feat: complete device onboarding and mobile binding workflows

internal/onboarding/crypto.go

@@ -0,0 +1,158 @@
+package onboarding
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/google/uuid"
+)
+
+const ContractVersion = "ONBOARDING-1.1"
+const maxBody = 8 << 10
+
+func digest(b []byte) string   { sum := sha256.Sum256(b); return hex.EncodeToString(sum[:]) }
+func randomToken(n int) string { return base64.RawURLEncoding.EncodeToString(randomBytes(n)) }
+func randomBytes(n int) []byte {
+	b := make([]byte, n)
+	if _, err := rand.Read(b); err != nil {
+		panic("secure random source unavailable")
+	}
+	return b
+}
+func uuidV4(s string) bool {
+	u, e := uuid.Parse(s)
+	return e == nil && u.Version() == 4 && u.String() == s
+}
+func uuidValid(s string) bool { u, e := uuid.Parse(s); return e == nil && u.String() == s }
+func validB64(s string, n int) bool {
+	b, e := base64.RawURLEncoding.DecodeString(s)
+	return e == nil && len(b) == n && base64.RawURLEncoding.EncodeToString(b) == s
+}
+func validDigest(s string) bool {
+	b, e := hex.DecodeString(s)
+	return e == nil && len(b) == 32 && strings.ToLower(s) == s
+}
+
+func RequestMAC(key []byte, method, path, deviceID string, version, timestamp int64, nonce, requestID string, body []byte) string {
+	canonical := strings.Join([]string{"DEVREQ1", strings.ToUpper(method), path, deviceID, strconv.FormatInt(version, 10), strconv.FormatInt(timestamp, 10), nonce, requestID, digest(body)}, "\n")
+	return domainMAC(key, canonical)
+}
+func domainMAC(key []byte, message string) string {
+	m := hmac.New(sha256.New, key)
+	m.Write([]byte(message))
+	return hex.EncodeToString(m.Sum(nil))
+}
+
+type cryptor struct {
+	aead    cipher.AEAD
+	hashKey []byte
+}
+
+func newCryptor(master string) (cryptor, error) {
+	key, err := hex.DecodeString(master)
+	if err != nil || len(key) != 32 {
+		return cryptor{}, errors.New("onboarding master key must be 32 bytes encoded as hex")
+	}
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return cryptor{}, err
+	}
+	aead, err := cipher.NewGCM(block)
+	derived := sha256.Sum256(append([]byte("ONBOARDING-HASH-KEY1:"), key...))
+	return cryptor{aead: aead, hashKey: derived[:]}, err
+}
+func (c cryptor) seal(plain []byte, aad string) []byte {
+	nonce := randomBytes(c.aead.NonceSize())
+	return c.aead.Seal(nonce, nonce, plain, []byte(aad))
+}
+func (c cryptor) open(value []byte, aad string) ([]byte, error) {
+	n := c.aead.NonceSize()
+	if len(value) < n {
+		return nil, errors.New("invalid encrypted onboarding record")
+	}
+	return c.aead.Open(nil, value[:n], value[n:], []byte(aad))
+}
+func keyAAD(device string, version int64) string {
+	return fmt.Sprintf("ONBOARDING-KEY1\n%s\n%d", device, version)
+}
+
+// Validate JSON before decoding structs: Go's regular decoder accepts duplicate
+// keys and repairs invalid UTF-8, both of which are forbidden by this contract.
+func StrictJSON(raw []byte, target any) error {
+	if len(raw) == 0 || len(raw) > maxBody || !utf8.Valid(raw) {
+		return fail(400, "INVALID_JSON", "请求正文不合法")
+	}
+	dec := json.NewDecoder(bytes.NewReader(raw))
+	dec.UseNumber()
+	var visit func(int) error
+	visit = func(depth int) error {
+		if depth > 12 {
+			return errors.New("JSON nesting exceeds 12")
+		}
+		token, err := dec.Token()
+		if err != nil {
+			return err
+		}
+		delim, ok := token.(json.Delim)
+		if !ok {
+			return nil
+		}
+		switch delim {
+		case '{':
+			seen := map[string]bool{}
+			for dec.More() {
+				k, err := dec.Token()
+				if err != nil {
+					return err
+				}
+				name, ok := k.(string)
+				if !ok || seen[name] {
+					return errors.New("duplicate JSON key")
+				}
+				seen[name] = true
+				if err := visit(depth + 1); err != nil {
+					return err
+				}
+			}
+		case '[':
+			for dec.More() {
+				if err := visit(depth + 1); err != nil {
+					return err
+				}
+			}
+		default:
+			return errors.New("invalid JSON delimiter")
+		}
+		_, err = dec.Token()
+		return err
+	}
+	if err := visit(1); err != nil {
+		return fail(400, "INVALID_JSON", "JSON格式、深度或字段重复")
+	}
+	if _, err := dec.Token(); err != io.EOF {
+		return fail(400, "INVALID_JSON", "只能提交一个JSON对象")
+	}
+	trimmed := bytes.TrimSpace(raw)
+	if len(trimmed) == 0 || trimmed[0] != '{' {
+		return fail(400, "INVALID_JSON", "必须提交JSON对象")
+	}
+	decoder := json.NewDecoder(bytes.NewReader(raw))
+	decoder.DisallowUnknownFields()
+	if err := decoder.Decode(target); err != nil {
+		return fail(400, "VALIDATION_FAILED", "请求字段或类型不正确")
+	}
+	return nil
+}