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

Fuzzer details

Fuzzer: fuzz-accept-sec-context

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

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 296 60.7%
gold [1:9] 10 2.05%
yellow [10:29] 10 2.05%
greenyellow [30:49] 1 0.20%
lawngreen 50+ 170 34.9%
All colors 487 100

Fuzz blockers

The followings are the branches where fuzzer fails to bypass.

Unique non-covered Complexity Unique Reachable Complexities Unique Reachable Functions All non-covered Complexity All Reachable Complexity Function Name Function Callsite Blocked Branch
413 442 10 :

['debug_gss_errors.245', 'gssntlm_srv_auth', 'time', 'ntlm_verify_channel_bindings', 'ntlm_encrypted_session_key', 'gssntlm_copy_name', 'memcmp', 'ntlm_verify_mic', 'ntlm_signseal_keys', 'gssntlm_duplicate_name']

413 602 gssntlm_accept_sec_context call site: 00273 /src/gss-ntlmssp/src/gss_sec_ctx.c:936
186 186 1 :

['get_creds_from_store']

186 199 gssntlm_acquire_cred_from call site: 00279 /src/gss-ntlmssp/src/gss_creds.c:454
135 135 2 :

['get_user_file_creds', 'free']

135 156 gssntlm_acquire_cred_from call site: 00331 /src/gss-ntlmssp/src/gss_creds.c:460
4 12 4 :

['strdup', 'gssntlm_release_attrs', 'malloc', 'calloc']

4 12 gssntlm_copy_attrs call site: 00029 /src/gss-ntlmssp/src/gss_names.c:439
4 4 2 :

['strndup', 'strchr']

14 229 gssntlm_import_name_by_mech call site: 00046 /src/gss-ntlmssp/src/gss_names.c:292
4 4 2 :

['malloc', 'strlen']

6 146 gssntlm_import_name_by_mech call site: 00053 /src/gss-ntlmssp/src/gss_names.c:331
4 4 2 :

['iconv_close', '__errno_location']

4 4 ntlm_init_ctx call site: 00148 /src/gss-ntlmssp/src/ntlm.c:87
2 52 2 :

['strndup', 'debug_gss_errors']

2 98 parse_user_name call site: 00076 /src/gss-ntlmssp/src/gss_names.c:216
2 2 1 :

['strndup']

6 6 netbios_get_names call site: 00128 /src/gss-ntlmssp/src/gss_names.c:812
2 2 1 :

['strlen']

4 124 ntlm_encode_target_info call site: 00176 /src/gss-ntlmssp/src/ntlm.c:541
2 2 1 :

['open64']

4 4 gssntlm_debug_init call site: 00005 /src/gss-ntlmssp/src/debug.c:35
2 2 1 :

['strdup']

2 2 get_user_file_envvar call site: 00332 /src/gss-ntlmssp/src/gss_creds.c:44

Runtime coverage analysis

Covered functions
60
Functions that are reachable but not covered
105
Reachable functions
165
Percentage of reachable functions covered
36.36%
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.
Function name source code lines source lines hit percentage hit

Files reached

filename functions hit
/src/gss-ntlmssp/fuzzing/fuzz-accept-sec-context.c 1
gss_sec_ctx.c 2
debug.h 1
debug.c 2
gss_ntlmssp.h 1
gss_names.c 13
external.c 5
gss_ntlmssp.c 7
ntlm.c 24
/usr/include/x86_64-linux-gnu/bits/uintn-identity.h 3
crypto.c 12
gss_creds.c 8
ntlm_crypto.c 26
gss_auth.c 2
gss_spi.c 3

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
gss_init_sec_context /src/gss-ntlmssp/src/gss_spi.c 13 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'int', 'int', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 8 0 64 3 2 156 0 907 236
gss_import_sec_context /src/gss-ntlmssp/src/gss_spi.c 3 ['N/A', 'N/A', 'N/A'] 6 0 24 3 2 33 0 149 72
gss_export_sec_context /src/gss-ntlmssp/src/gss_spi.c 3 ['N/A', 'N/A', 'N/A'] 5 0 24 3 2 33 0 138 68
gss_unwrap /src/gss-ntlmssp/src/gss_spi.c 6 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 6 0 36 3 2 40 0 140 52
gss_inquire_sec_context_by_oid /src/gss-ntlmssp/src/gss_spi.c 4 ['N/A', 'N/A', 'N/A', 'N/A'] 5 0 28 3 2 19 0 68 39
gss_inquire_cred_by_mech /src/gss-ntlmssp/src/gss_spi.c 7 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 8 0 40 3 2 80 0 388 35

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

Functions statically reachable by fuzzers
72.0%
156 / 217
Cyclomatic complexity statically reachable by fuzzers
78.0%
1329 / 1695

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

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
[] []
/usr/include/x86_64-linux-gnu/bits/uintn-identity.h ['fuzz-accept-sec-context'] []
/src/gss-ntlmssp/src/gss_spi.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/usr/include/x86_64-linux-gnu/bits/byteswap.h [] []
/src/gss-ntlmssp/src/gss_sec_ctx.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/debug.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/ntlm_crypto.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/fuzzing/fuzz-accept-sec-context.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/gss_auth.c ['fuzz-accept-sec-context'] []
/src/gss-ntlmssp/src/gss_creds.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/gss_names.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/external.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/crypto.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/gss_err.c [] []
/src/gss-ntlmssp/src/gss_serialize.c [] []
/src/gss-ntlmssp/src/debug.h ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/gss_signseal.c [] []
/src/gss-ntlmssp/src/ntlm.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/gss_ntlmssp.h ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']
/src/gss-ntlmssp/src/gss_ntlmssp.c ['fuzz-accept-sec-context'] ['fuzz-accept-sec-context']

Directories in report

Directory
/src/gss-ntlmssp/src/
/usr/include/x86_64-linux-gnu/bits/
/src/gss-ntlmssp/fuzzing/