开启 OCSP Stapling

发表于 2016-07-26 更新于 2024-04-17 分类于 Server 本文字数： 11k 阅读时长 ≈ 10 分钟

前言

昨天更新了博客，全站开启 HTTP/2 模式。基本设置完了以后，又发现了一些好玩的，今天这个算是补充说明吧。

介绍

先说说 OCSP 是个什么东东，其全名是 Online Certificate Status Protocol，简单说，就是一个可以检测 SSL 证书是否有效的在线证书状态查询协议。有些客户端在访问的时候，会通过 CA 提供的 OCSP URL 去查询证书的有效性，而这个过程实际上是一个阻断式的 HTTP 请求。客户端完成诸如 DNS 查询、TCP 链接建立、HTTP 请求、验证证书等操作后，用户可以开始正常浏览网站，而这中间可能会耗时很长，尤其是在中国这种奇葩的网络状况下，访问海外 CA 提供的 OCSP URL 更是如此。

而 OCSP Stapling 其实是服务器先去 CA 指定的 OCSP URL 获取 OCSP 查询结果，并将结果直接发送给客户端，免去客户端再去 CA 服务器验证的动作，从而提升访问时的连接速度和用户体验，说白了都是为了加速一丢丢。

OCSP 状态查询

先查看一下未修改 Nginx 配置之前的查询结果：

1 2	$ openssl s_client -connect tommy.net.cn:443 -servername tommy.net.cn -status -tlsextdebug < /dev/null 2>&1 \| grep -i "OCSP response" OCSP response: no response sent

嗯，妥妥的，no response sent，表示服务器没有开启 OCSP 支持。下面是重新修改和配置好 Nginx 以后的 OCSP 查询结果：

$  openssl s_client -connect tommy.net.cn:443 -servername tommy.net.cn -status -tlsextdebug < /dev/null 2>&1 | grep -i "OCSP response"
OCSP response:
OCSP Response Data:
    OCSP Response Status: successful (0x0)
    Response Type: Basic OCSP Response

可以看到 OCSP 查询验证成功。

验证 OCSP Response

在配置 Nginx 配置文件之前，我们需要先在命令行验证一下，得到正确的 OCSP Response 先，首先是获得 OCSP URL：

1 2	$ openssl x509 -in cert.pem -ocsp_uri -noout http://ocsp.startssl.com

嗯，一看就暴露了我使用 StartSSL 的事实，接下来验证 OCSP Response，证书签发用的是 StartSSL 的 Intermediate DV1 证书，cert.pem 是服务器证书：

$ openssl ocsp -issuer intermediate.pem -cert cert.pem -no_nonce -text -url http://ocsp.startssl.com
OCSP Request Data:
    Version: 1 (0x0)
    Requestor List:
        Certificate ID:
          Hash Algorithm: sha1
          Issuer Name Hash: 5168159AB1999B3A55E860C022C9D519E0303D29
          Issuer Key Hash: D7914E01C4B0BFF8C86793449CE733FAAD930CAF
          Serial Number: 560E798B0AA4C055417AAB147A96F207
OCSP Response Data:
    OCSP Response Status: successful (0x0)
    Response Type: Basic OCSP Response
    Version: 1 (0x0)
    Responder Id: C = IL, O = StartCom Ltd., OU = StartCom Certification Authority, CN = StartCom Class 1 DV Server CA OCSP Responder
    Produced At: Jul 25 10:07:29 2016 GMT
    Responses:
    Certificate ID:
      Hash Algorithm: sha1
      Issuer Name Hash: 5168159AB1999B3A55E860C022C9D519E0303D29
      Issuer Key Hash: D7914E01C4B0BFF8C86793449CE733FAAD930CAF
      Serial Number: 560E798B0AA4C055417AAB147A96F207
    Cert Status: good
    This Update: Jul 25 10:07:29 2016 GMT
    Next Update: Jul 29 10:17:29 2016 GMT

    Signature Algorithm: sha256WithRSAEncryption
         81:18:0b:fc:7e:3f:db:19:7d:c5:35:fa:8d:12:5a:5d:5b:24:
         ea:2c:fe:69:c1:55:08:f7:8b:8b:51:f7:74:39:fa:43:dc:02:
         7f:5e:b0:eb:d8:68:b4:4b:3e:a6:5c:55:d2:19:1e:84:66:86:
         7d:e1:98:77:4c:6a:e1:61:a1:3b:08:a2:55:76:9e:79:8f:1c:
         4f:d7:12:e1:75:92:9d:aa:85:0b:b5:bf:18:4d:e4:ba:bc:8a:
         9c:35:4c:f4:46:f0:44:a5:fd:82:96:4e:7c:f2:56:95:d3:9b:
         b5:47:98:6f:b1:47:3f:64:f3:4c:e0:71:f2:5c:df:71:80:8a:
         05:b6:82:cf:ec:5a:86:53:55:9e:33:e1:1b:8b:44:ca:7f:5e:
         24:a7:40:2b:fc:a2:9e:be:cb:a8:a1:ed:f0:45:3f:95:50:e8:
         4e:0a:28:0a:0a:5a:68:75:cc:c7:17:57:67:93:3b:01:b1:40:
         12:ef:c0:70:23:24:68:d2:28:34:65:68:4d:ac:98:05:e6:4b:
         fb:09:b4:c7:46:0f:0d:b2:57:61:78:2e:f3:75:c5:48:1b:8a:
         65:8e:5e:ff:40:cb:20:87:a1:c5:a7:c9:6d:c3:5f:63:db:9d:
         c4:28:b0:9c:f8:14:70:dd:b5:0a:75:47:a1:2b:57:49:f3:cf:
         41:cc:c0:cf
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            24:dd:c9:af:57:42:41:b8:ca:bc:8d:bf:96:9e:82:dc
    Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=IL, O=StartCom Ltd., OU=StartCom Certification Authority, CN=StartCom Class 1 DV Server CA
        Validity
            Not Before: Jun 10 01:59:42 2016 GMT
            Not After : Sep 28 01:59:42 2016 GMT
        Subject: C=IL, O=StartCom Ltd., OU=StartCom Certification Authority, CN=StartCom Class 1 DV Server CA OCSP Responder
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (2048 bit)
                Modulus:
                    00:ef:a0:56:07:82:f3:21:f8:a3:58:ca:7d:ef:f0:
                    51:f8:f0:67:4b:23:56:cb:d2:f5:5e:55:fa:d9:ef:
                    37:e2:c4:02:07:ba:a9:b2:d7:b3:67:bb:5e:fd:2f:
                    fd:a9:4d:80:94:1d:a4:7c:5f:5f:d4:fb:d5:c7:c8:
                    07:61:8a:4f:d5:6f:95:8b:43:33:78:f2:87:d6:a4:
                    43:c7:57:b9:fe:ea:2f:88:83:69:0b:25:6a:ba:67:
                    ad:03:ec:59:1a:9b:f9:2a:74:22:9e:44:aa:77:f6:
                    1f:15:94:22:9e:63:86:4c:00:3b:f3:fd:7c:6b:70:
                    f7:f5:17:32:c9:d1:96:46:80:86:be:9b:d2:7c:13:
                    db:3f:dd:2d:7f:cf:3f:9a:31:d1:35:b4:d8:ac:db:
                    6d:1f:87:10:ec:f7:98:b1:88:27:44:6d:4a:7a:91:
                    29:be:0f:bc:7f:33:d9:ac:ea:b2:f0:a6:eb:58:cb:
                    e6:29:05:6b:74:57:0b:d3:4b:3a:94:05:53:56:9c:
                    07:e4:53:5d:19:1d:42:04:76:78:b1:4a:d7:b2:99:
                    25:97:64:3b:51:5d:f3:f0:7d:c1:d8:f0:89:f8:b0:
                    4a:2c:37:df:b2:2a:e3:fa:dc:3a:f0:ec:fb:c3:a7:
                    74:7e:f5:3a:07:77:93:b3:42:1b:59:34:48:10:9a:
                    a7:6b
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Key Usage: critical
                Digital Signature, Key Encipherment, Key Agreement
            X509v3 Extended Key Usage:
                OCSP Signing
            OCSP No Check:

            X509v3 Basic Constraints: critical
                CA:FALSE
            X509v3 Subject Key Identifier:
                17:47:77:8E:AD:70:4C:F6:0C:E0:2F:9B:9E:86:38:54:9B:C2:15:18
            X509v3 Authority Key Identifier:
                keyid:D7:91:4E:01:C4:B0:BF:F8:C8:67:93:44:9C:E7:33:FA:AD:93:0C:AF

            Authority Information Access:
                OCSP - URI:http://ocsp.startssl.com
                CA Issuers - URI:http://aia.startssl.com/certs/sca.server1.crt

            X509v3 CRL Distribution Points:

                Full Name:
                  URI:http://crl.startssl.com/sca-server1.crl

    Signature Algorithm: sha256WithRSAEncryption
         69:67:fa:4f:23:91:f0:56:61:b2:88:09:b4:eb:cd:d0:e7:f4:
         22:a0:2c:f8:2d:cc:6f:7c:bd:1e:2e:17:8b:19:c5:be:3d:70:
         90:6e:a6:94:2d:98:d9:a6:44:97:e6:53:c6:d9:9a:f8:1f:01:
         f7:c3:9b:b4:22:4c:c0:81:72:49:f8:a7:bc:9d:18:49:47:d8:
         7c:c6:5d:ef:3b:dc:b4:7c:3b:48:9a:d4:f3:ab:50:9c:fc:02:
         75:5f:69:30:2a:bc:b4:65:d3:a2:02:b8:1b:4a:c9:ab:cf:d1:
         03:38:cf:b3:df:a0:60:5b:e3:a1:a2:c7:f8:9d:9b:74:f3:08:
         fa:8d:d8:21:b1:ec:65:b7:a0:cb:51:ec:2b:d7:01:0b:bb:54:
         1b:63:af:df:f9:9e:ce:80:c8:09:60:57:ec:cd:f4:2b:d6:e4:
         01:e4:00:00:59:ef:b1:75:28:96:82:47:16:0e:db:e5:3a:2e:
         b5:2f:d5:9d:bf:f5:60:4c:02:fc:7e:f5:41:10:58:5d:9d:bd:
         c8:1d:e7:02:71:82:60:28:c4:7f:1e:6f:95:c1:53:8b:f1:7e:
         2a:46:ce:81:c6:18:e3:0b:e4:e7:df:aa:60:b0:80:10:60:86:
         20:31:88:f5:46:8d:ba:d9:f9:7e:ed:1f:b3:16:ca:ba:ff:4f:
         13:d3:9a:94
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
Response Verify Failure
139666926626464:error:27069065:OCSP routines:OCSP_basic_verify:certificate verify error:ocsp_vfy.c:126:Verify error:unable to get local issuer certificate
cert.pem: good
    This Update: Jul 25 10:07:29 2016 GMT
    Next Update: Jul 29 10:17:29 2016 GMT

可以看到证书验证成功，但是 Response Verify Failure，主要原因是无法找到本地证书签发者，其实这个指定 CA 证书便可，需要注意的是，这个 CA 证书必须是 CA Chained 证书，即包含 CA 和 Intermediate 的证书，这些证书根据不同的公司会有所不同，需要根据自己的情况实际调整。

$ openssl ocsp -CAfile chained.pem -issuer intermediate.pem -cert cert.pem -no_nonce -text -url http://ocsp.startssl.com
OCSP Request Data:

...

Response verify OK
cert.pem: good
    This Update: Jul 25 06:14:54 2016 GMT
    Next Update: Jul 29 06:24:54 2016 GMT

简化了中间结果，可以看到 OCSP 查询结果已经变成了 Response verify OK，表示一起都冇问题了。

配置 Nginx

其实，配置 Nginx 可以作弊，比如说使用 Mozilla SSL Configuration Generator，可以快速地按照需要生成各类常用 Web Server 的配置文件。我配置的时候，选择的配置如下：

Nginx
Intermediate
Server version: 1.9.5
OpenSSL Version: 1.0.2
HSTS Enabled

最后的配置结果如下：

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    # Redirect all HTTP requests to HTTPS with a 301 Moved Permanently response.
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;

    # certs sent to the client in SERVER HELLO are concatenated in ssl_certificate
    ssl_certificate /path/to/cert.pem;
    ssl_certificate_key /path/to/key.pem;
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_session_tickets off;

    # Diffie-Hellman parameter for DHE ciphersuites, recommended 2048 bits
    ssl_dhparam /path/to/dhparam.pem;

    # intermediate configuration. tweak to your needs.
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers 'ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS';
    ssl_prefer_server_ciphers on;

    # HSTS (ngx_http_headers_module is required) (15768000 seconds = 6 months)
    add_header Strict-Transport-Security max-age=15768000;

    # OCSP Stapling ---
    # fetch OCSP records from URL in ssl_certificate and cache them
    ssl_stapling on;
    ssl_stapling_verify on;

    ## verify chain of trust of OCSP response using Root CA and Intermediate certs
    ssl_trusted_certificate /path/to/chained.pem;

    resolver 8.8.8.8;

    ....
}

几个地方修改一下便可，cert.pem 是服务器证书，key.pem 是服务器私钥，chained.pem 是包含 CA 和 Intermediate 的证书。配置好后，重启服务器，再查询一下便发现 OCSP Stapling 已经生效了。注意，第一次请求的时候，服务器要去 CA OCSP URL 获取 OCSP Response，所以会提示没有 OCSP 查询结果，多运行一次就可以了。

$ openssl s_client -connect tommy.net.cn:443 -servername tommy.net.cn -status -tlsextdebug < /dev/null 2>&1 | grep -i "OCSP response"
OCSP response:
OCSP Response Data:
    OCSP Response Status: successful (0x0)
    Response Type: Basic OCSP Response