File security_headers.py
has 319 lines of code (exceeds 250 allowed). Consider refactoring. Open
"""
Check if the https site uses HSTS to tell the browser the site should only be reached over HTTPS.
(useful until browsers do https by default, instead of by choice)
"""
import logging
Cyclomatic complexity is too high in function analyze_headers. (9) Open
@app.task(queue="storage")
def analyze_headers(headers: Dict[str, str], endpoint_id):
# todo: remove code paths, and make a more clear case per header type. That's easier to understand edge cases.
# todo: Content-Security-Policy, Referrer-Policy
- Read upRead up
- Exclude checks
Cyclomatic Complexity
Cyclomatic Complexity corresponds to the number of decisions a block of code contains plus 1. This number (also called McCabe number) is equal to the number of linearly independent paths through the code. This number can be used as a guide when testing conditional logic in blocks.
Radon analyzes the AST tree of a Python program to compute Cyclomatic Complexity. Statements have the following effects on Cyclomatic Complexity:
Construct | Effect on CC | Reasoning |
---|---|---|
if | +1 | An if statement is a single decision. |
elif | +1 | The elif statement adds another decision. |
else | +0 | The else statement does not cause a new decision. The decision is at the if. |
for | +1 | There is a decision at the start of the loop. |
while | +1 | There is a decision at the while statement. |
except | +1 | Each except branch adds a new conditional path of execution. |
finally | +0 | The finally block is unconditionally executed. |
with | +1 | The with statement roughly corresponds to a try/except block (see PEP 343 for details). |
assert | +1 | The assert statement internally roughly equals a conditional statement. |
Comprehension | +1 | A list/set/dict comprehension of generator expression is equivalent to a for loop. |
Boolean Operator | +1 | Every boolean operator (and, or) adds a decision point. |
Cyclomatic complexity is too high in function discover_service_type. (6) Open
def discover_service_type(headers: Dict = None):
"""
Try to discover some meaning of the webserver headers, because some HTTP servers are used for entirely different
purposes than hosting web pages. For example SOAP is used for XML messages and has their own security paradigm.
- Read upRead up
- Exclude checks
Cyclomatic Complexity
Cyclomatic Complexity corresponds to the number of decisions a block of code contains plus 1. This number (also called McCabe number) is equal to the number of linearly independent paths through the code. This number can be used as a guide when testing conditional logic in blocks.
Radon analyzes the AST tree of a Python program to compute Cyclomatic Complexity. Statements have the following effects on Cyclomatic Complexity:
Construct | Effect on CC | Reasoning |
---|---|---|
if | +1 | An if statement is a single decision. |
elif | +1 | The elif statement adds another decision. |
else | +0 | The else statement does not cause a new decision. The decision is at the if. |
for | +1 | There is a decision at the start of the loop. |
while | +1 | There is a decision at the while statement. |
except | +1 | Each except branch adds a new conditional path of execution. |
finally | +0 | The finally block is unconditionally executed. |
with | +1 | The with statement roughly corresponds to a try/except block (see PEP 343 for details). |
assert | +1 | The assert statement internally roughly equals a conditional statement. |
Comprehension | +1 | A list/set/dict comprehension of generator expression is equivalent to a for loop. |
Boolean Operator | +1 | Every boolean operator (and, or) adds a decision point. |
Function analyze_headers
has a Cognitive Complexity of 10 (exceeds 5 allowed). Consider refactoring. Open
def analyze_headers(headers: Dict[str, str], endpoint_id):
# todo: remove code paths, and make a more clear case per header type. That's easier to understand edge cases.
# todo: Content-Security-Policy, Referrer-Policy
# if scan task failed, ignore the result (exception) and report failed status
- Read upRead up
Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Function analyze_website_headers
has a Cognitive Complexity of 8 (exceeds 5 allowed). Consider refactoring. Open
def analyze_website_headers(endpoint_id: int, url: int, protocol: str, headers: Dict[str, str]):
"""
#125: CSP can replace X-XSS-Protection and X-Frame-Options. Thus if a (more modern) CSP header is present, assume
that decisions have been made about what's in it and ignore the previously mentioned headers.
- Read upRead up
Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Avoid too many return
statements within this function. Open
return "UNKNOWN"
Avoid too many return
statements within this function. Open
return analyze_soap_headers(endpoint_id)
Avoid too many return
statements within this function. Open
return clean_up_existing_headers(endpoint_id, service_type=service_type, reason="unknown_content_type")
Avoid too many return
statements within this function. Open
return clean_up_existing_headers(endpoint_id, service_type=service_type, reason="authentication_required")