diff --git a/hapsigntool_cpp/api/include/service_api.h b/hapsigntool_cpp/api/include/service_api.h
index 968df287baec4243debdd77685da4c4383d2a455..11f5a88993c5a58c07a6bbcb14f04bfb4ab01f09 100644
--- a/hapsigntool_cpp/api/include/service_api.h
+++ b/hapsigntool_cpp/api/include/service_api.h
@@ -24,7 +24,7 @@ namespace SignatureTools {
 class ServiceApi {
 public:
     ServiceApi() = default;
-    ~ServiceApi() = default;
+    virtual ~ServiceApi() = default;
 
     virtual bool GenerateKeyStore(Options* params) = 0;
     virtual bool GenerateCsr(Options* params) = 0;
diff --git a/hapsigntool_cpp/api/src/cert_tools.cpp b/hapsigntool_cpp/api/src/cert_tools.cpp
index e634a2e15fd0d97b8d381e37466f64ef2a13b295..7f245c2cf8f2c0de36376ccdff4f36f9e471ea9d 100644
--- a/hapsigntool_cpp/api/src/cert_tools.cpp
+++ b/hapsigntool_cpp/api/src/cert_tools.cpp
@@ -361,7 +361,7 @@ bool CertTools::SetKeyUsage(X509* cert, Options* options)
         }
     } else {
         bool keyUsageCritical = options->GetBool(Options::KEY_USAGE_CRITICAL);
-        int crit = keyUsageCritical > 0 ? 1 : 0;
+        int crit = keyUsageCritical ? 1 : 0;
         std::vector<std::string> vecs = StringUtils::SplitString(keyUsage.c_str(), ',');
         key = std::accumulate(vecs.begin(), vecs.end(), key,
             [&](long key, const std::string& vec) { return key | externDic[vec]; });
diff --git a/hapsigntool_cpp/hap/entity/src/sign_content_info.cpp b/hapsigntool_cpp/hap/entity/src/sign_content_info.cpp
index 1ef57cf0dcb462029e31a0f5721ab8c0ce020bd3..de1c6b9aeef2f61622c1239ac03767ec601800f1 100644
--- a/hapsigntool_cpp/hap/entity/src/sign_content_info.cpp
+++ b/hapsigntool_cpp/hap/entity/src/sign_content_info.cpp
@@ -76,12 +76,32 @@ std::vector<int8_t> SignContentInfo::GetByteContent()
     }
 
     for (const auto& tmp : m_hashData) {
+        if (index >= ret.size()) {
+            PrintErrorNumberMsg("SIGN_ERROR", SIGN_ERROR, "InsertShortToByteArray failed.");
+            return std::vector<int8_t>();
+        }
         ret[index] = tmp.m_type;
         index++;
+
+        if (index >= ret.size()) {
+            PrintErrorNumberMsg("SIGN_ERROR", SIGN_ERROR, "InsertShortToByteArray failed.");
+            return std::vector<int8_t>();
+        }
         ret[index] = tmp.m_tag;
         index++;
+
         index = ByteArrayUtils::InsertShortToByteArray(ret, ret.size(), index, tmp.m_algId);
+        if (index < 0) {
+            PrintErrorNumberMsg("SIGN_ERROR", SIGN_ERROR, "InsertShortToByteArray failed.");
+            return std::vector<int8_t>();
+        }
+
         index = ByteArrayUtils::InsertIntToByteArray(ret, index, tmp.m_length);
+        if (index < 0) {
+            PrintErrorNumberMsg("SIGN_ERROR", SIGN_ERROR, "InsertShortToByteArray failed.");
+            return std::vector<int8_t>();
+        }
+
         index = ByteArrayUtils::InsertByteToByteArray(ret, index, tmp.m_hash, tmp.m_hash.size());
         if (index < 0) {
             PrintErrorNumberMsg("SIGN_ERROR", SIGN_ERROR, "InsertShortToByteArray failed.");
diff --git a/hapsigntool_cpp/utils/src/string_utils.cpp b/hapsigntool_cpp/utils/src/string_utils.cpp
index 662065d7e6b3407e2c3f9011caedf3c4c3770a1a..b5ccd7c8792af8c0afb7c3f156c583f21607ed02 100644
--- a/hapsigntool_cpp/utils/src/string_utils.cpp
+++ b/hapsigntool_cpp/utils/src/string_utils.cpp
@@ -62,7 +62,7 @@ std::string StringUtils::FormatLoading(std::string& dealStr)
     char comma = ',';
     char slash = '/';
     std::string del = dealStr.substr(dealStr.find_first_of("/") + 1, dealStr.size());
-    int position = 0;
+    std::string::size_type position = 0;
     while ((position = del.find(slash, position)) != std::string::npos) {
         del.insert(position + 1, " ");
         position++;