SSL cipher specifications

When an SSL connection is established, the client (web browser) and the web server negotiate the cipher to use for the connection. The web server has an ordered list of ciphers, and the first cipher in the list that is supported by the client is selected.

Introduction

View the list of current of SSL ciphers.

Attention: This list of ciphers could change as a result of updates to industry standards. You can determine the list of ciphers supported in a particular version of IBM HTTP Server by configuring it to load mod_ibm_ssl and running bin/apachectl -t -f path/to/httpd.conf -DDUMP_SSL_CIPHERS.

The SSLFIPSEnable directive enables Federal Information Processing Standards (FIPS). When the SSLFIPSEnable directive is enabled, the set of ciphers available is restricted as shown, and SSLv2 and SSLv3 are disabled as well as TLSv11 and TLSv12. Only TLSv10 is enabled for FIPS compliance.

Avoid trouble:

Ciphers containing "ECDHE_RSA" in their name use a standard RSA certificate and can coexist with older RSA ciphers and clients.
Ciphers containing "ECDHE_ECDSA" in their name requires an ECC (Elliptic Curve Cryptography) certificate/key to be created (with gskcapicmd if you are running on a distributed platform, or gskkyman if you are running on z/OS).
On z/OS, several criteria must be met to use "ECDHE" ciphers:
- ICSF must be available to use ECC or AES-GCM ciphers. See RACF CSFSERV Resource Requirements in the z/OS Cryptographic Services System SSL Programming for more information.
- Ciphers containing "ECDHE" or "GCM" in their name must be explicitly enabled and should be enabled via their "long name". These ciphers will fail at runtime if the RACF CSFSERV Resource Requirements are not met.

SSL and TLS ciphers

Attention: SSL and TLS cipher values:

"-" = cipher that is not valid for the protocol
"d" = cipher is enabled by default
"d*"= cipher is enabled by default on distributed platforms only
"y" = cipher is valid but not enabled by default
"y*" = In prior maintenance levels, cipher was enabled by default ("d" or "d*").
- cipher is valid but not enabled by default.
- cipher is valid and enabled by default.

For transitioning users: To improve security, IBM HTTP Server Version 8.0 disables weak SSL ciphers, export SSL ciphers, and the SSL version 2 protocol by default. SSL Version 2, weak ciphers, and export ciphers are generally unsuitable for production SSL workloads on the internet and are flagged by security scanners. To enable ciphers, use the SSLCipherSpec directive.

Table 1. TLS ciphers
Short name	Long name	Key size (bits)	FIPS	SSLV2	SSLV3	TLSv10	TLSv11	TLSv12
C030	TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384	256	y	-	-	-	-	d*
C02F	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256	128	y	-	-	-	-	d*
C028	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384	256	y	-	-	-	-	d*
C027	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256	128	y	-	-	-	-	d*
C014	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA	256	y	-	-	-	-	d*
C013	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA	128	y	-	-	-	-	d*
9D	TLS_RSA_WITH_AES_256_GCM_SHA384	256	y	-	-	-	-	y*
9C	TLS_RSA_WITH_AES_128_GCM_SHA256	128	y	-	-	-	-	y*
3D	TLS_RSA_WITH_AES_256_CBC_SHA256	256	y	-	-	-	-	y*
3C	TLS_RSA_WITH_AES_128_CBC_SHA256	128	y	-	-	-	-	y*
35b	TLS_RSA_WITH_AES_256_CBC_SHA	256	y	-	y	y*	y*	y*
2F	TLS_RSA_WITH_AES_128_CBC_SHA	128	y	-	y	y*	y*	y*
C023	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256	128	y	-	-	-	-	d*
C024	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384	256	y	-	-	-	-	d*
C009	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA	128	y	-	-	-	-	d*
C00A	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA	256	y	-	-	-	-	d*
C02B	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256	128	y	-	-	-	-	d*
C02C	TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384	256	y	-	-	-	-	d*

Note: The TLSv10 and TLSv11 protocols are not enabled by default after IBM HTTP Server versions 9.0.5.9. and 8.5.5.20.

Note: 3DES ciphers are disabled by default on IBM HTTP Server version 8.5.5.13 and later.

Attention: * indicates that SSLv3 is disabled by default in version 8.5.5.4 and later with PI27904.

Attention: ** indicates that the ECDHE cipher is enabled by default for TLSv1.2 in versions 8.5.5.12 and 8.0.0.14 and after.

Weaker ciphers, not enabled by default:

Table 2. Other TLS ciphers
Short name	Long name	Key size (bits)	FIPS	SSLV2	SSLV3	TLSv10	TLSv11	TLSv12
C010	TLS_ECDHE_RSA_WITH_NULL_SHA	0	y	-	-	-	-	y
C008	TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA	168	y	-	-	-	-	y
C012	TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA	168	y	-	-	-	-	y
3A	SSL_RSA_WITH_3DES_EDE_CBC_SHA	168	y	-	y	y	y	y
C007	TLS_ECDHE_ECDSA_WITH_RC4_128_SHA	128	y	-	-	-	-	y
C011	TLS_ECDHE_RSA_WITH_RC4_128_SHA	128	y	-	-	-	-	y
35	SSL_RSA_WITH_RC4_128_SHA	128	-	-	y	y	y	y
34	SSL_RSA_WITH_RC4_128_MD5	128	-	-	y	y	y	-
39	SSL_RSA_WITH_DES_CBC_SHA	56	-	-	y	y	y	-
33	SSL_RSA_EXPORT_WITH_RC4_40_MD5	40	-	-	y	y	-	-
36	SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5	40	-	-	y	y	-	-
62	TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA	56	-	-	y	y	-	-
64	TLS_RSA_EXPORT1024_WITH_RC4_56_SHA	56	-	-	y	y	-	-
32	SSL_RSA_WITH_NULL_SHA	0	-	-	y	y	y	y
31	SSL_RSA_WITH_NULL_MD5	0	-	-	y	y	y	-
3B	TLS_RSA_WITH_NULL_SHA256	0	y	-	-	-	-	y
30	SSL_NULL_WITH_NULL_NULL	0	-	-	y	y	y	y
27	SSL_DES_192_EDE3_CBC_WITH_MD5	168	-	y	-	-	-	-
21	SSL_RC4_128_WITH_MD5	128	-	y	-	-	-	-
23	SSL_RC2_CBC_128_CBC_WITH_MD5	128	-	y	-	-	-	-
26	SSL_DES_64_CBC_WITH_MD5	56	-	y	-	-	-	-
24	SSL_RC2_CBC_128_CBC_EXPORT40_WITH_MD5	40	-	y	-	-	-	-
22	SSL_RC4_128_EXPORT40_WITH_MD5	40	-	y	-	-	-	-
FE	SSL_RSA_FIPS_WITH_DES_CBC_SHA	56	-	-	-	-	-	-
FF	SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA	168	-	-	-	-	-	-