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testssl
testssl.sh
Shell2016–2026
testssl / testssl.sh

testssl.sh

Testing TLS/SSL encryption anywhere on any port

7Distinct people
39Mentions
0Explicit recommenders
9.3KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Testing TLS/SSL encryption anywhere on any port

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

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 1:49:46 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 year39 dated mentions

Observed mentions: 2016-02-03 16:22:53 UTC to 2026-05-03 15:22:54 UTC.

024682016-01-01 00:00:00 UTC to 2017-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments20162017-01-01 00:00:00 UTC to 2018-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2018-01-01 00:00:00 UTC to 2019-01-01 00:00:00 UTC (exclusive): 3 mentions; 3 submissions, 0 comments2019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 6 mentions; 2 submissions, 4 comments2020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 4 mentions; 3 submissions, 1 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 7 mentions; 5 submissions, 2 comments20212022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 8 mentions; 1 submissions, 7 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 3 mentions; 0 submissions, 3 comments2026-01-01 00:00:00 UTC to 2027-01-01 00:00:00 UTC (exclusive): 2 mentions; 1 submissions, 1 comments. Incomplete calendar period.2026*

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20162016-01-01 00:00:00 UTC2017-01-01 00:00:00 UTC202
20172017-01-01 00:00:00 UTC2018-01-01 00:00:00 UTC101
20182018-01-01 00:00:00 UTC2019-01-01 00:00:00 UTC330
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC624
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC431
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC752
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC817
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC202
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC101
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC303
2026 (partial)2026-01-01 00:00:00 UTC2027-01-01 00:00:00 UTC211

What Hacker News says

39 sources
We also it at my work, where it's used both for mass scans of internal hosts, and scanning the same host many times during incidents/configuration changes. And the 20s is extra annoying because it's completely unnecessary. The tool is so slow because it's thousands of lines of pure bash, manipulating individual bytes. And because it's bash, it also breaks in confusing ways when you look at it wrong[1]. [1] https://github.com/testssl/testssl.sh/pull/2429
In SSL Configuration Generator
Seems like they support more than 3DES. It might be interesting if they shared stats on how many legit MTA's are using old ciphers. Should exclude bots, scanners, etc... There are of course other mitigating factors such as PGP encrypting emails, accepting that some information is still disclosed. That can be further mitigated by using gmail to only perform the initial communication then go out of band for anything sensitive. SSLv2 not offered (OK) SSLv3 not offered (OK) TLS 1 offered (deprecated) TLS 1.1 offered (deprecated) TLS 1.2 offered (OK) TLS 1.3 offered (OK): final Testing cipher categories NULL ciphers (no encryption) not offered (OK) Anonymous NULL Ciphers (no authentication) not offered (OK) Export ciphers (w/o A
Read the rest
DH+NULL) not offered (OK) LOW: 64 Bit + DES, RC[2,4], MD5 (w/o export) not offered (OK) Triple DES Ciphers / IDEA offered Obsoleted CBC ciphers (AES, ARIA etc.) offered Strong encryption (AEAD ciphers) with no FS offered (OK) Forward Secrecy strong encryption (AEAD ciphers) offered (OK) Tested with testssl.sh [1] [1] - https://github.com/testssl/testssl.sh
In Gmail will soon stop support for the 3DES encryption cipher for incoming SMTP
Appears good for me, tested with testssl.sh [1]. Here is the fingerprint I see in the event you may have a MitM issue. openssl s_client -servername dash.cloudflare.com -connect dash.cloudflare.com:443 < /dev/null 2>/dev/null | openssl x509 -fingerprint -noout -in /dev/stdin SHA1 Fingerprint=23:80:59:61:1E:82:7F:85:96:5F:06:38:D1:7F:C0:19:7C:D1:90:07 #sha256 openssl s_client -servername dash.cloudflare.com -connect dash.cloudflare.com:443 < /dev/null 2>/dev/null | openssl x509 -fingerprint -sha256 -noout -in /dev/stdin sha256 Fingerprint=A8:F7:20:54:02:B2:61:0A:1C:1E:21:D7:64:79:A9:EA:05:7B:AE:BF:11:FD:78:C5:F9:68:BB:EB:F4:7F:69:6A Tested both IPv4 and IPv6, same results. [1] - https://github.com/drwetter/testssl.sh
In Ask HN: Getting a certificate error with Cloudflare dashboard?
As indigodaddy mentioned the cert is only signed for www and not the apex. [1]. The alternate name should be one or the other www vs apex. To run a test similar to Qualys one could clone testssl.sh [2] and run against a local development version of the site. requires bash and openssl Some headers may be missing [3]. Follow the links from Qualys and SecurityHeaders to get more information on how to remediate the findings. It might also not hurt to open a ticket with Cloudflare to see what else is going on here if you have a paid account. [1] - https://www.ssllabs.com/ssltest/analyze.html?d=www.teamkenne... [2] - https://github.com/drwetter/testssl.sh [3] - https://securityheaders.com/?q=https%3A%2F%2Fwww.teamkennedy...
In Team Kennedy needs some HTTPS help?
For which domain? joinpeertube.org or one of the video hosting nodes? Use Qualys [1] to test the domain in question to link here or use the testssl.sh [2] code only depends on openssl and bash to test from your machine. If one of the many self hosted nodes, see if you can find a way to reach out to them and kindly suggest they set up certbot or a cron job to renew their certs. Joinpeertube.org looks good to me [3] so I assume you find a self-hosted node that needs some attention. If someone here knows of a way to query a list of all the self-hosted domains joined into peertube perhaps we could run testssl.sh against all of them to generate reports. I am not opposed to doing this if someone knows how I can get a list of all the domains using curl. [1] - https://www.ssllabs.com/ssltest/ [2] - https://github.com/drwetter/testssl.sh [3] -
Read the rest
In What 2023 will bring for PeerTube
It appears they have blocked or rate limited qualys for scanning them too much, but testssl [1] still works. I am not worried about being blocked since I just closed my account from 2001. The only serious warning I see is "Secure Client-Initiated Renegotiation VULNERABLE (NOT ok), DoS threat (6 attempts)" They otherwise get an "A+". Perhaps they have wan accelerators or anycast proxies with bad certs that are region specific? [1] - https://github.com/drwetter/testssl.sh [depends on bash and openssl]
In Paypal.com is using revoked certificate
If it's useful, here [1] is a tool for auditing the SSH config of a server from the internet and suggesting hardening options for both server and client. And here [2] is a tool for configuring TLS on various web servers, load balancers, mail servers and databases. One could also clone testssl.sh [3] to audit their TLS daemons on IP's not open to the internet. Depends on openssl and bash If hardening SSH it may be safest to first harden the SSH client and ensure one can still connect. Then harden the ssh daemon of a local machine using the same version of openssh used on ones servers to minimize the risk of locking one out of their own machine and having to use a rescue console or ILO. This may be counter-intuitive but going through the hardening process significantly speeds up SSH handshake time which may be most useful to those using
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In DHEat Attack: DoS attack by enforcing the Diffie-Hellman key exchange
Qualys [1][2] For testing SSL of publicly accessible sites. TestSSL.sh [3] for testing SSL of any site including private endpoints you can reach from your machine Only requires openssl and bash. SecurityHeaders [4] for testing what headers are missing from a website. URLScan [5] for diagnosing a websites behavior. bgp.he.net [6] for looking up information about an IP/AS Number/domain. Robtex [7] also for looking up information about IP/AS/domain as well as org mapping. WhatIsMyDNS [8] for checking DNS propagation re-run this 3 times as their probe timeouts are way too low. Old-school VirusTotal [9] for old browsers for scanning malware. WhoisDS [10] targeting newly registered domains. Mozilla TLS configuration tool [11] for setting up proper TLS/HTTPS configuration on Nginx, Apache, HAproxy, etc... Certificate Search [12] for ce
Read the rest
rt transparency logs, certificate fingerprints and more. Thousand Eyes [13] free dashboard on a commercial site. DownDetector [14] for uptime of popular sites and services. EDNS Validator [15] for verification of your DNS EDNS support. Shodan [16] for looking up detected vulnerabilities of an IP. W3C Validator [17] for testing HTML/CSS. [1] - https://www.ssllabs.com/ssltest/ [2] - https://dev.ssllabs.com/ssltest/ [3] - https://github.com/drwetter/testssl.sh [4] - https://securityheaders.com/ [5] - https://urlscan.io/ [6] - https://bgp.he.net/ [7] - https://www.robtex.com/ [8] - https://www.whatsmydns.net/ [9] - https://www.virustotal.com/old-browsers/ [10] - https://www.whoisds.com/ [11] - https://ssl-config.mozilla.org/ [12] - https://crt.sh/ [13] - https://www.thousandeyes.com/outages/ [commercial site but priceless in my opinion] [14] - https://downdetector.com/ [15] - https://ednscomp.isc.org/ednscomp?zone=ycombinator.com [16] - https://www.shodan.io/ [17] - https://validator.w3.org/
In Badssl.com (2017)
If you like minimal dependencies another one to take a peek at may be acme.sh [1]. It depends on bash, openssl and curl. It seems to work fine in ash as well. It has code to handle most API's and most importantly to me is the great documentation. In the same spirit of minimal and light weight there is also testssh.sh [2] for testing TLS on HTTPS/SMTPS servers that also depends on bash and openssl. [1] - https://github.com/acmesh-official/acme.sh [2] - https://github.com/drwetter/testssl.sh
In Uacme: ACMEv2 client written in plain C with minimal dependencies

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