<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:content="http://purl.org/rss/1.0/modules/content/"><channel><title>MediaDrm on +5 Security Research</title><link>https://overkazaf.github.io/blogs/tags/mediadrm/</link><description>Recent content in MediaDrm on +5 Security Research</description><generator>Hugo</generator><language>zh-cn</language><lastBuildDate>Mon, 24 Aug 2026 17:18:00 +0800</lastBuildDate><atom:link href="https://overkazaf.github.io/blogs/tags/mediadrm/index.xml" rel="self" type="application/rss+xml"/><item><title>有了 PSSH 还是拿不到 Key，从 L3 到 L1 有多远</title><link>https://overkazaf.github.io/blogs/posts/widevine-pssh-license-l1-deep-dive/</link><pubDate>Sat, 22 Aug 2026 14:00:00 +0800</pubDate><guid>https://overkazaf.github.io/blogs/posts/widevine-pssh-license-l1-deep-dive/</guid><description>从 Widevine SystemID、PSSH protobuf 与 CENC box 结构开始，沿 Chrome/Android 通信架构、License Proxy、设备 Provisioning、MediaDrm、OEMCrypto、L1/L2/L3 和安全输出还原完整信任链。</description></item><item><title>把 Netflix MSL 拆成字节 - 一次协议逆向的路线、踩坑与经验</title><link>https://overkazaf.github.io/blogs/posts/netflix-msl-protocol-reverse-engineering/</link><pubDate>Sat, 15 Aug 2026 00:00:00 +0000</pubDate><guid>https://overkazaf.github.io/blogs/posts/netflix-msl-protocol-reverse-engineering/</guid><description>围绕 Netflix Message Security Layer (MSL) 的协议逆向记录：为什么 HTTPS 之上还要再套一层加密信道、encrypt-then-MAC 到底签的是什么、CBOR integer key 编码的字节细节、MasterToken/UserIdToken 的绑定关系，以及 MSL 相对国内外流媒体与音乐加密方案（爱奇艺/腾讯视频/优酷/ChinaDRM/网易云/QQ音乐）强在哪</description></item></channel></rss>