47 lines
1.6 KiB
Python
47 lines
1.6 KiB
Python
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#!/bin/python3
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import argparse
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import pcapng
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import zipfile
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import hashlib
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def extract_packets(pcap_file):
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"""Reads a wireshark packet capture and extracts the binary packets"""
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packets = []
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with open(pcap_file, 'rb') as fp:
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scanner = pcapng.FileScanner(fp)
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for block in scanner:
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if isinstance(block, pcapng.blocks.EnhancedPacket):
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packets.append(block.packet_data)
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return packets
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def build_corpus_zip(zip_file_output, packets):
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"""Builds a zip file with a file per packet
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The structure of this zip corpus is a simple content addressable storage
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i.e. seed_file_name == sha256_digest(packet).
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"""
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with zipfile.ZipFile(zip_file_output, 'a') as out:
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for packet in packets:
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hash = hashlib.sha256(packet).hexdigest()
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if hash not in out.namelist():
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out.writestr(hash, packet)
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def main(pcap_file, output_zip_file):
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packets = extract_packets(pcap_file)
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build_corpus_zip(output_zip_file, packets)
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if __name__ == "__main__":
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parser = argparse.ArgumentParser(
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prog = "pcapng_to_corpus.py",
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description="""Converts a wireshark capture to a zip of binary packet
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files suitable for an oss-fuzz corpus. In the case the
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zip corpus already exists, this script will modify
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the zip file in place adding seed entries.""")
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parser.add_argument('pcapng_capture_file')
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parser.add_argument('oss_fuzz_corpus_zip')
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args = parser.parse_args()
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main(args.pcapng_capture_file, args.oss_fuzz_corpus_zip)
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