file encryption/decryption needed

[Venkat Bagam]

Hi Folks,

Yesterday, in my ruby application, I was needed to
encrypt/decrypt a file. I searched for a 2-way encryption technique and
ended up with ezcrypto gem. I thought to give it a test. I was able to
encrypt the content and store it in a file but getting errors while
decrypting the file content and writing to console. I couldn't figure
out the problem. here is my code

require 'rubygems'
require 'ezcrypto'

@key = EzCrypto::Key.with_password "private documents","salted hash"
file1 = File.new("crypto.txt", "w")
@encrypted = @key.encrypt "These are private documents"
file1.puts @encrypted
file1.close
puts "Here is the content"
file2 = File.read("crypto.txt")
puts @key.decrypt file2

Can anyone figure out the problem? or suggest me a different crypting
technique other than ezcrypto or suggest me a ruby app implementing such
a requirement..
or a code snippet

any help appreciated

thanks&regards,
Venkat

Attachments:
http://www.ruby-forum.com/attachment/304/test.rb

 

[Morton Goldberg]

Hi Folks,

Yesterday, in my ruby application, I was needed to
encrypt/decrypt a file. I searched for a 2-way encryption technique
and
ended up with ezcrypto gem. I thought to give it a test. I was able to
encrypt the content and store it in a file but getting errors while
decrypting the file content and writing to console. I couldn't figure
out the problem. here is my code

require 'rubygems'
require 'ezcrypto'

@key = EzCrypto::Key.with_password "private documents","salted hash"
file1 = File.new("crypto.txt", "w")
@encrypted = @key.encrypt "These are private documents"
file1.puts @encrypted
file1.close
puts "Here is the content"
file2 = File.read("crypto.txt")
puts @key.decrypt file2

I think puts is adding a "\n" at the end of the file you write out as
crypto.txt. So from the point of view of @key.decrypt the file has
been corrupted. Try the following:

<untested>
@key = EzCrypto::Key.with_password "private documents","salted hash"
File.open("crypto.txt", "w") do |file1|
@encrypted = @key.encrypt "These are private documents"
file1.write @encrypted
end
puts "Here is the content"
file2 = File.read("crypto.txt")
puts @key.decrypt file2
</untested>

I couldn't test the above code because I don't have the ezcrypt gem.

Regards, Morton

 

[Axel Etzold]

-------- Original-Nachricht --------

Datum: Tue, 18 Sep 2007 15:15:28 +0900
Von: Venkat Bagam <[email protected]>
An: (e-mail address removed)
Betreff: file encryption/decryption needed

Hi Folks,

Yesterday, in my ruby application, I was needed to
encrypt/decrypt a file. I searched for a 2-way encryption technique and
ended up with ezcrypto gem. I thought to give it a test. I was able to
encrypt the content and store it in a file but getting errors while
decrypting the file content and writing to console. I couldn't figure
out the problem. here is my code

require 'rubygems'
require 'ezcrypto'

@key = EzCrypto::Key.with_password "private documents","salted hash"
file1 = File.new("crypto.txt", "w")
@encrypted = @key.encrypt "These are private documents"
file1.puts @encrypted
file1.close
puts "Here is the content"
file2 = File.read("crypto.txt")
puts @key.decrypt file2

Can anyone figure out the problem? or suggest me a different crypting
technique other than ezcrypto or suggest me a ruby app implementing such
a requirement..
or a code snippet

any help appreciated

thanks&regards,
Venkat

Attachments:
http://www.ruby-forum.com/attachment/304/test.rb

Dear Venkat,

I tried your code and I got a problem about "wrong final block length (OpenSSL::Cipher)", which comes from the fact that you are writing
an additional newline at the end of the encrypted text when
you store it in a file.
So read in the encrypted text from that file, chop off the last newline, and decrypt:

require 'rubygems'
require 'ezcrypto'
@key = EzCrypto::Key.with_password "mighty mouse","salted hash"
file1 = File.new("crypto.txt", "w")
@encrypted = @key.encrypt "This is my super-secret message"
file1.puts @encrypted
file1.close
file2=File.read("crypto.txt").chop
puts @key.decrypt(file2) # => "This is my super-secret message"


Best regards,

Axel

 

[Venkat Bagam]

Dear Axel,

Thanks. It works great. I have been trying for two days but
unable to
figure out that. I need to be little bit careful with files.

once again, thanks to you and the forum....

regards,
venkat