<div dir="ltr"><br><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Feb 17, 2014 at 7:25 PM, Ron Teitelbaum <span dir="ltr"><<a href="mailto:ron@usmedrec.com" target="_blank" class="vt-p">ron@usmedrec.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div lang="EN-US" link="blue" vlink="purple"><div><p class="MsoNormal">
<span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Hi Mariano,<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Before I give you an answer, you should never ever ever not even for any reason, ever, did I mention ever, store a user’s password. You can hash a password, which means you store the hash value of the password. You can make it more secure by salting the hash or embedding your own key to the hash, or doing a number of other things. But you should always store an encrypted hash and never a recoverable password. The way this works is that your user knows the password and can generate a hash at any time that you can compare. You store the hash of the password to compare. The reason for this should be obvious. You don’t want anyone to have access to that password. Not even programmers. Your program doesn’t need it either since the user can generate that hash for you at any time. It really is all you ever need to store.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u> </span></p></div></div></blockquote><div><br></div><div>Hi Ron,</div><div><br></div><div>Thanks for the advice. I have been warned about this in the past so I am NOT using this for storing passwords. Instead, there are instVars from certain objects that are "password protected" because they represent some sensible data. So these fields need to be encrypted/decrypted. The user needs to supply a password for editing/viewing them. These fields were encrypted/decrypted with Blowfish. And the key for the blowfish is the " SecureHashAlgorithm new hashMessage: aString" of the password used to protect them...</div>
<div><br></div><div>Anyway.... I do need encrypt/decrypt and it should be fast. I have just tried ARC4 and seems to be fast. I have a few questions:</div><div><br></div><div>- If I make the ARC4 key larger is it likely to be safer? </div>
<div>- How does ARC4 compare to blowfish from security point of view? Is blowfish much more secure or not that much?</div><div> </div><div>Thanks in advance!</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div lang="EN-US" link="blue" vlink="purple"><div><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u></span></p><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">If you are looking for a simple cypher for something other than a password how about ARC4 from <a href="http://www.squeaksrouce.com/Cryptography" target="_blank" class="vt-p">www.squeaksrouce.com/Cryptography</a> <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">|key cText pText|<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">key := SecureRandom picker nextBits: 254. <u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">cText := (ARC4 new key: key) encrypt: 'This is a very secure but meaningless string' asByteArray.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">pText := (ARC4 new key: key) decrypt: cText.<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">^pText asString<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"> 'This is a very secure but meaningless string'<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">It’s pretty simple. To get the plainText back all you need is the key. <u></u><u></u></span></p><p class="MsoNormal">
<span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">All the best,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Ron Teitelbaum<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u> <u></u></span></p><div style="border-style:none none none solid;border-left-color:blue;border-left-width:1.5pt;padding:0in 0in 0in 4pt">
<div><div style="border-style:solid none none;border-top-color:rgb(181,196,223);border-top-width:1pt;padding:3pt 0in 0in"><p class="MsoNormal"><b><span style="font-size:10pt;font-family:Tahoma,sans-serif">From:</span></b><span style="font-size:10pt;font-family:Tahoma,sans-serif"> Pharo-dev [mailto:<a href="mailto:pharo-dev-bounces@lists.pharo.org" target="_blank" class="vt-p">pharo-dev-bounces@lists.pharo.org</a>] <b>On Behalf Of </b>Mariano Martinez Peck<br>
<b>Sent:</b> Monday, February 17, 2014 4:17 PM<br><b>To:</b> Pharo Development List; <a href="mailto:glass@lists.gemtalksystems.com" target="_blank" class="vt-p">glass@lists.gemtalksystems.com</a>; The general-purpose Squeak developers list<br>
<b>Subject:</b> [Pharo-dev] FFI blowfish for encrypting / decrypting [WAS] Re: How to encrypt a password?<u></u><u></u></span></p></div></div><div><div class="h5"><p class="MsoNormal"><u></u> <u></u></p><div><div><p class="MsoNormal" style="margin-bottom:12pt">
<u></u> <u></u></p><div><p class="MsoNormal">On Thu, Nov 21, 2013 at 3:53 PM, Paul DeBruicker <<a href="mailto:pdebruic@gmail.com" target="_blank" class="vt-p">pdebruic@gmail.com</a>> wrote:<u></u><u></u></p><p class="MsoNormal">
Mariano Martinez Peck wrote<u></u><u></u></p><div><p class="MsoNormal">> Hi Paul, and just to be sure I understand...none of them could work as a<br>> two-way encryption, right?<br>> The only one is your Pharo's version of Blowfish but that only works with<br>
> 8<br>> chars long. Is it like this? Or is there any other two-way encryption?<br>><br>> Thanks!<br>><u></u><u></u></p></div><p class="MsoNormal" style="margin-bottom:12pt">> --<br>> Mariano<br>> <a href="http://marianopeck.wordpress.com" target="_blank" class="vt-p">http://marianopeck.wordpress.com</a><br>
<br><br>Yes that's right. The PasswordHashingFFI stuff is all one way encryption.<br>Blowfish is two way, and the current implementation only works for 8 byte<br>chunks. I stopped working on it when the Smalltalk bcrypt implementation I<br>
wanted proved to be 5000x times slower than the FFI version. Someone needs<br>to add the CBC part to Blowfish to encrypt longer strings. I do not know of<br>another in image two way encryption scheme, but there may be something in<br>
the Cryptography repo. I'm not sure.<br><br><u></u><u></u></p><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Hi Paul,<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p>
</div><div><p class="MsoNormal">Sorry for the cross posting. <u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">I was using the Smalltalk version of the Blowfish you did to encrypt and decrypt things. But now I realize it is very very slow for the usage I need. You seem to have faced the same problem. <u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">I am encrypting pieces of 8 characters long. But I wonder if the <b>decryption</b> is available as well in FFI version? I see #ffiCrypt:with: but nothing to decrypt...<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Thanks in advance <u></u><u></u></p></div></div><p class="MsoNormal"><br clear="all"><u></u><u></u></p><div><p class="MsoNormal"><u></u> <u></u></p>
</div><p class="MsoNormal">-- <br>Mariano<br><a href="http://marianopeck.wordpress.com" target="_blank" class="vt-p">http://marianopeck.wordpress.com</a><u></u><u></u></p></div></div></div></div></div></div></div></blockquote>
</div><br><br clear="all"><div><br></div>-- <br>Mariano<br><a href="http://marianopeck.wordpress.com" target="_blank" class="vt-p">http://marianopeck.wordpress.com</a><br>
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