JSON Encoding issue Ruby 2.0.0 - ruby

Question

So I have a secure messaging script written up that uses JSON to send messages between a client and server. At one point I'm generating signed message digests using SHA1 and this is giving me some characters that I can't parse in JSON.generate to send my messages in JSON format around. Can anyone help me get around this error "in `encode': "\xAB" from ASCII-8BIT to UTF-8 (Encoding::UndefinedConversionError)" ?
The main problem I'm having is with this section of code:
#make new private / public rsa key-pair
rsakey = OpenSSL::PKey::RSA.new 2048
#hash the key using sha1
sha1 = OpenSSL::Digest::SHA1.new
digest = sha1.digest(rsakey.public_key.to_pem)
pubkey = JSON.generate({
key: rsakey.public_key.to_pem,
digest: digest
})
It's not allowing me to do a JSON.generate of digest. Does anyone know of a workaround or another way to encode my message digest?
My full code is below:
# encoding: utf-8
require 'socket'
require 'openssl'
require 'json'
port = 9090
s = TCPServer.open(port)
#make new private / public rsa key-pair
rsakey = OpenSSL::PKey::RSA.new 2048
#hash the key using sha1
sha1 = OpenSSL::Digest::SHA1.new
digest = sha1.digest(rsakey.public_key.to_pem)
pubkey = JSON.generate({
key: rsakey.public_key.to_pem,
digest: digest
})
loop {
client = s.accept
#get public key from alice
incoming = client.gets()
alice = JSON.parse(incoming)
alice_key = OpenSSL::PKey::RSA.new alice['key']
#send public key to alice
puts pubkey
client.puts pubkey
#get encrypted package from alice
json_full_package = client.gets()
full_package = JSON.parse(json_full_package)
#decrypt and print package
cipher = OpenSSL::Cipher.new("DES3")
cipher.decrypt
key = rsakey.private_decrypt(full_package['key'])
iv = rsakey.private_decrypt(full_package['iv'])
json_package = cipher.update(full_package['package'])
package = JSON.parse(json_package)
decrypted_digest = alice_key.public_decrypt(package['signed_digest'])
sha1 = OpenSSL::Digest::SHA1.new
digest = sha1.digest(package['data'])
throw 'failed digest' unless digest == decrypted_digest
puts package['data']
client.close
}
# encoding: utf-8
require 'socket'
require 'openssl'
require 'json'
host = 'lab1-15.eng.utah.edu'
port = 9090
s = TCPSocket.open(host, port)
pubkey_q = false
keyF = File.new("public_key.pem", 'w')
#generate alice's key pair
key = OpenSSL::PKey::RSA.new 2048
to_bob_public = JSON.generate({
key: key.public_key.to_pem
})
s.send(to_bob_public)
#get public key certificate from bob
while line = s.gets
puts line.chop
bob = JSON.parse(line)
end
bob_key = OpenSSL::PKey::RSA.new bob['key']
bob_digest = bob['digest']
#verify public key
sha1 = OpenSSL::Digest::SHA1.new
t_digest = sha1.digest(bob['key'])
throw "not verified" unless t_digest == bob_digest
data = File.read('document') #data is original message
#hash the document using sha1
sha1 = OpenSSL::Digest::SHA1.new
digest = sha1.digest(data)
#sign with private key
signed_digest = key.private_encrypt(digest)
#package this in json
package = JSON.generate({
signed_digest: signed_digest,
data: data
})
#make cipher for encryption
cipher = OpenSSL::Cipher.new("DES3")
cipher.encrypt
key = cipher.random_key
iv = cipher.random_iv
#encrypt data
encrypted = cipher.update(package)
#encrypt key and iv using bob's public key
encrypted_cipher_key = bob_key.public_encrypt(key)
encrypted_cipher_iv = bob_key.public_encrypt(iv)
full_package = JSON.generate({
key: encrypted_cipher_key,
iv: encrypted_cipher_iv,
package: encrypted
})
#send full_package to bob
s.send(full_package)
s.close

Answer 1

Use #hexdigest instead of #digest and you'll get hex. Right now you're attempting to encode binary into JSON (as that's what #digest returns) and that is causing the encode failure.