High level conclusions

Fuzzers reach 23.12% of cyclomatic complexity.

Fuzzers reach 6.790% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

55 / 810

Cyclomatic complexity statically reachable by fuzzers

2999 / 12969

Runtime code coverage of functions

50 / 810

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	Runtime reached by Fuzzers	Combined 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: fuzz-filters

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	2	5.88%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	32	94.1%
All colors	34	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
1	5	LLVMFuzzerTestOneInput	call site: 00005	strjoker_bounded
1	16	strjoker_impl	call site: 00016	strlen

Runtime coverage analysis

Covered functions

9

Functions that are reachable but not covered

6

Reachable functions

15

Percentage of reachable functions covered

60.0%

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.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
fuzz/fuzz-filters.c	1
fuzz/fuzz.h	1
src/htsfilters.c	6
src/./htslib.h	1

Fuzzer: fuzz-meta

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	0	0.0%
gold	[1:9]	1	4.16%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	23	95.8%
All colors	24	100

Runtime coverage analysis

Covered functions

8

Functions that are reachable but not covered

1

Reachable functions

9

Percentage of reachable functions covered

88.89%

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
fuzz/fuzz-meta.c	1
fuzz/fuzz.h	1
src/htscharset.c	6

Fuzzer: fuzz-url

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	22	36.0%
gold	[1:9]	0	0.0%
yellow	[10:29]	1	1.63%
greenyellow	[30:49]	1	1.63%
lawngreen	50+	37	60.6%
All colors	61	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
5	8	strcpy_safe_	call site: 00008	log_abort_
5	44	ident_url_absolute	call site: 00044	strncat_safe_
4	22	ident_url_absolute	call site: 00022	strcpy_safe_
2	55	ident_url_absolute	call site: 00055	strcpy_safe_
1	3	LLVMFuzzerTestOneInput	call site: 00003	strlen
1	6	ident_url_absolute	call site: 00006	strcpy_safe_
1	27	ident_url_absolute	call site: 00027	strcmp
1	34	jump_protocol_const	call site: 00034	strfield
1	36	jump_protocol_const	call site: 00036	strncmp
1	58	ident_url_absolute	call site: 00058	jump_identification_const

Runtime coverage analysis

Covered functions

11

Functions that are reachable but not covered

15

Reachable functions

26

Percentage of reachable functions covered

42.31%

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
fuzz/fuzz-url.c	1
fuzz/fuzz.h	1
src/htslib.c	7
src/./htslib.h	1
src/./htssafe.h	5

Fuzzer: fuzz-idna

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	6	17.1%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	29	82.8%
All colors	35	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
5	8	hts_convertStringUTF8ToIDNA	call site: 00008	log_abort_
1	27	punycode_decode	call site: 00027	realloc

Runtime coverage analysis

Covered functions

11

Functions that are reachable but not covered

9

Reachable functions

20

Percentage of reachable functions covered

55.0%

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.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
fuzz/fuzz-idna.c	1
fuzz/fuzz.h	1
src/htscharset.c	4
src/./htssafe.h	2
src/htslib.c	1
src/punycode.c	6

Fuzzer: fuzz-charset

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	2	5.71%
gold	[1:9]	2	5.71%
yellow	[10:29]	1	2.85%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	30	85.7%
All colors	35	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
1	9	hts_convertStringToUTF8	call site: 00009	strdup
1	11	hts_convertStringCharset	call site: 00011	hts_stringMemCopy

Runtime coverage analysis

Covered functions

14

Functions that are reachable but not covered

7

Reachable functions

21

Percentage of reachable functions covered

66.67%

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
fuzz/fuzz-charset.c	1
fuzz/fuzz.h	1
src/htscharset.c	12

Fuzzer: fuzz-entities

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	10	28.5%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	25	71.4%
All colors	35	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
5	4	hts_unescapeEntitiesWithCharset	call site: 00004	log_abort_
2	28	hts_convertStringCharset	call site: 00028	realloc
1	17	hts_unescapeEntitiesWithCharset	call site: 00017	strdup
1	22	hts_convertStringFromUTF8	call site: 00022	strdup
1	24	hts_convertStringCharset	call site: 00024	hts_stringMemCopy

Runtime coverage analysis

Covered functions

13

Functions that are reachable but not covered

14

Reachable functions

27

Percentage of reachable functions covered

48.15%

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
fuzz/fuzz-entities.c	1
fuzz/fuzz.h	1
src/htsencoding.c	3
src/./htssafe.h	2
src/htslib.c	1
src/./htsentities.h	1
src/htscharset.c	7

Fuzzer: fuzz-unescape

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	31	67.3%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	15	32.6%
All colors	46	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
18	25	hts_unescapeEntitiesWithCharset	call site: 00025	hts_convertStringFromUTF8
8	3	unescape_http	call site: 00003	ehex
2	16	LLVMFuzzerTestOneInput	call site: 00016	hts_unescapeEntities
1	13	unescape_http_unharm	call site: 00013	ehex
1	23	hts_isCharsetUTF8	call site: 00023	strcasecmp
1	44	hts_unescapeEntitiesWithCharset	call site: 00044	abortf_

Runtime coverage analysis

Covered functions

13

Functions that are reachable but not covered

19

Reachable functions

32

Percentage of reachable functions covered

40.62%

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
fuzz/fuzz-unescape.c	1
fuzz/fuzz.h	1
src/htslib.c	6
src/./htssafe.h	2
src/htsencoding.c	3
src/./htsentities.h	1
src/htscharset.c	7

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
httpmirror	/src/httrack/src/htscore.c	2	['N/A', 'N/A']	22	0	12336	2099	626	711	0	11930	8898
hts_buildtopindex	/src/httrack/src/htstools.c	3	['N/A', 'N/A', 'N/A']	11	0	1636	310	68	109	0	779	145
is_unicode_utf8	/src/httrack/src/htslib.c	2	['N/A', 'size_t']	3	0	1412	289	119	6	0	132	119
hts_free_opt	/src/httrack/src/htslib.c	1	['N/A']	7	0	990	157	36	36	0	145	56
htsAddLink	/src/httrack/src/htscore.c	2	['N/A', 'N/A']	21	0	1199	140	52	542	0	6122	52
hts_getcategories	/src/httrack/src/htstools.c	2	['N/A', 'int']	11	0	1233	234	48	85	0	405	48
copy_htsopt	/src/httrack/src/htscore.c	2	['N/A', 'N/A']	1	0	1169	174	43	3	0	49	43

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

Functions statically reachable by fuzzers

628 / 810

Cyclomatic complexity statically reachable by fuzzers

12182 / 12969

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	Runtime reached by Fuzzers	Combined 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

This sections provides heuristics that can be used as input to a fuzz engine when running a given fuzz target. The current focus is on providing input that is usable by libFuzzer.

fuzz/fuzz-filters.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['LLVMFuzzerTestOneInput', 'strjoker_impl']

fuzz/fuzz-meta.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

fuzz/fuzz-url.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['strcpy_safe_', 'ident_url_absolute', 'LLVMFuzzerTestOneInput', 'jump_protocol_const']

fuzz/fuzz-idna.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['hts_convertStringUTF8ToIDNA', 'punycode_decode']

fuzz/fuzz-charset.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['hts_convertStringToUTF8', 'hts_convertStringCharset']

fuzz/fuzz-entities.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['hts_unescapeEntitiesWithCharset', 'hts_convertStringCharset', 'hts_convertStringFromUTF8']

fuzz/fuzz-unescape.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['hts_unescapeEntitiesWithCharset', 'unescape_http', 'LLVMFuzzerTestOneInput', 'unescape_http_unharm', 'hts_isCharsetUTF8']

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

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
	[]	[]
/src/httrack/src/htsftp.c	[]	[]
/src/httrack/src/htslib.c	['fuzz-url', 'fuzz-idna', 'fuzz-entities', 'fuzz-unescape']	['fuzz-url', 'fuzz-unescape']
/src/httrack/src/minizip/mztools.c	[]	[]
/src/httrack/fuzz/fuzz-url.c	['fuzz-url']	['fuzz-url']
/src/httrack/src/htscore.c	[]	[]
/src/httrack/src/htsfilters.c	['fuzz-filters']	['fuzz-filters']
/src/httrack/src/minizip/zip.c	[]	[]
/src/httrack/src/htscharset.c	['fuzz-meta', 'fuzz-idna', 'fuzz-charset', 'fuzz-entities', 'fuzz-unescape']	['fuzz-meta', 'fuzz-idna', 'fuzz-charset', 'fuzz-entities', 'fuzz-unescape']
/src/httrack/src/htscodec.c	[]	[]
/src/httrack/src/htsindex.c	[]	[]
/src/httrack/src/htsrobots.c	[]	[]
/src/httrack/src/htsencoding.c	['fuzz-entities', 'fuzz-unescape']	['fuzz-entities', 'fuzz-unescape']
/src/httrack/fuzz/fuzz-entities.c	['fuzz-entities']	['fuzz-entities']
/src/httrack/src/htsbauth.c	[]	[]
/src/httrack/fuzz/fuzz-unescape.c	['fuzz-unescape']	['fuzz-unescape']
/src/httrack/fuzz/fuzz-charset.c	['fuzz-charset']	['fuzz-charset']
/src/httrack/src/punycode.c	['fuzz-idna']	['fuzz-idna']
/src/httrack/src/md5.c	[]	[]
/src/httrack/src/htscache.c	[]	[]
/src/httrack/src/./htsentities.h	['fuzz-entities', 'fuzz-unescape']	[]
/src/httrack/src/htsmodules.c	[]	[]
/src/httrack/src/htsmd5.c	[]	[]
/src/httrack/src/./htssafe.h	['fuzz-url', 'fuzz-idna', 'fuzz-entities', 'fuzz-unescape']	[]
/src/httrack/src/htsname.c	[]	[]
/src/httrack/src/minizip/crypt.h	[]	[]
/src/httrack/src/./htslib.h	['fuzz-filters', 'fuzz-url']	[]
/src/httrack/fuzz/fuzz-meta.c	['fuzz-meta']	['fuzz-meta']
/src/httrack/src/htsthread.c	[]	[]
/src/httrack/src/coucal/murmurhash3.h	[]	[]
/src/httrack/src/htssniff.c	[]	[]
/src/httrack/src/./htsarrays.h	[]	[]
/src/httrack/src/htsback.c	[]	[]
/src/httrack/fuzz/fuzz.h	['fuzz-filters', 'fuzz-meta', 'fuzz-url', 'fuzz-idna', 'fuzz-charset', 'fuzz-entities', 'fuzz-unescape']	['fuzz-filters', 'fuzz-meta', 'fuzz-url', 'fuzz-idna', 'fuzz-charset', 'fuzz-entities', 'fuzz-unescape']
/src/httrack/src/htshash.c	[]	[]
/src/httrack/src/./htscore.h	[]	[]
/src/httrack/src/htstools.c	[]	[]
/src/httrack/src/htswizard.c	[]	[]
/src/httrack/fuzz/fuzz-filters.c	['fuzz-filters']	['fuzz-filters']
/src/httrack/src/./htsnet.h	[]	[]
/src/httrack/src/htsproxy.c	[]	[]
/src/httrack/src/minizip/unzip.c	[]	[]
/src/httrack/fuzz/fuzz-idna.c	['fuzz-idna']	['fuzz-idna']
/src/httrack/src/htszlib.c	[]	[]
/src/httrack/src/htsconcat.c	[]	[]
/src/httrack/src/minizip/ioapi.c	[]	[]
/src/httrack/src/coucal/coucal.c	[]	[]
/src/httrack/src/./htsname.h	[]	[]
/src/httrack/src/htsparse.c	[]	[]

Directories in report

Directory
/src/httrack/fuzz/
/src/httrack/src/
/src/httrack/src/minizip/
/src/httrack/src/./
/src/httrack/src/coucal/