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TYPO3camp Munich - 11./12. September 2010

Secure password storing with saltedpasswords

Image: Carlos Porto / FreeDigitalPhotos.net

Inspiring people toshareSecure password storing with saltedpasswords

Secure password storing with TYPO3’ssystem extension “saltedpasswords”

Steffen Gebert <steffen@steffen-gebert.de>

TYPO3camp Munich- 11./12. September 2010

Translated slides, original title:“TYPO3-Passwörter sicher speichern mit saltedpasswords”

http://www.slideshare.net/StephenKing/passwrter-in-typo3-sicher-speichern-mit

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Introduction

Your Speaker

Steffen Gebert

Student, Freelancer

TYPO3 Core Team Member

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Introduction

Secure password storing with saltedpasswords

Ouch!TYPO3 Assicciation, 3rd Quarterly Report 2008

“What happened? An unauthorized person gained administrative access to the typo3.org website. As far as we can tell, an admin password was stolen and used to find out more passwords on typo3.org.”

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Introduction

Secure password storing with saltedpasswords

Saving passwordsDefinite no-go: Storing cleartext password

Instead

Saving of a hash (“check sum”)

Comparing with hash during login

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Introduction

Secure password storing with saltedpasswords

Fundamental knowledge: HashingOne-way function

identical input => identical outputmd5(‘joh316’) = ‘bacb98acf97e0b6112b1d1b650b84971’

opposite direction not argorithmically computable

Most frequently used algorithm: MD5

not considered secure since ages (clashes easy to compute, huge rainbow tables available)

Alternatives (SHA) only provide bigger result set=> just new rainbow tables needed

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Introduction

Secure password storing with saltedpasswords

Saving a salted passwordUser input: ‘joh316’

Generate salt, e.g. ‘7deb882cf’

Compute Hashmd5(‘7deb882cf’ . ‘joh316’) = ‘bacedc598493cb316044207d95f7ad54’

Save salt and hash

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Introduction

Secure password storing with saltedpasswords

Validating a salted passwordUser intut: ‘joh316’

Read used salt from database: ‘7deb882cf’

Compute hashmd5(‘7deb882cf’ . ‘joh316’) = ‘bacedc598493cb316044207d95f7ad54’

Compare with saved hash

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The Extension

Secure password storing with saltedpasswords

System extension saltedpasswordsFormerly t3sec_saltedpasswords by Marcus Krause, Member of the TYPO3 security team

Integration into TYPO3 Core version 4.3 after rework by Steffen Ritter

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The Extension

Secure password storing with saltedpasswords

Implemented salting methodsSalted MD5

Portable PHP password hashing framework

Available for various PHP applications (Drupal etc.)

Repetetive exectution of MD5 (slow)

Blowfish

Availability dependent of environment

Starting with PHP 5.3 implementation shipped with PHP

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The Extension

Secure password storing with saltedpasswords

Crux of the matter...Password must be available in plaintext

TYPO3 by default transfers MD5 hash

Plaintext transfer unsecure

Prerequisite (at least one)

SSL secured connection

System extension rsaauthEncrypts passwords prior transfer using RSA algorithm

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Installation & Configuration

Secure password storing with saltedpasswords

rsaauthPrerequisite

OpenSSL: PHP extension recommended, binary as fallback

JavaScript

Activation

Frontend$TYPO3_CONF_VARS[FE][loginSecurityLevel] = ‘rsa’

Backend$TYPO3_CONF_VARS[BE][loginSecurityLevel] = ‘rsa’;

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Installation & Configuration

Secure password storing with saltedpasswords

saltedpasswords with SSL encryptionFrontend

$TYPO3_CONF_VARS[FE][loginSecurityLevel] = ‘normal’

Backend

$TYPO3_CONF_VARS[BE][lockSSL] > 0

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Installation & Configuration

Secure password storing with saltedpasswords

Installation of saltedpasswordsChecks availability of rsaauth or lockSSL

Separate activation for Frontend and Backend

Choice of hashing method

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Compatibility

Secure password storing with saltedpasswords

Backwards compatibilityExisting passwords? (unsalted MD5)

immediate conversion not possible, as cleartext not available

only possible moment: during Login

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Compatibility

Secure password storing with saltedpasswords

ExtensionsFrontend

felogin compatibel

srfeuserregister_t3secsaltedpw

Alternative FE-User registrations?

Adjustions for own extensions might be needed

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Background knowledge

Secure password storing with saltedpasswords

Password formatsMD5 without saltbacb98acf97e0b6112b1d1b650b84971

MD5 with Saltstarts with $1$, 12 characters of salt$1$13NETowd$WFpl6npZF71YKkCCzGds2.

Blowfishstarts with $2a$, 22 characters of salt$2a$07$DZpLLz7wtIfhSSMwyEXjA.Nbh6rpDlqbgwVKa.IoDLyuLe5C7Jp8W

PHPASSstarts with $P$$P$Ccw7UIZ..SkvKBXDWnZlZ.qHcbktrB.

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Background knowledge

Secure password storing with saltedpasswords

Password formats: Pro & ContraPHPASS

Low system requirements (compatible with every PHP version)

Requires PHPASS implementation in application

MD5 / Blowfish

Format of Unix’ crypt(), compatible with system services (/etc/passwd)

The better choice (?)

Availability of algorithms system dependent

with PHP 5.3.2 also SHA-256/512 possible

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Background knowledge

Secure password storing with saltedpasswords

Usage of crypt()Password validation:crypt($user_input, $encrypted_password) == $encrypted_password

Saved hash (including salt):$1$13NETowd$WFpl6npZF71YKkCCzGds2.

Checking against saved password ‘joh316’

crypt(joh316, $1$13NETowd$WFpl6npZF71YKkCCzGds2.) = $1$13NETowd$WFpl6npZF71YKkCCzGds2.

crypt(password, $1$13NETowd$WFpl6npZF71YKkCCzGds2.) = $1$13NETowd$SeAArtswHd8jzc9SQvH691

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Web linksFree Rainbow Tableshttp://www.freerainbowtables.com

PHPASShttp://www.openwall.com/phpass/

PHP Manual: crypt()http://de2.php.net/manual/en/function.crypt.php

Wikipedia: crypt (Unix)http://en.wikipedia.org/wiki/Crypt_(Unix)#Library_Function

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