TLS is a set of security protocols that provide communication security over networks. The Internet Engineering Task Force (IETF) is the regulatory organization that defines, updates, and releases TLS standards. TLS 1.3 is the latest version.
The Celigo platform supports TLS 1.2 and 1.3.
Important
As of September 30, 2025, the Celigo platform no longer supports TLS 1.0 and TLS 1.1. Verify that all your custom integrations use endpoints that are TLS 1.2 or higher.
TLS 1.0 and 1.1 are susceptible to security vulnerabilities because both use weak hash algorithms (e.g. SHA-1, MD5) and have inadequate support for modern ciphers. Legacy ciphers use weak encryption, are incompatible with compliance standards (PCI-DSS, NIST), and are vulnerable to known attacks like BEAST, POODLE, and SWEET32.
The Celigo platform does NOT support the following deprecated legacy ciphers.
RC4
3DES
DES
EXPORT and NULL ciphers
MD5 and SHA1-based suites
- Anonymous cipher suites (e.g., ADH)
The Celigo platform supports modern, secure ciphers to be used with TLS 1.2 and TLS 1.3:
ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-RSA-AES256-GCM-SHA384
ECDHE-ECDSA-CHACHA20-POLY1305
-
TLS 1.3 default ciphers (non-configurable):
TLS_AES_128_GCM_SHA256
TLS_AES_256_GCM_SHA384
- TLS_CHACHA20_POLY1305_SHA256
If you are connecting to an endpoint that doesn't provide documentation that identifies the TLS version, you can use sslyze (a Python-based tool that can scan servers for SSL/TLS configuration).
EPROTO (final_renegotiate:unsafe legacy renegotiation disabled)
ERR_CRYPTO_UNSUPPORTED_OPERATION
SSL_ERROR_UNSUPPORTED_VERSION
ERR_SSL_VERSION_OR_CIPHER_MISMATCH
handshake_failure messages in logs
Clients unable to connect to endpoints due to unsupported cipher negotiation
API gateway failures when interfacing with third-party systems still using deprecated protocols