CS-Notes/notes/HTTP.md

<!-- GFM-TOC -->
* [????????](#????????)
    * [Web????](#web????)
    * [URL](#url)
    * [????????????](#????????????)
* [HTTP ????](#http-????)
    * [GET????????](#get????????)
    * [POST?????????????](#post?????????????)
    * [HEAD????????????](#head????????????)
    * [PUT????????](#put???θ????)
    * [DELETE????????](#delete????????)
    * [OPTIONS????????????](#options????????????)
    * [RACE?????·??](#race?????·??)
    * [CONNECT??????????Э?????????](#connect??????????э?????????)
* [HTTP ????](#http-????)
    * [2XX ???](#2xx-???)
    * [3XX ?????](#3xx-?????)
    * [4XX ????????](#4xx-????????)
    * [5XX ??????????](#5xx-??????????)
* [HTTP???](#http???)
    * [?????????](#?????????)
    * [??????????](#??????????)
    * [?????????](#?????????)
    * [?????????](#?????????)
* [???????](#???????)
    * [Cookie](#cookie)
    * [????](#????)
    * [???????](#???????)
    * [????](#????)
    * [??鴫??](#??鴫??)
    * [????????](#????????)
    * [??Χ????](#??χ????)
    * [????Э??](#????э??)
    * [????????](#????????)
    * [??????????](#??????????)
* [HTTPs](#https)
    * [????](#????)
    * [???](#???)
    * [??????](#??????)
<!-- GFM-TOC -->

# ????????

## Web????

HTTP??HyperText Transfer Protocol???????????Э?飩??

WWW??Word Wide Web?????????????HTML??HTTP??URL??

RFC??Request for Comments??????????????飩??????????????????

## URL

URI??Uniform Resource Indentifier????????????????URL??Uniform Resource Locator?????????λ??????URN??Uniform Resource Name?????????????????? urn:isbn:0-486-27557-4 ??URI ???? URL ?? URN???? WEB ??? URL ??????У????????????????? URL??

URL?????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/4102b7d0-39b9-48d8-82ae-ac4addb7ebfb.jpg)

## ????????????

**??????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/9dbb5fc2-936b-4c6d-b3a7-9617aae45080.jpg)

**???????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c634b5ed-a14b-4302-b40e-3ee387dd3c8a.jpg)

# HTTP ????

?????????????????????????У????????????Ρ?

## GET????????

## POST?????????????

POST ???????????????????????????????????

GET ?? POST ???????????????????????? GET ?????????????????????? URL?У??? POST ??????洢????????岿???

```
GET /test/demo_form.asp?name1=value1&name2=value2 HTTP/1.1
```
```
POST /test/demo_form.asp HTTP/1.1
Host: w3schools.com
name1=value1&name2=value2
```

GET ????η??????? POST ?????????? GET ????????? URL ????????????й????????????? GET ???? ASCII ???????????????????????????????? POST ????????????

## HEAD????????????

?? GET ???????????????????????????岿???

?????????? URL ????Ч??????????????????????

## PUT????????

???????????????????κ????????????????????????????????? WEB ????????÷?????

## DELETE????????

?? PUT ???????????????????????????

## OPTIONS????????????

???????? URL ????????????

???? Allow: GET, POST, HEAD, OPTIONS ???????????

## RACE?????·??

???????????·?????????????

????????????? Max-Forwards ??????????????????????????????????? 1???????? 0 ?????????

TRACE ?????????????????????? XST ??????Cross-Site Tracing???????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/ca711108-e937-4d7d-99aa-61b325c61f1a.jpg)

## CONNECT??????????Э?????????

?????Э????? TCP ????

?????? SSL??Secure Sokets Layer????????????? TLS??Transport Layer Security??????????Э?????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/d8355d56-aa2b-4452-8001-8475cc095af1.jpg)

# HTTP ????

???????????????????е????????У???????????????????????????????????????

| ???? | ??? | ?????? |
| --- | --- | --- |
| 1XX | Informational??????????? | ???????????????? |
| 2XX | Success????????? | ??????????????? |
| 3XX | Redirection??????????? | ??????и??????????????? |
| 4XX | Client Error?????????????? | ????????????????? |
| 5XX | Server Error???????????????? | ????????????????? |

## 2XX ???

**200 OK**

**204 No Content**???????????????????????????????????????????岿?????????????????????????????????????????????????????á?

**206 Partial Content**

## 3XX ?????

**301 Moved Permanently**?????????????

**302 Found**????????????

**303 See Other**

?????? HTTP Э??涨 301??302 ????????????????? POST ??????? GET ???????????????????????? 301??302 ?? 303 ??????????? POST ??????? GET ??????

**304 Not Modified**???????????????????Щ?????????磺If-Match??If-ModifiedSince??If-None-Match??If-Range??If-Unmodified-Since???????????????????????????? 304 ????

**307 Temporary Redirect**???????????? 302 ?????????????? 307 ??????????????????????? POST ??????? GET ??????

## 4XX ????????

**400 Bad Request**?????????д?????????

**401 Unauthorized**??????????????????????????? HTTP ?????BASIC ?????DIGEST ????????????????????????й??????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/b1b4cf7d-c54a-4ff1-9741-cd2eea331123.jpg)

**403 Forbidden**????????????????????б?????????????????ɡ?

**404 Not Found**

## 5XX ??????????

**500 Internal Server Error**????????????????????????????

**503 Service Unavilable**????????????????????????????????????????????????????????????

# HTTP???

HTTP ??????????????????????????? 4 ????????????Σ?????????Ρ??????????Ρ?????????κ?????????Ρ??????????μ??京???????????????????????????

## ?????????

| ???????? | ??? |
| -- | -- |
| Cache-Control | ??????????? |
| Connection | ????????? ???????? |
| Date | ???????????????? |
| Pragma | ??????? |
| Trailer | ?????????????? |
| Transfer-Encoding | ??????????????????? |
| Upgrade | ?????????Э?? |
| Via | ????????????????? |
| Warning | ?????? |

## ??????????

| ???????? | ??? |
| -- | -- |
| Accept | ??????????????????? |
| Accept-Charset | ?????????? |
| Accept-Encoding | ???????????? |
| Accept-Language | ?????????????????? |
| Authorization | Web?????? |
| Expect | ????????????????? |
| From | ?????????????? |
| Host | ???????????????? |
| If-Match | ?????????ETag?? |
| If-Modified-Since | ?????????????? |
| If-None-Match | ??????????? If-Match ???? |
| If-Range | ???δ???????????? Byte ???Χ???? |
| If-Unmodified-Since | ????????????????If-Modified-Since???? |
| Max-Forwards | ??????????? |
| Proxy-Authorization | ??????????????????????? |
| Range | ????????Χ???? |
| Referer | ???????? URI ????????? |
| TE | ????????????? |
| User-Agent | HTTP ???????????? |

## ?????????

| ???????? | ??? |
| -- | -- |
| Accept-Ranges | ??????????Χ???? |
| Age | ?????????????????? |
| ETag | ??????????? |
| Location | ????????????????URI |
| Proxy-Authenticate | ?????????????????????? |
| Retry-After | ????η?????????????? |
| Server | HTTP????????????? |
| Vary | ???????????????????? |
| WWW-Authenticate | ??????????????????? |

## ?????????

| ???????? | ??? |
| -- | -- |
| Allow | ?????????HTTP???? |
| Content-Encoding | ???????????????? |
| Content-Language | ??????????????? |
| Content-Length | ?????????С????λ?? ???? |
| Content-Location | ???????????URI |
| Content-MD5 | ????????????? |
| Content-Range | ????????λ?÷?Χ |
| Content-Type | ??????????????? |
| Expires | ?????????????????? |
| Last-Modified | ?????????????????? |

# ???????

## Cookie

HTTP Э????????????????????? HTTP Э?龡?????????????????????????HTTP/1.1 ???? Cookie ?????????????

????????????????????? Set-Cookie ??Σ???????????????? Cookie ??????浽??????С????????????????????????ж??? Cookie ????????????а??? Cookie ??Σ??????????????????????????????Cookie ?????????????????????У???????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/ff17c103-750a-4bb8-9afa-576327023af9.png)

Set-Cookie ??????????????

| ???? | ??? |
| -- | -- |
| NAME=VALUE | ???? Cookie ?????????????????? |
| expires=DATE | Cookie ????Ч???????????????????????????????? |
| path=PATH | ??????????????????? Cookie ????????????????????????????????????? |
| domain=???? | ??? Cookie ??????????????????????????????? Cookie ??????????????? |
| Secure | ???? HTTPS ???????????? Cookie |
| HttpOnly | ?????????? Cookie ????? JavaScript ??????? |

**Session ?? Cookie ????**

Session ?????????????????????????Σ???? Session ???????Ψ??????Session ID??????????????????? Session ??????????????????????????? Set-Cookie ??Σ????????????? sid ?????????????????? Session ID?????????????? Cookie ????????????У?????????????????????? Session ID??HTTP ???? Session ?? Cookie ???????????????????????????????? Session ????????????Cookie ?????????

**????????? Cookie ?????**

????? URL ??д???????? URL ??????? sid=xxx ??

**??? Cookie ????????????????????д**

????????????? Cookie ?ж????????????????????????д??

## ????

????????淽?????????????????л??????????????????л??档

Cache-Control ????????????????

Cache-Control: no-cache ????????壬?????????????????????????????к??и???????????????????????????????????????????????????????????к??и???????????????????????????л??档

Expires ??ο????????????????????????????????????????? Cache-Control ????? max-age ???????????????? Expires??????????? max-age ??䶮

## ???????

?????????????????????????? HTML ????????????????? HTML ?????????????????????????????????? HTTP ??????????? TCP ?????????????????????????**???????** ??????????? TCP ?????????ж?? HTTP ????HTTP/1.1????????е??????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c73a0b78-5f46-4d2d-a009-dab2a999b5d8.jpg)

????????????? Connection ?????ν??й???HTTP/1.1 ???HTTP ????????????????????? TCP ??????????????????????????????????? Connection: close ??????HTTP/1.1?????????????????????????????????????? Keep-Alive??

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

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/6943e2af-5a70-4004-8bee-b33d60f39da3.jpg)

## ????

????Encoding???????????????????????????????У?gzip??compress??deflate??identity?????? identity ????????????????????

## ??鴫??

??鴫??Chunked Transfer Coding???????????????飬??????????????档

## ????????

???????????????ж???????????????????????????? boundary ??ζ???????????з???????????????????????Ρ?

???磬???????????????????·????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/decb0936-e83c-4a55-840a-fe8aa101ac61.png)

## ??Χ????

???????????ж???????????????????????????Χ???????????????????δ????????????????????????????????·????????????

???????????????? Range ??Σ?????????????Χ??????  Range : bytes = 5001-10000????????????????????? 206 Partial Content ????

## ????Э??

???????Э???????????????????????????????????????????????滹???????档

?漰?????????Σ?Accept??Accept-Charset??Accept-Encoding??Accept-Language??Content-Language??

## ????????

??????????????????????????????ж???????????????????????????????????

## ??????????

**????**

???????????????????????????????????????????????????????????????????? URL??

???????????????????桢?????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c07035c3-a9ba-4508-8e3c-d8ae4c6ee9ee.jpg)

**????**

????????????????????????????? HTTP ????????Э?????????????????? HTTP ???????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/81375888-6be1-476f-9521-42eea3e3154f.jpg)

**???**

??? SSL ???????Σ???????????????佨???????????????·??

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/64b95403-d976-421a-8b45-bac89c0b5185.jpg)

# HTTPs

HTTP ?????°????????

1. ?????????????????????????
2. ???????????????????п???????α???
3. ???????????????????????п??????????

HTTPs ????????Э?飬???? HTTP ??? SSL??Secure Socket Layer?????????? SSL ?? TCP ?????????? SSL??HTTPs ????????????????????????

## ????

??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????ù?????????м??????????????????????????????????

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

HTTPs ???? **??????????**????ù????????????????????????????????????????????????????У??????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/110b1a9b-87cd-45c3-a21d-824623715b33.jpg)

## ???

?????? **???** ???????????????????????й????????????????????????????????????????????????????????????????

????????????????CA??Certificate
Authority??????????????飬??????? CA ????????????

???? HTTPs ?????????????????鷢????????????????????е????????????????????????

??? OpenSSL ?????????????????????????????????????????????????????????????????顣??????????÷????????????????????????????????????????????????????????????

?????????????????а????????????????????????????????????飬???????????С?

## ??????

SSL ????????????????????