信息安全 - 在 Dovecot 中禁用 SSLv3 --> TLS 握手失败：没有共享密码？ - 吾爱随笔录

Ubuntu 12.04
OpenSSL 1.0.1-4ubuntu5.20 2012 年 3 月 14 日
鸽舍 2.0.19

情况是我试图通过添加!SSLv3到以下内容来禁用 Dovecot 中的 SSLv3 ssl_cipher_list：

ssl_cipher_list = EDH+CAMELLIA:EDH+aRSA:EECDH+aRSA+AESGCM:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH:+CAMELLIA256:+AES256:+CAMELLIA128:+AES128:!SSLv3:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!DSS:!RC4:!SEED:!ECDSA:CAMELLIA256-SHA:AES256-SHA:CAMELLIA128-SHA:AES128-SHA

重新启动 Dovecot，然后检查日志，我得到：

10 月 29 日 05:00:46 邮件 dovecot：imap-login：断开连接（无身份验证尝试）：rip=118.71.13.x，lip=107.170.105.y，TLS 握手：SSL_accept() 失败：错误：1408A0C1:SSL例程：SSL3_GET_CLIENT_HELLO：没有共享密码

我不明白的是：上面的密码列表支持一些 TLSv1.2：

openssl ciphers -v 'EDH+CAMELLIA:EDH+aRSA:EECDH+aRSA+AESGCM:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH:+CAMELLIA256:+AES256:+CAMELLIA128:+AES128:!SSLv3:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!DSS:!RC4:!SEED:!ECDSA:CAMELLIA256-SHA:AES256-SHA:CAMELLIA128-SHA:AES128-SHA' | grep -i tls
DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(256) Mac=AEAD
DHE-RSA-AES256-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA256
ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(256) Mac=AEAD
ECDHE-RSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA384
DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(128) Mac=AEAD
DHE-RSA-AES128-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA256
ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(128) Mac=AEAD
ECDHE-RSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA256

tcpdump在使用 Thunderbird 连接到 Dovecot 时运行：

Secure Sockets Layer
    SSL Record Layer: Handshake Protocol: Client Hello
        Content Type: Handshake (22)
        Version: TLS 1.0 (0x0301)
        Length: 177
        Handshake Protocol: Client Hello
            Handshake Type: Client Hello (1)
            Length: 173
            Version: TLS 1.2 (0x0303)
            Random
                GMT Unix Time: May  4, 2099 21:21:49.000000000 ICT
                Random Bytes: db3c676892cb86a10350aae7fa67868ed4935862593455bc...
            Session ID Length: 0
            Cipher Suites Length: 46
            Cipher Suites (23 suites)
                Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02b)
                Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xc02f)

你可以看到至少客户端和服务器都支持ECDHE-RSA-AES128-GCM-SHA256，为什么握手失败？

Secure Sockets Layer
    TLSv1.2 Record Layer: Alert (Level: Fatal, Description: Handshake Failure)
        Content Type: Alert (21)
        Version: TLS 1.2 (0x0303)
        Length: 2
        Alert Message
            Level: Fatal (2)
            Description: Handshake Failure (40)