SSH连接GitHub报错kex_exchange_identification，返回HTTP响应

不确定问题何时出现，但导致无法正常使用GitHub。执行与GitHub远程仓库交互的Git命令时，遇到key_exchange_identification: banner line too long错误，排查发现底层的ssh命令执行失败，因为banner行返回了完整的HTML文档。

以下是执行ssh -v -T git@ssh.github.com的输出：

OpenSSH_for_Windows_8.1p1, LibreSSL 3.0.2
debug1: Reading configuration data C:\Users\lwrubles/.ssh/config
debug1: Connecting to ssh.github.com [192.30.255.123] port 443.
debug1: Connection established.
debug1: identity file C:\Users\lwrubles\.ssh\id_rsa_test type 0
debug1: identity file C:\Users\lwrubles\.ssh\id_rsa_test-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_for_Windows_8.1
debug1: kex_exchange_identification: banner line 0: HTTP/1.0 500 handshakefailed
debug1: kex_exchange_identification: banner line 1: Content-Type: text/html
debug1: kex_exchange_identification: banner line 2: Cache-Control: no-cache
debug1: kex_exchange_identification: banner line 3: Content-Length: 17998
debug1: kex_exchange_identification: banner line 4: X-Frame-Options: deny
debug1: kex_exchange_identification: banner line 5: Proxy-Connection: Close
debug1: kex_exchange_identification: banner line 6:
debug1: kex_exchange_identification: banner line 7: <html><head>
debug1: kex_exchange_identification: banner line 8:     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
debug1: kex_exchange_identification: banner line 9:
debug1: kex_exchange_identification: banner line 10:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-300.woff2" type="font/woff2" crossorigin="">
debug1: kex_exchange_identification: banner line 11:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-300.woff" type="font/woff" crossorigin="">
debug1: kex_exchange_identification: banner line 12:
debug1: kex_exchange_identification: banner line 13:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-regular.woff2" type="font/woff2" crossorigin="">
debug1: kex_exchange_identification: banner line 14:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-regular.woff" type="font/woff" crossorigin="">
debug1: kex_exchange_identification: banner line 15:
debug1: kex_exchange_identification: banner line 16:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-italic.woff2" type="font/woff2" crossorigin="">
debug1: kex_exchange_identification: banner line 17:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-italic.woff" type="font/woff" crossorigin="">
debug1: kex_exchange_identification: banner line 18:
debug1: kex_exchange_identification: banner line 19:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-600.woff2" type="font/woff2" crossorigin="">
debug1: kex_exchange_identification: banner line 20:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-600.woff" type="font/woff" crossorigin="">
debug1: kex_exchange_identification: banner line 21:
debug1: kex_exchange_identification: banner line 22:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-700.woff2" type="font/woff2" crossorigin="">
debug1: kex_exchange_identification: banner line 23:     <link rel="preload" as="font" href="/mwg-internal/de5fs23hm64ds/files/default/font/Open_Sans/open-sans-v15-latin-700.woff" type="font/woff" crossorigin="">
debug1: kex_exchange_identification: banner line 24:     <link rel="stylesheet" type="text/css" href="/mwg-internal/de5fs23hm64ds/files/default/stylesheets/en.css">
debug1: kex_exchange_identification: banner line 25:     <script src="/mwg-internal/de5fs23hm64ds/files/javascript/sw.js" type="text/javascript"></script>
debug1: kex_exchange_identification: banner line 26: </head>
debug1: kex_exchange_identification: banner line 27:
debug1: kex_exchange_identification: banner line 28: <body>
debug1: kex_exchange_identification: banner line 29:     <div class="container">
debug1: kex_exchange_identification: banner line 30:         <div class="header">

已尝试以下操作，但均得到相同错误输出：

• 更换多个身份文件，修改配置文件及命令行参数
• 直接连接ssh.github.com和通过配置文件连接
• 使用全新的空白配置文件

另外在WSL2 Ubuntu 20.04环境下使用独立的身份文件和配置文件，连接完全正常，因此排除代理或网络问题。

内容的提问来源于stack exchange，提问作者lawruble13