加密解密以及CA签证

在当今互联网时代，数据越来越来重要。那么如何加密？解密？以及通过什么方式来认证了？？

接下来，我就会和大家谈谈加密，解密以及CA签证的实现。

首先大家的知道一些加密，解密的基本常识：

1. 互联网上中间人一般用的攻击方式有：
   1. 窃听
   2. 篡改别人数据
   3. 劫持会话
2. 数据加密的常用的三种方式有：
   1. 对称加密
   2. 非对称加密
   3. 单向加密
3. SSL:seure socket layer, 安全的套接字层
4. TSL:transport layer security,
   传输层安全，功能 与SSL相似
5. 随机数生成器：/dev/random和/dev/urandom 。 -salt:添加杂质，也就是依赖于随机数生成器
6. 随机数的来源：熵池和伪随机数生成器。熵池中的随机数来自快设备中断和键盘，鼠标的敲击时间间隔；伪随机数生成器中的随机数来自于熵池和软件产生。
7. openssl rand [-base64] num ：也可以用来生成随机数。

   [[email protected] ~]# openssl rand -base64 12

   v8qA8lKAa19aZAWV

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我直接把对称加密以及非对称加密以图片显示：

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下面来说下何谓对称加密，非对称加密(公钥加密)，单向加密

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1. 对称加密：
   

1、加密方和解密方使用同一个密钥。

2、加密解密的速度比较快，适合数据比较长时的使用。

3、密钥传输的过程不安全，且容易被破解，密钥管理也比较麻烦。

4、加密算法：DES（Data Encryption Standard）、3DES、AES（AdvancedEncryption Standard，支持128、192、256、512位密钥的加密）、Blowfish。

5、加密工具：openssl、gpg(pgp工具)

二．非对称加密（公钥加密）：

1、每个用户拥用一对密钥加密：公钥和私钥。

2、公钥加密，私钥解密；私钥加密，公钥解密。

3、公钥传输的过程不安全，易被窃取和替换。

4、由于公钥使用的密钥长度非常长，所以公钥加密速度非常慢，一般不使用其去加密。

5、某一个用户用其私钥加密，其他用户用其公钥解密，实现数字签名的作用。

6、公钥加密的另一个作用是实现密钥交换。

7、加密和签名算法：RSA、ELGamal。

8、公钥签名算法：DSA。

9、加密工具：gpg、openssl

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三．单向加密：

1、特征：雪崩效应、定长输出和不可逆。

2、作用是：确保数据的完整性。

3、加密算法：md5（标准密钥长度128位）、sha1（标准密钥长度160位）、md4、CRC-32

4、加密工具：md5sum、sha1sum、openssldgst。

5、计算某个文件的hash值，例如：md5sum/shalsum?FileName,openssl dgst–md5/-sha1 FileName。

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下面我就来谈谈openssl是什么？如何实现CA自签证？

openssl：

1）组件：libcrypto:加密库。

libssl：实现ssl功能的库。

openssl：多用途的加密工具，能够提供对称加密、公钥加密、单向加密，且可以作为一个简单的本地CA用。

2）openssl的主配置文件：/etc/pki/tls/openssl.cnf

使用openssl实现私有CA

建立私有CA(如下是实现的具体步骤)

????????????[[email protected] ~]# cd /etc/pki/tls

????????????

????????????[[email protected] tls]# ls

????????????cert.pem certs misc openssl.cnf private

????????????

????????????[[email protected] tls]# vim openssl.cnf

????????????

????????????[[email protected] tls]# cd ..

????????????

????????????[[email protected] pki]# ls

????????????CA ca-trust java nssdb rpm-gpg rsyslog tls

????????????

????????????[[email protected] pki]# cd CA/

????????????

????????????[[email protected] CA]# ls

????????????certs crl newcerts private

????????????

????????????[[email protected] CA]# (umask 077;openssl genrsa -out private/cakey.pem 2048)

????????????Generating RSA private key, 2048 bit long modulus

????????????.......................................................................................................................................................+++

????????????.................................+++

????????????e is 65537 (0x10001)

????????????[[email protected] CA]# ls

????????????certs crl newcerts private

????????????

????????????[[email protected] CA]# ls -l private/

????????????total 4

????????????-rw-------. 1 root root 1679 Dec 4 15:00 cakey.pem

????????????[[email protected] CA]# openssl req -new -x509 -key private/cakey.pem -out cacert.pem

????????????You are about to be asked to enter information that will be incorporated

????????????into your certificate request.

????????????What you are about to enter is what is called a Distinguished Name or a DN.

????????????There are quite a few fields but you can leave some blank

????????????For some fields there will be a default value,

????????????If you enter ‘.‘, the field will be left blank.

????????????-----

????????????Country Name (2 letter code) [CN]:

????????????State or Province Name (full name) [Beijin]:

????????????Locality Name (eg, city) [Beijin]:

????????????Organization Name (eg, company) [ChangSheng]:

????????????Organizational Unit Name (eg, section) []:OD

????????????Common Name (eg, your name or your server‘s hostname) []:ca.changsheng.com

????????????Email Address []:[email protected]

????????????

????????????[[email protected] CA]# ls

????????????cacert.pem certs crl newcerts private

????????????

????????????[[email protected] CA]# touch index.txt

????????????

????????????[[email protected] CA]# touch serial

????????????

????????????[[email protected] CA]# echo 01 >serial

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查看证书中的相关信息

????????????# openssl x509 -in /path/to/somefile.crt -noout -text|-subject|-serial

????

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假如在同一台主机上，：用httpd服务自己给自己签证，具体步骤如下：

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[[email protected] ~]# cd /etc/httpd

[[email protected] httpd]# ls

conf conf.d logs modules run

[[email protected] httpd]# mkdir ssl

[[email protected] httpd]# cd ssl/

[[email protected] ssl]# pwd

/etc/httpd/ssl

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[[email protected] ssl]# (umask 077;openssl genrsa -out httpd.key 1024) //创建密钥

Generating RSA private key, 1024 bit long modulus

...++++++

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

e is 65537 (0x10001)

[[email protected] ssl]# cat httpd.key

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

MIICXAIBAAKBgQDPtEGh9bGrkPrW+GNlmI/qBG5ggjAJwl3HOVcof/PkXq771LH/

EV28TvlQexZCnUnz/IeFesJKBZR6YmXB/bEm+gliRjBIXrzJ7j8hRa3L86foFFqw

dm98ID8Ix5RKNDb0QKAz8mk7urn8DsOzaNT2kq9VunbvpTOUI8cErLXdoQIDAQAB

AoGAOO+Tsj70hjBG4pjSPm5UvPScAS6O1o4GQO9x+fMhOy/NTdEfPelXxZ/sbehf

0MDnHc/Son9lNP9UlTvV4xiU77ighV90Dq/mOB9yVEVKHfqDgeiBRb7vuE/wvkkY

QPREJtbZBAboUredUmZ4MBB/+VYd/9/UaMzP+SAL5JWIpQECQQD1H2MUnEYzfn00

j0YzLcvp2jSpMoFSban4WXOeoz7CIhM7GLLuKVaWYlxNgREv7aDDVUzh0M1Un8I+

2hvXIF9RAkEA2OvK1vw3WavEcZq2f4VMHBRJ+7ECJpDCKHOmt9iw3ZwqlGpZs78q

o8di0z/j3KYoiWE3ddJXtMH2Sczo0GElUQJAENHbiaGDi6sFSmL+bSqaUGyhqm6F

wzM1M45nyZ3oA4g1C5wRQxhhEaakMMlHdaN3oY+r297pCAKCYK+0s1lMUQJAGpC1

5KI6vRaWFjuWQgO3EHFDpjlFRCfSP1X6guVcs6ceZ9Kmbabpt+kBJ1HZu/n1WO24

9wrthsuCOAOKN4rOIQJBAIBO36adQB2E1KI5VkxrlTc1snvTscTgiuowtM1gJUaL

aG/xT+1XYWpOWircRnH0d8dmGFajBF/EZpddoGX83jQ=

-----END RSA PRIVATE KEY-----

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[[email protected] ssl]# openssl req -new -key httpd.key -out httpd.csr //请求签证

You are about to be asked to enter information that will be incorporated

into your certificate request.

What you are about to enter is what is called a Distinguished Name or a DN.

There are quite a few fields but you can leave some blank

For some fields there will be a default value,

If you enter ‘.‘, the field will be left blank.

-----

Country Name (2 letter code) [CN]:

State or Province Name (full name) [Beijin]:

Locality Name (eg, city) [Beijin]:

Organization Name (eg, company) [ChangSheng]:

Organizational Unit Name (eg, section) []:OD

Common Name (eg, your name or your server‘s hostname) []:changsheng

Email Address []:[email protected]

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?

Please enter the following ‘extra‘ attributes

to be sent with your certificate request

A challenge password []:

An optional company name []:

[[email protected] ssl]# ls

httpd.csr httpd.key

[[email protected] ssl]# openssl ca -in httpd.csr -out httpd.crt -days 365 //开始签证

Using configuration from /etc/pki/tls/openssl.cnf

Check that the request matches the signature

Signature ok

Certificate Details:

Serial Number: 1 (0x1)

Validity

Not Before: Dec 4 07:33:59 2014 GMT

Not After : Dec 4 07:33:59 2015 GMT

Subject:

countryName = CN

stateOrProvinceName = Beijin

organizationName = ChangSheng

organizationalUnitName = OD

commonName = changsheng

emailAddress = [email protected]

X509v3 extensions:

X509v3 Basic Constraints:

CA:FALSE

Netscape Comment:

OpenSSL Generated Certificate

X509v3 Subject Key Identifier:

DD:96:A4:9F:9F:E0:3F:5D:AB:53:34:CA:FB:A8:4B:86:E9:EB:7B:99

X509v3 Authority Key Identifier:

keyid:64:E5:92:A2:63:25:7A:66:04:4C:A4:FB:8D:F5:0C:D3:89:CA:AC:EC

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Certificate is to be certified until Dec 4 07:33:59 2015 GMT (365 days)

Sign the certificate? [y/n]:y

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1 out of 1 certificate requests certified, commit? [y/n]y

Write out database with 1 new entries

Data Base Updated

[[email protected] ssl]# ll

total 12

-rw-r--r--. 1 root root 3865 Dec 4 15:34 httpd.crt

-rw-r--r--. 1 root root 696 Dec 4 15:33 httpd.csr

-rw-------. 1 root root 887 Dec 4 15:28 httpd.key

[[email protected] ssl]# cd /etc/pki/CA

[[email protected] CA]# cat index.txt //查看数据库

V????????151204073359Z????????????????01????????unknown????????/C=CN/ST=Beijin/O=ChangSheng/OU=OD/CN=changsheng/[email protected]

[[email protected] CA]# cat serial

02

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