ご返信ありがとうございます。
試してみましたが、証明書情報が返ってきましたので接続できているようです。
* Establish HTTP proxy tunnel to moodle.org:443
> CONNECT moodle.org:443 HTTP/1.1
> Host: moodle.org:443
> User-Agent: curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.19.1 Basic ECC zlib/1.2.3 libidn/1.18 libssh2/1.4.2
> Proxy-Connection: Keep-Alive
>
< HTTP/1.0 200 Connection established
HTTP/1.0 200 Connection established
<
* Proxy replied OK to CONNECT request
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* CAfile: /etc/pki/tls/certs/ca-bundle.crt
CApath: none
* SSL connection using TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
* Server certificate:
* subject: CN=sni.cloudflaressl.com,O="Cloudflare, Inc.",L=San Francisco,ST=CA,C=US
* start date: 3月 25 00:00:00 2020 GMT
* expire date: 10月 09 12:00:00 2020 GMT
* common name: sni.cloudflaressl.com
* issuer: CN=CloudFlare Inc ECC CA-2,O="CloudFlare, Inc.",L=San Francisco,ST=CA,C=US
> HEAD / HTTP/1.1
> User-Agent: curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.19.1 Basic ECC zlib/1.2.3 libidn/1.18 libssh2/1.4.2
> Host: moodle.org
> Accept: */*
>
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< Date: Mon, 20 Apr 2020 00:01:42 GMT
Date: Mon, 20 Apr 2020 00:01:42 GMT
< Content-Type: text/html; charset=utf-8
Content-Type: text/html; charset=utf-8
< Connection: keep-alive
Connection: keep-alive
< Set-Cookie: __cfduid=d14d41ceae7a17313d5aa6abcf736e1591587340901; expires=Wed, 20-May-20 00:01:41 GMT; path=/; domain=.moodle.org; HttpOnly; SameSite=Lax
Set-Cookie: __cfduid=d14d41ceae7a17313d5aa6abcf736e1591587340901; expires=Wed, 20-May-20 00:01:41 GMT; path=/; domain=.moodle.org; HttpOnly; SameSite=Lax
< Vary: Front-End-Https,User-Agent
Vary: Front-End-Https,User-Agent
< Set-Cookie: MoodleSession=24614f49e9bb763be9e377b9b579352f; path=/; secure; HttpOnly
Set-Cookie: MoodleSession=24614f49e9bb763be9e377b9b579352f; path=/; secure; HttpOnly
< Expires: Mon, 20 Aug 1969 09:23:00 GMT
Expires: Mon, 20 Aug 1969 09:23:00 GMT
< Cache-Control: no-store, no-cache, must-revalidate
Cache-Control: no-store, no-cache, must-revalidate
< Pragma: no-cache
Pragma: no-cache
< Content-Language: en
Content-Language: en
< Content-Script-Type: text/javascript
Content-Script-Type: text/javascript
< Content-Style-Type: text/css
Content-Style-Type: text/css
< X-UA-Compatible: IE=edge
X-UA-Compatible: IE=edge
< Cache-Control: post-check=0, pre-check=0, no-transform
Cache-Control: post-check=0, pre-check=0, no-transform
< Last-Modified: Mon, 20 Apr 2020 00:01:42 GMT
Last-Modified: Mon, 20 Apr 2020 00:01:42 GMT
< Accept-Ranges: none
Accept-Ranges: none
< X-Frame-Options: sameorigin
X-Frame-Options: sameorigin
< CF-Cache-Status: DYNAMIC
CF-Cache-Status: DYNAMIC
< Expect-CT: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
Expect-CT: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
< Server: cloudflare
Server: cloudflare
< CF-RAY: 586a979afd7cef9a-NRT
CF-RAY: 586a979afd7cef9a-NRT
< cf-request-id: 02367d14dc0000ef9a7ea2e200000001
cf-request-id: 02367d14dc0000ef9a7ea2e200000001