EPSF
application/postscript
Magic Bytes
Offset: 0
25 21 50 53 2D 41 64 6F 62 65 2D 33 2E 30 20 45 50 53 46 2D 33 2E 30
Encapsulated PostScript (EPSF) is a subset of the PostScript language developed by Adobe Systems for transferring vector graphics between layout applications. It is primarily used in commercial printing for high-resolution logos, illustrations, and advertisements that require scalability across various output devices. Although largely superseded by the Portable Document Format (PDF) in modern workflows, this legacy format remains supported for historical compatibility and is generally considered safe.
Validation Code
How to validate .epsf files in Python
Python
def is_epsf(file_path: str) -> bool:
"""Check if file is a valid EPSF by magic bytes."""
signature = bytes([0x25, 0x21, 0x50, 0x53, 0x2D, 0x41, 0x64, 0x6F, 0x62, 0x65, 0x2D, 0x33, 0x2E, 0x30, 0x20, 0x45, 0x50, 0x53, 0x46, 0x2D, 0x33, 0x2E, 0x30])
with open(file_path, "rb") as f:
return f.read(23) == signatureHow to validate .epsf files in Node.js
Node.js
function isEPSF(buffer: Buffer): boolean {
const signature = Buffer.from([0x25, 0x21, 0x50, 0x53, 0x2D, 0x41, 0x64, 0x6F, 0x62, 0x65, 0x2D, 0x33, 0x2E, 0x30, 0x20, 0x45, 0x50, 0x53, 0x46, 0x2D, 0x33, 0x2E, 0x30]);
return buffer.subarray(0, 23).equals(signature);
}
Go
func IsEPSF(data []byte) bool {
signature := []byte{0x25, 0x21, 0x50, 0x53, 0x2D, 0x41, 0x64, 0x6F, 0x62, 0x65, 0x2D, 0x33, 0x2E, 0x30, 0x20, 0x45, 0x50, 0x53, 0x46, 0x2D, 0x33, 0x2E, 0x30}
if len(data) < 23 {
return false
}
return bytes.Equal(data[:23], signature)
}API Endpoint
GET
/api/v1/epsf
curl https://filesignature.org/api/v1/epsf