feat: 增加商户消息加密密钥管理

server/utility/encrypt/aes.go

@@ -6,10 +6,56 @@
 package encrypt
 
 import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
 	"encoding/base64"
+	"fmt"
 	"github.com/forgoer/openssl"
+	"io"
 )
 
+const AESGCMKeySize = 32
+
+// AESGCMEncrypt encrypts plaintext with AES-256-GCM and a fresh random nonce.
+func AESGCMEncrypt(plaintext, key, additionalData []byte) (ciphertext, nonce []byte, err error) {
+	if len(key) != AESGCMKeySize {
+		return nil, nil, fmt.Errorf("AES-256-GCM key must be %d bytes", AESGCMKeySize)
+	}
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, nil, err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return nil, nil, err
+	}
+	nonce = make([]byte, gcm.NonceSize())
+	if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
+		return nil, nil, err
+	}
+	return gcm.Seal(nil, nonce, plaintext, additionalData), nonce, nil
+}
+
+// AESGCMDecrypt authenticates and decrypts ciphertext encrypted by AESGCMEncrypt.
+func AESGCMDecrypt(ciphertext, nonce, key, additionalData []byte) ([]byte, error) {
+	if len(key) != AESGCMKeySize {
+		return nil, fmt.Errorf("AES-256-GCM key must be %d bytes", AESGCMKeySize)
+	}
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return nil, err
+	}
+	if len(nonce) != gcm.NonceSize() {
+		return nil, fmt.Errorf("AES-GCM nonce must be %d bytes", gcm.NonceSize())
+	}
+	return gcm.Open(nil, nonce, ciphertext, additionalData)
+}
+
 // AesECBEncrypt 加密
 func AesECBEncrypt(src, key []byte) (dst []byte, err error) {
 	return openssl.AesECBEncrypt(src, key, openssl.PKCS7_PADDING)

server/utility/encrypt/aes_gcm_test.go

@@ -0,0 +1,34 @@
+package encrypt
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestAESGCMRoundTripAndRandomNonce(t *testing.T) {
+	key := bytes.Repeat([]byte{7}, AESGCMKeySize)
+	plain := []byte("message encryption key")
+	aad := []byte("tenant:1:version:1")
+	first, firstNonce, err := AESGCMEncrypt(plain, key, aad)
+	if err != nil {
+		t.Fatal(err)
+	}
+	second, secondNonce, err := AESGCMEncrypt(plain, key, aad)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if bytes.Equal(firstNonce, secondNonce) || bytes.Equal(first, second) {
+		t.Fatal("repeated encryption must use a different nonce and ciphertext")
+	}
+	decoded, err := AESGCMDecrypt(first, firstNonce, key, aad)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(decoded, plain) {
+		t.Fatalf("unexpected plaintext: %q", decoded)
+	}
+	first[0] ^= 1
+	if _, err = AESGCMDecrypt(first, firstNonce, key, aad); err == nil {
+		t.Fatal("tampered ciphertext must fail authentication")
+	}
+}