{"success":true,"data":{"ext":"crt","name":"CRT","description":"CRT is a file extension commonly used for X.509 digital certificates, a standard defined by ITU-T and maintained through related public-key infrastructure specifications. It is used to distribute server, client, and certificate-authority certificates for TLS, HTTPS, email security, and other authenticated communication systems. Certificate files are generally safe to open, but their trust depends on the issuing authority and validity period; some legacy CRT files are PEM-encoded text rather than a distinct format.","mime":["application/octet-stream"],"risk_level":"Safe","signatures":[{"hex":"43 36 34 20 43 41 52 54 52 49 44 47 45 20 20 20","offset":0,"sources":[{"name":"Wikipedia","url":"https://en.wikipedia.org/wiki/List_of_file_signatures"}]},{"hex":"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","offset":0,"sources":[{"name":"Wikipedia","url":"https://en.wikipedia.org/wiki/List_of_file_signatures"}]}],"related":["asc","der","gpg","key","pem","pgp"],"usage":{"python":"def is_crt(file_path: str) -> bool:\n    \"\"\"Check if file is a valid CRT by magic bytes.\"\"\"\n    signature = bytes([0x43, 0x36, 0x34, 0x20, 0x43, 0x41, 0x52, 0x54, 0x52, 0x49, 0x44, 0x47, 0x45, 0x20, 0x20, 0x20])\n    with open(file_path, \"rb\") as f:\n        return f.read(16) == signature","node":"function isCRT(buffer: Buffer): boolean {\n  const signature = Buffer.from([0x43, 0x36, 0x34, 0x20, 0x43, 0x41, 0x52, 0x54, 0x52, 0x49, 0x44, 0x47, 0x45, 0x20, 0x20, 0x20]);\n  return buffer.subarray(0, 16).equals(signature);\n}","go":"func IsCRT(data []byte) bool {\n    signature := []byte{0x43, 0x36, 0x34, 0x20, 0x43, 0x41, 0x52, 0x54, 0x52, 0x49, 0x44, 0x47, 0x45, 0x20, 0x20, 0x20}\n    if len(data) < 16 {\n        return false\n    }\n    return bytes.Equal(data[:16], signature)\n}"},"category":"Certificates & Keys"}}