下面，让我们一起来看看，gpg如何加密和解密的吧。
创建密钥
gpg --gen-key
你要求输入一下内容，这些内容，基本英文，还是很好明白
root@g140:~# gpg --gen-key
gpg (GnuPG) 1.4.11; Copyright (C) 2010 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.
gpg: directory `/root/.gnupg' created
gpg: new configuration file `/root/.gnupg/gpg.conf' created
gpg: WARNING: options in `/root/.gnupg/gpg.conf' are not yet active during this run
gpg: keyring `/root/.gnupg/secring.gpg' created
gpg: keyring `/root/.gnupg/pubring.gpg' created
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?
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048)
Requested keysize is 2048 bits
Please specify how long the key should be valid.
0 = key does not expire
= key expires in n days
w = key expires in n weeks
m = key expires in n months
y = key expires in n years
Key is valid for? (0)
Key does not expire at all
Is this correct? (y/N) y
You need a user ID to identify your key; the software constructs the user ID
from the Real Name, Comment and Email Address in this form:
"Heinrich Heine (Der Dichter) "
Real name: chenshake
Email address: shake.chen@gmail.com
Comment:
You selected this USER-ID:
"chenshake "
Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O
You need a Passphrase to protect your secret key.
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
gpg: /root/.gnupg/trustdb.gpg: trustdb created
gpg: key AEAA16F3 marked as ultimately trusted
public and secret key created and signed.
gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0 valid: 1 signed: 0 trust: 0-, 0q, 0n, 0m, 0f, 1u
pub 2048R/AEAA16F3 2013-10-21
Key fingerprint = B93B 05F8 9D63 54 6DEE 6A08 EB9E D2BB AEAA 16F3
uid chenshake
sub 2048R/02B4038D 2013-10-21
就是上面这个过程
在这个生成密钥的过程中,有个步骤很重要,就是生成内存随机数,命令如下:
dd if=/dev/zero of=test.dbf bs=9000 count=1000k .直到生成key为止。
查看私钥
# gpg -k
/root/.gnupg/pubring.gpg
------------------------
pub 2048R/AEAA16F3 2013-10-21
uid chenshake
sub 2048R/02B4038D 2013-10-21
查看公钥
# gpg --list-keys
/root/.gnupg/pubring.gpg
------------------------
pub 2048R/AEAA16F3 2013-10-21
uid chenshake
sub 2048R/02B4038D 2013-10-21
导出公钥
gpg -o chenshake.gpg -a --export chenshake
其中chenshake为用户ID
chenshake.gpg为导出的公钥文件
导出私钥
gpg -o chenshake-private.gpg --export-secret-keys chenshake
导入秘钥
公钥和私钥的导入，都是一样。
gpg --import filename
公钥
(另外一台机器)
当然你需要通过scp把公钥复制到远程的机器
# gpg --import chenshake.gpg
gpg: directory `/root/.gnupg' created
gpg: new configuration file `/root/.gnupg/gpg.conf' created
gpg: WARNING: options in `/root/.gnupg/gpg.conf' are not yet active during this run
gpg: keyring `/root/.gnupg/secring.gpg' created
gpg: keyring `/root/.gnupg/pubring.gpg' created
gpg: /root/.gnupg/trustdb.gpg: trustdb created
gpg: key AEAA16F3: public key "chenshake " imported
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)
你也可以查看到导入的公钥
# gpg --list-keys
/root/.gnupg/pubring.gpg
------------------------
pub 2048R/AEAA16F3 2013-10-21
uid chenshake
sub 2048R/02B4038D 2013-10-21
公钥加密
一个文件，我这里是加密cobbler.ks 这个文件，加密后是 cobbler.ks.gpg文件，需要私钥才能查看。
# gpg -o cobbler.ks.gpg -er chenshake cobbler.ks
gpg: 02B4038D: There is no assurance this key belongs to the named user
pub 2048R/02B4038D 2013-10-21 chenshake
Primary key fingerprint: B93B 05F8 9D63 54 6DEE 6A08 EB9E D2BB AEAA 16F3
Subkey fingerprint: FCCA 50DD C98D 4E 00FB 804C 4CD2 9544 02B4 038D
It is NOT certain that the key belongs to the person named
in the user ID. If you *really* know what you are doing,
you may answer the next question with yes.
Use this key anyway? (y/N) y
私钥解密
私钥查看 cobbler.ks.gpg
# gpg -o cobbler.ks -d cobbler.ks.gpg
You need a passphrase to unlock the secret key for
user: "chenshake "
2048-bit RSA key, ID 02B4038D, created 2013-10-21 (main key ID AEAA16F3)
gpg: gpg-agent is not available in this session
gpg: encrypted with 2048-bit RSA key, ID 02B4038D, created 2013-10-21
"chenshake "
需要你输入你当初创建秘钥的时候设置的那个密码。这个时候，你就可以查看到加密的文件。
