curl -H 'Host: crashwebservices.apple.com' \ -H 'X-Apple-I-Identity-Id: myIdentityId' \ -H 'User-Agent: Xcode' \ -H 'X-Apple-GS-Token: myToken' \ -H 'X-Apple-I-MD-LU: myMDId' \ -H 'X-Apple-App-Info: com.apple.gs.xcode.auth' \ -H 'X-Mme-Device-Id: myDeviceId' \ -H 'X-Apple-I-MD-M: myMDM' \ -H 'X-Apple-I-Locale: en_GB' \ -H 'X-Apple-I-MD: myIMD==' \ --compressed 'https://crashwebservices.apple.com/api/v2/crashpoint/...'
Researchers and "jailbreakers" often hunt for this header. They use tools like mitmdump to catch the sentry in the act, trying to understand how Apple keeps its ecosystem so tightly locked [10]. For them, x-apple-i-md-m is the key to "Grand Slam" authentication—the ultimate proof that a device is exactly who it says it is [15].
: Routing information metrics that aid in session assignment. Visualizing the Grand Slam Auth Architecture Poor Privacy Practices Of The Apple App Store
If you're a regular user, you will almost never see it. If you do, it’s a strong indication that your device is managed by an organization, and the string is likely part of a behind-the-scenes communication process.
: The static hardware identifier ("Machine Data — Machine Information"). X-Apple-I-MD-LU : Local User ID data.
Like many Apple security mechanisms, it’s:
x-apple-i-md-m . What if it wasn’t a technical header?
The x-apple-i-md-m header is a critical, yet largely undocumented, component of Apple’s authentication framework. It is primarily used to verify the "trusted" status of a machine during requests to iCloud , the App Store , and Apple ID services. 🛠 What is x-apple-i-md-m?
D.M. Dee-em. The initials of the only person she knew who lived far away, on a research vessel in the Pacific. The person she’d been trying to reach for weeks. The person whose satellite phone was the last device to go silent.
Demystifying X-Apple-I-MD-M : Inside Apple’s Cryptographic Device Fingerprinting
Every custom URL scheme follows a standardized, modular syntax designed to inform the operating system which software component should intercept and parse the execution string: Components Technical Purpose x-apple-
A perfect example is the story of ipatool . ipatool was a popular open-source command-line tool that allowed users to download iOS app IPA files directly from Apple's servers. For years, it worked by using older, legacy cookie-based authentication endpoints.
In essence, x-apple-i-md-m is the machine's long-term identity credential, while x-apple-i-md is the session-based proof that the machine is currently in control of that identity.
Both the client and server compute a shared session key ( ) using a blend of private keys, public keys, and salts.
In essence, the X-Apple-I-MD header proves the action is happening right now , while the X-Apple-I-MD-M header proves it is happening from an authorized device .
Header: x-apple-i-md-m Timestamp: 04:47 GMT+2
