71 lines
1.9 KiB
Ruby
71 lines
1.9 KiB
Ruby
require 'openssl'
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module ActiveSupport
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# MessageEncryptor is a simple way to encrypt values which get stored somewhere
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# you don't trust.
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#
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# The cipher text and initialization vector are base64 encoded and returned to you.
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#
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# This can be used in situations similar to the MessageVerifier, but where you don't
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# want users to be able to determine the value of the payload.
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class MessageEncryptor
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class InvalidMessage < StandardError; end
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OpenSSLCipherError = OpenSSL::Cipher.const_defined?(:CipherError) ? OpenSSL::Cipher::CipherError : OpenSSL::CipherError
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def initialize(secret, cipher = 'aes-256-cbc')
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@secret = secret
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@cipher = cipher
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end
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def encrypt(value)
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cipher = new_cipher
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# Rely on OpenSSL for the initialization vector
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iv = cipher.random_iv
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cipher.encrypt
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cipher.key = @secret
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cipher.iv = iv
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encrypted_data = cipher.update(Marshal.dump(value))
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encrypted_data << cipher.final
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[encrypted_data, iv].map {|v| ActiveSupport::Base64.encode64s(v)}.join("--")
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end
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def decrypt(encrypted_message)
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cipher = new_cipher
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encrypted_data, iv = encrypted_message.split("--").map {|v| ActiveSupport::Base64.decode64(v)}
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cipher.decrypt
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cipher.key = @secret
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cipher.iv = iv
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decrypted_data = cipher.update(encrypted_data)
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decrypted_data << cipher.final
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Marshal.load(decrypted_data)
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rescue OpenSSLCipherError, TypeError
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raise InvalidMessage
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end
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def encrypt_and_sign(value)
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verifier.generate(encrypt(value))
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end
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def decrypt_and_verify(value)
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decrypt(verifier.verify(value))
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end
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private
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def new_cipher
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OpenSSL::Cipher::Cipher.new(@cipher)
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end
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def verifier
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MessageVerifier.new(@secret)
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end
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end
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end
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