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问题:
i need to do encryption and decryption in my rails app. Im trying to use ezcrypto, but whenever i do decryption i get this error.
OpenSSL::Cipher::CipherError in ProfilesController#show wrong final block length
What would need to be changed to stop this error. I tried using another implementation of openssl like this (methods to be called from my model)
def encrypt_attr(unencrypted) c = OpenSSL::Cipher.new("aes-256-cbc") c.encrypt c.key = Digest::SHA1.hexdigest('pass') e = c.update(unencrypted) e << c.final return e end def decrypt_attr(encrypted_attr) if encrypted_attr != "" c = OpenSSL::Cipher::Cipher.new("aes-256-cbc") c.decrypt c.key = Digest::SHA1.hexdigest('pass') d = c.update(encrypted_attr) d << c.final return d end end
It throws the exact same error on decryption. How should i do encryption and decryption and not get this openssl error.
回答1:
require 'openssl' require 'base64' class AesEncryptDecrypt KEY = "EncryptDecryptGurudathBN" ALGORITHM = 'AES-128-ECB' def self.encryption(msg) begin cipher = OpenSSL::Cipher.new(ALGORITHM) cipher.encrypt() cipher.key = KEY crypt = cipher.update(msg) + cipher.final() crypt_string = (Base64.encode64(crypt)) return crypt_string rescue Exception => exc puts ("Message for the encryption log file for message #{msg} = #{exc.message}") end end def self.decryption(msg) begin cipher = OpenSSL::Cipher.new(ALGORITHM) cipher.decrypt() cipher.key = KEY tempkey = Base64.decode64(msg) crypt = cipher.update(tempkey) crypt << cipher.final() return crypt rescue Exception => exc puts ("Message for the decryption log file for message #{msg} = #{exc.message}") end end end
Encryption
irb(main):007:0> AesEncryptDecrypt.encryption('gurudath') => "rUPKObydUJd9cY9agm3Glw==\n"
Decryption
irb(main):008:0> AesEncryptDecrypt.decryption('rUPKObydUJd9cY9agm3Glw==') => "gurudath"
回答2:
I know that the documentation is pretty sparse for Ruby's openssl package. However, if you would like to use cipher-block chaining, here is a brief snippet of code that outlines how to use the AES-256-CBC cipher:
require 'openssl' # your data raw = 'the data to be encrypted goes here' pwd = 'secret' salt = OpenSSL::Random.random_bytes(8) # prepare cipher for encryption e = OpenSSL::Cipher.new('AES-256-CBC') e.encrypt # next, generate a PKCS5-based string for your key + initialization vector key_iv = OpenSSL::PKCS5.pbkdf2_hmac_sha1(pwd, salt, 2000, e.key_len+e.iv_len) key = key_iv[0, e.key_len] iv = key_iv[e.key_len, e.iv_len] # now set the key and iv for the encrypting cipher e.key = key e.iv = iv # encrypt the data! encrypted = '' << e.update(raw) << e.final p encrypted # and now we prepare to decrypt d = OpenSSL::Cipher.new('AES-256-CBC') d.decrypt # now set the key and iv for the decrypting cipher # this assumes that the password, salt, and iv are known, # so then you would be able to generate the key as per above d.key = key d.iv = iv # decrypt the data! decrypted = '' << d.update(encrypted) << d.final p decrypted
This snippet is taken pretty much verbatim from the Japanese (original?) version of the Ruby standard library documentation on openssl. However, it does raise a few questions for you and your application design:
- You need to save the
salt value. This is used along with the password to generate the key (you do not need to save the key). - You need to save the
iv initialization vector. This is used to start the very first block in the cipher-block chain. There is no need to encrypt this value, but this value should be generated for each and every message you encrypt.
Good luck!
回答3:
I had the same problem as you and this is how I solved it:
- Your database column has to be: t.column :data, :binary, :limit => 10.megabyte.
- Use the exact code as this blog post.
- Choose AES-256-ECB
- Leave ivs as nil
- Choose a long key
