Support webauthn (#17957)

Migrate from U2F to Webauthn

Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

vendor/github.com/duo-labs/webauthn/protocol/googletpm/googletpm.go

@@ -0,0 +1,152 @@
+package googletpm
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+)
+
+// From github.com/google/go-tpm
+// Portions of existing package conflicted with existing build environment
+// and only needed very small amount of code for pubarea and certinfo structs
+// so copied them out to this package
+
+// Supported Algorithms.
+const (
+	AlgUnknown   Algorithm = 0x0000
+	AlgRSA       Algorithm = 0x0001
+	AlgSHA1      Algorithm = 0x0004
+	AlgAES       Algorithm = 0x0006
+	AlgKeyedHash Algorithm = 0x0008
+	AlgSHA256    Algorithm = 0x000B
+	AlgSHA384    Algorithm = 0x000C
+	AlgSHA512    Algorithm = 0x000D
+	AlgNull      Algorithm = 0x0010
+	AlgRSASSA    Algorithm = 0x0014
+	AlgRSAES     Algorithm = 0x0015
+	AlgRSAPSS    Algorithm = 0x0016
+	AlgOAEP      Algorithm = 0x0017
+	AlgECDSA     Algorithm = 0x0018
+	AlgECDH      Algorithm = 0x0019
+	AlgECDAA     Algorithm = 0x001A
+	AlgKDF2      Algorithm = 0x0021
+	AlgECC       Algorithm = 0x0023
+	AlgCTR       Algorithm = 0x0040
+	AlgOFB       Algorithm = 0x0041
+	AlgCBC       Algorithm = 0x0042
+	AlgCFB       Algorithm = 0x0043
+	AlgECB       Algorithm = 0x0044
+)
+
+// UnpackBuf recursively unpacks types from a reader just as encoding/binary
+// does under binary.BigEndian, but with one difference: it unpacks a byte
+// slice by first reading an integer with lengthPrefixSize bytes, then reading
+// that many bytes. It assumes that incoming values are pointers to values so
+// that, e.g., underlying slices can be resized as needed.
+func UnpackBuf(buf io.Reader, elts ...interface{}) error {
+	for _, e := range elts {
+		v := reflect.ValueOf(e)
+		k := v.Kind()
+		if k != reflect.Ptr {
+			return fmt.Errorf("all values passed to Unpack must be pointers, got %v", k)
+		}
+
+		if v.IsNil() {
+			return errors.New("can't fill a nil pointer")
+		}
+
+		iv := reflect.Indirect(v)
+		switch iv.Kind() {
+		case reflect.Struct:
+			// Decompose the struct and copy over the values.
+			for i := 0; i < iv.NumField(); i++ {
+				if err := UnpackBuf(buf, iv.Field(i).Addr().Interface()); err != nil {
+					return err
+				}
+			}
+		case reflect.Slice:
+			var size int
+			_, isHandles := e.(*[]Handle)
+
+			switch {
+			// []Handle always uses 2-byte length, even with TPM 1.2.
+			case isHandles:
+				var tmpSize uint16
+				if err := binary.Read(buf, binary.BigEndian, &tmpSize); err != nil {
+					return err
+				}
+				size = int(tmpSize)
+			// TPM 2.0
+			case lengthPrefixSize == tpm20PrefixSize:
+				var tmpSize uint16
+				if err := binary.Read(buf, binary.BigEndian, &tmpSize); err != nil {
+					return err
+				}
+				size = int(tmpSize)
+			// TPM 1.2
+			case lengthPrefixSize == tpm12PrefixSize:
+				var tmpSize uint32
+				if err := binary.Read(buf, binary.BigEndian, &tmpSize); err != nil {
+					return err
+				}
+				size = int(tmpSize)
+			default:
+				return fmt.Errorf("lengthPrefixSize is %d, must be either 2 or 4", lengthPrefixSize)
+			}
+
+			// A zero size is used by the TPM to signal that certain elements
+			// are not present.
+			if size == 0 {
+				continue
+			}
+
+			// Make len(e) match size exactly.
+			switch b := e.(type) {
+			case *[]byte:
+				if len(*b) >= size {
+					*b = (*b)[:size]
+				} else {
+					*b = append(*b, make([]byte, size-len(*b))...)
+				}
+			case *[]Handle:
+				if len(*b) >= size {
+					*b = (*b)[:size]
+				} else {
+					*b = append(*b, make([]Handle, size-len(*b))...)
+				}
+			default:
+				return fmt.Errorf("can't fill pointer to %T, only []byte or []Handle slices", e)
+			}
+
+			if err := binary.Read(buf, binary.BigEndian, e); err != nil {
+				return err
+			}
+		default:
+			if err := binary.Read(buf, binary.BigEndian, e); err != nil {
+				return err
+			}
+		}
+
+	}
+
+	return nil
+}
+
+// lengthPrefixSize is the size in bytes of length prefix for byte slices.
+//
+// In TPM 1.2 this is 4 bytes.
+// In TPM 2.0 this is 2 bytes.
+var lengthPrefixSize int
+
+const (
+	tpm12PrefixSize = 4
+	tpm20PrefixSize = 2
+)
+
+// UseTPM20LengthPrefixSize makes Pack/Unpack use TPM 2.0 encoding for byte
+// arrays.
+func UseTPM20LengthPrefixSize() {
+	lengthPrefixSize = tpm20PrefixSize
+}