compat handlers: add X-Registry-Auth header support

* Support the `X-Registry-Auth` http-request header.

 * The content of the header is a base64 encoded JSON payload which can
   either be a single auth config or a map of auth configs (user+pw or
   token) with the corresponding registries being the keys.  Vanilla
   Docker, projectatomic Docker and the bindings are transparantly
   supported.

 * Add a hidden `--registries-conf` flag.  Buildah exposes the same
   flag, mostly for testing purposes.

 * Do all credential parsing in the client (i.e., `cmd/podman`) pass
   the username and password in the backend instead of unparsed
   credentials.

 * Add a `pkg/auth` which handles most of the heavy lifting.

 * Go through the authentication-handling code of most commands, bindings
   and endpoints.  Migrate them to the new code and fix issues as seen.
   A final evaluation and more tests is still required *after* this
   change.

 * The manifest-push endpoint is missing certain parameters and should
   use the ABI function instead.  Adding auth-support isn't really
   possible without these parts working.

 * The container commands and endpoints (i.e., create and run) have not
   been changed yet.  The APIs don't yet account for the authfile.

 * Add authentication tests to `pkg/bindings`.

Fixes: #6384
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

vendor/github.com/mattn/go-isatty/isatty_windows.go

@@ -0,0 +1,125 @@
+// +build windows
+// +build !appengine
+
+package isatty
+
+import (
+	"errors"
+	"strings"
+	"syscall"
+	"unicode/utf16"
+	"unsafe"
+)
+
+const (
+	objectNameInfo uintptr = 1
+	fileNameInfo           = 2
+	fileTypePipe           = 3
+)
+
+var (
+	kernel32                         = syscall.NewLazyDLL("kernel32.dll")
+	ntdll                            = syscall.NewLazyDLL("ntdll.dll")
+	procGetConsoleMode               = kernel32.NewProc("GetConsoleMode")
+	procGetFileInformationByHandleEx = kernel32.NewProc("GetFileInformationByHandleEx")
+	procGetFileType                  = kernel32.NewProc("GetFileType")
+	procNtQueryObject                = ntdll.NewProc("NtQueryObject")
+)
+
+func init() {
+	// Check if GetFileInformationByHandleEx is available.
+	if procGetFileInformationByHandleEx.Find() != nil {
+		procGetFileInformationByHandleEx = nil
+	}
+}
+
+// IsTerminal return true if the file descriptor is terminal.
+func IsTerminal(fd uintptr) bool {
+	var st uint32
+	r, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, fd, uintptr(unsafe.Pointer(&st)), 0)
+	return r != 0 && e == 0
+}
+
+// Check pipe name is used for cygwin/msys2 pty.
+// Cygwin/MSYS2 PTY has a name like:
+//   \{cygwin,msys}-XXXXXXXXXXXXXXXX-ptyN-{from,to}-master
+func isCygwinPipeName(name string) bool {
+	token := strings.Split(name, "-")
+	if len(token) < 5 {
+		return false
+	}
+
+	if token[0] != `\msys` &&
+		token[0] != `\cygwin` &&
+		token[0] != `\Device\NamedPipe\msys` &&
+		token[0] != `\Device\NamedPipe\cygwin` {
+		return false
+	}
+
+	if token[1] == "" {
+		return false
+	}
+
+	if !strings.HasPrefix(token[2], "pty") {
+		return false
+	}
+
+	if token[3] != `from` && token[3] != `to` {
+		return false
+	}
+
+	if token[4] != "master" {
+		return false
+	}
+
+	return true
+}
+
+// getFileNameByHandle use the undocomented ntdll NtQueryObject to get file full name from file handler
+// since GetFileInformationByHandleEx is not avilable under windows Vista and still some old fashion
+// guys are using Windows XP, this is a workaround for those guys, it will also work on system from
+// Windows vista to 10
+// see https://stackoverflow.com/a/18792477 for details
+func getFileNameByHandle(fd uintptr) (string, error) {
+	if procNtQueryObject == nil {
+		return "", errors.New("ntdll.dll: NtQueryObject not supported")
+	}
+
+	var buf [4 + syscall.MAX_PATH]uint16
+	var result int
+	r, _, e := syscall.Syscall6(procNtQueryObject.Addr(), 5,
+		fd, objectNameInfo, uintptr(unsafe.Pointer(&buf)), uintptr(2*len(buf)), uintptr(unsafe.Pointer(&result)), 0)
+	if r != 0 {
+		return "", e
+	}
+	return string(utf16.Decode(buf[4 : 4+buf[0]/2])), nil
+}
+
+// IsCygwinTerminal() return true if the file descriptor is a cygwin or msys2
+// terminal.
+func IsCygwinTerminal(fd uintptr) bool {
+	if procGetFileInformationByHandleEx == nil {
+		name, err := getFileNameByHandle(fd)
+		if err != nil {
+			return false
+		}
+		return isCygwinPipeName(name)
+	}
+
+	// Cygwin/msys's pty is a pipe.
+	ft, _, e := syscall.Syscall(procGetFileType.Addr(), 1, fd, 0, 0)
+	if ft != fileTypePipe || e != 0 {
+		return false
+	}
+
+	var buf [2 + syscall.MAX_PATH]uint16
+	r, _, e := syscall.Syscall6(procGetFileInformationByHandleEx.Addr(),
+		4, fd, fileNameInfo, uintptr(unsafe.Pointer(&buf)),
+		uintptr(len(buf)*2), 0, 0)
+	if r == 0 || e != 0 {
+		return false
+	}
+
+	l := *(*uint32)(unsafe.Pointer(&buf))
+	return isCygwinPipeName(string(utf16.Decode(buf[2 : 2+l/2])))
+}