NULL-SHA
TLS_RSA_WITH_NULL_SHA
NULL-SHA is a no-encryption cipher suite – data is transmitted in plaintext. The only protection is SHA-1 integrity checking. NULL cipher suites exist for testing and debugging only. No production system should ever negotiate a NULL cipher suite. Most modern TLS implementations refuse to negotiate NULL suites by default.
Key Exchange
RSA
Authentication
RSA
Encryption
None
MAC / Integrity
SHA-1
Details
NULL cipher suites disable all encryption. They were included in TLS for testing environments where traffic analysis is needed without the complexity of encryption. Any network observer can read the complete session contents. NULL suites are disabled by default in all production TLS libraries (OpenSSL, GnuTLS, NSS). Their presence in a cipher suite list indicates a severely misconfigured server.