# Decrypt challenge - perl encrypt with ruby decrypt

**URL:** <https://www.ruby-forum.com/t/decrypt-challenge-perl-encrypt-with-ruby-decrypt/106779>\
**Category:** Ruby\
**Created:** [June 14, 2007, 1:00am UTC](https://www.ruby-forum.com/t/decrypt-challenge-perl-encrypt-with-ruby-decrypt/106779 "2007-06-14T01:00:55Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [June 14, 2007, 1:00am UTC](https://www.ruby-forum.com/t/decrypt-challenge-perl-encrypt-with-ruby-decrypt/106779/1 "2007-06-14T01:00:55Z")

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Ok, so I am trying integrate with someone who is sending me a string  
that is triple des encrypted thru perl.  
I need to decrypt the string thru ruby.

I have had no luck decrypting, so decided I would try to encrypt in  
ruby as a sanity check…of course…I get different results.

HELP please 🙂

Here is the perl…then the ruby. Oh yes, and I am so glad there are  
no ; in ruby !

#========================= perl  
use Crypt::TripleDES;  
use URI::Escape;

my $key=“AKJSAYOQWOEIQWLEKJQLKNDDOIQQLWEL”;  
my $token=“1234567890”;

my $des = new Crypt::TripleDES;  
my $string= $des-\>encrypt3($token,$key);  
#print “string=$string\n\n”;  
$string=uri\_escape($string);  
print “string=$string\n\n”;

> > string=%0AP%91%06%0APq%7D%12%E83%DD%87%1C%7Cz

#========================= ruby  
require ‘openssl’  
require ‘cgi’  
require ‘uri’

key = “AKJSAYOQWOEIQWLEKJQLKNDDOIQQLWEL”  
token = “1234567890”

e = OpenSSL::Cipher::Cipher.new ‘DES-EDE3’  
e.encrypt key  
s = e.update token  
s \<\< e.final  
puts URI.escape(s)

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<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [June 14, 2007, 4:48pm UTC](https://www.ruby-forum.com/t/decrypt-challenge-perl-encrypt-with-ruby-decrypt/106779/2 "2007-06-14T16:48:53Z")

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The problem with your code is that you are using two different  
encryption  
algorithims.

You are implementing TripleDES in ECB mode in perl, and TripleDES in  
DES\_EDE3 mode in ruby. The latter being a block cipher that is  
expecting  
data to be fed to it in 8-bit blocks one at a time. To match them up  
you  
would have to use Crypt::DES\_EDE3 in perl, however that would mean your  
data  
would have to be supplied in 8-bit blocks which would be very  
inconvenient  
unless you were operating on binary data and supplying some kind of  
padding  
as needed. I would suggest finding out how to implement the ECB mode in  
ruby to match up with your perl code. I looked online at [ruby-lang.org](http://ruby-lang.org)  
but  
couldn’t find a list of ciphers that the .new method accepts. Good  
luck.

- Nathan

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<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [June 16, 2007, 3:31pm UTC](https://www.ruby-forum.com/t/decrypt-challenge-perl-encrypt-with-ruby-decrypt/106779/3 "2007-06-16T15:31:39Z")

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“Nathan T.-Hoover” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

> The problem with your code is that you are using two different encryption  
> algorithims.

Not quite; see [/docs/manmaster/man1/enc.html](http://www.openssl.org/docs/apps/enc.html) - in brief:

des-ede3-cbc Three key triple DES EDE in CBC mode  
des-ede3 Three key triple DES EDE in ECB mode  
des3 Alias for des-ede3-cbc  
des-ede3-cfb Three key triple DES EDE CFB mode  
des-ede3-ofb Three key triple DES EDE in OFB mode

So the cipher being used should in theory work, but it clearly doesn’t  
at all. I can’t find any decent information relating what  
Crypt:TripleDES does to an equivalent operation for openssl. (openssl  
in ruby or otherwise) I also don’t know that passing the key as the  
argument to encrypt is the appropriate behavior.

Openssl has both keys and initial values, which are derived from  
passphrases in a manner I don’t understand. Crypt::TripleDES uses  
only a key, and I don’t know how those two correspond to each other.