In this post, I’ll walk through why you’d want a JWS-to-CSV converter, the structure of a JWS, and a simple Python script to get the job done. A JSON Web Signature (JWS) is a way to securely transmit JSON data between parties with a signature. It’s the technical backbone of JWT (when signed). A JWS has three parts, each base64url-encoded, separated by dots:
"user": "id": 123, "name": "Alice", "permissions": ["read", "write"] jws to csv converter
Opening a raw .log file full of base64url-encoded strings isn’t practical. But dropping that data into a CSV? Now you can sort, filter, and pivot. In this post, I’ll walk through why you’d
for token in tokens: if not token.strip(): continue payload = decode_jws_payload(token) # If no fields specified, take all top-level keys if fields_of_interest is None: rows.append(payload) else: filtered = field: payload.get(field, None) for field in fields_of_interest rows.append(filtered) A JWS has three parts, each base64url-encoded, separated
Replace the row-building section with:
If you work with JWT (JSON Web Tokens) or JWS (JSON Web Signatures) in logging, analytics, or batch processing, you’ve likely run into the same headache: how do you analyze hundreds or thousands of these tokens in a human-readable way?
def jws_to_csv(input_file, output_file, fields_of_interest=None): """ Convert a file of JWS tokens (one per line) to CSV. fields_of_interest: list of claim names to extract (e.g., ['sub', 'exp', 'role']) """ tokens = Path(input_file).read_text().splitlines() rows = []