copilot-swe-agent[bot]
6ae017b142
- Auto-format all Python files with black and isort - Remove unused imports with autoflake - Fix flake8 issues (missing newlines, blank lines, etc.) - Fix nonlocal/global scope issues in main.py - Fix security.py import order (E402) - Remove f-string without placeholders - Add nosec comment for intentional exception handling - Fix test imports to match refactored DMARCParser API Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
241 lines
9.5 KiB
Python
241 lines
9.5 KiB
Python
import gzip
|
|
import io
|
|
import logging
|
|
import zipfile
|
|
from datetime import datetime
|
|
from typing import Any, Dict, Optional
|
|
|
|
import defusedxml.ElementTree as ET
|
|
|
|
# Set up logging
|
|
logging.basicConfig(level=logging.INFO)
|
|
logger = logging.getLogger(__name__)
|
|
|
|
# Security constants for file upload protection
|
|
MAX_FILE_SIZE = 10 * 1024 * 1024 # 10 MB
|
|
MAX_UNCOMPRESSED_SIZE = 100 * 1024 * 1024 # 100 MB for zip bomb protection
|
|
MAX_FILES_IN_ARCHIVE = 10 # Maximum number of files in a zip archive
|
|
|
|
|
|
class DMARCParser:
|
|
"""
|
|
Parser for DMARC Aggregate Reports (XML format)
|
|
"""
|
|
|
|
@staticmethod
|
|
def parse_file(file_content: bytes, filename: str) -> Dict[str, Any]:
|
|
"""
|
|
Parse a DMARC report file (XML, zip, or gzip) into a dictionary
|
|
|
|
Args:
|
|
file_content: The binary content of the file
|
|
filename: The name of the file (used to determine type)
|
|
|
|
Returns:
|
|
Dict containing the parsed report data
|
|
|
|
Raises:
|
|
ValueError: If file is invalid, too large, or potentially malicious
|
|
"""
|
|
# Security: Check file size
|
|
if len(file_content) > MAX_FILE_SIZE:
|
|
raise ValueError(
|
|
f"File too large. Maximum size is {MAX_FILE_SIZE / (1024*1024):.1f} MB"
|
|
)
|
|
|
|
# Determine file type and extract XML content
|
|
xml_content = DMARCParser._extract_xml_content(file_content, filename)
|
|
if not xml_content:
|
|
raise ValueError("Could not extract XML content from file")
|
|
|
|
# Security: Check uncompressed XML size
|
|
if len(xml_content) > MAX_UNCOMPRESSED_SIZE:
|
|
raise ValueError(
|
|
f"Uncompressed content too large ({len(xml_content) / (1024*1024):.1f} MB). "
|
|
f"Maximum is {MAX_UNCOMPRESSED_SIZE / (1024*1024):.1f} MB. "
|
|
"Possible zip bomb attack detected."
|
|
)
|
|
|
|
# Parse the XML content
|
|
return DMARCParser._parse_xml(xml_content)
|
|
|
|
@staticmethod
|
|
def _extract_xml_content(file_content: bytes, filename: str) -> Optional[bytes]:
|
|
"""
|
|
Extract XML content from various file formats (ZIP, GZIP, or plain XML)
|
|
|
|
Raises:
|
|
ValueError: If archive contains too many files or is potentially malicious
|
|
"""
|
|
# Try to handle as ZIP file
|
|
if filename.lower().endswith(".zip"):
|
|
try:
|
|
with zipfile.ZipFile(io.BytesIO(file_content)) as z:
|
|
# Security: Check number of files in archive
|
|
file_list = z.infolist()
|
|
if len(file_list) > MAX_FILES_IN_ARCHIVE:
|
|
raise ValueError(
|
|
f"ZIP archive contains too many files ({len(file_list)}). "
|
|
f"Maximum is {MAX_FILES_IN_ARCHIVE}."
|
|
)
|
|
|
|
# Security: Check for zip bomb by examining compression ratios
|
|
total_uncompressed = sum(f.file_size for f in file_list)
|
|
if total_uncompressed > MAX_UNCOMPRESSED_SIZE:
|
|
raise ValueError(
|
|
f"ZIP archive uncompressed size too large ({total_uncompressed / (1024*1024):.1f} MB). "
|
|
f"Maximum is {MAX_UNCOMPRESSED_SIZE / (1024*1024):.1f} MB. "
|
|
"Possible zip bomb attack detected."
|
|
)
|
|
|
|
# Find the first XML file in the archive
|
|
for file_info in file_list:
|
|
if file_info.filename.lower().endswith(".xml"):
|
|
# Security: Double-check individual file size
|
|
if file_info.file_size > MAX_UNCOMPRESSED_SIZE:
|
|
raise ValueError(
|
|
f"XML file in archive too large ({file_info.file_size / (1024*1024):.1f} MB)"
|
|
)
|
|
return z.read(file_info.filename)
|
|
except zipfile.BadZipFile:
|
|
pass
|
|
|
|
# Try to handle as GZIP file
|
|
if filename.lower().endswith(".gz") or filename.lower().endswith(".gzip"):
|
|
try:
|
|
return gzip.decompress(file_content)
|
|
except gzip.BadGzipFile:
|
|
pass
|
|
|
|
# Assume it's plain XML
|
|
if filename.lower().endswith(".xml"):
|
|
return file_content
|
|
|
|
return None
|
|
|
|
@staticmethod
|
|
def _parse_xml(xml_content: bytes) -> Dict[str, Any]:
|
|
"""
|
|
Parse DMARC XML content according to RFC 7489
|
|
"""
|
|
try:
|
|
root = ET.fromstring(xml_content)
|
|
report = {}
|
|
|
|
# Parse report metadata
|
|
metadata = root.find("report_metadata")
|
|
if metadata is not None:
|
|
report["report_id"] = metadata.findtext("report_id", "")
|
|
report["org_name"] = metadata.findtext("org_name", "")
|
|
report["email"] = metadata.findtext("email", "")
|
|
|
|
# Parse date range
|
|
date_range = metadata.find("date_range")
|
|
if date_range is not None:
|
|
begin_ts = int(date_range.findtext("begin", 0))
|
|
end_ts = int(date_range.findtext("end", 0))
|
|
report["begin_date"] = datetime.fromtimestamp(begin_ts).isoformat()
|
|
report["end_date"] = datetime.fromtimestamp(end_ts).isoformat()
|
|
report["begin_timestamp"] = begin_ts
|
|
report["end_timestamp"] = end_ts
|
|
|
|
# Parse policy published
|
|
policy = root.find("policy_published")
|
|
if policy is not None:
|
|
report["domain"] = policy.findtext("domain", "")
|
|
report["policy"] = {
|
|
"p": policy.findtext("p", "none"),
|
|
"sp": policy.findtext("sp", ""),
|
|
"pct": policy.findtext("pct", "100"),
|
|
}
|
|
|
|
# Parse records
|
|
records = []
|
|
for record_elem in root.findall("record"):
|
|
record = {}
|
|
|
|
# Parse row
|
|
row = record_elem.find("row")
|
|
if row is not None:
|
|
record["source_ip"] = row.findtext("source_ip", "")
|
|
record["count"] = int(row.findtext("count", 0))
|
|
|
|
policy_evaluated = row.find("policy_evaluated")
|
|
if policy_evaluated is not None:
|
|
record["disposition"] = policy_evaluated.findtext("disposition", "none")
|
|
record["dkim_result"] = policy_evaluated.findtext("dkim", "").lower()
|
|
record["spf_result"] = policy_evaluated.findtext("spf", "").lower()
|
|
|
|
# Parse identifiers
|
|
identifiers = record_elem.find("identifiers")
|
|
if identifiers is not None:
|
|
record["header_from"] = identifiers.findtext("header_from", "")
|
|
|
|
# Parse auth results
|
|
auth_results = record_elem.find("auth_results")
|
|
if auth_results is not None:
|
|
# SPF results
|
|
spf_entries = []
|
|
for spf in auth_results.findall("spf"):
|
|
spf_entries.append(
|
|
{
|
|
"domain": spf.findtext("domain", ""),
|
|
"result": spf.findtext("result", "").lower(),
|
|
}
|
|
)
|
|
if spf_entries:
|
|
record["spf"] = spf_entries
|
|
|
|
# DKIM results
|
|
dkim_entries = []
|
|
for dkim in auth_results.findall("dkim"):
|
|
dkim_entries.append(
|
|
{
|
|
"domain": dkim.findtext("domain", ""),
|
|
"result": dkim.findtext("result", "").lower(),
|
|
"selector": dkim.findtext("selector", ""),
|
|
}
|
|
)
|
|
if dkim_entries:
|
|
record["dkim"] = dkim_entries
|
|
|
|
records.append(record)
|
|
|
|
report["records"] = records
|
|
|
|
# Calculate summary stats
|
|
total_count = sum(r["count"] for r in records)
|
|
|
|
# Count records that pass either SPF or DKIM (or both)
|
|
passed_count = sum(
|
|
r["count"]
|
|
for r in records
|
|
if r.get("spf_result") == "pass" or r.get("dkim_result") == "pass"
|
|
)
|
|
|
|
failed_count = total_count - passed_count
|
|
|
|
# Log parse results for debugging
|
|
logger.info(f"Parsed DMARC report for domain: {report.get('domain')}")
|
|
logger.info(f"Found {len(records)} record entries with {total_count} total messages")
|
|
logger.info(f"Messages passed: {passed_count}, failed: {failed_count}")
|
|
|
|
if len(records) > 0:
|
|
# Log the first record for debugging
|
|
logger.info(
|
|
f"Sample record - SPF: {records[0].get('spf_result')}, DKIM: {records[0].get('dkim_result')}"
|
|
)
|
|
|
|
report["summary"] = {
|
|
"total_count": total_count,
|
|
"passed_count": passed_count,
|
|
"failed_count": failed_count,
|
|
"pass_rate": (passed_count / total_count * 100) if total_count > 0 else 0,
|
|
}
|
|
|
|
return report
|
|
|
|
except Exception as e:
|
|
logger.error(f"Error parsing DMARC XML: {str(e)}")
|
|
raise ValueError(f"Error parsing DMARC XML: {str(e)}")
|