ssl - 用于检查服务器是否提供证书的 OpenSSL 命令

Question

我正在尝试运行 openssl 命令以缩小尝试从我们的系统发送出站消息时可能出现的 SSL 问题的范围。

我在另一个主题中找到了这个命令:Using openssl to get the certificate from a server

openssl s_client -connect ip:port -prexit

这个结果的输出

CONNECTED(00000003)
15841:error:140790E5:SSL routines:SSL23_WRITE:ssl handshake failure:s23_lib.c:188:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 121 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
---

这是否意味着服务器没有提供任何证书？我在不同的 ip:port 上尝试了其他系统，它们成功地提供了证书。

相互身份验证是否会影响带有 -prexit 的此命令？

--更新--

我再次运行命令

openssl s_client -connect ip:port -prexit

我现在收到了这个回复

CONNECTED(00000003)
write:errno=104
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 121 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
---

我在命令中添加了-ssl3

openssl s_client -connect ip:port -prexit -ssl3

响应:

CONNECTED(00000003)
write:errno=104
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 0 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
SSL-Session:
    Protocol  : SSLv3
    Cipher    : 0000
    Session-ID: 
    Session-ID-ctx: 
    Master-Key: 
    Key-Arg   : None
    Krb5 Principal: None
    Start Time: 1403907236
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
---

同时尝试 -tls1

CONNECTED(00000003)
write:errno=104
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 0 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
SSL-Session:
    Protocol  : TLSv1
    Cipher    : 0000
    Session-ID: 
    Session-ID-ctx: 
    Master-Key: 
    Key-Arg   : None
    Krb5 Principal: None
    Start Time: 1403907267
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
---

Answer 1

我今天正在调试一个 SSL 问题，它导致了同样的 write:errno=104 错误。最终我发现这种行为的原因是服务器需要 SNI(servername TLS 扩展)才能正常工作。向 openssl 提供 -servername 选项使其连接成功:

openssl s_client -connect domain.tld:443 -servername domain.tld