mac安装GnuGP

1、首先查看gnugp最新的稳定版：

localhost:~ jack$ brew search gnupg
==> Formulae
gnupg               gnupg-pkcs11-scd    gnupg@1.4           gnupg@2.0

localhost:~ jack$ brew info gnupg
gnupg: stable 2.2.9 (bottled)
GNU Pretty Good Privacy (PGP) package
https://gnupg.org/
Not installed

2、安装，系统给出的说明：

==> Caveats 说明
Once you run this version of gpg you may find it difficult to return to using
a prior 1.4.x or 2.0.x. Most notably the prior versions will not automatically
know about new secret keys created or imported by this version. We recommend
creating a backup of your `~/.gnupg` prior to first use.

For full details on each change and how it could impact you please see
  https://www.gnupg.org/faq/whats-new-in-2.1.html

一旦运行该版的gpg，您可能会发现很难返回使用的版本。比如：1.4.x或2.x版本。最明显的区别是：先前的版本不会自动的辨认出由该版创建或导入的新密钥。我们推荐在第一次使用之前创建你的'~/.GNUPG备份。

3、安装及说明：

localhost:~ jack$ brew install gnupg
==> Installing dependencies for gnupg: npth, libtasn1, nettle, libunistring, libffi, p11-kit, gnutls, gettext, adns

==> libffi
This formula is keg-only, which means it was not symlinked into /usr/local,
because some formulae require a newer version of libffi.

For compilers to find this software you may need to set:
    LDFLAGS:  -L/usr/local/opt/libffi/lib

==> gettext
This formula is keg-only, which means it was not symlinked into /usr/local,
because macOS provides the BSD gettext library & some software gets confused if both are in the library path.

If you need to have this software first in your PATH run:
  echo 'export PATH="/usr/local/opt/gettext/bin:$PATH"' >> ~/.bash_profile

For compilers to find this software you may need to set:
    LDFLAGS:  -L/usr/local/opt/gettext/lib
    CPPFLAGS: -I/usr/local/opt/gettext/include

4、按照步骤3修改配置文件：

# added by GnuGP

  PATH="/usr/local/opt/gettext/bin:$PATH"
  PATH="/usr/local/opt/gnupg@2.2/bin:$PATH"

  export PATH

5、运行：

localhost:~ jack$ gpg --version
gpg (GnuPG) 2.2.9
libgcrypt 1.8.3
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: /Users/jack/.gnupg
支持的算法：
公钥：RSA, ELG, DSA, ECDH, ECDSA, EDDSA
对称加密：IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256,
TWOFISH, CAMELLIA128, CAMELLIA192, CAMELLIA256
散列：SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
压缩：不压缩, ZIP, ZLIB, BZIP2