# Ruby encryption

**URL:** <https://www.ruby-forum.com/t/ruby-encryption/155648>\
**Category:** Ruby\
**Created:** [December 15, 2008, 9:49am UTC](https://www.ruby-forum.com/t/ruby-encryption/155648 "2008-12-15T09:49:39Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![archanab25](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ba9def/32.png) [@archanab25](https://www.ruby-forum.com/u/archanab25)\
**Post date:** [December 15, 2008, 9:49am UTC](https://www.ruby-forum.com/t/ruby-encryption/155648/1 "2008-12-15T09:49:39Z")

</div>

I want to translate exactly the below php code into ruby for encryption.  
echo up\_getEncrypted(‘mypassword’, 1);  
function up\_getEncrypted($password, $user\_id)  
{  
srand();

```
    $td = mcrypt_module_open('rijndael-128', '', 'cbc', '');
    $keylen = mcrypt_enc_get_key_size($td);
    $key = substr($password, 0, $keylen);
    $key = str_pad($key, $keylen);
    $iv_size = mcrypt_enc_get_iv_size($td);
    $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
    if (mcrypt_generic_init($td, $key, $iv) != -1)
    {
        $pad = 16 - strlen($user_id);
        $mypadded = $user_id . str_repeat(chr($pad), $pad);
        $c_t = mcrypt_generic($td, pack('H*',

```

md5($user\_id)).$user\_id);  
mcrypt\_generic\_deinit($td);  
$result = base64\_encode($iv.$c\_t);  
return $result;  
}  
else  
{  
return “”;  
}  
}

result = up\_getEncrypted(‘mypassword’, 1)  
puts result  
def up\_getEncrypted(password, user\_id)  
c = OpenSSL::Cipher::Cipher.new(“aes-128-cbc”)  
c.encrypt  
c.key = key =  
Digest::SHA1.hexdigest(password).unpack(‘a2’\*32).map{|x|  
x.hex}.pack(‘c’\*32)  
c.iv = c.random\_iv  
e = c.update(user\_id.to\_s)  
e \<\< c.final  
return e  
end

Output of php encryption code and output of rails encryption code are  
not same.Please any one can modify my rails code such that i will get  
results from both php and rails.

---

<div class="post-metadata">

**Author:** ![archanab25](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ba9def/32.png) [@archanab25](https://www.ruby-forum.com/u/archanab25)\
**Post date:** [December 15, 2008, 1:05pm UTC](https://www.ruby-forum.com/t/ruby-encryption/155648/2 "2008-12-15T13:05:21Z")

</div>

Archana T. wrote:

> Output of php encryption code and output of rails encryption code are  
> not same.

Presumably they’re not doing the same things. In particular, I see that  
you’re doing an SHA1 on the key in the Ruby code, but not the php.

Try inserting debugging to look at intermediate values, e.g.

puts “key = #{key.inspect}”

(and whatever the PHP equivalent is in the PHP code)

Also, I have no idea what you’re doing with all that SHA1 unpacking,  
mapping and packing. It seems that the final result is the same as a  
simple Digest::SHA1.digest, but with 12 extra zeros on the end.

irb(main):001:0\> password = “foobar”  
=\> “foobar”  
irb(main):002:0\> require ‘digest/sha1’  
=\> true  
irb(main):003:0\>  
Digest::SHA1.hexdigest(password).unpack(‘a2’\*32).map{|x|  
x.hex}.pack(‘c’\*32)  
=\>  
“\210C\327\371$\026!\035\351\353\271c\377L\342\201%\223(x\000\000\000\000\000\000\000\000\000\000\000\000”  
irb(main):004:0\> Digest::SHA1.digest(password)  
=\> “\210C\327\371$\026!\035\351\353\271c\377L\342\201%\223(x”

---

<div class="post-metadata">

**Author:** ![archanab25](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ba9def/32.png) [@archanab25](https://www.ruby-forum.com/u/archanab25)\
**Post date:** [December 16, 2008, 12:53pm UTC](https://www.ruby-forum.com/t/ruby-encryption/155648/3 "2008-12-16T12:53:10Z")

</div>

Brian C. wrote:

> Archana T. wrote:
> 
> > Output of php encryption code and output of rails encryption code are  
> > not same.
> 
> Presumably they’re not doing the same things. In particular, I see that  
> you’re doing an SHA1 on the key in the Ruby code, but not the php.

Hi Candler,

Thanks for your reply. Basically, I don’t know how to use encryption  
algorithms in ruby. I couldn’t even find what equivalent methods are in  
ruby for the above php code which is actually being used to send info to  
a third party app.

Can any please suggest me a method to achieve the same encryption &  
decryption algorithms in ruby for those written in php above?

Thanks again!

-Archana

> Try inserting debugging to look at intermediate values, e.g.
> 
> puts “key = #{key.inspect}”
> 
> (and whatever the PHP equivalent is in the PHP code)
> 
> Also, I have no idea what you’re doing with all that SHA1 unpacking,  
> mapping and packing. It seems that the final result is the same as a  
> simple Digest::SHA1.digest, but with 12 extra zeros on the end.
> 
> irb(main):001:0\> password = “foobar”  
> =\> “foobar”  
> irb(main):002:0\> require ‘digest/sha1’  
> =\> true  
> irb(main):003:0\>  
> Digest::SHA1.hexdigest(password).unpack(‘a2’\*32).map{|x|  
> x.hex}.pack(‘c’\*32)  
> =\>  
> “\210C\327\371$\026!\035\351\353\271c\377L\342\201%\223(x\000\000\000\000\000\000\000\000\000\000\000\000”  
> irb(main):004:0\> Digest::SHA1.digest(password)  
> =\> “\210C\327\371$\026!\035\351\353\271c\377L\342\201%\223(x”

---

<div class="post-metadata">

**Author:** ![archanab25](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/ba9def/32.png) [@archanab25](https://www.ruby-forum.com/u/archanab25)\
**Post date:** [December 16, 2008, 4:27pm UTC](https://www.ruby-forum.com/t/ruby-encryption/155648/4 "2008-12-16T16:27:33Z")

</div>

Archana T. wrote:

> Basically, I don’t know how to use encryption  
> algorithms in ruby. I couldn’t even find what equivalent methods are in  
> ruby for the above php code which is actually being used to send info to  
> a third party app.
> 
> Can any please suggest me a method to achieve the same encryption &  
> decryption algorithms in ruby for those written in php above?

You seem to have most of the basics there. Insert debugging to find out  
where your code diverges from the PHP. I don’t use PHP, and don’t have  
it installed, so I can’t do this for you.

Only you can explain why you included SHA1 hashing in the Ruby version,  
where the original PHP appears not to.

My guess is that you’re using the wrong encryption key.