diff --git a/internal/applicant/applicant.go b/internal/applicant/applicant.go
index 17e97cb5..128704b4 100644
--- a/internal/applicant/applicant.go
+++ b/internal/applicant/applicant.go
@@ -98,7 +98,7 @@ func newApplyUser(ca, email string) (*ApplyUser, error) {
 		if err != nil {
 			return nil, err
 		}
-		keyStr, err := x509.PrivateKeyToPEM(privateKey)
+		keyStr, err := x509.ConvertECPrivateKeyToPEM(privateKey)
 		if err != nil {
 			return nil, err
 		}
@@ -122,7 +122,7 @@ func (u ApplyUser) GetRegistration() *registration.Resource {
 }
 
 func (u *ApplyUser) GetPrivateKey() crypto.PrivateKey {
-	rs, _ := x509.ParsePrivateKeyFromPEM(u.key)
+	rs, _ := x509.ParseECPrivateKeyFromPEM(u.key)
 	return rs
 }
 
diff --git a/internal/pkg/core/uploader/uploader_aliyun_cas.go b/internal/pkg/core/uploader/uploader_aliyun_cas.go
index 64d2e94c..b6a1f792 100644
--- a/internal/pkg/core/uploader/uploader_aliyun_cas.go
+++ b/internal/pkg/core/uploader/uploader_aliyun_cas.go
@@ -15,9 +15,9 @@ import (
 )
 
 type AliyunCASUploaderConfig struct {
-	Region          string `json:"region"`
 	AccessKeyId     string `json:"accessKeyId"`
 	AccessKeySecret string `json:"accessKeySecret"`
+	Region          string `json:"region"`
 }
 
 type AliyunCASUploader struct {
@@ -28,9 +28,9 @@ type AliyunCASUploader struct {
 
 func NewAliyunCASUploader(config *AliyunCASUploaderConfig) (Uploader, error) {
 	client, err := (&AliyunCASUploader{}).createSdkClient(
-		config.Region,
 		config.AccessKeyId,
 		config.AccessKeySecret,
+		config.Region,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create sdk client: %w", err)
@@ -81,12 +81,12 @@ func (u *AliyunCASUploader) Upload(ctx context.Context, certPem string, privkeyP
 					if *getUserCertificateDetailResp.Body.Cert == certPem {
 						isSameCert = true
 					} else {
-						cert, err := x509.ParseCertificateFromPEM(*getUserCertificateDetailResp.Body.Cert)
+						oldCertX509, err := x509.ParseCertificateFromPEM(*getUserCertificateDetailResp.Body.Cert)
 						if err != nil {
 							continue
 						}
 
-						isSameCert = x509.EqualCertificate(certX509, cert)
+						isSameCert = x509.EqualCertificate(certX509, oldCertX509)
 					}
 
 					// 如果已存在相同证书,直接返回已有的证书信息
@@ -133,7 +133,7 @@ func (u *AliyunCASUploader) Upload(ctx context.Context, certPem string, privkeyP
 	}, nil
 }
 
-func (u *AliyunCASUploader) createSdkClient(region, accessKeyId, accessKeySecret string) (*cas20200407.Client, error) {
+func (u *AliyunCASUploader) createSdkClient(accessKeyId, accessKeySecret, region string) (*cas20200407.Client, error) {
 	if region == "" {
 		region = "cn-hangzhou" // CAS 服务默认区域:华东一杭州
 	}
@@ -147,10 +147,6 @@ func (u *AliyunCASUploader) createSdkClient(region, accessKeyId, accessKeySecret
 	switch region {
 	case "cn-hangzhou":
 		endpoint = "cas.aliyuncs.com"
-	case "ap-southeast-1":
-		endpoint = "cas.ap-southeast-1.aliyuncs.com"
-	case "eu-central-1":
-		endpoint = "cas.eu-central-1.aliyuncs.com"
 	default:
 		endpoint = fmt.Sprintf("cas.%s.aliyuncs.com", region)
 	}
diff --git a/internal/pkg/utils/x509/x509.go b/internal/pkg/utils/x509/x509.go
index 0239df69..09d67d3a 100644
--- a/internal/pkg/utils/x509/x509.go
+++ b/internal/pkg/utils/x509/x509.go
@@ -7,6 +7,23 @@ import (
 	"fmt"
 )
 
+// 比较两个 x509.Certificate 对象,判断它们是否是同一张证书。
+// 注意,这不是精确比较,而只是基于证书序列号和数字签名的快速判断,但对于权威 CA 签发的证书来说不会存在误判。
+//
+// 入参:
+//   - a: 待比较的第一个 x509.Certificate 对象。
+//   - b: 待比较的第二个 x509.Certificate 对象。
+//
+// 出参:
+//   - 是否相同。
+func EqualCertificate(a, b *x509.Certificate) bool {
+	return string(a.Signature) == string(b.Signature) &&
+		a.SignatureAlgorithm == b.SignatureAlgorithm &&
+		a.SerialNumber.String() == b.SerialNumber.String() &&
+		a.Issuer.SerialNumber == b.Issuer.SerialNumber &&
+		a.Subject.SerialNumber == b.Subject.SerialNumber
+}
+
 // 从 PEM 编码的证书字符串解析并返回一个 x509.Certificate 对象。
 //
 // 入参:
@@ -31,26 +48,40 @@ func ParseCertificateFromPEM(certPem string) (cert *x509.Certificate, err error)
 	return cert, nil
 }
 
-// 比较两个 x509.Certificate 对象,判断它们是否是同一张证书。
-// 注意,这不是精确比较,而只是基于证书序列号和数字签名的快速判断,但对于权威 CA 签发的证书来说不会存在误判。
+// 从 PEM 编码的私钥字符串解析并返回一个 ECDSA 私钥对象。
 //
 // 入参:
-//   - a: 待比较的第一个 x509.Certificate 对象。
-//   - b: 待比较的第二个 x509.Certificate 对象。
+//   - privkeyPem: 私钥 PEM 内容。
 //
 // 出参:
-//   - 是否相同。
-func EqualCertificate(a, b *x509.Certificate) bool {
-	return string(a.Signature) == string(b.Signature) &&
-		a.SignatureAlgorithm == b.SignatureAlgorithm &&
-		a.SerialNumber.String() == b.SerialNumber.String() &&
-		a.Issuer.SerialNumber == b.Issuer.SerialNumber &&
-		a.Subject.SerialNumber == b.Subject.SerialNumber
+//   - privkey: ecdsa.PrivateKey 对象。
+//   - err: 错误。
+func ParseECPrivateKeyFromPEM(privkeyPem string) (privkey *ecdsa.PrivateKey, err error) {
+	pemData := []byte(privkeyPem)
+
+	block, _ := pem.Decode(pemData)
+	if block == nil {
+		return nil, fmt.Errorf("failed to decode PEM block")
+	}
+
+	privkey, err = x509.ParseECPrivateKey(block.Bytes)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse private key: %w", err)
+	}
+
+	return privkey, nil
 }
 
-// 将 ECDSA 私钥转换为 PEM 格式的字符串。
-func PrivateKeyToPEM(privateKey *ecdsa.PrivateKey) (string, error) {
-	data, err := x509.MarshalECPrivateKey(privateKey)
+// 将 ECDSA 私钥转换为 PEM 编码的字符串。
+//
+// 入参:
+//   - privkey: ecdsa.PrivateKey 对象。
+//
+// 出参:
+//   - privkeyPem: 私钥 PEM 内容。
+//   - err: 错误。
+func ConvertECPrivateKeyToPEM(privkey *ecdsa.PrivateKey) (privkeyPem string, err error) {
+	data, err := x509.MarshalECPrivateKey(privkey)
 	if err != nil {
 		return "", fmt.Errorf("failed to marshal EC private key: %w", err)
 	}
@@ -62,20 +93,3 @@ func PrivateKeyToPEM(privateKey *ecdsa.PrivateKey) (string, error) {
 
 	return string(pem.EncodeToMemory(block)), nil
 }
-
-// 从 PEM 编码的私钥字符串解析并返回一个 ECDSA 私钥对象。
-func ParsePrivateKeyFromPEM(privateKeyPem string) (*ecdsa.PrivateKey, error) {
-	pemData := []byte(privateKeyPem)
-
-	block, _ := pem.Decode(pemData)
-	if block == nil {
-		return nil, fmt.Errorf("failed to decode PEM block")
-	}
-
-	privateKey, err := x509.ParseECPrivateKey(block.Bytes)
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse private key: %w", err)
-	}
-
-	return privateKey, nil
-}