简介
GNU Privacy Guard（GnuPG或GPG）是一种加密软件，它是PGP加密软件的满足GPL的替代物。GnuPG依照由IETF订定的OpenPGP技术标准设计。GnuPG用于加密、数字签名及产生非对称钥匙对的软件。
2.GPG公钥生成
输入“gpg —gen-key”开始生成

[root@localhost ~]$ gpg --gen-key
gpg (GnuPG) 2.0.22; Copyright (C) 2013 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
Your selection? 1

3.询问密钥对位数，这里输入1024

RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 1024

4.提示输入密钥的有效期，这里选择不过期‘0’

Please specify how long the key should be valid.
         0 = key does not expire
      <n>  = key expires in n days
      <n>w = key expires in n weeks
      <n>m = key expires in n months
      <n>y = key expires in n years
Key is valid for? (0) 0

5.提示密码将永不过期，输入y

Key does not expire at all
Is this correct? (y/N) y

6.输入密钥对的名称

GnuPG needs to construct a user ID to identify your key.
Real name: test

7.输入邮箱和备注

Real name: test
Email address: test@qq.com
Comment: test
You selected this USER-ID:
    "test (test) <test@qq.com>"

8.输入o确认

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o

9.这时候会弹出一个提示窗输入密码，自己设置一个密码即可
10.密码设置好了之后，系统会开始生成密钥对
11.查看公钥

gpg --list-key

12.查看私钥

gpg --list-secret-keys

13.导出公钥，默认导入到当前路径，也可以自己设置路径

gpg -a --export test > gongyao.asc

14.将公钥发送给需要文件加密的服务器即可
15.导出私钥，路径同公钥一样

gpg -a --export-secret-keys test > siyao.asc

16.加密文件，本机加密

gpg --encrypt --recipient "test" test.txt
文件加密后会生成一个test.txt.gpg文件，vi打开后显示乱码

17.本机解密

gpg --decrypt test.txt.gpg > test.txt

18.其他服务器加密，先将公钥传至该服务器，再导入公钥

#文件传输可用scp或rsync任意方法这里不做赘述
gpg --import gongyao.asc

19.公钥导入成功后开始加密文件,出现提示输入y即可

gpg --encrypt --recipient "test" test.txt

20.文件解密

gpg --decrypt test.txt.gpg > test.txt

注：如果将加密的文件发送给其他服务器，则需要在接收文件的服务器导入公钥，再执行解密，当执行解密时会提示你输入步骤9设置的密码，密码正确则解密成功