如题, 测试ssl / tls 可以用这个工具.
参考连结如下:
https://www.gnutls.org/manual/html_node/gnutls_002dcli-Invocation.html
Debian , Ubuntu 用这个命令装
$ sudo apt-get install gnutls-bin
yum的话用这个
$ yum install gnutls-utils
这边是 gmail IMAP port 993测试结果
$ gnutls-cli -d 5 imap.gmail.com -p 993 Resolving 'imap.gmail.com'... Connecting to '2607:f8b0:400d:c00::6d:993'... ... (略) ... - Peer's certificate issuer is unknown - Peer's certificate is NOT trusted - Version: TLS1.2 - Key Exchange: RSA - Cipher: ARCFOUR-128 - MAC: SHA1 - Compression: NULL - Handshake was completed ...
或者这样用 , 可以打印出他的凭证.
$ gnutls-cli --print-cert www.google.com ... (略) ... - Status: The certificate is trusted. ... (略) ... - MAC: AEAD - Compression: NULL - Options: safe renegotiation, - Handshake was completed
这边有红帽的文档, 有兴趣可以参考看看.
https://access.redhat.com/articles/1493153
原文:大专栏 [linux] SSL / TLS 测试工具 GnuTLS
来源：博客园
作者：老特特傻
链接：https://www.cnblogs.com/chinatrump/p/11468327.html