How to save cipher text to db if it has illegal characters? - mysql

Question

I am working on encrypting text strings that contain sensitive data. I need to save these encrypted strings to a MySQL db. The strings are cipher text, and all character (printable ASCII to control characters to null are equally likely).
These strings are not long (< 40 characters). I am using Ruby 2.1 (no Rails) along with the encryptor gem with a custom salt and iv to do the encryption. The encryptor gem is a wrapper for Ruby's openssl.
For many strings this works fine. However, I have run into a small number of these strings that, once encrypted, contain illegal or improperly quoted characters. As a result, when the string is saved I get an error.
What is the best way to handle the encrypted value so it can be reliably saved to MySQL?
Here is my encryption command:
require 'encryptor'
encrypted_value = Encryptor.encrypt(#sensitive_string,
:key => #config["encryption"]["key"],
:iv = #config["encryption"]["iv"],
:salt => #config["encryption"]["salt"])
Here is the encrypted value:
encrypted_value: /:Z`߉Nc??"v'??\??؟??????Oa?jR
and a screenshot since some of the characters did not copy correctly:
MySQL update statement:
query = "UPDATE db.table
SET `key` = mysql_real_escape_string(#{encrypted_value})"
With the value in the query it looks like:
query UPDATE db.table
SET `key` = mysql_real_escape_string(/:Z`߉Nc??"v'??\??؟??????Oa?jR)
I have tried both the MySQL Quote and mysql_real_escape_string functions. I get the same error with both and also wrapping the encrypted_value in double and single quotes.
Then I get this error:
wrong number of arguments (0 for 2) (ArgumentError)
What is the best way to tackle this? Any advice is appreciated.

Answer 1

You can perform base64 encoding of encrypted string, and store the encoded value in DB.
When retrieving the value, you can decode it back to binary and decrypt it.
require "base64"
enc = Base64.encode64('Send reinforcements')
# -> "U2VuZCByZWluZm9yY2VtZW50cw==\n"
plain = Base64.decode64(enc)
# -> "Send reinforcements"
http://ruby-doc.org/stdlib-2.2.0/libdoc/base64/rdoc/Base64.html