feature 2727: improve password security with the use of PasswordHash class.

This class performs salt and multiple iterations. Already used in Wordpress,
Drupal, phpBB and many other web applications.

$conf['pass_convert'] is replaced by $conf['password_hash'] + $conf['password_verify']


git-svn-id: http://piwigo.org/svn/trunk@18889 68402e56-0260-453c-a942-63ccdbb3a9ee

1 files changed, 253 insertions, 0 deletions

diff --git a/include/passwordhash.class.php b/include/passwordhash.class.php
new file mode 100644
index 000000000..12958c7f1
--- /dev/null
+++ b/include/passwordhash.class.php
@@ -0,0 +1,253 @@
+<?php
+#
+# Portable PHP password hashing framework.
+#
+# Version 0.3 / genuine.
+#
+# Written by Solar Designer <solar at openwall.com> in 2004-2006 and placed in
+# the public domain.  Revised in subsequent years, still public domain.
+#
+# There's absolutely no warranty.
+#
+# The homepage URL for this framework is:
+#
+#	http://www.openwall.com/phpass/
+#
+# Please be sure to update the Version line if you edit this file in any way.
+# It is suggested that you leave the main version number intact, but indicate
+# your project name (after the slash) and add your own revision information.
+#
+# Please do not change the "private" password hashing method implemented in
+# here, thereby making your hashes incompatible.  However, if you must, please
+# change the hash type identifier (the "$P$") to something different.
+#
+# Obviously, since this code is in the public domain, the above are not
+# requirements (there can be none), but merely suggestions.
+#
+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();
+		if (function_exists('getmypid'))
+			$this->random_state .= getmypid();
+	}
+
+	function get_random_bytes($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';
+
+		$id = substr($setting, 0, 3);
+		# We use "$P$", phpBB3 uses "$H$" for the same thing
+		if ($id != '$P$' && $id != '$H$')
+			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;
+	}
+}
+
+?>