Several methods of generating random passwords in PHP

The use of PHP to develop applications, especially web programs, often need to generate random passwords , such as user registration to generate random passwords, user reset password also need to generate a random password. Random password is a string of fixed length, here I collected several methods to generate random strings, for your reference.

Method One :

1. Generate a random integer, such as 35, in 33–126

2, convert 35 to the corresponding ASCII code characters, such as 35 corresponding #

3, repeat the above 1, 2 steps n times, connected to the N-bit password

The algorithm mainly uses two functions, the Mt_rand (int $min, int $max) function is used to generate random integers, where $min – $max for the range of ASCII code, which takes 33-126, can adjust the range according to the need, such as the ASCII code table 97– 122-bit corresponding a–z letter, the specific reference to the ASCII table; the Chr (int $ascii) function is used to convert the corresponding integer $ascii to the corresponding character.

function Create_password ($PW _length = 8) { $randpwd = '; for ($i = 0; $i < $PW _length; $i + +) { $randpwd. = Chr (Mt_rand (33, 126)); } return $randpwd; } Call the function, passing the length parameter $pw_length = 6 Echo Create_password (6);

Method Two :

1, preset a string $chars, including A–z,a–z,0–9, as well as some special characters

2. Randomly take a character in a $chars string

3, repeat the second step n times, can get a length of n password

function Generate_password ($length = 8) { Password character set, you can add any character you need $chars = ' abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&* ()-_ []{}<>~ ' +=,.;:/?| '; $password = '; for ($i = 0; $i < $length; $i + +) { Here are two ways to get a character The first is to use SUBSTR to intercept any one character in the $chars; The second is to take any element $chars the character array $password. = substr ($chars, Mt_rand (0, strlen ($chars)-1), 1); $password. = $chars [Mt_rand (0, strlen ($chars)-1)]; } return $password; }

Method Three :

1, preset a character array $chars, including a–z,a–z,0–9, as well as some special characters

2. Randomly select $length elements from the array $chars by Array_rand ()