sdk: add a logger interface

we are now ready to make the sdk a separate module

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>
This commit is contained in:
Nicola Murino
2022-01-04 16:07:41 +01:00
parent a6fe802370
commit 2912b2e92e
30 changed files with 225 additions and 134 deletions

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@@ -1,139 +0,0 @@
package kms
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"crypto/sha256"
"encoding/hex"
"errors"
"io"
sdkkms "github.com/drakkan/sftpgo/v2/sdk/kms"
)
var (
errMalformedCiphertext = errors.New("malformed ciphertext")
)
type builtinSecret struct {
sdkkms.BaseSecret
}
func init() {
sdkkms.RegisterSecretProvider(sdkkms.SchemeBuiltin, sdkkms.SecretStatusAES256GCM, newBuiltinSecret)
}
func newBuiltinSecret(base sdkkms.BaseSecret, url, masterKey string) sdkkms.SecretProvider {
return &builtinSecret{
BaseSecret: base,
}
}
func (s *builtinSecret) Name() string {
return "Builtin"
}
func (s *builtinSecret) IsEncrypted() bool {
return s.Status == sdkkms.SecretStatusAES256GCM
}
func (s *builtinSecret) deriveKey(key []byte) []byte {
var combined []byte
combined = append(combined, key...)
if s.AdditionalData != "" {
combined = append(combined, []byte(s.AdditionalData)...)
}
combined = append(combined, key...)
hash := sha256.Sum256(combined)
return hash[:]
}
func (s *builtinSecret) Encrypt() error {
if s.Payload == "" {
return sdkkms.ErrInvalidSecret
}
switch s.Status {
case sdkkms.SecretStatusPlain:
key := make([]byte, 32)
if _, err := io.ReadFull(rand.Reader, key); err != nil {
return err
}
block, err := aes.NewCipher(s.deriveKey(key))
if err != nil {
return err
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return err
}
nonce := make([]byte, gcm.NonceSize())
if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
return err
}
var aad []byte
if s.AdditionalData != "" {
aad = []byte(s.AdditionalData)
}
ciphertext := gcm.Seal(nonce, nonce, []byte(s.Payload), aad)
s.Key = hex.EncodeToString(key)
s.Payload = hex.EncodeToString(ciphertext)
s.Status = sdkkms.SecretStatusAES256GCM
return nil
default:
return sdkkms.ErrWrongSecretStatus
}
}
func (s *builtinSecret) Decrypt() error {
switch s.Status {
case sdkkms.SecretStatusAES256GCM:
encrypted, err := hex.DecodeString(s.Payload)
if err != nil {
return err
}
key, err := hex.DecodeString(s.Key)
if err != nil {
return err
}
block, err := aes.NewCipher(s.deriveKey(key))
if err != nil {
return err
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return err
}
nonceSize := gcm.NonceSize()
if len(encrypted) < nonceSize {
return errMalformedCiphertext
}
nonce, ciphertext := encrypted[:nonceSize], encrypted[nonceSize:]
var aad []byte
if s.AdditionalData != "" {
aad = []byte(s.AdditionalData)
}
plaintext, err := gcm.Open(nil, nonce, ciphertext, aad)
if err != nil {
return err
}
s.Status = sdkkms.SecretStatusPlain
s.Payload = string(plaintext)
s.Key = ""
s.AdditionalData = ""
return nil
default:
return sdkkms.ErrWrongSecretStatus
}
}
func (s *builtinSecret) Clone() sdkkms.SecretProvider {
baseSecret := sdkkms.BaseSecret{
Status: s.Status,
Payload: s.Payload,
Key: s.Key,
AdditionalData: s.AdditionalData,
Mode: s.Mode,
}
return newBuiltinSecret(baseSecret, "", "")
}

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@@ -1,2 +0,0 @@
// Package kms provides built-in Key Management Services support
package kms

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@@ -1,143 +0,0 @@
package kms
import (
"context"
"crypto/sha256"
"encoding/base64"
"encoding/hex"
"io"
"gocloud.dev/secrets/localsecrets"
"golang.org/x/crypto/hkdf"
sdkkms "github.com/drakkan/sftpgo/v2/sdk/kms"
)
func init() {
sdkkms.RegisterSecretProvider(sdkkms.SchemeLocal, sdkkms.SecretStatusSecretBox, NewLocalSecret)
}
type localSecret struct {
sdkkms.BaseSecret
masterKey string
}
// NewLocalSecret returns a SecretProvider that use a locally provided symmetric key
func NewLocalSecret(base sdkkms.BaseSecret, url, masterKey string) sdkkms.SecretProvider {
return &localSecret{
BaseSecret: base,
masterKey: masterKey,
}
}
func (s *localSecret) Name() string {
return "Local"
}
func (s *localSecret) IsEncrypted() bool {
return s.Status == sdkkms.SecretStatusSecretBox
}
func (s *localSecret) Encrypt() error {
if s.Status != sdkkms.SecretStatusPlain {
return sdkkms.ErrWrongSecretStatus
}
if s.Payload == "" {
return sdkkms.ErrInvalidSecret
}
secretKey, err := localsecrets.NewRandomKey()
if err != nil {
return err
}
key, err := s.deriveKey(secretKey[:], false)
if err != nil {
return err
}
keeper := localsecrets.NewKeeper(key)
defer keeper.Close()
ciphertext, err := keeper.Encrypt(context.Background(), []byte(s.Payload))
if err != nil {
return err
}
s.Key = hex.EncodeToString(secretKey[:])
s.Payload = base64.StdEncoding.EncodeToString(ciphertext)
s.Status = sdkkms.SecretStatusSecretBox
s.Mode = s.getEncryptionMode()
return nil
}
func (s *localSecret) Decrypt() error {
if !s.IsEncrypted() {
return sdkkms.ErrWrongSecretStatus
}
encrypted, err := base64.StdEncoding.DecodeString(s.Payload)
if err != nil {
return err
}
secretKey, err := hex.DecodeString(s.Key)
if err != nil {
return err
}
key, err := s.deriveKey(secretKey[:], true)
if err != nil {
return err
}
keeper := localsecrets.NewKeeper(key)
defer keeper.Close()
plaintext, err := keeper.Decrypt(context.Background(), encrypted)
if err != nil {
return err
}
s.Status = sdkkms.SecretStatusPlain
s.Payload = string(plaintext)
s.Key = ""
s.AdditionalData = ""
s.Mode = 0
return nil
}
func (s *localSecret) deriveKey(key []byte, isForDecryption bool) ([32]byte, error) {
var masterKey []byte
if s.masterKey == "" || (isForDecryption && s.Mode == 0) {
var combined []byte
combined = append(combined, key...)
if s.AdditionalData != "" {
combined = append(combined, []byte(s.AdditionalData)...)
}
combined = append(combined, key...)
hash := sha256.Sum256(combined)
masterKey = hash[:]
} else {
masterKey = []byte(s.masterKey)
}
var derivedKey [32]byte
var info []byte
if s.AdditionalData != "" {
info = []byte(s.AdditionalData)
}
kdf := hkdf.New(sha256.New, masterKey, key, info)
if _, err := io.ReadFull(kdf, derivedKey[:]); err != nil {
return derivedKey, err
}
return derivedKey, nil
}
func (s *localSecret) getEncryptionMode() int {
if s.masterKey == "" {
return 0
}
return 1
}
func (s *localSecret) Clone() sdkkms.SecretProvider {
baseSecret := sdkkms.BaseSecret{
Status: s.Status,
Payload: s.Payload,
Key: s.Key,
AdditionalData: s.AdditionalData,
Mode: s.Mode,
}
return NewLocalSecret(baseSecret, "", s.masterKey)
}