YAyagizdegirmenci·Mar 5, 2021Submission
Microsoft's list of banned C functions
108 points · Open discussionx509cert
banned
C2019–2021
x509cert / banned
banned
Banned.h - deprecated C runtime functions
3Distinct people
3Mentions
0Explicit recommenders
115GitHub stars
What to know before exploring
What it is
Banned.h - deprecated C runtime functions
GitHub
Where it is used
No documented product use has been verified yet.
What people are saying
No recommendation phrase was found in the indexed comments.
No classified warning is attached to this page. Read the discussions before treating silence as approval.
Also in these discussions
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This week on Hacker News
Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by month3 dated mentions
Observed mentions: 2019-01-11 11:00:19 UTC to 2021-03-05 05:15:59 UTC.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| Jan 2019 | 2019-01-01 00:00:00 UTC | 2019-02-01 00:00:00 UTC | 1 | 0 | 1 |
| Feb 2019 | 2019-02-01 00:00:00 UTC | 2019-03-01 00:00:00 UTC | 0 | 0 | 0 |
| Mar 2019 | 2019-03-01 00:00:00 UTC | 2019-04-01 00:00:00 UTC | 0 | 0 | 0 |
| Apr 2019 | 2019-04-01 00:00:00 UTC | 2019-05-01 00:00:00 UTC | 0 | 0 | 0 |
| May 2019 | 2019-05-01 00:00:00 UTC | 2019-06-01 00:00:00 UTC | 0 | 0 | 0 |
| Jun 2019 | 2019-06-01 00:00:00 UTC | 2019-07-01 00:00:00 UTC | 0 | 0 | 0 |
| Jul 2019 | 2019-07-01 00:00:00 UTC | 2019-08-01 00:00:00 UTC | 0 | 0 | 0 |
| Aug 2019 | 2019-08-01 00:00:00 UTC | 2019-09-01 00:00:00 UTC | 1 | 0 | 1 |
| Sep 2019 | 2019-09-01 00:00:00 UTC | 2019-10-01 00:00:00 UTC | 0 | 0 | 0 |
| Oct 2019 | 2019-10-01 00:00:00 UTC | 2019-11-01 00:00:00 UTC | 0 | 0 | 0 |
| Nov 2019 | 2019-11-01 00:00:00 UTC | 2019-12-01 00:00:00 UTC | 0 | 0 | 0 |
| Dec 2019 | 2019-12-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 0 | 0 | 0 |
| Jan 2020 | 2020-01-01 00:00:00 UTC | 2020-02-01 00:00:00 UTC | 0 | 0 | 0 |
| Feb 2020 | 2020-02-01 00:00:00 UTC | 2020-03-01 00:00:00 UTC | 0 | 0 | 0 |
| Mar 2020 | 2020-03-01 00:00:00 UTC | 2020-04-01 00:00:00 UTC | 0 | 0 | 0 |
| Apr 2020 | 2020-04-01 00:00:00 UTC | 2020-05-01 00:00:00 UTC | 0 | 0 | 0 |
| May 2020 | 2020-05-01 00:00:00 UTC | 2020-06-01 00:00:00 UTC | 0 | 0 | 0 |
| Jun 2020 | 2020-06-01 00:00:00 UTC | 2020-07-01 00:00:00 UTC | 0 | 0 | 0 |
| Jul 2020 | 2020-07-01 00:00:00 UTC | 2020-08-01 00:00:00 UTC | 0 | 0 | 0 |
| Aug 2020 | 2020-08-01 00:00:00 UTC | 2020-09-01 00:00:00 UTC | 0 | 0 | 0 |
| Sep 2020 | 2020-09-01 00:00:00 UTC | 2020-10-01 00:00:00 UTC | 0 | 0 | 0 |
| Oct 2020 | 2020-10-01 00:00:00 UTC | 2020-11-01 00:00:00 UTC | 0 | 0 | 0 |
| Nov 2020 | 2020-11-01 00:00:00 UTC | 2020-12-01 00:00:00 UTC | 0 | 0 | 0 |
| Dec 2020 | 2020-12-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 0 | 0 | 0 |
| Jan 2021 | 2021-01-01 00:00:00 UTC | 2021-02-01 00:00:00 UTC | 0 | 0 | 0 |
| Feb 2021 | 2021-02-01 00:00:00 UTC | 2021-03-01 00:00:00 UTC | 0 | 0 | 0 |
| Mar 2021 | 2021-03-01 00:00:00 UTC | 2021-04-01 00:00:00 UTC | 1 | 1 | 0 |
What Hacker News says
3 sourcesYou can find an up-to-date, authoritative version of banned.h here: https://github.com/x509cert/banned
In Banned C standard library functions in Git source codeI would say learning a bit about the security implications involved. You don't have certain things given to you like other languages.
You have to watch what compiler flags you use, like someone turning off stack cookies, not using clang's sanitizers. Check out https://clang.llvm.org/docs/AddressSanitizer.html it would have prevented the Heartbleed vulnerability if it existed at the time.
You need proper bounds checking everywhere! You should fuzz your code with something like AFL and if you don't have the time to setup test cases for it, just send your program random junk and see if you can get it to seg. fault.
Multithreading is hard, and detecting multithreaded bugs is even harder. Random monkey testing can sometime's help find these, but they are very hard indeed. Monkey testing is just literally if a monkey was smashing your keyboard
Read the rest
and your program was open, what would happen?
Know the most vulnerable function calls by taking a look at banned.h from Microsoft's SDL. It looks like it's no longer on the official website, but the author put it up here Take a look at https://github.com/x509cert/banned/blob/master/banned.h. Sometimes you can't avoid using these functions but know why they can be considered bad.
A proper Makefile is your team's best friend. The same can be said with one build machine for your whole team. It is easier now than ever to build and distribute it between your team with Docker. This is just a personal opinion, but I think downloading all the exact library versions you need once and putting them in a Docker image will save your team some pain in the future.