gpg-agent正在运行，但总是提示我输入密码。

Question

当我运行gpg2时，每次使用它时都会被提示输入密码。根据我对gpg-agent手册页的阅读，应该只在第一次提示我。

gpg-agent  is a daemon to manage secret (private)
keys independently from any proto-col. It is
used as a backend for gpg and gpgsm as well as
for  a  couple  of other utilities.

The agent is automatically started on demand
by gpg, gpgsm, gpgconf, or gpg-connect-agent.
Thus there is no reason to start it manually.

...

--default-cache-ttl n
    Set the time a cache entry is valid to n
    seconds.  The default  is  600  sec- onds.
    Each  time a cache entry is accessed, the
    entry's timer is reset.  To set an entry's
    maximum lifetime, use max-cache-ttl.

--max-cache-ttl n
    Set the maximum time a cache entry is valid
    to n seconds.  After this time  a cache
    entry will be expired even if it has been
    accessed recently or has been set using
    gpg-preset-passphrase.  The default is 2
    hours (7200 seconds).

如果我正确地读取了它，调用gpg2应该在我第一次使用它时提示输入密码，那么，如果我在接下来的600秒内再次运行它，我将不会再次被提示。正在运行

gpg2 --export-secret-keys --armor john.doe@example.com > /dev/null

给我这个：

┌─┐
│ Please enter the passphrase to export the OpenPGP secret key:  │
│ "John Doe (asdf) "                       │
│ 2048-bit RSA key, ID EB7B49EAD38DE665,                         │         
│ created 2018-10-09.                                            │         
│                                                                │         
│                                                                │         
│ Passphrase: _ │
│                                                                │         
│                                                    │
└─┘

一个快速的ps aux显示gpg-agent正在运行：

ps aux | grep gpg-agent
jdoe   14089  0.1  0.1 100884  3588 ?        SLs  18:50   0:07 /usr/bin/gpg-agent --supervised

唉，再次运行gpg2 --export-secret-keys...将提示我再次输入密码。

还有几个细节：

• 我用的是pinentry-curses
• 我已经在我的.bashrc中输出了D15
• gpg2 --version -> gpg (GnuPG) 2.2.4
• 我读过为什么要求密码，即使与gpg-代理？和我怎么知道gpg代理缓存了哪些密钥？(添加-l如何向您显示缓存的ssh键的比如ssh)，但我没有完全理解。

Answer 1

来自GnuPG 2.2.4手册，关于--export-secret-keys (特别是)：

GnuPG可能要求您输入密码作为密钥。这是必需的，因为秘密密钥的内部保护方法不同于OpenPGP协议指定的方法。