JavaKeyStore file
application/x-java-keystore
Magic Bytes
Offset: 0
FE ED FE ED
The JavaKeyStore (JKS) is a proprietary binary repository format developed by Sun Microsystems, now Oracle, for the Java Runtime Environment. It serves as a secure container for cryptographic keys, private keys, and certificates used to authenticate clients and servers during SSL/TLS encryption. Because modern Java distributions have adopted the industry-standard PKCS#12 format as the default, JKS is effectively a legacy standard maintained for backward compatibility with older applications.
Validation Code
How to validate .jks files in Python
Python
def is_jks(file_path: str) -> bool:
"""Check if file is a valid JKS by magic bytes."""
signature = bytes([0xFE, 0xED, 0xFE, 0xED])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .jks files in Node.js
Node.js
function isJKS(buffer: Buffer): boolean {
const signature = Buffer.from([0xFE, 0xED, 0xFE, 0xED]);
return buffer.subarray(0, 4).equals(signature);
}
Go
func IsJKS(data []byte) bool {
signature := []byte{0xFE, 0xED, 0xFE, 0xED}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
GET
/api/v1/jks
curl https://filesignature.org/api/v1/jks