diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index 1ae255e..09a5184 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -14,3 +14,4 @@
     - [Tools](./ops/tools/main.md)
         - [Ansible](./ops/tools/ansible.md)
         - [MongoDB](./ops/tools/mongodb.md)
+        - [OpenSSL](./ops/tools/openssl.md)
diff --git a/src/ops/tools/openssl.md b/src/ops/tools/openssl.md
new file mode 100644
index 0000000..027eb45
--- /dev/null
+++ b/src/ops/tools/openssl.md
@@ -0,0 +1,15 @@
+# OpenSSL
+
+## Checking
+
+### CSR
+
+    openssl req -text -noout -verify -in request.csr
+
+### Key
+
+    openssl rsa -in privkey.key -check
+
+### Cert
+
+    openssl x509 -in certficate.crt -text -noout