PEM
application/x-x509-cert;format=pem
Magic Bytes
Offset: 0
2D 2D 2D 2D 2D 42 45 47 49 4E 20 43 45 52 54 49 46 49 43 41 54 45 2D 2D 2D 2D 2D
Privacy Enhanced Mail (PEM) is a text-based file format defined by the Internet Engineering Task Force (IETF) for representing cryptographic data. It is widely employed to store and exchange X.509 certificates, private keys, and public keys within web servers, authentication systems, and TLS configurations. While originally developed for securing email, this format remains a global standard for facilitating the transfer of binary information through text-only communication channels without data corruption.
Validation Code
How to validate .pem files in Python
Python
def is_pem(file_path: str) -> bool:
"""Check if file is a valid PEM by magic bytes."""
signature = bytes([0x2D, 0x2D, 0x2D, 0x2D, 0x2D, 0x42, 0x45, 0x47, 0x49, 0x4E, 0x20, 0x43, 0x45, 0x52, 0x54, 0x49, 0x46, 0x49, 0x43, 0x41, 0x54, 0x45, 0x2D, 0x2D, 0x2D, 0x2D, 0x2D])
with open(file_path, "rb") as f:
return f.read(27) == signatureHow to validate .pem files in Node.js
Node.js
function isPEM(buffer: Buffer): boolean {
const signature = Buffer.from([0x2D, 0x2D, 0x2D, 0x2D, 0x2D, 0x42, 0x45, 0x47, 0x49, 0x4E, 0x20, 0x43, 0x45, 0x52, 0x54, 0x49, 0x46, 0x49, 0x43, 0x41, 0x54, 0x45, 0x2D, 0x2D, 0x2D, 0x2D, 0x2D]);
return buffer.subarray(0, 27).equals(signature);
}
Go
func IsPEM(data []byte) bool {
signature := []byte{0x2D, 0x2D, 0x2D, 0x2D, 0x2D, 0x42, 0x45, 0x47, 0x49, 0x4E, 0x20, 0x43, 0x45, 0x52, 0x54, 0x49, 0x46, 0x49, 0x43, 0x41, 0x54, 0x45, 0x2D, 0x2D, 0x2D, 0x2D, 0x2D}
if len(data) < 27 {
return false
}
return bytes.Equal(data[:27], signature)
}API Endpoint
GET
/api/v1/pem
curl https://filesignature.org/api/v1/pem