一个简单的代码应该是这样的:

function generatePassword($len){
    $az = range("a","z");
    $AZ = range("A","Z");
    $num = range(0,9);
    $password = array_merge($az,$AZ,$num);
    return substr(str_shuffle(implode("",$password)),0, $len);
}
// testing 
$generate = range(8,32);
foreach($generate as $g){
    print "Len:{$g} = " . generatePassword($g)."\n";
}

输出:

Len:8 = G5uFhPKS
Len:9 = aU9x2NjvI
Len:10 = lJE9kxy3oD
Len:11 = tVh2CmpMdHW
Len:12 = ToXYHCPb58Ar
Len:13 = KIFVoLg5NdDzX
Len:14 = eFUabML28tXhf0
Len:15 = iegDCQcIMaxH0ST
Len:16 = sRvDmPo5IkaMqNO0
Len:17 = T5rwVDs6XGAqSU9KN
Len:18 = QwROWAfh1lpoCSaX0H
Len:19 = HP0trD4B9SQeUkNuAGV
Len:20 = P9Fdwqmu782ARHDiKGZM
Len:21 = 3Gxia9LPmCZM68dwe4YOf
Len:22 = ywFjuA2GDg0Oz8LVnCI94M
Len:23 = 16MiEVUgqPRueahlyvJfBz5
Len:24 = sPt0H9NSu5KrJTYeMXbOFgi7
Len:25 = QFKGTypaZlsMRnHPgNbVfIwxm
Len:26 = hbyJXtV81AEuMazS4GdFTINBUg
Len:27 = H3AiD95S4Z8xwMrz2L71GqUunaW
Len:28 = m8W2geIiO7Phc3H5Kyr1XCAs09Dv
Len:29 = MusNfYgOWnbrI62twRBvj38XEcDdi
Len:30 = VgNeILaRT2wvb4J7hzCMSHsquUBtnA
Len:31 = nhUvCxgOS94dsYjzBtcaTou1WIArMQP
Len:32 = AFSVQqCijuPMp0cGJNdDtzYX78erKB9w

安全警告:rand()不是一个加密安全的伪随机数生成器。在其他地方寻找在PHP中生成加密安全的伪随机字符串的方法。

试试这个(使用strlen而不是count，因为count在字符串上总是1):

function randomPassword() {
    $alphabet = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
    $pass = array(); //remember to declare $pass as an array
    $alphaLength = strlen($alphabet) - 1; //put the length -1 in cache
    for ($i = 0; $i < 8; $i++) {
        $n = rand(0, $alphaLength);
        $pass[] = $alphabet[$n];
    }
    return implode($pass); //turn the array into a string
}

Demo

以下是我对选项列表的贡献。

该功能可以确保密码策略被满足。

  function password_generate($length=8, $min_lowercases=1, $min_uppercases=1, $min_numbers=1, $min_specials=0) {

    $lowercases = 'abcdefghijklmnopqrstuvwxyz';
    $uppercases = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $numbers = '0123456789';
    $specials = '!#%&/(){}[]+-';

    $absolutes = '';
    if ($min_lowercases && !is_bool($min_lowercases)) $absolutes .= substr(str_shuffle(str_repeat($lowercases, $min_lowercases)), 0, $min_lowercases);
    if ($min_uppercases && !is_bool($min_uppercases)) $absolutes .= substr(str_shuffle(str_repeat($uppercases, $min_uppercases)), 0, $min_uppercases);
    if ($min_numbers && !is_bool($min_numbers)) $absolutes .= substr(str_shuffle(str_repeat($numbers, $min_numbers)), 0, $min_numbers);
    if ($min_specials && !is_bool($min_specials)) $absolutes .= substr(str_shuffle(str_repeat($specials, $min_specials)), 0, $min_specials);

    $remaining = $length - strlen($absolutes);

    $characters = '';
    if ($min_lowercases !== false) $characters .= substr(str_shuffle(str_repeat($lowercases, $remaining)), 0, $remaining);
    if ($min_uppercases !== false) $characters .= substr(str_shuffle(str_repeat($uppercases, $remaining)), 0, $remaining);
    if ($min_numbers !== false) $characters .= substr(str_shuffle(str_repeat($numbers, $remaining)), 0, $remaining);
    if ($min_specials !== false) $characters .= substr(str_shuffle(str_repeat($specials, $remaining)), 0, $remaining);

    $password = str_shuffle($absolutes . substr($characters, 0, $remaining));

    return $password;
  }

参数$min_*可以有以下值:

1-999 =需要 True =可选 False =禁用

它可以像下面这样使用:

echo password_generate(8); // Outputs a random 8 characters long password

10个字符的密码，每组至少有2个字符:

echo password_generate(10, 2, 2, 2, 2);

只输出6个随机数

echo password_generate(6, false, false, true, false);

快速。简单，干净和一致的格式，如果这是你想要的

$pw = chr(mt_rand(97,122)).mt_rand(0,9).chr(mt_rand(97,122)).mt_rand(10,99).chr(mt_rand(97,122)).mt_rand(100,999);

这是我的密码助手

class PasswordHelper
{
    /**
    * generate a secured random password
    */
    public static function generatePassword(
        int $lowerCaseCount=8, 
        int $upperCaseCount=8, 
        int $numberCount=8, 
        int $specialCount=4
    ): string
    {
        $lowerCase  = 'abcdefghijklmnopqrstuvwxyz';
        $upperCase  = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
        $number     = '0123456789';
        $special    = '!@#$%^&*';

        $password = self::getRandom($lowerCase, $lowerCaseCount);
        $password .= self::getRandom($upperCase, $upperCaseCount);
        $password .= self::getRandom($number, $numberCount);
        $password .= self::getRandom($special, $specialCount);

        return str_shuffle($password);
    }

    /**
     * get a random string from a set of characters
     */
    public static function getRandom($set, $length): string
    {
        $rand = '';
        $setLength = strlen($set);

        for ($i = 0; $i < $length; $i++)
        {
            $rand .= $set[random_int(0, $setLength - 1)];
        }

        return $rand;
    }
}

用法:

PasswordHelper::generatePassword()或PasswordHelper::generatePassword(2,4,5,3)

这是基于本页的另一个答案，https://stackoverflow.com/a/21498316/525649

这个答案只生成十六进制字符，0-9,a-f。对于一些看起来不像hex的东西，试试这个:

str_shuffle(
  rtrim(
    base64_encode(bin2hex(openssl_random_pseudo_bytes(5))),
    '='
  ). 
  strtoupper(bin2hex(openssl_random_pseudo_bytes(7))).
  bin2hex(openssl_random_pseudo_bytes(13))
)

Base64_encode返回更广泛的字母数字字符 Rtrim有时会在结尾删除=

例子:

32 efvfgdg891be5e7293e54z1d23110m3zu3fmjb30z9a740ej0jz4 b280R72b48eOm77a25YCj093DE5d9549Gc73Jg8TdD9Z0Nj4b98760 051年b33654c0eg201cfw0e6na4b9614ze8d2fn49e12y0zy557aucb8 y67Q86ffd83G0z00M0Z152f7O2ADcY313gD7a774fc5FF069zdb5b7

对于为用户创建界面来说，这不是很可配置的，但对于某些目的来说，这是可以的。增加字符数，以弥补特殊字符的不足。