ONE
application/onenote;format=one
Magic Bytes
Offset: 0
7B 5C 52 E4
The ONE file format is a proprietary binary format developed and maintained by Microsoft as the default storage container for individual OneNote notebook sections. It is primarily utilized for organizing free-form information, including typed text, handwritten notes, drawings, and multimedia elements within a hierarchical digital notebook structure. Although the binary structure is generally safe, the format supports embedded attachments, which actors may exploit to deliver malicious payloads or links if the source is untrusted.
Validation Code
How to validate .one files in Python
Python
def is_one(file_path: str) -> bool:
"""Check if file is a valid ONE by magic bytes."""
signature = bytes([0x7B, 0x5C, 0x52, 0xE4])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .one files in Node.js
Node.js
function isONE(buffer: Buffer): boolean {
const signature = Buffer.from([0x7B, 0x5C, 0x52, 0xE4]);
return buffer.subarray(0, 4).equals(signature);
}
Go
func IsONE(data []byte) bool {
signature := []byte{0x7B, 0x5C, 0x52, 0xE4}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
GET
/api/v1/one
curl https://filesignature.org/api/v1/one