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PHP sha1() Function

❮ PHP String Reference

Example

Calculate the SHA-1 hash of the string "Hello":

<?php
$str = "Hello";
echo sha1($str);
?>
Run example »

Definition and Usage

The sha1() function calculates the SHA-1 hash of a string.

The sha1() function uses the US Secure Hash Algorithm 1.

From RFC 3174 - The US Secure Hash Algorithm 1: "SHA-1 produces a 160-bit output called a message digest. The message digest can then, for example, be input to a signature algorithm which generates or verifies the signature for the message. Signing the message digest rather than the message often improves the efficiency of the process because the message digest is usually much smaller in size than the message. The same hash algorithm must be used by the verifier of a digital signature as was used by the creator of the digital signature."

Tip: To calculate the SHA-1 hash of a file, use the sha1_file() function.


Syntax

sha1(string,raw)

Parameter Description
string Required. The string to be calculated
raw Optional. Specify hex or binary output format:
  • TRUE - Raw 20 character binary format
  • FALSE - Default. 40 character hex number


Technical Details

Return Value: Returns the calculated SHA-1 hash on success, or FALSE on failure
PHP Version: 4.3.0+
Changelog: The raw parameter became optional in PHP 5.0

More Examples

Example 1

Print the result of sha1():

<?php
$str = "Hello";
echo "The string: ".$str."<br>";
echo "TRUE - Raw 20 character binary format: ".sha1($str, TRUE)."<br>";
echo "FALSE - 40 character hex number: ".sha1($str)."<br>";
?>
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Example 2

Print the result of sha1() and then test it:

<?php
$str = "Hello";
echo sha1($str);

if (sha1($str) == "f7ff9e8b7bb2e09b70935a5d785e0cc5d9d0abf0")
  {
  echo "<br>Hello world!";
  exit;
  }
?>
Run example »

❮ PHP String Reference