Add save camera parameter services

orbbec_camera/src/utils.cpp

@@ -933,4 +933,21 @@ std::string getDistortionModels(OBCameraDistortion distortion) {
       return sensor_msgs::distortion_models::PLUMB_BOB;
   }
 }
+
+std::string calcMD5(const std::string &data) {
+    unsigned char digest[EVP_MAX_MD_SIZE];
+    unsigned int digest_len = 0;
+
+    EVP_MD_CTX* ctx = EVP_MD_CTX_new();
+    EVP_DigestInit_ex(ctx, EVP_md5(), nullptr);
+    EVP_DigestUpdate(ctx, data.data(), data.size());
+    EVP_DigestFinal_ex(ctx, digest, &digest_len);
+    EVP_MD_CTX_free(ctx);
+
+    std::stringstream ss;
+    ss << std::hex << std::setfill('0');
+    for (unsigned int i = 0; i < digest_len; ++i)
+        ss << std::setw(2) << (int)digest[i];
+    return ss.str();
+}
 }  // namespace orbbec_camera