Description

The CTL_SSL_CIPHER_LIST option specifies the acceptable and preferred SSL/TLS cipher suites to use for the control session between UDM components, or it can be used to disable the SSL/TLS protocol.

The SSL/TLS protocol uses the cipher suites to specify which encryption and message authentication (or message digest) algorithms to use.

Usage

Method	Syntax	IBM i	UNIX	Windows	z/OS
Command Line, Short Form	n/a
Command Line, Long Form	-ctl_ssl_cipher_list list
Environment Variable	UDMCTLSSLCIPHERLIST=list
Configuration File Keyword	ctl_ssl_cipher_list list
STRUDM Parameter	CTLCPHRLST(cipherlist)

Values

list is a comma-separated list of SSL/TLS cipher suites. The following table identifies the list of SSL/TLS cipher suites supported for this option.

The list is in default order, with the most preferred suite first and the least preferred suite last.

Cipher Suite Name	Description
AES256-GCM-SHA384	256-bit AES encryption in Galois Counter Mode, SHA-2 384-bit message digest.
AES256-SHA	256-bit AES encryption with SHA-1 message digest.
AES128-GCM-SHA256	128-bit AES encryption in Galois Counter Mode, SHA-2 256-bit message digest.
AES128-SHA	128-bit AES encryption with SHA-1 message digest.
ECDHE-RSA-AES256-GCM-SHA384	Ephemeral Elliptic Curve Diffie-Hellman Key Exchange, RSA authentication, 256-bit AES encryption in Galois Counter Mode, SHA-2 384-bit message digest.
ECDHE-ECDSA-AES256-GCM-SHA384	Ephemeral Elliptic Curve Diffie-Hellman Key Exchange, ECDSA authentication, 256-bit AES encryption in Galois Counter Mode, SHA-2 384-bit message digest.
ECDHE-RSA-AES128-GCM-SHA256	Ephemeral Elliptic Curve Diffie-Hellman Key Exchange, RSA authentication, 128-bit AES encryption in Galois Counter Mode, SHA-2 256-bit message digest.
ECDHE-ECDSA-AES128-GCM-SHA256	Ephemeral Elliptic Curve Diffie-Hellman Key Exchange, ECDSA authentication, 128-bit AES encryption in Galois Counter Mode, SHA-2 256-bit message digest.
RC4-SHA	128-bit RC4 encryption with SHA-1 message digest.
RC4-MD5	128-bit RC4 encryption with MD5 message digest.
DES-CBC3-SHA	128-bit Triple-DES encryption with SHA-1 message digest.
DES-CBC-SHA	128-bit DES encryption with SHA-1 message digest. Note As of Universal Agent 6.7.0.0, DES-CBC-SHA is supported only on HP-UX. Additionally, any Agents on HP-UX that accept connections from, or attempt connections to, Agents on other platforms must be configured with at least one currently supported cipher suite besides DES-CBC-SHA. Therefore, those HP-UX Agents cannot be configured only with DES-CBC-SHA in their list of cipher suites.
NULL-SHA256	No encryption and SHA-2 256-bit message digest.
NULL-SHA	No encryption and SHA-1 message digest.
NULL-MD5	No encryption and MD5 message digest.
NULL-NULL	No encryption, no data authentication, SSL is not used; instead, Universal V2 Protocol(UNVv2) is used.

A single value of NULL-NULL instead of the list disables the SSL/TLS protocol. The legacy Universal Products (UNVv2) protocol without encryption and message authentication is used instead of SSL/TLS.

No data privacy or data integrity is provided with the UNVv2 network communications protocol.

NULL-NULL can be specified if the UDM Server ENCRYPT_CONTROL_SESSION configuration option value is no.

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