I am attempting to decrypt a number encrypted by another program that uses the BouncyCastle library for Java.
In Java, I can set the key like this: key = Hex.decode("5F3B603AFCE22359");
I am trying to figure out how to represent that same step in Ruby.
To get Integer — just str.hex. You may get byte array in several ways:
str.scan(/../).map(&:hex)
[str].pack('H*').unpack('C*')
[str].pack('H*').bytes.to_a
See other options for pack/unpack and examples (by codeweblog).
For a string str:
"".tap {|binary| str.scan(/../) {|hn| binary << hn.to_i(16).chr}}
Related
I need a Delphi reversible Hashed ID function that is quick.
Short, obfuscated and efficient IDs
No collisions (at least up to 32-bit unsigned integer at least)
Reversible
Fast
preferably something that has an input Key, so it can be randomised a bit...
otherwise, a '3' will always be 23zkJ5 on all my software modules.
works cross-platform
Something like Youtube's video identifier.
Encode(3); // => "23zkJ5"
Decode('23zkJ5'); // => 3
PHP seems to have quite a few of these; I can't find one for Delphi.
I look at this but not really what I wanted, plus I need something in Delphi.
Reversible hash function?
$generator->encode(6); // => "43Vht7"
$generator->decode('43Vht7'); // => 6
I need something like what PHP offers:
https://github.com/delight-im/PHP-IDs
I can't use MD5 as it's not reversible; using Lockbox encryption/decryption seems a bit over-kill? (if really no choice, which algorithm in Lockbox would be the best choice for this?)
Use AES and convert the cypher byte array to a hex string or to Base64.
for a code example see here
AES encrypt string in Delphi (10 Seattle) with DCrypt, decrypt with PHP/OpenSSL
I'm trying to generate an RSA keypair in ruby with:
OpenSSL::PKey::RSA.generate(aReallyLongBignum, 65537)
but I am getting the following error:
bignum too big to convert into long
However it works in python using RSA.construct. Is there any way for this to work in ruby? I've looked everywhere. Really lost here. I am not trying to only take a section of this number at a time, I need to be able to pass the whole number to RSA.generate
I was able to solve this using OpenSSL::BN and setting it after creating an instance of OpenSSL::Pkey::RSA
key = OpenSSL::PKey::RSA.new
key.e = OpenSSL::BN.new(65537)
key.n = OpenSSL::BN.new(aReallyLongBignum)
I have a string that is encrypted in c#.net which I have to decrypt in java using a key and a IV provided by the client. Used algorithm is AES.
I have tried few things. The key looks something like
key = "QWEEqweASDreefERTfdf45fefdWERfsdf34fedfdwn5=" //length 44 bytes
iv = "nkfghER24dfdfdf56YUIgH==" // lenght=24 bytes
When I use this with Cipher class with algorith AES/CBC/PKCS5Padding
passing the above key to Secretkeyspec class it says invalid key lenth 44 bytes
I am not able makeout whats wrong with the key. Tried all suggested solutions for few days nothing works. Can some one help please? Thank you.
Use java native for C# code.
First write C# code for decrypt the key.
and calling the code in java using native.
for reference
http://www.codeproject.com/Articles/378826/How-to-wrap-a-Csharp-library-for-use-in-Java
I would like to be able to take an arbitrary string, run it through a hashing function (like MD5), and then interpret the resulting digest in base-36.
I know there already exists a Digest library in Ruby, but as far as I can tell I can't get at the raw bytes of a digest; the to_s function is mapped to hexdigest, which is, of course, base-16.
Fixnum#to_s accepts a base as the argument. So does string#to_i. Because of this, you can convert from the base-16 string to an int, then to base 36 string:
i = hexstring.to_i(16)
base_36 = i.to_s(36)
You can access the raw digest bytes using Digest::Class#digest:
Digest::SHA1.digest("test")
# => "\xA9J\x8F\xE5\xCC\xB1\x9B\xA6\x1CL\bs\xD3\x91\xE9\x87\x98/\xBB\xD3"
Unfortunately from that point I'm not sure how to get it into base36 without first going via another number base like in Sammy Larbi's answer..
bytes = Digest::SHA1.digest("test")
Digest.hexencode(bytes).to_i(16).to_s(36)
Hopefully you can find a better way to go from raw bytes to base36.
I'm trying to read unsigned integers from a file (stored as consecutive byte) and convert them to Integers. I've tried this:
file = File.new(filename,"r")
num = file.read(2).unpack("S") #read an unsigned short
puts num #value will be less than expected
What am I doing wrong here?
You're not reading enough bytes. As you say in the comment to tadman's answer, you get 202 instead of 3405691582
Notice that the first 2 bytes of 0xCAFEBABE is 0xCA = 202
If you really want all 8 bytes in a single number, then you need to read more than the unsigned short
try
num = file.read(8).unpack("L_")
The underscore is assuming that the native long is going to be 8 bytes, which definitely is not guaranteed.
How about looking in The Pickaxe? (Ruby 1.9, p. 44)
File.open("testfile")
do |file|
file.each_byte {|ch| print "#{ch.chr}:#{ch} " }
end
each_byte iterates over a file byte by byte.
There are a couple of libraries that help with parsing binary data in Ruby, by letting you declare the data format in a simple high-level declarative DSL and then figure out all the packing, unpacking, bit-twiddling, shifting and endian-conversions by themselves.
I have never used one of these, but here's two examples. (There are more, but I don't know them):
BitStruct
BinData
Ok, I got it to work:
num = file.read(8).unpack("N")
Thanks for all of your help.
What format are the numbers stored in the file? Is it in hex? Your code looks correct to me.
When dealing with binary data you need to be sure you're opening the file in binary mode if you're on Windows. This goes for both reading and writing.
open(filename, "rb") do |file|
num = file.read(2).unpack("S")
puts num
end
There may also be issues with "endian" encoding depending on the source platform. For instance, PowerPC-based machines, which include old Mac systems, IBM Power servers, PS3 clusters, or Sun Sparc servers.
Can you post an example of how it's "less"? Usually there's an obvious pattern to the data.
For example, if you want 0x1234 but you get 0x3412 it's an endian problem.