Fuzz introspector
For issues and ideas: https://github.com/ossf/fuzz-introspector/issues
Project coverage

Table of contents

Project overview: toolbelt
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: fuzz_multipart
Call tree
Fuzz blockers
Runtime coverage analysis
Files reached
Analyses and suggestions
Optimal target analysis
Remaining optimal interesting functions
All functions overview
Runtime coverage analysis
Complex functions with low coverage
Files and Directories in report
Files in report
Directories in report
Metadata section
Function call coverage
Function in each files in report
Report generation date: 2023-06-07

Project overview: toolbelt

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
2.0%
14 / 589
Cyclomatic complexity statically reachable by fuzzers
2.0%
45 / 2022
Runtime code coverage of functions
17.0%
103 / 589

Warning: The number of runtime covered functions are larger than the number of reachable functions. This means that Fuzz Introspector found there are more functions covered at runtime than what is considered reachable based on the static analysis. This is a limitation in the analysis as anything covered at runtime is by definition reachable by the fuzzers.
This is likely due to a limitation in the static analysis. In this case, the count of functions covered at runtime is the true value, which means this is what should be considered "achieved" by the fuzzer.

Use the project functions table below to query all functions that were not covered at runtime.

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
fuzz_multipart /src/fuzz_multipart.py 50 1411 7 6 10 150 fuzz_multipart.py

Project functions overview

The following table shows data about each function in the project. The functions included in this table correspond to all functions that exist in the executables of the fuzzers. As such, there may be functions that are from third-party libraries.

For further technical details on the meaning of columns in the below table, please see the Glossary .

Func name Functions filename Args Function call depth Reached by Fuzzers Fuzzers runtime hit Func lines hit % I Count BB Count Cyclomatic complexity Functions reached Reached by functions Accumulated cyclomatic complexity Undiscovered complexity

Fuzzer details

Fuzzer: fuzz_multipart

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Full calltree

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 2 3.33%
gold [1:9] 0 0.0%
yellow [10:29] 0 0.0%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 58 96.6%
All colors 60 100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked Calltree index Parent function Callsite Largest blocked function
2 42 requests_toolbelt.multipart.decoder._header_parser call site: 00042 requests_toolbelt.multipart.encoder.encode_with

Runtime coverage analysis

Covered functions
163
Functions that are reachable but not covered
35
Reachable functions
50
Percentage of reachable functions covered
30.0%
NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.
Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.
Function name source code lines source lines hit percentage hit

Files reached

filename functions hit
/ 1
...fuzz_multipart 4
mock.mock 8
requests_toolbelt.multipart.decoder 28
requests_toolbelt.multipart.encoder 2
requests.structures 7

Analyses and suggestions

Optimal target analysis

Remaining optimal interesting functions

The following table shows a list of functions that are optimal targets. Optimal targets are identified by finding the functions that in combination, yield a high code coverage.

Func name Functions filename Arg count Args Function depth hitcount instr count bb count cyclomatic complexity Reachable functions Incoming references total cyclomatic complexity Unreached complexity
requests.sessions.SessionRedirectMixin.resolve_redirects requests.sessions 10 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 3 0 16 8 6 235 10 736 682
requests.models.PreparedRequest.prepare_body requests.models 4 ['N/A', 'N/A', 'N/A', 'N/A'] 1 0 2 10 7 75 0 235 202
mock.mock._patch.__enter__ mock.mock 1 ['N/A'] 4 0 5 38 18 60 1 222 179
requests.adapters.HTTPAdapter.send requests.adapters 7 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 3 0 3 10 7 138 0 439 163
requests_toolbelt.auth.guess.GuessProxyAuth.handle_407 requests_toolbelt.auth.guess 3 ['N/A', 'N/A', 'N/A'] 3 0 0 2 4 49 0 162 120
requests.models.RequestEncodingMixin._encode_files requests.models 2 ['N/A', 'N/A'] 1 0 4 11 7 29 0 95 62
requests_toolbelt.multipart.encoder.MultipartEncoder.read requests_toolbelt.multipart.encoder 2 ['N/A', 'N/A'] 2 0 2 2 4 25 3 82 58
mock.mock._patch_dict.__call__ mock.mock 2 ['N/A', 'N/A'] 2 0 0 2 4 22 0 71 53
requests.models.PreparedRequest.prepare_url requests.models 3 ['N/A', 'N/A', 'N/A'] 2 0 1 12 8 63 0 198 53
requests_toolbelt.adapters.x509.X509Adapter.__init__ requests_toolbelt.adapters.x509 3 ['N/A', 'N/A', 'N/A'] 1 0 3 4 5 18 0 60 48

Implementing fuzzers that target the above functions will improve reachability such that it becomes:

Functions statically reachable by fuzzers
22.0%
129 / 589
Cyclomatic complexity statically reachable by fuzzers
25.0%
509 / 2022

All functions overview

If you implement fuzzers for these functions, the status of all functions in the project will be:

Func name Functions filename Args Function call depth Reached by Fuzzers Fuzzers runtime hit Func lines hit % I Count BB Count Cyclomatic complexity Functions reached Reached by functions Accumulated cyclomatic complexity Undiscovered complexity

Runtime coverage analysis

This section shows analysis of runtime coverage data.

For futher technical details on how this section is generated, please see the Glossary .

Complex functions with low coverage

Func name Function total lines Lines covered at runtime percentage covered Reached by fuzzers
mock.mock._patch.__enter__ 101 0 0.0% []
mock.mock._Call.__eq__ 38 1 2.631% []
mock.mock.create_autospec 69 0 0.0% []
re.compile 37 13 35.13% []
name.replace 67 13 19.40% []
collections.namedtuple 212 72 33.96% []
requests.auth.HTTPDigestAuth.build_digest_header.sha512_utf8 44 0 0.0% []
request.headers.copy 103 46 44.66% []
requests.utils.get_netrc_auth 32 0 0.0% []
d.items 189 25 13.22% []
url.append 206 60 29.12% []
requests.sessions.SessionRedirectMixin.resolve_redirects 50 0 0.0% []
requests.sessions.Session.send 36 0 0.0% []
requests.adapters.HTTPAdapter.send 45 0 0.0% []
requests.models.RequestEncodingMixin._encode_files 38 0 0.0% []
requests.models.PreparedRequest.prepare_url 39 0 0.0% []
requests.models.PreparedRequest.prepare_body 38 0 0.0% []
urllib3.util.retry.Retry.from_int 174 61 35.05% []
urllib3.poolmanager.PoolManager.connection_pool_kw.pop 232 86 37.06% []
urllib3.contrib.socks.SOCKSProxyManager 87 9 10.34% []
fields.items 93 20 21.50% []
urllib3.filepost.encode_multipart_formdata 37 13 35.13% []
response.iter_content 562 133 23.66% []

Files and Directories in report

This section shows which files and directories are considered in this report. The main reason for showing this is fuzz introspector may include more code in the reasoning than is desired. This section helps identify if too many files/directories are included, e.g. third party code, which may be irrelevant for the threat model. In the event too much is included, fuzz introspector supports a configuration file that can exclude data from the report. See the following link for more information on how to create a config file: link

Files in report

Source file Reached by Covered by
[] []
zipfile [] []
charset_normalizer [] []
json [] []
pprint [] []
requests_toolbelt.utils.formdata [] []
dummy_threading [] []
base64 [] []
requests.hooks [] []
unittest [] []
requests_toolbelt.threaded [] []
requests_toolbelt.threaded.pool [] []
contextlib [] []
requests.__version__ [] []
urllib3 [] []
requests_toolbelt.adapters.ssl [] []
tempfile [] []
requests_toolbelt.streaming_iterator [] []
requests_toolbelt.utils.user_agent [] []
codecs [] []
requests.cookies [] []
requests_toolbelt.auth [] []
requests.utils [] []
simplejson [] []
requests_toolbelt.adapters.source [] []
certifi [] []
requests_toolbelt.utils.dump [] []
http [] []
mock.mock ['fuzz_multipart'] []
chardet [] []
netrc [] []
collections [] []
requests_toolbelt.utils.deprecated [] []
sys [] []
requests_toolbelt._compat [] []
hashlib [] []
os [] []
requests_toolbelt [] []
requests_toolbelt.threaded.thread [] []
requests_toolbelt.adapters.x509 [] []
mock [] []
socket [] []
requests.structures ['fuzz_multipart'] []
io [] []
[] []
requests_toolbelt.utils [] []
inspect [] []
queue [] []
asyncio [] []
requests_toolbelt.cookies [] []
requests.auth [] []
urllib [] []
requests_toolbelt.adapters.fingerprint [] []
requests.compat [] []
requests_toolbelt.auth._digest_auth_compat [] []
requests_toolbelt.adapters [] []
requests_toolbelt.auth.handler [] []
...fuzz_multipart ['fuzz_multipart'] []
threading [] []
requests.models [] []
requests_toolbelt.auth.http_proxy_digest [] []
urlparse [] []
requests_toolbelt.multipart.encoder ['fuzz_multipart'] []
copy [] []
calendar [] []
requests_toolbelt.downloadutils.stream [] []
re [] []
requests.adapters [] []
requests._internal_utils [] []
cryptography [] []
requests.help [] []
requests_toolbelt.downloadutils [] []
requests_toolbelt.auth.guess [] []
logging [] []
platform [] []
requests_toolbelt.downloadutils.tee [] []
requests_toolbelt.exceptions [] []
OpenSSL [] []
datetime [] []
requests_toolbelt.adapters.socket_options [] []
requests.status_codes [] []
mock.backports [] []
requests_toolbelt.sessions [] []
requests_toolbelt.adapters.host_header_ssl [] []
requests_toolbelt.cookies.forgetful [] []
requests_toolbelt.multipart.decoder ['fuzz_multipart'] []
requests.api [] []
requests.certs [] []
requests.packages [] []
uuid [] []
struct [] []
multiprocessing [] []
functools [] []
winreg [] []
requests.exceptions [] []
requests.sessions [] []
requests_toolbelt.multipart [] []
idna [] []
requests [] []
atheris [] []
warnings [] []
time [] []

Directories in report

Directory

Metadata section

This sections shows the raw data that is used to produce this report. This is mainly used for further processing and developer debugging.

Fuzzer Calltree file Program data file Coverage file
fuzz_multipart fuzzerLogFile-fuzz_multipart.data fuzzerLogFile-fuzz_multipart.data.yaml all_cov.json