of the mount command.
// If you need to have additional mount point options, you can pass them in as
// the first parameter. Second parameter is the label that you wish to apply
// to all content in the mount point.
func FormatMountLabel(src, mountLabel string) string {
if mountLabel != "" {
switch src {
case "":
src = fmt.Sprintf("context=%q", mountLabel)
default:
src = fmt.Sprintf("%s,context=%q", src, mountLabel)
}
}
return src
}
// SetProcessLabel takes a process label and tells the kernel to assign the
// label to the next program executed by the current process.
func SetProcessLabel(processLabel string) error {
if processLabel == "" {
return nil
}
return selinux.SetExecLabel(processLabel)
}
// ProcessLabel returns the process label that the kernel will assign
// to the next program executed by the current process. If "" is returned
// this indicates that the default labeling will happen for the process.
func ProcessLabel() (string, error) {
return selinux.ExecLabel()
}
// GetFileLabel returns the label for specified path
func FileLabel(path string) (string, error) {
return selinux.FileLabel(path)
}
// SetFileLabel modifies the "path" label to the specified file label
func SetFileLabel(path string, fileLabel string) error {
if selinux.GetEnabled() && fileLabel != "" {
return selinux.SetFileLabel(path, fileLabel)
}
return nil
}
// SetFileCreateLabel tells the kernel the label for all files to be created
func SetFileCreateLabel(fileLabel string) error {
if selinux.GetEnabled() {
return selinux.SetFSCreateLabel(fileLabel)
}
return nil
}
// Relabel changes the label of path to the filelabel string.
// It changes the MCS label to s0 if shared is true.
// This will allow all containers to share the content.
func Relabel(path string, fileLabel string, shared bool) error {
if !selinux.GetEnabled() {
return nil
}
if fileLabel == "" {
return nil
}
exclude_paths := map[string]bool{"/": true, "/usr": true, "/etc": true}
if exclude_paths[path] {
return fmt.Errorf("SELinux relabeling of %s is not allowed", path)
}
if shared {
c := selinux.NewContext(fileLabel)
c["level"] = "s0"
fileLabel = c.Get()
}
if err := selinux.Chcon(path, fileLabel, true); err != nil {
return err
}
return nil
}
// PidLabel will return the label of the process running with the specified pid
func PidLabel(pid int) (string, error) {
return selinux.PidLabel(pid)
}
// Init initialises the labeling system
func Init() {
selinux.GetEnabled()
}
// ReserveLabel will record the fact that the MCS label has already been used.
// This will prevent InitLabels from using the MCS label in a newly created
// container
func ReserveLabel(label string) error {
selinux.ReserveLabel(label)
return nil
}
// ReleaseLabel will remove the reservation of the MCS label.
// This will allow InitLabels to use the MCS label in a newly created
// containers
func ReleaseLabel(label string) error {
selinux.ReleaseLabel(label)
return nil
}
// DupSecOpt takes a process label and returns security options that
// can be used to set duplicate labels on future container processes
func DupSecOpt(src string) []string {
return selinux.DupSecOpt(src)
}
// DisableSecOpt returns a security opt that can disable labeling
// support for future container processes
func DisableSecOpt() []string {
return selinux.DisableSecOpt()
}
// Validate checks that the label does not include unexpected options
func Validate(label string) error {
if strings.Contains(label, "z") && strings.Contains(label, "Z") {
return ErrIncompatibleLabel
}
return nil
}
// RelabelNeeded checks whether the user requested a relabel
func RelabelNeeded(label string) bool {
return strings.Contains(label, "z") || strings.Contains(label, "Z")
}
// IsShared checks that the label includes a "shared" mark
func IsShared(label string) bool {
return strings.Contains(label, "z")
}

View File

@@ -0,0 +1,593 @@
// +build linux
package selinux
import (
"bufio"
"crypto/rand"
"encoding/binary"
"fmt"
"io"
"os"
"path/filepath"
"regexp"
"strconv"
"strings"
"sync"
"syscall"
)
const (
// Enforcing constant indicate SELinux is in enforcing mode
Enforcing = 1
// Permissive constant to indicate SELinux is in permissive mode
Permissive = 0
// Disabled constant to indicate SELinux is disabled
Disabled = -1
selinuxDir = "/etc/selinux/"
selinuxConfig = selinuxDir + "config"
selinuxTypeTag = "SELINUXTYPE"
selinuxTag = "SELINUX"
selinuxPath = "/sys/fs/selinux"
xattrNameSelinux = "security.selinux"
stRdOnly = 0x01
)
type selinuxState struct {
enabledSet bool
enabled bool
selinuxfsSet bool
selinuxfs string
mcsList map[string]bool
sync.Mutex
}
var (
assignRegex = regexp.MustCompile(`^([^=]+)=(.*)$`)
state = selinuxState{
mcsList: make(map[string]bool),
}
)
// Context is a representation of the SELinux label broken into 4 parts
type Context map[string]string
func (s *selinuxState) setEnable(enabled bool) bool {
s.Lock()
defer s.Unlock()
s.enabledSet = true
s.enabled = enabled
return s.enabled
}
func (s *selinuxState) getEnabled() bool {
s.Lock()
enabled := s.enabled
enabledSet := s.enabledSet
s.Unlock()
if enabledSet {
return enabled
}
enabled = false
if fs := getSelinuxMountPoint(); fs != "" {
if con, _ := CurrentLabel(); con != "kernel" {
enabled = true
}
}
return s.setEnable(enabled)
}
// SetDisabled disables selinux support for the package
func SetDisabled() {
state.setEnable(false)
}
func (s *selinuxState) setSELinuxfs(selinuxfs string) string {
s.Lock()
defer s.Unlock()
s.selinuxfsSet = true
s.selinuxfs = selinuxfs
return s.selinuxfs
}
func (s *selinuxState) getSELinuxfs() string {
s.Lock()
selinuxfs := s.selinuxfs
selinuxfsSet := s.selinuxfsSet
s.Unlock()
if selinuxfsSet {
return selinuxfs
}
selinuxfs = ""
f, err := os.Open("/proc/self/mountinfo")
if err != nil {
return selinuxfs
}
defer f.Close()
scanner := bufio.NewScanner(f)
for scanner.Scan() {
txt := scanner.Text()
// Safe as mountinfo encodes mountpoints with spaces as \040.
sepIdx := strings.Index(txt, " - ")
if sepIdx == -1 {
continue
}
if !strings.Contains(txt[sepIdx:], "selinuxfs") {
continue
}
fields := strings.Split(txt, " ")
if len(fields) < 5 {
continue
}
selinuxfs = fields[4]
break
}
if selinuxfs != "" {
var buf syscall.Statfs_t
syscall.Statfs(selinuxfs, &buf)
if (buf.Flags & stRdOnly) == 1 {
selinuxfs = ""
}
}
return s.setSELinuxfs(selinuxfs)
}
// getSelinuxMountPoint returns the path to the mountpoint of an selinuxfs
// filesystem or an empty string if no mountpoint is found. Selinuxfs is
// a proc-like pseudo-filesystem that exposes the selinux policy API to
// processes. The existence of an selinuxfs mount is used to determine
// whether selinux is currently enabled or not.
func getSelinuxMountPoint() string {
return state.getSELinuxfs()
}
// GetEnabled returns whether selinux is currently enabled.
func GetEnabled() bool {
return state.getEnabled()
}
func readConfig(target string) (value string) {
var (
val, key string
bufin *bufio.Reader
)
in, err := os.Open(selinuxConfig)
if err != nil {
return ""
}
defer in.Close()
bufin = bufio.NewReader(in)
for done := false; !done; {
var line string
if line, err = bufin.ReadString('\n'); err != nil {
if err != io.EOF {
return ""
}
done = true
}
line = strings.TrimSpace(line)
if len(line) == 0 {
// Skip blank lines
continue
}
if line[0] == ';' || line[0] == '#' {
// Skip comments
continue
}
if groups := assignRegex.FindStringSubmatch(line); groups != nil {
key, val = strings.TrimSpace(groups[1]), strings.TrimSpace(groups[2])
if key == target {
return strings.Trim(val, "\"")
}
}
}
return ""
}
func getSELinuxPolicyRoot() string {
return selinuxDir + readConfig(selinuxTypeTag)
}
func readCon(name string) (string, error) {
var val string
in, err := os.Open(name)
if err != nil {
return "", err
}
defer in.Close()
_, err = fmt.Fscanf(in, "%s", &val)
return val, err
}
// SetFileLabel sets the SELinux label for this path or returns an error.
func SetFileLabel(path string, label string) error {
return lsetxattr(path, xattrNameSelinux, []byte(label), 0)
}
// Filecon returns the SELinux label for this path or returns an error.
func FileLabel(path string) (string, error) {
label, err := lgetxattr(path, xattrNameSelinux)
if err != nil {
return "", err
}
// Trim the NUL byte at the end of the byte buffer, if present.
if len(label) > 0 && label[len(label)-1] == '\x00' {
label = label[:len(label)-1]
}
return string(label), nil
}
/*
SetFSCreateLabel tells kernel the label to create all file system objects
created by this task. Setting label="" to return to default.
*/
func SetFSCreateLabel(label string) error {
return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/fscreate", syscall.Gettid()), label)
}
/*
FSCreateLabel returns the default label the kernel which the kernel is using
for file system objects created by this task. "" indicates default.
*/
func FSCreateLabel() (string, error) {
return readCon(fmt.Sprintf("/proc/self/task/%d/attr/fscreate", syscall.Gettid()))
}
// CurrentLabel returns the SELinux label of the current process thread, or an error.
func CurrentLabel() (string, error) {
return readCon(fmt.Sprintf("/proc/self/task/%d/attr/current", syscall.Gettid()))
}
// PidLabel returns the SELinux label of the given pid, or an error.
func PidLabel(pid int) (string, error) {
return readCon(fmt.Sprintf("/proc/%d/attr/current", pid))
}
/*
ExecLabel returns the SELinux label that the kernel will use for any programs
that are executed by the current process thread, or an error.
*/
func ExecLabel() (string, error) {
return readCon(fmt.Sprintf("/proc/self/task/%d/attr/exec", syscall.Gettid()))
}
func writeCon(name string, val string) error {
out, err := os.OpenFile(name, os.O_WRONLY, 0)
if err != nil {
return err
}
defer out.Close()
if val != "" {
_, err = out.Write([]byte(val))
} else {
_, err = out.Write(nil)
}
return err
}
/*
SetExecLabel sets the SELinux label that the kernel will use for any programs
that are executed by the current process thread, or an error.
*/
func SetExecLabel(label string) error {
return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/exec", syscall.Gettid()), label)
}
// Get returns the Context as a string
func (c Context) Get() string {
return fmt.Sprintf("%s:%s:%s:%s", c["user"], c["role"], c["type"], c["level"])
}
// NewContext creates a new Context struct from the specified label
func NewContext(label string) Context {
c := make(Context)
if len(label) != 0 {
con := strings.SplitN(label, ":", 4)
c["user"] = con[0]
c["role"] = con[1]
c["type"] = con[2]
c["level"] = con[3]
}
return c
}
// ReserveLabel reserves the MLS/MCS level component of the specified label
func ReserveLabel(label string) {
if len(label) != 0 {
con := strings.SplitN(label, ":", 4)
mcsAdd(con[3])
}
}
func selinuxEnforcePath() string {
return fmt.Sprintf("%s/enforce", selinuxPath)
}
// EnforceMode returns the current SELinux mode Enforcing, Permissive, Disabled
func EnforceMode() int {
var enforce int
enforceS, err := readCon(selinuxEnforcePath())
if err != nil {
return -1
}
enforce, err = strconv.Atoi(string(enforceS))
if err != nil {
return -1
}
return enforce
}
/*
SetEnforce sets the current SELinux mode Enforcing, Permissive.
Disabled is not valid, since this needs to be set at boot time.
*/
func SetEnforceMode(mode int) error {
return writeCon(selinuxEnforcePath(), fmt.Sprintf("%d", mode))
}
/*
DefaultEnforceMode returns the systems default SELinux mode Enforcing,
Permissive or Disabled. Note this is is just the default at boot time.
EnforceMode tells you the systems current mode.
*/
func DefaultEnforceMode() int {
switch readConfig(selinuxTag) {
case "enforcing":
return Enforcing
case "permissive":
return Permissive
}
return Disabled
}
func mcsAdd(mcs string) error {
state.Lock()
defer state.Unlock()
if state.mcsList[mcs] {
return fmt.Errorf("MCS Label already exists")
}
state.mcsList[mcs] = true
return nil
}
func mcsDelete(mcs string) {
state.Lock()
defer state.Unlock()
state.mcsList[mcs] = false
}
func intToMcs(id int, catRange uint32) string {
var (
SETSIZE = int(catRange)
TIER = SETSIZE
ORD = id
)
if id < 1 || id > 523776 {
return ""
}
for ORD > TIER {
ORD = ORD - TIER
TIER--
}
TIER = SETSIZE - TIER
ORD = ORD + TIER
return fmt.Sprintf("s0:c%d,c%d", TIER, ORD)
}
func uniqMcs(catRange uint32) string {
var (
n uint32
c1, c2 uint32
mcs string
)
for {
binary.Read(rand.Reader, binary.LittleEndian, &n)
c1 = n % catRange
binary.Read(rand.Reader, binary.LittleEndian, &n)
c2 = n % catRange
if c1 == c2 {
continue
} else {
if c1 > c2 {
c1, c2 = c2, c1
}
}
mcs = fmt.Sprintf("s0:c%d,c%d", c1, c2)
if err := mcsAdd(mcs); err != nil {
continue
}
break
}
return mcs
}
/*
ReleaseLabel will unreserve the MLS/MCS Level field of the specified label.
Allowing it to be used by another process.
*/
func ReleaseLabel(label string) {
if len(label) != 0 {
con := strings.SplitN(label, ":", 4)
mcsDelete(con[3])
}
}
var roFileLabel string
// ROFileLabel returns the specified SELinux readonly file label
func ROFileLabel() (fileLabel string) {
return roFileLabel
}
/*
ContainerLabels returns an allocated processLabel and fileLabel to be used for
container labeling by the calling process.
*/
func ContainerLabels() (processLabel string, fileLabel string) {
var (
val, key string
bufin *bufio.Reader
)
if !GetEnabled() {
return "", ""
}
lxcPath := fmt.Sprintf("%s/contexts/lxc_contexts", getSELinuxPolicyRoot())
in, err := os.Open(lxcPath)
if err != nil {
return "", ""
}
defer in.Close()
bufin = bufio.NewReader(in)
for done := false; !done; {
var line string
if line, err = bufin.ReadString('\n'); err != nil {
if err == io.EOF {
done = true
} else {
goto exit
}
}
line = strings.TrimSpace(line)
if len(line) == 0 {
// Skip blank lines
continue
}
if line[0] == ';' || line[0] == '#' {
// Skip comments
continue
}
if groups := assignRegex.FindStringSubmatch(line); groups != nil {
key, val = strings.TrimSpace(groups[1]), strings.TrimSpace(groups[2])
if key == "process" {
processLabel = strings.Trim(val, "\"")
}
if key == "file" {
fileLabel = strings.Trim(val, "\"")
}
if key == "ro_file" {
roFileLabel = strings.Trim(val, "\"")
}
}
}
if processLabel == "" || fileLabel == "" {
return "", ""
}
if roFileLabel == "" {
roFileLabel = fileLabel
}
exit:
mcs := uniqMcs(1024)
scon := NewContext(processLabel)
scon["level"] = mcs
processLabel = scon.Get()
scon = NewContext(fileLabel)
scon["level"] = mcs
fileLabel = scon.Get()
return processLabel, fileLabel
}
// SecurityCheckContext validates that the SELinux label is understood by the kernel
func SecurityCheckContext(val string) error {
return writeCon(fmt.Sprintf("%s.context", selinuxPath), val)
}
/*
CopyLevel returns a label with the MLS/MCS level from src label replaces on
the dest label.
*/
func CopyLevel(src, dest string) (string, error) {
if src == "" {
return "", nil
}
if err := SecurityCheckContext(src); err != nil {
return "", err
}
if err := SecurityCheckContext(dest); err != nil {
return "", err
}
scon := NewContext(src)
tcon := NewContext(dest)
mcsDelete(tcon["level"])
mcsAdd(scon["level"])
tcon["level"] = scon["level"]
return tcon.Get(), nil
}
// Prevent users from relabing system files
func badPrefix(fpath string) error {
var badprefixes = []string{"/usr"}
for _, prefix := range badprefixes {
if fpath == prefix || strings.HasPrefix(fpath, fmt.Sprintf("%s/", prefix)) {
return fmt.Errorf("relabeling content in %s is not allowed", prefix)
}
}
return nil
}
// Chcon changes the fpath file object to the SELinux label label.
// If the fpath is a directory and recurse is true Chcon will walk the
// directory tree setting the label
func Chcon(fpath string, label string, recurse bool) error {
if label == "" {
return nil
}
if err := badPrefix(fpath); err != nil {
return err
}
callback := func(p string, info os.FileInfo, err error) error {
return SetFileLabel(p, label)
}
if recurse {
return filepath.Walk(fpath, callback)
}
return SetFileLabel(fpath, label)
}
// DupSecOpt takes an SELinux process label and returns security options that
// can will set the SELinux Type and Level for future container processes
func DupSecOpt(src string) []string {
if src == "" {
return nil
}
con := NewContext(src)
if con["user"] == "" ||
con["role"] == "" ||
con["type"] == "" ||
con["level"] == "" {
return nil
}
return []string{"user:" + con["user"],
"role:" + con["role"],
"type:" + con["type"],
"level:" + con["level"]}
}
// DisableSecOpt returns a security opt that can be used to disabling SELinux
// labeling support for future container processes
func DisableSecOpt() []string {
return []string{"disable"}
}

View File

@@ -0,0 +1,78 @@
// +build linux
package selinux
import (
"syscall"
"unsafe"
)
var _zero uintptr
// Returns a []byte slice if the xattr is set and nil otherwise
// Requires path and its attribute as arguments
func lgetxattr(path string, attr string) ([]byte, error) {
var sz int
pathBytes, err := syscall.BytePtrFromString(path)
if err != nil {
return nil, err
}
attrBytes, err := syscall.BytePtrFromString(attr)
if err != nil {
return nil, err
}
// Start with a 128 length byte array
sz = 128
dest := make([]byte, sz)
destBytes := unsafe.Pointer(&dest[0])
_sz, _, errno := syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
switch {
case errno == syscall.ENODATA:
return nil, errno
case errno == syscall.ENOTSUP:
return nil, errno
case errno == syscall.ERANGE:
// 128 byte array might just not be good enough,
// A dummy buffer is used ``uintptr(0)`` to get real size
// of the xattrs on disk
_sz, _, errno = syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(unsafe.Pointer(nil)), uintptr(0), 0, 0)
sz = int(_sz)
if sz < 0 {
return nil, errno
}
dest = make([]byte, sz)
destBytes := unsafe.Pointer(&dest[0])
_sz, _, errno = syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
if errno != 0 {
return nil, errno
}
case errno != 0:
return nil, errno
}
sz = int(_sz)
return dest[:sz], nil
}
func lsetxattr(path string, attr string, data []byte, flags int) error {
pathBytes, err := syscall.BytePtrFromString(path)
if err != nil {
return err
}
attrBytes, err := syscall.BytePtrFromString(attr)
if err != nil {
return err
}
var dataBytes unsafe.Pointer
if len(data) > 0 {
dataBytes = unsafe.Pointer(&data[0])
} else {
dataBytes = unsafe.Pointer(&_zero)
}
_, _, errno := syscall.Syscall6(syscall.SYS_LSETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(dataBytes), uintptr(len(data)), uintptr(flags), 0)
if errno != 0 {
return errno
}
return nil
}