Merge pull request #53 from SigmaHQ/analyze_logsource

Feat: Analyze logsources

pyproject.toml

@@ -27,16 +27,23 @@ pysigma = "^0.11.9"
 colorama = "^0.4.6"
 
 [tool.poetry.dev-dependencies]
-pytest = "^6.2.2"
-pytest-cov = "^2.11.1"
+pytest = "^7.3.0"
+pytest-cov = "^4.0.0"
 defusedxml = "^0.7.1"
 
 [tool.poetry.scripts]
 sigma = "sigma.cli.main:main"
 
 [tool.pytest.ini_options]
-python_paths = ["."]
-testpaths = ["tests"]
+minversion = "6.0"
+python_files = "test_*.py"
+addopts = "--cov=sigma --cov-report term --cov-report xml:cov.xml"
+testpaths = [
+    "tests",
+]
+filterwarnings = [
+    'ignore:Unverified HTTPS request'
+]
 
 [build-system]
 requires = ["poetry-core>=1.0.0"]

sigma/analyze/stats.py

@@ -0,0 +1,55 @@
+import copy
+from typing import Dict, List
+from sigma.rule import SigmaRule, SigmaLevel
+from sigma.collection import SigmaCollection
+
+
+rule_level_mapping = {
+    None: "None",
+    SigmaLevel.INFORMATIONAL: "Informational",
+    SigmaLevel.LOW: "Low",
+    SigmaLevel.MEDIUM: "Medium",
+    SigmaLevel.HIGH: "High",
+    SigmaLevel.CRITICAL: "Critical",
+}
+
+template_stat_detail = {
+    "Overall": 0,
+    "Critical": 0,
+    "High": 0,
+    "Medium": 0,
+    "Low": 0,
+    "Informational": 0,
+    "None": 0,
+}
+
+
+def format_row(row: str, column_widths: List) -> str:
+    """Format rows for table."""
+    return " | ".join(
+        f"{str(item).ljust(width)}" for item, width in zip(row, column_widths)
+    )
+
+
+def get_rulelevel_mapping(rule: SigmaRule) -> int:
+    """Calculate rule score according to rule_level_scores."""
+    return rule_level_mapping[rule.level]
+
+
+def create_logsourcestats(rules: SigmaCollection) -> Dict[str, int]:
+    """
+    Iterate through all the rules and count SigmaLevel grouped by
+    Logsource Category Name.
+    """
+    stats = {}
+
+    for rule in rules:
+        if hasattr(rule, "logsource"):
+            # Create stats key for logsource category.
+            if not rule.logsource.category in stats:
+                stats[rule.logsource.category] = copy.deepcopy(template_stat_detail)
+
+            stats[rule.logsource.category]["Overall"] += 1
+            stats[rule.logsource.category][get_rulelevel_mapping(rule)] += 1
+
+    return stats

sigma/cli/analyze.py

@@ -8,6 +8,7 @@
     mitre_attack_techniques_tactics_mapping,
     mitre_attack_version,
 )
+from sigma.analyze.stats import create_logsourcestats, format_row
 
 
 @click.group(name="analyze", help="Analyze Sigma rule sets")
@@ -126,3 +127,58 @@ def analyze_attack(
         "techniques": layer_techniques,
     }
     json.dump(layer, output, indent=2)
+
+@analyze_group.command(name="logsource", help="Create stats about logsources.")
+@click.option(
+    "--file-pattern",
+    "-P",
+    default="*.yml",
+    show_default=True,
+    help="Pattern for file names to be included in recursion into directories.",
+)
+@click.option(
+    "--sort-by",
+    "-k",
+    type=str,
+    default="Overall",
+    show_default=True,
+    help="Sort by column.",
+)
+@click.argument(
+    "output",
+    type=click.File("w"),
+)
+@click.argument(
+    "input",
+    nargs=-1,
+    required=True,
+    type=click.Path(exists=True, allow_dash=True, path_type=pathlib.Path),
+)
+def analyze_logsource(
+    file_pattern,
+    sort_by,
+    output,
+    input,
+):
+    rules = load_rules(input, file_pattern)
+    stats = create_logsourcestats(rules)
+
+    # Extract column header
+    headers = ["Logsource"] + list(next(iter(stats.values())).keys())
+
+    # Prepare rows
+    rows = [[key] + list(value.values()) for key, value in stats.items()]
+    sort_index = headers.index(sort_by)
+    rows.sort(key=lambda x: x[sort_index], reverse=True)
+
+    # Determine col width
+    column_widths = [
+        max(len(str(item)) for item in column) for column in zip(*([headers] + rows))
+    ]
+
+    # Print table
+    print("-+-".join("-" * width for width in column_widths), file=output)
+    print(format_row(headers, column_widths), file=output)
+    print("-+-".join("-" * width for width in column_widths), file=output)
+    for row in rows:
+        print(format_row(row, column_widths), file=output)