


PHP encryption function—sha1() function encryption
First of all, let’s introduce what sha1 is?
The full name of sha is: Secure Hash Algorithm (Secure Hash Algorithm) is mainly applicable to the Digital Signature Algorithm DSA defined in the Digital Signature Standard (Digital Signature Standard DSS). For messages less than 2^64 bits in length, SHA1 produces a 160-bit message digest. When a message is received, this message digest can be used to verify the integrity of the data. During the transmission process, the data is likely to change, and different message digests will be generated at this time. The sha1() function provided by PHP uses the SHA algorithm!
In the two articles introduced before, "PHP encryption function—crypt() function encryption" and "PHP encryption function—md5() function encryption", I believe it Everyone has a certain understanding of encryption. In this chapter, we will continue to introduce the sha1() function algorithm, which is similar to the MD5() function.
The syntax format of the sha1() function is as follows:
string sha1 ( string $str [, bool $raw_output = false ] )
Parameters | Description |
string | Required. Specifies the string to be calculated. |
raw | Optional. Specifies hexadecimal or binary output format: TRUE - raw 20-character binary format FALSE - default. 40-character hexadecimal number |
The function returns a 40-digit hexadecimal number. If the parameter raw_output is true, then a 20-digit binary number will be returned. , the default is raw_output is false.
Here we would like to emphasize that the 1 after
sha is the 1 in Arabic numerals (123456). It’s not the letter l (L). Many people will think of it as a letter, but it is an Arabic numeral. Everyone must pay attention here and don’t make a mistake!
The following is an example of the sha1() function. The specific code is as follows:
<?php header("Content-Type:text/html; charset=utf-8"); $str = "中文网"; echo "字符串:".$str."<br>"; echo "TRUE - 原始 20 字符二进制格式:".sha1($str, TRUE)."<br>"; echo "FALSE - 40 字符十六进制数:".sha1($str)."<br>"; ?>
The output result is:
The following example is the result of outputting sha1() and testing it:
<?php header("Content-Type:text/html; charset=utf-8"); $str = "中文网"; echo sha1($str); if (sha1($str) == "b1d5e6240057f21930892531def6597f135252ca ") { echo "<br>I love 中文网!"; exit; } ?>
The output result is:
The following example is a comparison of MD5 and SHA encryption operations. The specific code is as follows:
<?php header("Content-Type:text/html; charset=utf-8"); $str = "中文网"; echo "MD5的加密结果:".md5($str)."<br>"; echo "<br>"; echo "sha1的加密结果:".sha1($str)."<br>"; ?>
The output result is:
The main three data encryption functions in PHP, crypt(), md5() and sha1(), have been introduced. In the following article, we will introduce the PHP encryption library: two extension libraries of Mcrypt and Mhash!
【Related Recommendations】
1. Relevant topic recommendations: "PHP Encryption Function"
2. PHP encryption function—crypt() function encryption usage example
3.PHP encryption function—md5() function encryption usage example
4 .PHP encryption technology video tutorial
The above is the detailed content of PHP encryption function—Instance usage of sha1() function encryption. For more information, please follow other related articles on the PHP Chinese website!

Absolute session timeout starts at the time of session creation, while an idle session timeout starts at the time of user's no operation. Absolute session timeout is suitable for scenarios where strict control of the session life cycle is required, such as financial applications; idle session timeout is suitable for applications that want users to keep their session active for a long time, such as social media.

The server session failure can be solved through the following steps: 1. Check the server configuration to ensure that the session is set correctly. 2. Verify client cookies, confirm that the browser supports it and send it correctly. 3. Check session storage services, such as Redis, to ensure that they are running normally. 4. Review the application code to ensure the correct session logic. Through these steps, conversation problems can be effectively diagnosed and repaired and user experience can be improved.

session_start()iscrucialinPHPformanagingusersessions.1)Itinitiatesanewsessionifnoneexists,2)resumesanexistingsession,and3)setsasessioncookieforcontinuityacrossrequests,enablingapplicationslikeuserauthenticationandpersonalizedcontent.

Setting the httponly flag is crucial for session cookies because it can effectively prevent XSS attacks and protect user session information. Specifically, 1) the httponly flag prevents JavaScript from accessing cookies, 2) the flag can be set through setcookies and make_response in PHP and Flask, 3) Although it cannot be prevented from all attacks, it should be part of the overall security policy.

PHPsessionssolvetheproblemofmaintainingstateacrossmultipleHTTPrequestsbystoringdataontheserverandassociatingitwithauniquesessionID.1)Theystoredataserver-side,typicallyinfilesordatabases,anduseasessionIDstoredinacookietoretrievedata.2)Sessionsenhances

PHPsessionscanstorestrings,numbers,arrays,andobjects.1.Strings:textdatalikeusernames.2.Numbers:integersorfloatsforcounters.3.Arrays:listslikeshoppingcarts.4.Objects:complexstructuresthatareserialized.

TostartaPHPsession,usesession_start()atthescript'sbeginning.1)Placeitbeforeanyoutputtosetthesessioncookie.2)Usesessionsforuserdatalikeloginstatusorshoppingcarts.3)RegeneratesessionIDstopreventfixationattacks.4)Considerusingadatabaseforsessionstoragei

Session regeneration refers to generating a new session ID and invalidating the old ID when the user performs sensitive operations in case of session fixed attacks. The implementation steps include: 1. Detect sensitive operations, 2. Generate new session ID, 3. Destroy old session ID, 4. Update user-side session information.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Linux new version
SublimeText3 Linux latest version

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
