TLS_ECDH_ECDSA_WITH_NULL_SHA

What each component means

A cipher suite names the algorithms a client and server agree on in one handshake. TLS_ECDH_ECDSA_WITH_NULL_SHA combines ECDH key exchange, ECDSA authentication, NULL encryption and SHA1 integrity protection. Each part is explained below with its known weaknesses; for the bigger picture see how cipher suites work.

Key exchange: static ECDH. The server's elliptic-curve DH key is fixed in its certificate, so there is no forward secrecy, and a server that reuses one ECDH key without validating the client's point is open to invalid-curve attacks (Jager, Schwenk and Somorovsky, 2015). The ECDSA in the name is the algorithm the CA used to sign the ECDH certificate, not a signature made during the handshake.

Encryption: none. Records are only protected by the SHA1 MAC, so anyone on the path can read the plaintext. RFC 9325 (2022) says implementations MUST NOT negotiate NULL-encryption suites, while noting they can still be useful for testing and debugging.

Integrity: HMAC-SHA1. SHA-1 collisions are practical (SHAttered, 2017), but HMAC does not rely on collision resistance, so HMAC-SHA1 record MACs are not considered broken; this suite's weak points lie elsewhere. When TLS 1.2 is negotiated, keys are derived with the SHA-256 PRF, which RFC 5246 (2008) applies to every cipher suite defined before it.

Why this rating

ssl.sh rating: Insecure. The reasons:

• No encryption (NULL cipher): traffic is sent in clear text.

How ssl.sh rates cipher suites

Which TLS libraries support it

Support for TLS_ECDH_ECDSA_WITH_NULL_SHA as read from each library's own source code or official documentation on 2026-11-10. “Enabled by default” means the library negotiates it with no configuration; “off by default” means it is implemented but has to be switched on.

None of the 9 libraries tracked here enables it by default. Supported but off by default in: NSS 3.133 and Java 21 (SunJSSE).

NSS shows the library's own defaults; Firefox switches every NSS suite off at start-up and re-enables only those with a security.ssl3.* or security.tls13.* preference. Java defaults are derived from the jdk.tls.disabledAlgorithms value Oracle documents for JDK 21, which later updates may extend. The OpenSSL and GnuTLS rows only show whether the suite is implemented.

History and standards status

TLS_ECDH_ECDSA_WITH_NULL_SHA (0xC0,0x01) is registered in the IANA TLS Cipher Suites registry with RFC 8422, “Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS) Versions 1.2 and Earlier” (August 2018, Standards Track) as its specification. RFC 8422 has since been obsoleted by RFC 9846 (2026). RFC 9325 (2022), part of BCP 195, says implementations MUST NOT negotiate suites with NULL encryption. RFC 9325 (2022), part of BCP 195, says implementations SHOULD NOT negotiate static DH or ECDH key agreement because neither has forward secrecy. RFC 10015 (2026) also says clients SHOULD NOT offer and servers SHOULD NOT select non-ephemeral ECDH suites in (D)TLS 1.2, and IANA changed this entry's Recommended value to D.

Enable or disable it in Nginx and Apache

OpenSSL 3.5 doesn't implement this suite, so stock Nginx and Apache httpd builds can't offer it and you don't need to disable it.

How to test whether a server accepts it

OpenSSL 3.5 cannot offer TLS_ECDH_ECDSA_WITH_NULL_SHA, so openssl s_client can't test it directly; use a scanner that implements the suite itself.

nmap's ssl-enum-ciphers script connects repeatedly, trying one suite at a time, and lists every suite the server accepts with a grade from A to F. Look for TLS_ECDH_ECDSA_WITH_NULL_SHA in its output:

nmap --script ssl-enum-ciphers -p 443 example.com

To decode a name or hex code, use the cipher suite lookup; the SSL checker shows which protocol versions a live server accepts and the cipher suite it negotiates.