> [TOC]

# 1、TLS/SSL 协议的工作原理

## 1.1、设计目的

![image-20220817212031071](assets/image-20220817212031071.png)

## 1.2、TLS/SSL 发展

![image-20220817212051206](assets/image-20220817212051206.png)

## 1.3、TLS 协议

![image-20220817212109183](assets/image-20220817212109183.png)

![image-20220817212308198](assets/image-20220817212308198.png)

# 2、对称加密的工作原理

## 2.1、定义

![image-20220817212442343](assets/image-20220817212442343.png)

## 2.2、AES 对称加密在网络中的应用

![image-20220817212505949](assets/image-20220817212505949.png)

## 2.3、原理

![image-20220817212603946](assets/image-20220817212603946.png)

## 2.4、填充

![image-20220817212651251](assets/image-20220817212651251.png)

# 3、对称加密的工作原理（2）：工作模式

## 3.1、定义

![image-20220817213857230](assets/image-20220817213857230.png)

## 3.2、ECB（Electronic codebook）模式

![image-20220817213952227](assets/image-20220817213952227.png)

## 3.3、CBC（Cipher-block chaining）模式

![image-20220817214010222](assets/image-20220817214010222.png)

## 3.4、CTR（Counter）模式

![image-20220817214101437](assets/image-20220817214101437.png)

## 3.5、完整性校验

![image-20220817214203638](assets/image-20220817214203638.png)

## 3.6、验证完整性：MAC（Message AuthenticationCode）

![image-20220817214224192](assets/image-20220817214224192.png)

## 3.7、GCM

![image-20220817214310075](assets/image-20220817214310075.png)

# 4、AES算法

## 4.1、定义

![image-20220817214522765](assets/image-20220817214522765.png)

![image-20220817215134263](assets/image-20220817215134263.png)

## 4.2、步骤

![image-20220817215216891](assets/image-20220817215216891.png)

![image-20220817215247745](assets/image-20220817215247745.png)

![image-20220817215324654](assets/image-20220817215324654.png)

![image-20220817215332252](assets/image-20220817215332252.png)

![image-20220817215445932](assets/image-20220817215445932.png)

![image-20220817215454646](assets/image-20220817215454646.png)

![image-20220817215503390](assets/image-20220817215503390.png)

![image-20220817215511069](assets/image-20220817215511069.png)

# 5、非对称密码与RSA 算法（解决密钥传递问题）

## 5.1、定义

![image-20220817215623302](assets/image-20220817215623302.png)

## 5.2、算法过程

![image-20220817215644744](assets/image-20220817215644744.png)

## 5.3、RAS算法

![image-20220817215806745](assets/image-20220817215806745.png)

![image-20220817215821569](assets/image-20220817215821569.png)

![image-20220817215830689](assets/image-20220817215830689.png)

# 6、非对称密码应用：PKI 证书体系

## 6.1、定义

![image-20220817221038193](assets/image-20220817221038193.png)

## 6.2、签发证书流程

![image-20220817221245923](assets/image-20220817221245923.png)

## 6.3、签名与验签流程

![image-20220817221323734](assets/image-20220817221323734.png)

## 6.4、证书信任链

![image-20220817221531118](assets/image-20220817221531118.png)

## 6.5、PKI 公钥基础设施

![image-20220817221557232](assets/image-20220817221557232.png)

## 6.6、证书类型

![image-20220817221736019](assets/image-20220817221736019.png)

# 7、非对称密码应用：DH密钥交换协议（沟通协商AES使用的密钥）

## 7.1、RSA密钥交换

![image-20220817222203075](assets/image-20220817222203075.png)

* 前向保密性：如果破解server私钥，可以解出公钥

## 7.2、DH 密钥交换

![image-20220817222402686](assets/image-20220817222402686.png)

## 7.3、存在的问题

![image-20220817222532964](assets/image-20220817222532964.png)

* 可以使用PKI解决

# 8、ECC 椭圆曲线的原理

## 8.1、定义

![image-20220817222743245](assets/image-20220817222743245.png)

## 8.2、特性

![image-20220817222756877](assets/image-20220817222756877.png)

![image-20220817223025507](assets/image-20220817223025507.png)

# 9、DH 协议升级：基于椭圆曲线的ECDH协议

## 9.1、定义

![image-20220817223113940](assets/image-20220817223113940.png)

## 9.2、步骤和原理

![image-20220817223136812](assets/image-20220817223136812.png)

![image-20220817223142765](assets/image-20220817223142765.png)

# 10、TLS1.2 与TLS1.3 中的ECDH协议

## 10.1、TLS1.2 通讯过程

![image-20220817223230693](assets/image-20220817223230693.png)

## 10.2、FREAK 攻击

![image-20220817223328253](assets/image-20220817223328253.png)

## 10.3、openssl 1.1.1 版本对TLS1.3 的支持情况

![image-20220817223457659](assets/image-20220817223457659.png)

## 10.4、密钥交换

![image-20220817223551821](assets/image-20220817223551821.png)

# 11、握手的优化

## 11.1、session 缓存

![image-20220817223718720](assets/image-20220817223718720.png)

## 11.2、session ticket

![image-20220817223732948](assets/image-20220817223732948.png)

## 11.3、TLS1.3 的 0RTT 握手

![image-20220817223748524](assets/image-20220817223748524.png)

## 11.4、0-RTT 面临的重放攻击

![image-20220817223806114](assets/image-20220817223806114.png)