PHP sha1() Function

PHP String Reference : Calculate the SHA-1 hash of the string "Hello"

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 Values

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+

More Examples

Example

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>";
?>

Example

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

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

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

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