diff --git a/src/main.rs b/src/main.rs
index 90281d5..bd6b8a8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,6 +6,7 @@ use std::{
     collections::BTreeMap,
     path::{Path, PathBuf},
     pin::Pin,
+    sync::Arc,
 };
 use tokio::{
     fs::{self, File},
@@ -288,61 +289,28 @@ impl VarsFile {
     }
 }
 
-struct Certs {
+trait ICryptoProvider {
+    async fn request(&self) -> Result<()>;
+    async fn sign(&self) -> Result<()>;
+}
+
+struct OpenSSLProvider {
+    vars: BTreeMap<String, String>,
     base_dir: PathBuf,
-    encoding: String,
-    req_days: u32,
+    openssl_cnf: PathBuf,
+    openssl: String,
     ca_file: PathBuf,
     req_file: PathBuf,
     key_file: PathBuf,
     cert_file: PathBuf,
-    config_file: PathBuf,
-    template_file: PathBuf,
-    openssl_cnf: PathBuf,
-    openssl: String,
-    vars: BTreeMap<String, String>,
+    req_days: u32,
 }
 
-impl Certs {
-    fn new(cfg: &AppConfig, vars: BTreeMap<String, String>) -> Self {
-        let base_dir = PathBuf::from(&cfg.base_directory);
-        let keys_dir = base_dir.clone().join(cfg.keys_subdir.clone());
-        let config_dir = base_dir.clone().join(cfg.config_subdir.clone());
-
-        let mut vars = vars;
-        let name = cfg.name.clone();
-
-        vars.insert("KEY_CN".into(), name.clone());
-        vars.insert("KEY_NAME".into(), name.clone());
-        vars.insert("KEY_EMAIL".into(), cfg.email.clone());
-
-        Self {
-            base_dir: base_dir.clone(),
-            encoding: cfg.encoding.clone(),
-            req_days: cfg.req_days,
-            ca_file: keys_dir.join(cfg.ca_filename.clone()),
-            req_file: keys_dir.join(format!("{}.csr", &name)),
-            key_file: keys_dir.join(format!("{}.key", &name)),
-            cert_file: keys_dir.join(format!("{}.crt", &name)),
-            config_file: config_dir.join(format!("{}.ovpn", &name)),
-            template_file: base_dir.clone().join(cfg.template_file.clone()),
-            openssl_cnf: base_dir.clone().join(
-                std::env::var(cfg.openssl_cnf_env.clone())
-                    .unwrap_or(cfg.openssl_default_cnf.clone()),
-            ),
-            openssl: cfg.openssl.clone(),
-            vars,
-        }
-    }
-
+impl OpenSSLProvider {
     async fn is_ca_exists(&self) -> bool {
         is_file_exist(&self.ca_file).await
     }
 
-    async fn is_config_exists(&self) -> bool {
-        is_file_exist(&self.config_file).await
-    }
-
     async fn is_cert_exists(&self) -> bool {
         is_file_exist(&self.cert_file).await
     }
@@ -351,6 +319,39 @@ impl Certs {
         is_file_exist(&self.req_file).await
     }
 
+    fn from_cfg(cfg: &AppConfig, vars: BTreeMap<String, String>) -> Self {
+        let base_dir = PathBuf::from(&cfg.base_directory);
+        let keys_dir = base_dir.clone().join(cfg.keys_subdir.clone());
+        let name = cfg.name.clone();
+        let mut vars = vars;
+
+        vars.insert("KEY_CN".into(), name.clone());
+        vars.insert("KEY_NAME".into(), name.clone());
+        vars.insert("KEY_EMAIL".into(), cfg.email.clone());
+
+        let ca_file = keys_dir.join(cfg.ca_filename.clone());
+        let req_file = keys_dir.join(format!("{}.csr", &name));
+        let key_file = keys_dir.join(format!("{}.key", &name));
+        let cert_file = keys_dir.join(format!("{}.crt", &name));
+        let openssl_cnf = base_dir.clone().join(
+            std::env::var(cfg.openssl_cnf_env.clone()).unwrap_or(cfg.openssl_default_cnf.clone()),
+        );
+
+        Self {
+            vars,
+            base_dir,
+            openssl_cnf,
+            openssl: cfg.openssl.clone(),
+            ca_file,
+            req_file,
+            key_file,
+            cert_file,
+            req_days: cfg.req_days,
+        }
+    }
+}
+
+impl ICryptoProvider for OpenSSLProvider {
     async fn request(&self) -> Result<()> {
         if self.is_req_exists().await {
             return Ok(());
@@ -422,6 +423,57 @@ impl Certs {
             false => Err(anyhow!("ssl ca execution failed")),
         }
     }
+}
+
+struct Certs<T>
+where
+    T: ICryptoProvider,
+{
+    encoding: String,
+    ca_file: PathBuf,
+    key_file: PathBuf,
+    cert_file: PathBuf,
+    config_file: PathBuf,
+    template_file: PathBuf,
+    provider: Arc<T>,
+}
+
+fn make_certs_provider(cfg: &AppConfig, vars: BTreeMap<String, String>) -> impl ICryptoProvider {
+    OpenSSLProvider::from_cfg(cfg, vars)
+}
+
+impl<T> Certs<T>
+where
+    T: ICryptoProvider,
+{
+    fn new(cfg: &AppConfig, provider: T) -> Self {
+        let base_dir = PathBuf::from(&cfg.base_directory);
+        let keys_dir = base_dir.clone().join(cfg.keys_subdir.clone());
+        let config_dir = base_dir.clone().join(cfg.config_subdir.clone());
+        let name = cfg.name.clone();
+
+        Certs {
+            encoding: cfg.encoding.clone(),
+            ca_file: keys_dir.join(cfg.ca_filename.clone()),
+            key_file: keys_dir.join(format!("{}.key", &name)),
+            cert_file: keys_dir.join(format!("{}.crt", &name)),
+            config_file: config_dir.join(format!("{}.ovpn", &name)),
+            template_file: base_dir.clone().join(cfg.template_file.clone()),
+            provider: Arc::new(provider),
+        }
+    }
+
+    async fn is_config_exists(&self) -> bool {
+        is_file_exist(&self.config_file).await
+    }
+
+    async fn request(&self) -> Result<()> {
+        self.provider.request().await
+    }
+
+    async fn sign(&self) -> Result<()> {
+        self.provider.sign().await
+    }
 
     async fn build_client_config(&self) -> Result<bool> {
         if self.is_config_exists().await {
@@ -470,7 +522,8 @@ async fn main() -> Result<()> {
     println!("found vars: {}", vars.filepath.to_str().expect("fff"));
     println!("loaded: {:#?}", &vars.vars);
 
-    let certs = Certs::new(&config, vars.vars.unwrap());
+    let provider = make_certs_provider(&config, vars.vars.unwrap());
+    let certs = Certs::new(&config, provider);
     let created = certs.build_client_config().await?;
 
     let result_file = certs.config_file.to_str().unwrap();