TLS 1.3 KEM configuration

Server info

  • UBI9 Base Image
  • OpenSSL version: 3.5.4
  • nginx version: nginx/1.29.3

nginx configuration

    server {
        listen 8443 ssl;
        listen [::]:8443 ssl;
        server_name keysupport.net;
        add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
        ssl_certificate ...;
        ssl_certificate_key ...;
        ssl_protocols TLSv1.3;
        ssl_early_data off;
        ssl_prefer_server_ciphers on;
        ssl_ecdh_curve SecP384r1MLKEM1024:SecP256r1MLKEM768:X25519MLKEM768:secp384r1;
        ssl_conf_command Ciphersuites TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256:TLS_AES_128_CCM_SHA256;
        ...
    }

TestSSL.sh results as of 20251107

testssl.sh


#####################################################################
  testssl.sh version 3.3dev from https://testssl.sh/dev/
  (f219fd6c 2025-11-03 23:39:04)

  This program is free software. Distribution and modification under
  GPLv2 permitted. USAGE w/o ANY WARRANTY. USE IT AT YOUR OWN RISK!

  Please file bugs @ https://testssl.sh/bugs/
#####################################################################

  Using OpenSSL 3.5.4 (Nov 3 2025)  [~96 ciphers]
  on Vostro:/usr/local/openssl/bin/openssl

Testing all IPv4 addresses (port 443): 71.185.218.5
-------------------------------------------------------------------------------------------------------------------------------------------------------------
 Start 2025-11-07 19:32:15        -->> 71.185.218.5:443 (keysupport.net) <<--

 rDNS (71.185.218.5):    pool-71-185-218-5.phlapa.fios.verizon.net.
 Service detected:       HTTP

 Testing protocols via sockets except NPN+ALPN 

 SSLv2      not offered (OK)
 SSLv3      not offered (OK)
 TLS 1      not offered
 TLS 1.1    not offered
 TLS 1.2    not offered
 TLS 1.3    offered (OK): final
 QUIC       not offered or timed out
 NPN/SPDY   There's no such thing as NPN on TLS 1.3-only hosts
 ALPN/HTTP2 h2, http/1.1 (offered)

 Testing cipher categories 

 NULL ciphers (no encryption)                      not offered (OK)
 Anonymous NULL Ciphers (no authentication)        not offered (OK)
 Export ciphers (w/o ADH+NULL)                     not offered (OK)
 LOW: 64 Bit + DES, RC[2,4], MD5 (w/o export)      not offered (OK)
 Triple DES Ciphers / IDEA                         not offered
 Obsoleted CBC ciphers (AES, ARIA etc.)            not offered
 Strong encryption (AEAD ciphers) with no FS       not offered
 Forward Secrecy strong encryption (AEAD ciphers)  offered (OK)


 Testing server's cipher preferences 

Hexcode  Cipher Suite Name (OpenSSL)       KeyExch.   Encryption  Bits     Cipher Suite Name (IANA/RFC)
-----------------------------------------------------------------------------------------------------------------------------
SSLv2
 - 
SSLv3
 - 
TLSv1
 - 
TLSv1.1
 - 
TLSv1.2
 - 
TLSv1.3 (server order)
 x1302   TLS_AES_256_GCM_SHA384            ECDH/MLKEM AESGCM      256      TLS_AES_256_GCM_SHA384                             
 x1301   TLS_AES_128_GCM_SHA256            ECDH/MLKEM AESGCM      128      TLS_AES_128_GCM_SHA256                             
 x1304   TLS_AES_128_CCM_SHA256            ECDH/MLKEM AESCCM      128      TLS_AES_128_CCM_SHA256                             

 Has server cipher order?     yes (TLS 1.3 only)


 Testing robust forward secrecy (FS) -- omitting Null Authentication/Encryption, 3DES, RC4 

 FS is offered (OK)           TLS_AES_256_GCM_SHA384 TLS_AES_128_GCM_SHA256 TLS_AES_128_CCM_SHA256 
 KEMs offered                 SecP256r1MLKEM768 X25519MLKEM768 SecP384r1MLKEM1024 
 Elliptic curves offered:     secp384r1 
 TLS 1.3 sig_algs offered:    RSA-PSS-RSAE+SHA256 RSA-PSS-RSAE+SHA384 RSA-PSS-RSAE+SHA512 

 Testing server defaults (Server Hello) 

 TLS extensions (standard)    "server name/#0" "supported_groups/#10" "supported versions/#43" "key share/#51"
 Session Ticket RFC 5077 hint no -- no lifetime advertised
 SSL Session ID support       no
 Session Resumption           tickets no, ID: no
 TLS 1.3 early data support   no early data (no SSL session ID)
 TLS clock skew               Random values, no fingerprinting possible 
 Certificate Compression      none
 Client Authentication        none
 Signature Algorithm          SHA256 with RSA
 Server key size              RSA 4096 bits (exponent is 65537)
 Server key usage             Digital Signature, Key Encipherment
 Server extended key usage    TLS Web Server Authentication, TLS Web Client Authentication
 Serial                       060F34CE6403B02A6B922A49E18B12EE2BBE (OK: length 18)
 Fingerprints                 SHA1 9C2A62B3EC8E01A4E8BF70A5450C07F2E3253263
                              SHA256 284F5141A347BFBDE45CB356F4B99836EEF5B5DD62ECD55062A814CF2C9245AD
 Common Name (CN)             home.keysupport.net 
 subjectAltName (SAN)         home.keysupport.net home.keysupport.org keysupport.net 
 Trust (hostname)             Ok via SAN (same w/o SNI)
 Chain of trust               Ok   
 EV cert (experimental)       no 
 Certificate Validity (UTC)   88 >= 30 days (2025-11-06 16:48 --> 2026-02-04 16:48)
 ETS/"eTLS", visibility info  not present
 Certificate Revocation List  http://r12.c.lencr.org/63.crl
 OCSP URI                     --
 OCSP stapling                not offered
 OCSP must staple extension   --
 DNS CAA RR (experimental)    available - please check for match with "Issuer" below
                              issue=amazon.com, issue=letsencrypt.org
 Certificate Transparency     yes (certificate extension)
 Certificates provided        2
 Issuer                       R12 (Let's Encrypt from US)
 Intermediate cert validity   #1: ok > 40 days (2027-03-12 23:59). R12 <-- ISRG Root X1
 Intermediate Bad OCSP (exp.) Ok


 Testing HTTP header response @ "/" 

 HTTP Status Code             200 OK
 HTTP clock skew              0 sec from localtime
 Strict Transport Security    730 days=63072000 s, includeSubDomains, preload
 Public Key Pinning           --
 Server banner                nginx/1.29.3'
 Application banner           --
 Cookie(s)                    (none issued at "/")
 Security headers             X-Content-Type-Options: nosniff
 Reverse Proxy banner         --


 Testing vulnerabilities 

 Heartbleed (CVE-2014-0160)                not vulnerable (OK), no heartbeat extension
 CCS (CVE-2014-0224)                       not vulnerable (OK)
 Ticketbleed (CVE-2016-9244), experiment.  not vulnerable (OK), no session ticket extension
 Opossum (CVE-2025-49812)                  not vulnerable (OK)
 ROBOT                                     Server does not support any cipher suites that use RSA key transport
 Secure Renegotiation (RFC 5746)           not vulnerable (OK)
 Secure Client-Initiated Renegotiation     not vulnerable (OK)
 CRIME, TLS (CVE-2012-4929)                not vulnerable (OK)
 BREACH (CVE-2013-3587)                    no gzip/deflate/compress/br HTTP compression (OK)  - only supplied "/" tested
 POODLE, SSL (CVE-2014-3566)               not vulnerable (OK), no SSLv3 support
 TLS_FALLBACK_SCSV (RFC 7507)              No fallback possible (OK), TLS 1.3 is the only protocol
 SWEET32 (CVE-2016-2183, CVE-2016-6329)    not vulnerable (OK)
 FREAK (CVE-2015-0204)                     not vulnerable (OK)
 DROWN (CVE-2016-0800, CVE-2016-0703)      not vulnerable on this host and port (OK)
                                           make sure you don't use this certificate elsewhere with SSLv2 enabled services, see
                                           https://search.censys.io/search?resource=hosts&virtual_hosts=INCLUDE&q=284F5141A347BFBDE45CB356F4B99836EEF5B5DD62ECD55062A814CF2C9245AD
 LOGJAM (CVE-2015-4000), experimental      not vulnerable (OK): no DH EXPORT ciphers, no DH key detected with <= TLS 1.2
 BEAST (CVE-2011-3389)                     not vulnerable (OK), no SSL3 or TLS1
 LUCKY13 (CVE-2013-0169), experimental     not vulnerable (OK)
 Winshock (CVE-2014-6321), experimental    not vulnerable (OK)
 RC4 (CVE-2013-2566, CVE-2015-2808)        not vulnerable (OK)


 Running client simulations (HTTP) via sockets 

 Browser                      Protocol  Cipher Suite Name (OpenSSL)       Forward Secrecy
------------------------------------------------------------------------------------------------
 Android 7.0 (native)         No connection
 Android 8.1 (native)         No connection
 Android 9.0 (native)         TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Android 10.0 (native)        TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Android 11/12 (native)       TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Android 13/14 (native)       TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Android 15 (native)          TLSv1.3   TLS_AES_256_GCM_SHA384            X25519MLKEM768
 Chrome 101 (Win 10)          TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Chromium 137 (Win 11)        TLSv1.3   TLS_AES_256_GCM_SHA384            X25519MLKEM768
 Firefox 100 (Win 10)         TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Firefox 137 (Win 11)         TLSv1.3   TLS_AES_256_GCM_SHA384            X25519MLKEM768
 IE 8 Win 7                   No connection
 IE 11 Win 7                  No connection
 IE 11 Win 8.1                No connection
 IE 11 Win Phone 8.1          No connection
 IE 11 Win 10                 No connection
 Edge 15 Win 10               No connection
 Edge 101 Win 10 21H2         TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Edge 133 Win 11 23H2         TLSv1.3   TLS_AES_256_GCM_SHA384            X25519MLKEM768
 Safari 18.4 (iOS 18.4)       TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Safari 15.4 (macOS 12.3.1)   TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Safari 18.4 (macOS 15.4)     TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Java 7u25                    No connection
 Java 8u442 (OpenJDK)         TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Java 11.0.2 (OpenJDK)        TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Java 17.0.3 (OpenJDK)        TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 Java 21.0.6 (OpenJDK)        TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 go 1.17.8                    TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 LibreSSL 3.3.6 (macOS)       TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 OpenSSL 1.0.2e               No connection
 OpenSSL 1.1.1d (Debian)      TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 OpenSSL 3.0.15 (Debian)      TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)
 OpenSSL 3.5.0 (git)          TLSv1.3   TLS_AES_256_GCM_SHA384            X25519MLKEM768
 Apple Mail (16.0)            No connection
 Thunderbird (91.9)           TLSv1.3   TLS_AES_256_GCM_SHA384            384 bit ECDH (P-384)


 Rating (experimental) 

 Rating specs (not complete)  SSL Labs's 'SSL Server Rating Guide' (version 2009r from 2025-05-16)
 Specification documentation  https://github.com/ssllabs/research/wiki/SSL-Server-Rating-Guide
 Protocol Support (weighted)  100 (30)
 Key Exchange     (weighted)  100 (30)
 Cipher Strength  (weighted)  90 (36)
 Final Score                  96
 Overall Grade                A+

 Done 2025-11-07 19:33:19 [  66s] -->> 71.185.218.5:443 (keysupport.net) <<--

-------------------------------------------------------------------------------------------------------------------------------------------------------------
Done testing now all IP addresses (on port 443): 71.185.218.5