Files
filebrowser/encfs/kms.go

130 lines
3.6 KiB
Go

package encfs
import (
"bytes"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"os"
"strings"
"sync"
"time"
)
const LOCAL_MINI_KMS_ADDRESS = "LOCAL_MINI_KMS_ADDRESS"
const DISABLE_ENCRYPTION_MASTER_KEY = "DISABLE_ENCRYPTION_MASTER_KEY"
const ENCRYPTED_ENCRYPTION_MASTER_KEY = "ENCRYPTED_ENCRYPTION_MASTER_KEY"
type MultiViewValue struct {
ValueHex string `json:"value_hex"`
ValueBase64 string `json:"value_base64"`
}
type EncryptRequest struct {
EncryptedValue string `json:"encrypted_value"`
}
var cachedcEncryptionMasterKey *EncryptionMasterKey = nil
var cachedcEncryptionMasterKeyLock sync.Mutex
func GetCachedEncryptionMasterKey() (*EncryptionMasterKey, error) {
cachedcEncryptionMasterKeyLock.Lock()
defer cachedcEncryptionMasterKeyLock.Unlock()
if cachedcEncryptionMasterKey == nil {
var err error
cachedcEncryptionMasterKey, err = GetEncryptionMasterKey()
if err != nil {
return nil, err
}
}
return cachedcEncryptionMasterKey, nil
}
func GetEncryptionMasterKey() (*EncryptionMasterKey, error) {
disableEncryptionMasterKey := os.Getenv(DISABLE_ENCRYPTION_MASTER_KEY)
if disableEncryptionMasterKey == "1" ||
disableEncryptionMasterKey == "on" ||
disableEncryptionMasterKey == "yes" ||
disableEncryptionMasterKey == "true" {
return nil, nil
}
encryptedEncryptionMasterKey := os.Getenv(ENCRYPTED_ENCRYPTION_MASTER_KEY)
if encryptedEncryptionMasterKey == "" {
fmt.Println("[ERROR] encrypted encryption master key is not present")
return nil, errors.New("encrypted encryption master key is not present")
}
key, err := DecryptBytes(encryptedEncryptionMasterKey)
if err != nil {
return nil, err
}
return &EncryptionMasterKey{
key: key,
}, nil
}
func DecryptBytes(encryptedValue string) ([]byte, error) {
localMiniKmsAddress := os.Getenv(LOCAL_MINI_KMS_ADDRESS)
if localMiniKmsAddress == "" {
localMiniKmsAddress = "127.0.0.1:5567"
}
if !strings.HasPrefix(strings.ToLower(localMiniKmsAddress), "http://") {
localMiniKmsAddress = fmt.Sprintf("http://%s", localMiniKmsAddress)
}
multiViewValue, err := Decrypt(localMiniKmsAddress, encryptedValue)
if err != nil {
fmt.Println("[ERROR] Decrypt from", localMiniKmsAddress, "failed, error:", err)
return nil, err
}
valueBytes, err := hex.DecodeString(multiViewValue.ValueHex)
if err != nil {
return nil, err
}
return valueBytes, nil
}
func Decrypt(endpoint, encryptedValue string) (*MultiViewValue, error) {
encryptRequest := EncryptRequest{
EncryptedValue: encryptedValue,
}
encryptRequestBytes, err := json.Marshal(&encryptRequest)
if err != nil {
return nil, err
}
encryptRequestReader := bytes.NewReader(encryptRequestBytes)
client := http.Client{
Timeout: 5 * time.Second,
}
encryptResponse, err := client.Post(joinEnpointPath(endpoint, "/decrypt"), "application/json", encryptRequestReader)
if err != nil {
return nil, err
}
if encryptResponse.StatusCode != 200 {
return nil, fmt.Errorf("decrypt failed, http status: %d", encryptResponse.StatusCode)
}
encryptResponseBodyBytes, err := io.ReadAll(encryptResponse.Body)
if err != nil {
return nil, err
}
var multiViewValue MultiViewValue
err = json.Unmarshal(encryptResponseBodyBytes, &multiViewValue)
if err != nil {
return nil, err
}
return &multiViewValue, nil
}
func joinEnpointPath(endpoint, path string) string {
endpointEndsWithSlash := strings.HasSuffix(endpoint, "/")
pathStartsWithSlash := strings.HasPrefix(path, "/")
if endpointEndsWithSlash && pathStartsWithSlash {
return fmt.Sprintf("%s%s", endpoint, path[1:])
} else if endpointEndsWithSlash || pathStartsWithSlash {
return fmt.Sprintf("%s%s", endpoint, path)
} else {
return fmt.Sprintf("%s/%s", endpoint, path)
}
}