init: dec-music 项目初始化

mmkv/vault.go

@@ -0,0 +1,105 @@
+package mmkv
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"encoding/binary"
+	"fmt"
+	"hash/crc32"
+	"io"
+
+	"jsuse.com/dev/dec-music/mmkv/internal"
+)
+
+type vault map[string][]byte
+
+func (v vault) keys() []string {
+	keys := make([]string, 0, len(v))
+	for k := range v {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
+func (v vault) Keys() []string {
+	return v.keys()
+}
+
+func (v vault) GetRaw(key string) ([]byte, bool) {
+	val, ok := v[key]
+	return val, ok
+}
+
+func (v vault) GetBytes(key string) ([]byte, error) {
+	raw, ok := v[key]
+	if !ok {
+		return nil, fmt.Errorf("key not found: %s", key)
+	}
+
+	val, n := internal.ConsumeBytes(raw)
+	if n < 0 {
+		return nil, fmt.Errorf("invalid protobuf bytes")
+	}
+
+	return val, nil
+}
+
+func (v vault) GetString(key string) (string, error) {
+	val, err := v.GetBytes(key)
+	if err != nil {
+		return "", err
+	}
+	return string(val), nil
+}
+
+func loadVault(src io.Reader, m *metadata, cryptoKey string) (Vault, error) {
+	fileSizeBuf := make([]byte, 4)
+	_, err := io.ReadFull(src, fileSizeBuf)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read file size: %w", err)
+	}
+	size := binary.LittleEndian.Uint32(fileSizeBuf)
+
+	if m != nil && size != m.actualSize {
+		return nil, fmt.Errorf("metadata and vault payload size mismatch")
+	}
+
+	buf := make([]byte, size)
+	_, err = io.ReadFull(src, buf)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read file: %w", err)
+	}
+
+	if m != nil && m.crc32 != crc32.ChecksumIEEE(buf) {
+		return nil, fmt.Errorf("metadata and vault payload crc32 mismatch")
+	}
+
+	if len(cryptoKey) > 0 {
+		mKey := make([]byte, aes.BlockSize)
+		copy(mKey, cryptoKey)
+
+		block, err := aes.NewCipher(mKey)
+		if err != nil {
+			return nil, fmt.Errorf("failed to create aes cipher")
+		}
+		stream := cipher.NewCFBDecrypter(block, m.aesVector)
+		stream.XORKeyStream(buf, buf)
+	}
+
+	v := make(vault)
+	rd := internal.NewProtoBuffer(buf[4:])
+
+	for len(rd.Unread()) > 0 {
+		key, err := rd.DecodeStringBytes()
+		if err != nil {
+			return nil, fmt.Errorf("failed to decode key: %w", err)
+		}
+		val, err := rd.DecodeRawBytes(false)
+		if err != nil {
+			return nil, fmt.Errorf("failed to decode value: %w", err)
+		}
+		v[key] = val
+	}
+
+	return v, nil
+}