Ruby openssl AES128 CBC与随机静脉注射不起作用

Question

我正在使用一个相当简单的加密/解密ruby脚本，并且似乎有效 - 但解密损坏了消息的前几个字节。我想念什么？

这是代码：

key = OpenSSL::Random.random_bytes(16)
plain_text = "Some important txt we want to encrypt"
cipher = OpenSSL::Cipher::AES128.new(:CBC)
cipher.encrypt
cipher.key = key
cipher.random_iv
cipher_text = cipher.update(plain_text) + cipher.final
cipher = OpenSSL::Cipher::AES128.new(:CBC)
cipher.decrypt
cipher.key = key
cipher.random_iv
decrypted_plain_text = cipher.update(cipher_text) + cipher.final
puts "AES128 in CBC mode"
puts "Plain text: " + plain_text
puts "Cipher text: " + urlsafe_encode64(cipher_text)
puts "Decrypted plain text: " + decrypted_plain_text

和结果：

AES128 in CBC mode Plain text: Some important txt we want to encrypt
Cipher text:
P2fdC7cApQvxHnfxSEfB2iJaueK3xRoj-NN3bDR8JheL_VPFYTDF_RxpLfBwoRfp
Decrypted plain text: �܇�Σ }w�D�A:xt we want to encrypt

Answer 1

您在解密上使用了不同的随机IV。该值必须相同。那就是加密时捕获它：

iv = cipher.random_iv

然后您使用它解密：

cipher.iv = iv

然后正确解密。您需要相同的键 IV对才能取得成功。