361 httptraffic (#517)

* I improved the Securing HTTP Traffic to Upstream Servers topic by simplifying longer sentences and enhancing readability.

* Updated the purchase server certificate paragraph to improve for readability.

* These are suggested enhancements for readability.

* Apply suggestions from code review

---------

Co-authored-by: “jaypolansky1” <“[email protected]”>
Co-authored-by: Mike Jang <[email protected]>

Author: 3 people

content/nginx/admin-guide/security-controls/securing-http-traffic-upstream.md

@@ -9,7 +9,7 @@ type:
 - how-to
 ---
 
-This article explains how to encrypt HTTP traffic between NGINX and a upstream group or a proxied server.
+This article explains how to encrypt HTTP traffic between NGINX and an upstream group or a proxied server.
 
 
 ## Prerequisites
@@ -20,19 +20,19 @@ This article explains how to encrypt HTTP traffic between NGINX and a upstream g
 
 ## Obtaining SSL Server Certificates
 
-Purchase a server certificate from a trusted certificate authority (CA), or create your own internal CA with an [OpenSSL](https://www.openssl.org/) library and generate your own certificate. The server certificate together with a private key should be placed on each upstream server.
+You can purchase a server certificate from a trusted certificate authority (CA). You can create own internal CA with an [OpenSSL](https://www.openssl.org/) library and generate your own certificate instead. The server certificate, along with a private key, should be placed on each upstream server.
 
 <span id="client_certs"></span>
 ## Obtaining an SSL Client Certificate
 
-NGINX will identify itself to the upstream servers by using an SSL client certificate. This client certificate must be signed by a trusted CA and is configured on NGINX together with the corresponding private key.
+NGINX will identify itself to the upstream servers with an SSL client certificate. A trusted CA must sign the client certificate, which is configured on NGINX, together with the corresponding private key.
 
-You will also need to configure the upstream servers to require client certificates for all incoming SSL connections, and to trust the CA that issued NGINX’ client certificate. Then, when NGINX connects to the upstream, it will provide its client certificate and the upstream server will accept it.
+You will also need to configure the upstream servers to require client certificates for all incoming SSL connections. In addition, you will need to trust the CA that issued the NGINX client certificate. Then, when NGINX connects to the upstream server, it will provide its client certificate and the upstream server will accept it.
 
 <span id="config"></span>
 ## Configuring NGINX
 
-First, change the URL to an upstream group to support SSL connections. In the NGINX configuration file, specify the “`https`” protocol for the proxied server or an upstream group in the [proxy_pass](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_pass) directive:
+First, change the URL to an upstream group to support SSL connections. Specify the “https” protocol for the proxied server in the NGINX configuration file. Alternatively, [in the proxy_pass](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_pass) directive, specify an upstream group.) 
 
 ```nginx
 location /upstream {
@@ -176,8 +176,14 @@ http {
 
 In this example, the “`https`” protocol in the [proxy_pass](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_pass) directive specifies that the traffic forwarded by NGINX to upstream servers be secured.
 
-When a secure connection is passed from NGINX to the upstream server for the first time, the full handshake process is performed. The [proxy_ssl_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate) directive defines the location of the PEM-format certificate required by the upstream server, the [proxy_ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate_key) directive defines the location of the certificate’s private key, and the [proxy_ssl_protocols](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_protocols) and [proxy_ssl_ciphers](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_ciphers) directives control which protocols and ciphers are used.
+When a secure connection is passed from NGINX to the upstream server for the first time, the full handshake process is performed:
+
+- The [proxy_ssl_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate) directive defines the location of the PEM-format certificate required by the upstream server.
+- The [proxy_ssl_certificate_key](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_certificate_key) directive defines the location of the certificate’s private key.
+- The [proxy_ssl_protocols](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_protocols and [proxy_ssl_ciphers](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_ciphers) directives control which protocols and ciphers are used.
 
 The next time NGINX passes a connection to the upstream server, session parameters will be reused because of the [proxy_ssl_session_reuse](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_session_reuse) directive, and the secured connection is established faster.
 
-The trusted CA certificates in the file named by the [proxy_ssl_trusted_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_trusted_certificate) directive are used to verify the certificate on the upstream. The [proxy_ssl_verify_depth](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_verify_depth) directive specifies that two certificates in the certificates chain are checked, and the [proxy_ssl_verify](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_verify) directive verifies the validity of certificates.
+The trusted CA certificates in the file named by the [proxy_ssl_trusted_certificate](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_trusted_certificate) directive are used to verify the certificate on the upstream.
+The [proxy_ssl_verify_depth](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_verify_depth) directive specifies that two certificates in the certificates chain are checked. 
+The [proxy_ssl_verify](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_verify) directive verifies the validity of certificates.