我正在尝试从这个外壳脚本使用 OpenSSL 检查 APC 配电单元上的"安全"证书，但一直得到一个空的响应。
#!/bin/bash
host=192.168.242.27
port=443
cert=$(openssl s_client -connect "$host":"$port" 2>/dev/null | sed -n '/BEGIN CERT/,/END CERT/p')
echo "We got a cert:"
echo $cert
所以我做了一些调试。我使用的是 Mac，并且有一个 MacPorts 环境。使用MacPorts版本的OpenSSL连接到服务器，我什么也得不到：
❱ openssl version
OpenSSL 1.0.2h 3 May 2016
❱ openssl s_client -connect 192.168.242.27:443
CONNECTED(00000003)
140735258415184:error:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure:s23_clnt.c:769:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 7 bytes and written 308 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol : TLSv1
Cipher : 0000
Session-ID:
Session-ID-ctx:
Master-Key:
Key-Arg : None
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1464972048
Timeout : 300 (sec)
Verify return code: 0 (ok)
---
但是，使用内置版本，我得到一个响应：
❱ /usr/bin/openssl version
OpenSSL 0.9.8zh 14 Jan 2016
❱ /usr/bin/openssl s_client -connect 192.168.242.27:443
CONNECTED(00000003)
depth=0 /C=US/ST=Default State/L=Default Locality/O=American Power Conversion Corp/OU=Internally Generated Certificate/CN=5A1320E05051
verify error:num=20:unable to get local issuer certificate
verify return:1
depth=0 /C=US/ST=Default State/L=Default Locality/O=American Power Conversion Corp/OU=Internally Generated Certificate/CN=5A1320E05051
verify error:num=21:unable to verify the first certificate
verify return:1
---
Certificate chain
0 s:/C=US/ST=Default State/L=Default Locality/O=American Power Conversion Corp/OU=Internally Generated Certificate/CN=5A1320E05051
i:/C=US/ST=Default State/L=Default Locality/O=American Power Conversion Corp/OU=Internally Generated Certificate/CN=5A1320E05051
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=/C=US/ST=Default State/L=Default Locality/O=American Power Conversion Corp/OU=Internally Generated Certificate/CN=5A1320E05051
issuer=/C=US/ST=Default State/L=Default Locality/O=American Power Conversion Corp/OU=Internally Generated Certificate/CN=5A1320E05051
---
No client certificate CA names sent
---
SSL handshake has read 848 bytes and written 280 bytes
---
New, TLSv1/SSLv3, Cipher is RC4-MD5
Server public key is 768 bit
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
SSL-Session:
Protocol : TLSv1
Cipher : RC4-MD5
Session-ID: E07867E677700F3E7F69FFCC96B4A158
Session-ID-ctx:
Master-Key: 16CB13EF51575C010EB50D37C353A276C108B6673D5FEFEA7B196F84C7ECD858AC00A3137C5AAB9758C50ED35B92BC8B
Key-Arg : None
Start Time: 1464972023
Timeout : 300 (sec)
Verify return code: 21 (unable to verify the first certificate)
---
（是的，这是2年前硬件上的RC4-MD5密码;不，我不建议任何人购买这些东西之一。
在生产中，我希望能够从Linux服务器执行此操作，在那里我只能访问OpenSSL 1.0.2。我尝试了各种参数来openssl s_client禁用和启用SSL和TLS的各种组合，但没有运气。那么，有没有办法让OpenSSL的现代版本与加密较弱的设备通信？
它是编程，因为您可能必须从源代码构建自己的编程。
从OpenSSL 1.0.2g更新日志中查看以下内容：
在 SSLv3 和 OpenSSL 的默认版本中禁用弱密码。 未配置"启用弱 SSL 密码"的内部版本不会 提供任何"导出"或"低"强度密码。 [维克多·杜霍夫尼]
禁用 SSLv2 默认构建、默认协商和弱密码。 SSLv2 默认情况下在构建时禁用。 未配置的版本 "enable-ssl2"将不支持 SSLv2。