我有一台运行 Debian 8 的服务器。是的，相当老旧了。但它确实有些奇怪。我无法通过 HTTPS 连接到它：
$ curl -sSLv https://example.com
* Trying xx.yyy.xx.yyy:443...
* Connected to example.com (xx.yyy.xx.yyy) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* CAfile: /etc/ssl/certs/ca-certificates.crt
* CApath: none
} [5 bytes data]
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to example.com:443
* Closing connection 0
curl: (35) OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to example.com:443
$ sslscan example.com
Version: 2.0.11
OpenSSL 1.1.1m 14 Dec 2021
Connected to xx.yyy.xx.yyy
Testing SSL server example.com on port 443 using SNI name example.com
SSL/TLS Protocols:
SSLv2 disabled
SSLv3 disabled
TLSv1.0 disabled
TLSv1.1 disabled
TLSv1.2 disabled
TLSv1.3 disabled
TLS Fallback SCSV:
Connection failed - unable to determine TLS Fallback SCSV support
TLS renegotiation:
Session renegotiation not supported
TLS Compression:
OpenSSL version does not support compression
Rebuild with zlib1g-dev package for zlib support
Heartbleed:
Supported Server Cipher(s):
Certificate information cannot be retrieved.
$ dpkg -l | grep openssl
ii openssl 1.0.1t-1+deb8u12 amd64 Secure Sockets Layer toolkit - cryptographic utility
$ cat /etc/nginx/nginx.conf | grep ssl
ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
ssl_prefer_server_ciphers on;
$ dpkg -l | grep nginx
ii nginx 1.6.2-5 all small, powerful, scalable web/proxy server
ii nginx-common 1.6.2-5 all small, powerful, scalable web/proxy server - common files
ii nginx-full 1.6.2-5 amd64 nginx web/proxy server (standard version)
将其与另一个 Debian 8 服务器进行比较：
$ sslscan example2.com
Version: 2.0.11
OpenSSL 1.1.1m 14 Dec 2021
Connected to xx.xxx.xx.xxx
Testing SSL server example2.com on port 443 using SNI name example2.com
SSL/TLS Protocols:
SSLv2 disabled
SSLv3 disabled
TLSv1.0 enabled
TLSv1.1 enabled
TLSv1.2 enabled
TLSv1.3 disabled
TLS Fallback SCSV:
Server supports TLS Fallback SCSV
TLS renegotiation:
Secure session renegotiation supported
TLS Compression:
OpenSSL version does not support compression
Rebuild with zlib1g-dev package for zlib support
Heartbleed:
TLSv1.2 not vulnerable to heartbleed
TLSv1.1 not vulnerable to heartbleed
TLSv1.0 not vulnerable to heartbleed
Supported Server Cipher(s):
Preferred TLSv1.2 256 bits ECDHE-RSA-AES256-GCM-SHA384 Curve P-256 DHE 256
Accepted TLSv1.2 256 bits ECDHE-RSA-AES256-SHA384 Curve P-256 DHE 256
Accepted TLSv1.2 256 bits ECDHE-RSA-AES256-SHA Curve P-256 DHE 256
Accepted TLSv1.2 256 bits DHE-RSA-AES256-GCM-SHA384 DHE 1024 bits
Accepted TLSv1.2 256 bits DHE-RSA-AES256-SHA256 DHE 1024 bits
Accepted TLSv1.2 256 bits DHE-RSA-AES256-SHA DHE 1024 bits
Accepted TLSv1.2 256 bits DHE-RSA-CAMELLIA256-SHA DHE 1024 bits
Accepted TLSv1.2 256 bits AES256-GCM-SHA384
Accepted TLSv1.2 256 bits AES256-SHA256
Accepted TLSv1.2 256 bits AES256-SHA
Accepted TLSv1.2 256 bits CAMELLIA256-SHA
Accepted TLSv1.2 128 bits ECDHE-RSA-AES128-GCM-SHA256 Curve P-256 DHE 256
Accepted TLSv1.2 128 bits ECDHE-RSA-AES128-SHA256 Curve P-256 DHE 256
Accepted TLSv1.2 128 bits ECDHE-RSA-AES128-SHA Curve P-256 DHE 256
Accepted TLSv1.2 128 bits DHE-RSA-AES128-GCM-SHA256 DHE 1024 bits
Accepted TLSv1.2 128 bits DHE-RSA-AES128-SHA256 DHE 1024 bits
Accepted TLSv1.2 128 bits DHE-RSA-AES128-SHA DHE 1024 bits
Accepted TLSv1.2 128 bits DHE-RSA-CAMELLIA128-SHA DHE 1024 bits
Accepted TLSv1.2 128 bits AES128-GCM-SHA256
Accepted TLSv1.2 128 bits AES128-SHA256
Accepted TLSv1.2 128 bits AES128-SHA
Accepted TLSv1.2 128 bits CAMELLIA128-SHA
Preferred TLSv1.1 256 bits ECDHE-RSA-AES256-SHA Curve P-256 DHE 256
Accepted TLSv1.1 256 bits DHE-RSA-AES256-SHA DHE 1024 bits
Accepted TLSv1.1 256 bits DHE-RSA-CAMELLIA256-SHA DHE 1024 bits
Accepted TLSv1.1 256 bits AES256-SHA
Accepted TLSv1.1 256 bits CAMELLIA256-SHA
Accepted TLSv1.1 128 bits ECDHE-RSA-AES128-SHA Curve P-256 DHE 256
Accepted TLSv1.1 128 bits DHE-RSA-AES128-SHA DHE 1024 bits
Accepted TLSv1.1 128 bits DHE-RSA-CAMELLIA128-SHA DHE 1024 bits
Accepted TLSv1.1 128 bits AES128-SHA
Accepted TLSv1.1 128 bits CAMELLIA128-SHA
Preferred TLSv1.0 256 bits ECDHE-RSA-AES256-SHA Curve P-256 DHE 256
Accepted TLSv1.0 256 bits DHE-RSA-AES256-SHA DHE 1024 bits
Accepted TLSv1.0 256 bits DHE-RSA-CAMELLIA256-SHA DHE 1024 bits
Accepted TLSv1.0 256 bits AES256-SHA
Accepted TLSv1.0 256 bits CAMELLIA256-SHA
Accepted TLSv1.0 128 bits ECDHE-RSA-AES128-SHA Curve P-256 DHE 256
Accepted TLSv1.0 128 bits DHE-RSA-AES128-SHA DHE 1024 bits
Accepted TLSv1.0 128 bits DHE-RSA-CAMELLIA128-SHA DHE 1024 bits
Accepted TLSv1.0 128 bits AES128-SHA
Accepted TLSv1.0 128 bits CAMELLIA128-SHA
Server Key Exchange Group(s):
TLSv1.2 128 bits secp256r1 (NIST P-256)
SSL Certificate:
Signature Algorithm: sha256WithRSAEncryption
RSA Key Strength: 4096
Subject: example2.com
Altnames: DNS:example2.com
Issuer: R3
Not valid before: Dec 17 21:00:13 2021 GMT
Not valid after: Mar 17 21:00:12 2022 GMT
$ dpkg -l | grep openssl
ii openssl 1.0.1k-3+deb8u2 amd64 Secure Sockets Layer toolkit - cryptographic utility
$ cat /etc/nginx/nginx.conf | grep ssl
ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
ssl_prefer_server_ciphers on;
$ dpkg -l | grep nginx
ii nginx 1.6.2-5 all small, powerful, scalable web/proxy server
ii nginx-common 1.6.2-5 all small, powerful, scalable web/proxy server - common files
ii nginx-full 1.6.2-5 amd64 nginx web/proxy server (standard version)
第一个服务器出了什么问题？我该如何让 https 正常工作？
答案1
其中一个服务器（就 而言nginx）有listen 443 ssl，但没有ssl_*指令。在这种情况下，您会看到问题中描述的症状。也就是说，一个服务器（虚拟主机）的问题影响了另一个服务器（其余服务器）。
在故障服务器的错误日志中你会看到：
2022/01/12 02:44:46 [错误] 445#0：*23 SSL 握手时监听 SSL 端口的服务器中未定义“ssl_certificate”，客户端：xx.xxx.xx.xxx，服务器：0.0.0.0:443