Just Facts

DANG Fan‘s Blog

Ed25519 & X25519

Algorithms with 25519

Ed25519 is often used in SSH, then what does this number mean? Is there any other algorithms related to 25519?


Debug MIPI DSI of RK3399

RK3399 is the most recent hign-end SoC of Rockchip. Its previous generation RK3288 is widely used in various places. For example, ASUS C100PA Chromebook Flip uses the RK3288. As an upgraded model, RK3399 has a six-core CPU consisting of two A72 cores and four A53 cores, and the GPU has been upgraded to the Mali-T860.


The New Domain is Online

The new .fan TLD is launched on December 12, 2018. Then I got this domain: dang.fan.


Recommend Two Services

FastMail & LastPass

Some time ago, I migrated all my email services to FastMail. At the same time, the password management is also switched to LastPass. This article will introduce the motivation.


Using OpenSSL in Android

Taking HMAC-SHA256 as an example

Since Java is relatively easy to decompile, placing certain critical code inside .so files becomes a cost-effective choice. Although .so files can still be reverse-engineered, the barrier to analyzing them is significantly higher than that of analyzing Java bytecode. Many security-related implementations rely on OpenSSL, yet tutorials on using OpenSSL within the NDK are not commonly found online. After a day of experimentation, I finally managed to invoke OpenSSL from the NDK. This article uses the HMAC algorithm in OpenSSL as an example to demonstrate how to use OpenSSL in the NDK.