Sprint Music Store audio file
application/octet-stream
Magic Bytes
Offset: 0
49 49 1A 00 00 00 48 45 41 50 43 43 44 52 02 00
The KOZ file format is a proprietary audio container originally developed by Sprint for its mobile music distribution service. It was primarily employed to deliver over-the-air music downloads to compatible feature phones, enabling users to purchase and manage copyrighted tracks. This legacy format is now obsolete and typically utilizes Digital Rights Management (DRM) encryption, preventing playback on standard modern media players without specialized conversion software.
Validation Code
How to validate .koz files in Python
Python
def is_koz(file_path: str) -> bool:
"""Check if file is a valid KOZ by magic bytes."""
signature = bytes([0x49, 0x49, 0x1A, 0x00, 0x00, 0x00, 0x48, 0x45, 0x41, 0x50, 0x43, 0x43, 0x44, 0x52, 0x02, 0x00])
with open(file_path, "rb") as f:
return f.read(16) == signatureHow to validate .koz files in Node.js
Node.js
function isKOZ(buffer: Buffer): boolean {
const signature = Buffer.from([0x49, 0x49, 0x1A, 0x00, 0x00, 0x00, 0x48, 0x45, 0x41, 0x50, 0x43, 0x43, 0x44, 0x52, 0x02, 0x00]);
return buffer.subarray(0, 16).equals(signature);
}
Go
func IsKOZ(data []byte) bool {
signature := []byte{0x49, 0x49, 0x1A, 0x00, 0x00, 0x00, 0x48, 0x45, 0x41, 0x50, 0x43, 0x43, 0x44, 0x52, 0x02, 0x00}
if len(data) < 16 {
return false
}
return bytes.Equal(data[:16], signature)
}API Endpoint
GET
/api/v1/koz
curl https://filesignature.org/api/v1/koz