refactor(payment): 支付插件 - 宿主仅通过 RPC 包加载并保护订单版本

backend/payment-plugins/crypto.go

@@ -0,0 +1,84 @@
+package paymentplugins
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+func parseRSAPrivateKey(value string) (*rsa.PrivateKey, error) {
+	der, ok := decodePEMOrBase64(value)
+	if !ok {
+		return nil, errors.New("RSA 私钥 PEM 或 Base64 格式无效")
+	}
+	if key, err := x509.ParsePKCS8PrivateKey(der); err == nil {
+		if rsaKey, ok := key.(*rsa.PrivateKey); ok {
+			return rsaKey, nil
+		}
+	}
+	if key, err := x509.ParsePKCS1PrivateKey(der); err == nil {
+		return key, nil
+	}
+	return nil, errors.New("RSA 私钥必须为 PKCS#1 或 PKCS#8 格式")
+}
+
+func parseRSAPublicKey(value string) (*rsa.PublicKey, error) {
+	der, ok := decodePEMOrBase64(value)
+	if !ok {
+		return nil, errors.New("RSA 公钥 PEM 或 Base64 格式无效")
+	}
+	if key, err := x509.ParsePKIXPublicKey(der); err == nil {
+		if rsaKey, ok := key.(*rsa.PublicKey); ok {
+			return rsaKey, nil
+		}
+	}
+	if key, err := x509.ParsePKCS1PublicKey(der); err == nil {
+		return key, nil
+	}
+	if certificate, err := x509.ParseCertificate(der); err == nil {
+		if rsaKey, ok := certificate.PublicKey.(*rsa.PublicKey); ok {
+			return rsaKey, nil
+		}
+	}
+	return nil, errors.New("RSA 公钥格式无效")
+}
+
+func decodePEMOrBase64(value string) ([]byte, bool) {
+	normalized := strings.TrimSpace(value)
+	if block, _ := pem.Decode([]byte(normalized)); block != nil {
+		return block.Bytes, true
+	}
+	decoded, err := base64.StdEncoding.DecodeString(strings.Join(strings.Fields(normalized), ""))
+	if err != nil || len(decoded) == 0 {
+		return nil, false
+	}
+	return decoded, true
+}
+
+func rsaSHA256Sign(privateKey *rsa.PrivateKey, content []byte) (string, error) {
+	digest := sha256.Sum256(content)
+	signature, err := rsa.SignPKCS1v15(rand.Reader, privateKey, crypto.SHA256, digest[:])
+	if err != nil {
+		return "", err
+	}
+	return base64.StdEncoding.EncodeToString(signature), nil
+}
+
+func rsaSHA256Verify(publicKey *rsa.PublicKey, content []byte, signature string) error {
+	decoded, err := base64.StdEncoding.DecodeString(strings.TrimSpace(signature))
+	if err != nil {
+		return fmt.Errorf("签名不是有效 Base64：%w", err)
+	}
+	digest := sha256.Sum256(content)
+	if err := rsa.VerifyPKCS1v15(publicKey, crypto.SHA256, digest[:], decoded); err != nil {
+		return errors.New("RSA2 签名验证失败")
+	}
+	return nil
+}