# TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 cipher suite

> TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (0xCC,0xAA): DHE/RSA · ChaCha20-Poly1305 · TLS 1.2. ssl.sh rating: Secure. OpenSSL/GnuTLS names and Nginx/Apache config.

Source: https://ssl.sh/ciphers/tls-dhe-rsa-with-chacha20-poly1305-sha256/
Last updated: 2026-11-10

TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (0xCC,0xAA) is a cipher suite for TLS 1.2: DHE key exchange, RSA authentication, ChaCha20-Poly1305 encryption and AEAD message authentication. ssl.sh rates it Secure.

| Field | Value |
|---|---|
| IANA | TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 |
| Hex code | 0xCC,0xAA |
| OpenSSL | DHE-RSA-CHACHA20-POLY1305 |
| GnuTLS | TLS_DHE_RSA_CHACHA20_POLY1305 |
| Key exchange | DHE |
| Authentication | RSA |
| Encryption | ChaCha20-Poly1305 |
| MAC | AEAD |
| TLS versions | TLS 1.2 |
| Rating | Secure |
| IANA "Recommended" | D |
| References | RFC 7905, RFC 10015 |

## What each component means

A [cipher suite](https://ssl.sh/glossary/cipher-suite/) names the algorithms a client and server agree on in one handshake. TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 combines DHE key exchange, RSA authentication, ChaCha20-Poly1305 encryption and AEAD integrity protection. Each part is explained below with its known weaknesses; for the bigger picture see [how cipher suites work](https://ssl.sh/learn/cipher-suites/).

Key exchange: DHE, ephemeral finite-field [Diffie-Hellman](https://ssl.sh/glossary/diffie-hellman/). A new DH key pair per handshake gives [forward secrecy](https://ssl.sh/glossary/forward-secrecy/), but in TLS 1.2 the server alone picks the group and the client cannot ask for a stronger one; [RFC 7919](https://www.rfc-editor.org/rfc/rfc7919) (2016) added negotiated FFDHE groups, which saw little uptake. [Logjam](https://ssl.sh/glossary/logjam/) (CVE-2015-4000, 2015) broke servers that still accepted 512-bit export groups and showed that huge numbers of sites shared the same few 1024-bit primes, and the Raccoon timing attack (2020) exploits how TLS 1.2 strips leading zero bytes from the DH secret. Those are the reasons [RFC 9325](https://www.rfc-editor.org/rfc/rfc9325) (2022) gives for telling TLS 1.2 implementations not to negotiate TLS_DHE_* suites.

Authentication: the server proves its identity with an [RSA](https://ssl.sh/glossary/rsa/) certificate, signing the handshake's key-exchange parameters with its private key. The RSA key is only used to sign, so it does not weaken [forward secrecy](https://ssl.sh/glossary/forward-secrecy/). Publicly trusted CAs issue RSA certificates with keys of at least 2048 bits.

Encryption: [ChaCha20-Poly1305](https://ssl.sh/glossary/chacha20-poly1305/), an [AEAD](https://ssl.sh/glossary/aead/) pairing the ChaCha20 stream cipher (256-bit key) with the Poly1305 authenticator and a 16-byte tag. It is fast and constant-time in plain software, so it is the usual choice for devices without AES instructions. [RFC 7905](https://www.rfc-editor.org/rfc/rfc7905) (2016) brought it to TLS 1.2 and builds the 96-bit nonce by XORing the padded record sequence number with the sender's write IV, so no explicit nonce is sent with each record.

Integrity: there is no separate MAC because the AEAD tag authenticates every record. The SHA256 at the end of the name selects the TLS 1.2 PRF hash used to derive keys and compute the Finished messages.

## Why this rating

- Ephemeral key exchange (forward secrecy) plus an AEAD cipher, the combination TLS 1.2 best practice asks for.

## Which TLS libraries support it

Support for TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 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.

| Library | Status | Details |
|---|---|---|
| OpenSSL 3.5 | Implemented | cipher string `DHE-RSA-CHACHA20-POLY1305` |
| GnuTLS | Implemented | name `TLS_DHE_RSA_CHACHA20_POLY1305`; minimum protocol `TLS 1.2` |
| BoringSSL | Not supported | - |
| Go crypto/tls | Not supported | - |
| NSS 3.133 | Enabled by default | NSS library default |
| Firefox | Not supported | - |
| Java 21 (SunJSSE) | Enabled by default | - |
| Windows Schannel (Windows 11 / Server 2022) | Not supported | - |
| rustls 0.23.46 | Not supported | - |

Enabled by default in 2 of the 9 libraries tracked here: NSS 3.133 and Java 21 (SunJSSE). Also implemented by: OpenSSL 3.5 and GnuTLS.

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.

- [BoringSSL — ssl/ssl_cipher.cc (main)](https://boringssl.googlesource.com/boringssl/+/refs/heads/main/ssl/ssl_cipher.cc) (2026-11-10)
- [Go — src/crypto/tls/cipher_suites.go (master)](https://github.com/golang/go/blob/master/src/crypto/tls/cipher_suites.go) (2026-11-10)
- [Go — src/crypto/tls/defaults.go (master)](https://github.com/golang/go/blob/master/src/crypto/tls/defaults.go) (2026-11-10)
- [NSS — lib/ssl/ssl3con.c (as vendored in Firefox)](https://github.com/mozilla-firefox/firefox/blob/main/security/nss/lib/ssl/ssl3con.c) (2026-11-10)
- [NSS — TAG-INFO](https://github.com/mozilla-firefox/firefox/blob/main/security/nss/TAG-INFO) (2026-11-10)
- [Firefox — security/manager/ssl/nsNSSComponent.cpp](https://github.com/mozilla-firefox/firefox/blob/main/security/manager/ssl/nsNSSComponent.cpp) (2026-11-10)
- [Firefox — modules/libpref/init/StaticPrefList.yaml](https://github.com/mozilla-firefox/firefox/blob/main/modules/libpref/init/StaticPrefList.yaml) (2026-11-10)
- [Oracle — JDK 21 Providers Documentation: SunJSSE Cipher Suites](https://docs.oracle.com/en/java/javase/21/security/oracle-providers.html#GUID-7093246A-31A3-4304-AC5F-5FB6400405E2) (2026-11-10)
- [Oracle — JDK 21 JSSE Reference Guide: jdk.tls.disabledAlgorithms](https://docs.oracle.com/en/java/javase/21/security/java-secure-socket-extension-jsse-reference-guide.html) (2026-11-10)
- [Microsoft Learn — TLS Cipher Suites in Windows 11](https://learn.microsoft.com/en-us/windows/win32/secauthn/tls-cipher-suites-in-windows-11) (2026-11-10)
- [Microsoft Learn — TLS Cipher Suites in Windows Server 2022](https://learn.microsoft.com/en-us/windows/win32/secauthn/tls-cipher-suites-in-windows-server-2022) (2026-11-10)
- [docs.rs — rustls 0.23.46 crypto::aws_lc_rs (default provider)](https://docs.rs/rustls/0.23.46/src/rustls/crypto/aws_lc_rs/mod.rs.html) (2026-11-10)

## History and standards status

TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (0xCC,0xAA) is registered in the IANA TLS Cipher Suites registry with [RFC 7905](https://www.rfc-editor.org/rfc/rfc7905), “ChaCha20-Poly1305 Cipher Suites for Transport Layer Security (TLS)” (June 2016, Standards Track) as its specification. [RFC 9325](https://www.rfc-editor.org/rfc/rfc9325) (2022), part of BCP 195, says TLS 1.2 implementations SHOULD NOT negotiate TLS_DHE_* suites, citing the Raccoon attack and the poor uptake of negotiated groups. [RFC 10015](https://www.rfc-editor.org/rfc/rfc10015) (2026) now says clients MUST NOT offer and servers MUST NOT select FFDHE suites in (D)TLS 1.2, and IANA changed this entry's Recommended value to D.

## Nginx / Apache

Enable

```nginx
ssl_protocols TLSv1.2 TLSv1.3;
ssl_ciphers 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-CHACHA20-POLY1305';
ssl_prefer_server_ciphers off;
```

```apache
SSLProtocol -all +TLSv1.2 +TLSv1.3
SSLCipherSuite ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-CHACHA20-POLY1305
SSLHonorCipherOrder off
```

Disable

```nginx
ssl_ciphers 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:!DHE-RSA-CHACHA20-POLY1305';
```

```apache
SSLCipherSuite ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:!DHE-RSA-CHACHA20-POLY1305
```


## How to test whether a server accepts it

Offer only TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 with openssl s_client; if the handshake completes, the server accepts it:

```bash
openssl s_client -connect example.com:443 -tls1_2 -cipher DHE-RSA-CHACHA20-POLY1305 </dev/null
```

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_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 in its output:

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

To decode a name or hex code, use the [cipher suite lookup](https://ssl.sh/tools/cipher-suite-lookup/); the [SSL checker](https://ssl.sh/tools/ssl-checker/) shows which protocol versions a live server accepts and the cipher suite it negotiates.

## FAQ

### Is TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 secure?

Cryptographically, yes: ssl.sh rates it secure. Ephemeral key exchange (forward secrecy) plus an AEAD cipher, the combination TLS 1.2 best practice asks for. Standards have moved on, though: [RFC 10015](https://www.rfc-editor.org/rfc/rfc10015) (2026) now says clients MUST NOT offer and servers MUST NOT select FFDHE suites in (D)TLS 1.2, and IANA changed this entry's Recommended value to D.

### Can TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 be used with TLS 1.3?

No. TLS 1.3 has its own suites that name only the AEAD and the hash, and TLS 1.2 suites can't be used in a TLS 1.3 handshake. TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 works with TLS 1.2. The closest TLS 1.3 suite is [TLS_CHACHA20_POLY1305_SHA256](https://ssl.sh/ciphers/tls-chacha20-poly1305-sha256/), which TLS 1.3 combines with a separately negotiated key exchange such as X25519.

### How do I enable TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 in Nginx or Apache?

Add `DHE-RSA-CHACHA20-POLY1305` (its OpenSSL name) to `ssl_ciphers` in Nginx or to `SSLCipherSuite` in Apache httpd, keep TLS 1.2 enabled in `ssl_protocols` or `SSLProtocol`, and reload. The full snippet is in the configuration section above.

### Which clients and libraries still support TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256?

Out of the box: NSS 3.133 and Java 21 (SunJSSE). Implemented, default state not tracked here: OpenSSL 3.5 and GnuTLS. Not supported: BoringSSL, Go crypto/tls, Firefox, Windows Schannel (Windows 11 / Server 2022) and rustls 0.23.46.