https://blog.substitute.tech/en/tags/openssl/ Recent content in Openssl on Haoxiqiang's Blog Hugo en Mon, 08 Aug 2022 17:09:43 +0000 https://blog.substitute.tech/en/posts/openssl-rsa/ Mon, 08 Aug 2022 17:09:43 +0000 https://blog.substitute.tech/en/posts/openssl-rsa/ <p>I thought I had a solid understanding of the differences between RSA encryption schemes and their use cases. But while implementing RSA encryption today, I noticed something puzzling: the ciphertext was different every time, even with the same plaintext and public key. This was a blind spot for me. After researching the internals, here is what I found.</p> <h2 id="the-issue">The Issue</h2> <p>The following code uses OpenSSL&rsquo;s EVP API for RSA encryption. No random value is explicitly provided, yet the output differs on every call:</p>