1，对称加密

（1）复制fstab至当前目录，测试加密过程

[root@centos7 ~]# cp /etc/fstab ./

 

加密fstab至 fstab.ciphertext文件（设置机密密码）

[root@centos7 ~]# openssl  enc  -e  -des3  -a  -salt  -in fstab   -out fstab.ciphertext

enter des-ede3-cbc encryption password:

Verifying - enter des-ede3-cbc encryption password:

 

查看加密文件

[root@centos7 ~]# cat fstab.ciphertext

U2FsdGVkX187Ty1Sik0fuKuo3+XUxha/qfCFRuWWvvLE1eSw5yAtB/oqAGxhiUVn

GxtSKEj6Rg5l2gDWfMrdJDCjWHdHIB8/B+NDC/WTIj00kIGwY1h6DxDjFFePpXHm

Ido2oC6I+PvKujOz4u7xzAT0UTYsL9fr+EBTIXyVfMGlVN/QLrWnJPUHmf5kDQQi

bTLV82M7vgh5CBLu2jSYGRA5TlsP+TNuNZiTWrjbnPVp4tgs6h/ABH4wYZ0lFQFy

bUbEczgQourfxelzD5cXVY8kYHrZSSVTnicBA6S3LdcBxjvnVtz4BdCRZZlZG/Z1

TeV46HptpIB8tnroZU8EzYuJECF1OND4aUTHhCxuAu3RJjaKOO20L2Ts4u7T8fuy

jeA2gi9oijNhPgRo1fZwyNkKLR/GUBunJbcNiqhqIbcy5RxfwAREqwwuC2u+95mA

IFFeMujjg+XoSA4rDJJwmkPEBsp2dLZaX54gHqxEKLeUDUUpMOp6pyJxyfRtGfBq

JUSHKYmA1bKX5wWK0t0uaiY2HH6TPg8doueYRgaa5Xj4BAlmGevWnJ0nB3DfdK6y

PE+0A1hRbbvFCVjk4K7oaHEI5kgKFnpIgZcP2TglOHMEbvbwfuGgZF5NE7VfHgn8

LUWmE8kzCpVttNPKRmU52IVokJSMaaxEo4CP6O1VpYySioS9rpJmmaqRJMQYCSI1

ndWB6gqcsYtRz+KH32B9f6qLH/mqFhjLs3bkpCIyzck=

 

删除原文件

[root@centos7 ~]# rm fstab

rm：是否删除普通文件 "fstab"？y

 

测试解密（输入加密的密码）

[root@centos7 ~]# openssl  enc  -d  -des3  -a  -salt  -out fstab   -in fstab.ciphertext

enter des-ede3-cbc decryption password:

 

[root@centos7 ~]# cat fstab 

## /etc/fstab# Created by anaconda on Wed Oct 24 06:00:20 2018## Accessible filesystems, by reference, are maintained under '/dev/disk'# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info#/dev/mapper/centos-root /                       xfs     defaults        0 0UUID=1357b48c-e338-4292-a617-994e50b64e94 /boot                   xfs     defaults        0 0/dev/mapper/centos-home /home                   xfs     defaults        0 0/dev/mapper/centos-swap swap                    swap    defaults        0 0

 

2，单向加密

计算文件特征码

方法1

[root@centos7 ~]# md5sum fstab

8c2acfcfde2a825c2b176315cc9916aa  fstab

 

方法2

[root@centos7 ~]# openssl dgst -md5 fstab

MD5(fstab)= 8c2acfcfde2a825c2b176315cc9916aa

 

 

3，生成随机数

方法1

[root@centos7 ~]# openssl rand -base64 10

BhI3talqVWOVMg==

方法2

[root@centos7 ~]# openssl rand -hex 10

b343e42cc7d625a2de67

 

 

4，生成密码

[root@centos7 ~]# openssl  passwd  -1  -salt  suijishu

Password:

$1$suijishu$kTzp8EjARddLA5r/pbxLW/

 

5，随机生成密码

[root@centos7 ~]# openssl  passwd  -1  -salt  $(openssl rand -hex 4)

Password:

$1$e32e29ac$tlPp6ZD0FuhXTt.pfh.jg0

[root@centos7 ~]# openssl  passwd  -1  -salt  $(openssl rand -hex 4)

$1$297fe332$vd0iYQhqU8EClbKhW.yah.

 

6，生成密钥（1024位）及提取公钥

[root@centos7 ~]# openssl  genrsa 1024

Generating RSA private key, 1024 bit long modulus

...............++++++

..............................++++++

e is 65537 (0x10001)

-----BEGIN RSA PRIVATE KEY-----

MIICXAIBAAKBgQDMVUCBrwsPEmLlbui9vDmyEpYO3BGqDrjtSFzKHPQIKhhlCYu0

4zDTwuwJ5G/Na14SCt6HkRBOJHvlwugQl6q9reK8ITZnTu+IUNFSih/fpYQyrC9z

NkTTjHlwGy+C5yTgSruAzwAmyTMWKl86cGkwKGHJGAr1q+JrCXHL90Ys8wIDAQAB

AoGAZwwbcwtu/VPdci2jzIQPaMG80ZOkiOnR00CqIvfFDhUEpnfQ8BGffzwPQ9Hj

nGooT9sRbLb4zR/TKAVKeYuze/t0t4iQU8Y+/v5yKU0PXzR97rBFVewNMLxejdPK

HZnBUqfI5MzMvns5zlF7G406sO9CTrd+GWFHlP9dJj4MjOECQQD7BLSictRQvQyn

1lJ58DFliPGpeiADcXouOdS+RwmNBcbRUPbgwjTlZX7cJUS17YrNUqIPTNtrSINN

qUK0Kl4DAkEA0GNcucNorpjuq9Bss40lE4k+t1/V0z5zAHRmP6dEvLVImv8yFxCZ

lRsDC3LAGl8oBEaKnvZYKPg6opnrHlt6UQJAPxRGpFAA5K0tQfwMy9G9SAuq1vD2

nIbmsjkcKhjF4Kdj9/PFpmOHUWI5B+9hneosqD4stXWV6hbV0C1Jsua2qwJBAIrq

Md4DzbzWZgRTJKNs69JiI1TKphf0AWXEMoUsVD4X+xaYGCQYBMnI//aZwEXUOTDg

dXgScCKflzbdtEbAZIECQBKuJukydxWHuoawcpLYtS2/Is+p5aOcu5WCrHUVb2Sq

+kcbv0WKS+NbwWk7LgawhE661k9HYfv7o

 

密钥保存至文件方法

方法1,重定向

[root@centos7 ~]# openssl  genrsa 1024 > /tmp/key.private

Generating RSA private key, 1024 bit long modulus

............................................++++++

......++++++

e is 65537 (0x10001

 

方法2，-out

[root@centos7 ~]# openssl  genrsa -out /tmp/key.private1 1024

Generating RSA private key, 1024 bit long modulus

.................++++++

........++++++

e is 65537 (0x10001)

 

一步完成权限及生成密钥设定

[root@centos7 ~]# (umask 077;  openssl  genrsa  -out /tmp/key.private2 2048)

Generating RSA private key, 2048 bit long modulus

...........+++

.........................+++

e is 65537 (0x10001)

[root@centos7 ~]# ls /tmp -al | grep key

-rw-r--r--.  1 root root  887 10月 31 22:13 key.private

-rw-r--r--.  1 root root  887 10月 31 22:14 key.private1

-rw-------.  1 root root 1675 10月 31 22:16 key.private2

 

提出公钥：

[root@centos7 ~]# openssl rsa -in /tmp/key.private2 -pubout

writing RSA key

-----BEGIN PUBLIC KEY-----

MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAy0JvDHV1FiRcDWdUkoJW

cvRz7MkmNT132Wv9c10jNsA6wKi/eXrEjvMk26O7/xIPAADKXeiCid9pg4GLABOW

+L9QNaOcPNMXvXFFoRiJv+6HHtBuD7eGyIu1qTZhAy+oDPtBryQzH9z3M6vlhuTb

58AhLqTksNaGAjkKbKzjW7jSHNHEH+ftOrSrbsQgyE8Q5aAriMdrQhTW/2Ufpp/q

7g1g4WyQrT/dXAuejo6D8+EoGSJkROCRJKbF3fIZWGG1rD7UzfZVtunsRjW+DKDc

uHbo0MUk/eGSQT1OVvHLMYi/rdZJ0v2pcLafvYOx/+hmRBz+ez4XAathaCsT2leI

bQIDAQAB

-----END PUBLIC KEY-----