Basics of HTTP - Nafis Fuad

1. Basics of HTTP
All you need to know(for now)
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2. A little bit of History first
• Problems before HTTP
• What is HTTP?
• How HTTP solved the problem?
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3. TCP/IP model
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https://what-when-how.com/data-communications-and-networking/network-models-data-
communications-and-networking/

4. Pillars of HTTP
• Path
• Methods
• Status Codes
• Headers
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5. Client-Server workflow
• Open a TCP connection
• Send HTTP request
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https://developer.mozilla.org/en-US/docs/Web/HTTP/Overview

6. Client-Server workflow(cont.)
• Read the response sent by the server
• Close or reuse the connection for further requests
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https://developer.mozilla.org/en-US/docs/Web/HTTP/Overview

7. HTTP workflow
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https://rmohan.com/?p=1488
Bad practice

8. HTTP connection management
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https://developer.mozilla.org/en-US/docs/Web/HTTP/Connection_management_in_HTTP_1.x

9. HTTP status codes
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10. HTTP methods
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https://www.quora.com/What-are-HTTP-methods-and-what-are-they-used-for

11. HTTP headers
• End-to-end headers
• These headers must be transmitted to the final
recipient of the message
• Hop-by-hop headers
• These headers are meaningful only for a single
transport-level connection, and must not be
retransmitted by proxies or cached.
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12. A few headers
Authentication
• WWW-Authenticate
• Authorization
• Proxy-Authenticate
• Proxy-Authorization
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13. HTTP response caching
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https://developer.mozilla.org/en-US/docs/Web/HTTP/Caching

14. A few headers(cont.)
Caching
• Age
• Cache-Control(Pragma for HTTP/1.0)
• Clear-Site-Data
• Expires
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15. A few headers(cont.)
Conditionals
• ETag
• Last-Modified
• If-Match
• If-Modified-Since
• Vary
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16. A few headers(cont.)
Connection management
• Connection
• Keep-Alive(args = {timeout, max})
Content Negotiation
• Accept: <MIME_type>/<MIME_subtype>
• Accept-{Charset, Encoding, Language}
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17. A few headers(cont.)
Cookies
• Cookie: <cookie-list>
• Set-Cookie: <cookie-name>=<cookie-value>
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https://medium.com/@piraveenaparalogarajah/sessions-and-cookies-
2c0919552f29

18. A few headers(cont.)
CORS
• Access-Control-Allow-Origin
• Access-Control-Allow-Credentials
• Access-Control-Allow-Methods
• Access-Control-Allow-Headers
Security
• Content-Security-Policy
• Expect-CT
• Strict-Transport-Security (HSTS)
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19. A few headers(cont.)
Others
• Do Not Track
• Download
• Ranged Request
• Redirects, etc
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20. Why HTTP
• HTTP is simple
• HTTP is extensible
• HTTP is stateless, but not sessionless
• HTTP is connection efficient
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21. Finally HTTPS
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https://www.copahost.com/blog/http-vs-https/

22. Thank You
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