盐是否包含在 phpass 哈希中，或者您是否需要对其输入加盐？

Question

phpass 是一种广泛使用的哈希“框架”。
在将纯密码提供给PasswordHash（v0.2）之前，像这样对普通密码进行加盐是个好习惯吗？：

$dynamicSalt   = $record['salt'];
$staticSalt    = 'i5ininsfj5lt4hbfduk54fjbhoxc80sdf';
$plainPassword = $_POST['password'];
$password      = $plainPassword . $dynamicSalt . $staticSalt;

$passwordHash = new PasswordHash(8, false);
$storedPassword = $passwordHash->HashPassword($password);  

---

供参考 phpsalt 类：

# Portable PHP password hashing framework.
#
# Version 0.2 / genuine.
#
# Written by Solar Designer <solar at openwall.com> in 2004-2006 and placed in
# the public domain.
#
#
#
class PasswordHash {
    var $itoa64;
    var $iteration_count_log2;
    var $portable_hashes;
    var $random_state;

    function PasswordHash($iteration_count_log2, $portable_hashes)
    {
        $this->itoa64 = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';

        if ($iteration_count_log2 < 4 || $iteration_count_log2 > 31)
            $iteration_count_log2 = 8;
        $this->iteration_count_log2 = $iteration_count_log2;

        $this->portable_hashes = $portable_hashes;

        $this->random_state = microtime() . getmypid();
    }

    function get_random_bytes($count)
    {
        $output = '';
        if (is_readable('/dev/urandom') &&
            ($fh = @fopen('/dev/urandom', 'rb'))) {
            $output = fread($fh, $count);
            fclose($fh);
        }

        if (strlen($output) < $count) {
            $output = '';
            for ($i = 0; $i < $count; $i += 16) {
                $this->random_state =
                    md5(microtime() . $this->random_state);
                $output .=
                    pack('H*', md5($this->random_state));
            }
            $output = substr($output, 0, $count);
        }

        return $output;
    }

    function encode64($input, $count)
    {
        $output = '';
        $i = 0;
        do {
            $value = ord($input[$i++]);
            $output .= $this->itoa64[$value & 0x3f];
            if ($i < $count)
                $value |= ord($input[$i]) << 8;
            $output .= $this->itoa64[($value >> 6) & 0x3f];
            if ($i++ >= $count)
                break;
            if ($i < $count)
                $value |= ord($input[$i]) << 16;
            $output .= $this->itoa64[($value >> 12) & 0x3f];
            if ($i++ >= $count)
                break;
            $output .= $this->itoa64[($value >> 18) & 0x3f];
        } while ($i < $count);

        return $output;
    }

    function gensalt_private($input)
    {
        $output = '$P$';
        $output .= $this->itoa64[min($this->iteration_count_log2 +
            ((PHP_VERSION >= '5') ? 5 : 3), 30)];
        $output .= $this->encode64($input, 6);

        return $output;
    }

    function crypt_private($password, $setting)
    {
        $output = '*0';
        if (substr($setting, 0, 2) == $output)
            $output = '*1';

        if (substr($setting, 0, 3) != '$P$')
            return $output;

        $count_log2 = strpos($this->itoa64, $setting[3]);
        if ($count_log2 < 7 || $count_log2 > 30)
            return $output;

        $count = 1 << $count_log2;

        $salt = substr($setting, 4, 8);
        if (strlen($salt) != 8)
            return $output;

        # We're kind of forced to use MD5 here since it's the only
        # cryptographic primitive available in all versions of PHP
        # currently in use.  To implement our own low-level crypto
        # in PHP would result in much worse performance and
        # consequently in lower iteration counts and hashes that are
        # quicker to crack (by non-PHP code).
        if (PHP_VERSION >= '5') {
            $hash = md5($salt . $password, TRUE);
            do {
                $hash = md5($hash . $password, TRUE);
            } while (--$count);
        } else {
            $hash = pack('H*', md5($salt . $password));
            do {
                $hash = pack('H*', md5($hash . $password));
            } while (--$count);
        }

        $output = substr($setting, 0, 12);
        $output .= $this->encode64($hash, 16);

        return $output;
    }

    function gensalt_extended($input)
    {
        $count_log2 = min($this->iteration_count_log2 + 8, 24);
        # This should be odd to not reveal weak DES keys, and the
        # maximum valid value is (2**24 - 1) which is odd anyway.
        $count = (1 << $count_log2) - 1;

        $output = '_';
        $output .= $this->itoa64[$count & 0x3f];
        $output .= $this->itoa64[($count >> 6) & 0x3f];
        $output .= $this->itoa64[($count >> 12) & 0x3f];
        $output .= $this->itoa64[($count >> 18) & 0x3f];

        $output .= $this->encode64($input, 3);

        return $output;
    }

    function gensalt_blowfish($input)
    {
        # This one needs to use a different order of characters and a
        # different encoding scheme from the one in encode64() above.
        # We care because the last character in our encoded string will
        # only represent 2 bits.  While two known implementations of
        # bcrypt will happily accept and correct a salt string which
        # has the 4 unused bits set to non-zero, we do not want to take
        # chances and we also do not want to waste an additional byte
        # of entropy.
        $itoa64 = './ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';

        $output = '$2a$';
        $output .= chr(ord('0') + $this->iteration_count_log2 / 10);
        $output .= chr(ord('0') + $this->iteration_count_log2 % 10);
        $output .= '$';

        $i = 0;
        do {
            $c1 = ord($input[$i++]);
            $output .= $itoa64[$c1 >> 2];
            $c1 = ($c1 & 0x03) << 4;
            if ($i >= 16) {
                $output .= $itoa64[$c1];
                break;
            }

            $c2 = ord($input[$i++]);
            $c1 |= $c2 >> 4;
            $output .= $itoa64[$c1];
            $c1 = ($c2 & 0x0f) << 2;

            $c2 = ord($input[$i++]);
            $c1 |= $c2 >> 6;
            $output .= $itoa64[$c1];
            $output .= $itoa64[$c2 & 0x3f];
        } while (1);

        return $output;
    }

    function HashPassword($password)
    {
        $random = '';

        if (CRYPT_BLOWFISH == 1 && !$this->portable_hashes) {
            $random = $this->get_random_bytes(16);
            $hash =
                crypt($password, $this->gensalt_blowfish($random));
            if (strlen($hash) == 60)
                return $hash;
        }

        if (CRYPT_EXT_DES == 1 && !$this->portable_hashes) {
            if (strlen($random) < 3)
                $random = $this->get_random_bytes(3);
            $hash =
                crypt($password, $this->gensalt_extended($random));
            if (strlen($hash) == 20)
                return $hash;
        }

        if (strlen($random) < 6)
            $random = $this->get_random_bytes(6);
        $hash =
            $this->crypt_private($password,
            $this->gensalt_private($random));
        if (strlen($hash) == 34)
            return $hash;

        # Returning '*' on error is safe here, but would _not_ be safe
        # in a crypt(3)-like function used _both_ for generating new
        # hashes and for validating passwords against existing hashes.
        return '*';
    }

    function CheckPassword($password, $stored_hash)
    {
        $hash = $this->crypt_private($password, $stored_hash);
        if ($hash[0] == '*')
            $hash = crypt($password, $stored_hash);

        return $hash == $stored_hash;
    }
}

Answer 1

这是原作者本人的回答：

除了实际的散列之外，phpass 还透明地生成随机盐
当新密码或密码被哈希处理时，它会对哈希值进行编码
类型、盐和密码拉伸迭代计数到
它返回的“哈希编码字符串”。当 phpass 验证一个
针对存储的哈希的密码或密码短语，它同样透明
提取并使用哈希类型标识符、盐和迭代
从“哈希编码字符串”中计数。因此，您无需费心
自己加盐和拉伸 - phpass 会处理这些
你。

底线：在“phpassing”之前对密码加盐是没有意义的。

Answer 2

您实际上并不需要两种盐（即静态盐是多余的；动态盐是充足的） - 盐的主要目的是防止彩虹表攻击（如果哈希值被恶意方获取），原因是动态盐的目的是进一步防止特殊情况的彩虹表生成同时破坏所有密码。

除此之外，无论库是否内置加盐，它都不会伤害盐（尽管除非您传递给它的信息不仅仅是要散列的项目，否则它实际上没有任何可用的东西）作为一种动态盐，所以它很可能不适合你（如果它还不是很明显的话）。