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ciphers(1)



NAME

ciphers - SSL cipher display and cipher list tool.


SYNOPSIS

openssl ciphers [-v] [-V] [-ssl2] [-ssl3] [-tls1] [cipherlist]


DESCRIPTION

The ciphers command converts textual OpenSSL cipher lists into ordered SSL cipher preference lists. It can be used as a test tool to determine the appropriate cipherlist.


COMMAND OPTIONS

-v

Verbose option. List ciphers with a complete description of protocol version (SSLv2 or SSLv3; the latter includes TLS), key exchange, authentication, encryption and mac algorithms used along with any key size restrictions and whether the algorithm is classed as an ``export'' cipher. Note that without the -v option, ciphers may seem to appear twice in a cipher list; this is when similar ciphers are available for SSL v2 and for SSL v3/TLS v1.

-V

Like -V, but include cipher suite codes in output (hex format).

-ssl3

only include SSL v3 ciphers.

-ssl2

only include SSL v2 ciphers.

-tls1

only include TLS v1 ciphers.

-h, -?

print a brief usage message.

cipherlist

a cipher list to convert to a cipher preference list. If it is not included then the default cipher list will be used. The format is described below.


CIPHER LIST FORMAT

The cipher list consists of one or more cipher strings separated by colons. Commas or spaces are also acceptable separators but colons are normally used.

The actual cipher string can take several different forms.

It can consist of a single cipher suite such as RC4-SHA.

It can represent a list of cipher suites containing a certain algorithm, or cipher suites of a certain type. For example SHA1 represents all ciphers suites using the digest algorithm SHA1 and SSLv3 represents all SSL v3 algorithms.

Lists of cipher suites can be combined in a single cipher string using the + character. This is used as a logical and operation. For example SHA1+DES represents all cipher suites containing the SHA1 and the DES algorithms.

Each cipher string can be optionally preceded by the characters !, - or +.

If ! is used then the ciphers are permanently deleted from the list. The ciphers deleted can never reappear in the list even if they are explicitly stated.

If - is used then the ciphers are deleted from the list, but some or all of the ciphers can be added again by later options.

If + is used then the ciphers are moved to the end of the list. This option doesn't add any new ciphers it just moves matching existing ones.

If none of these characters is present then the string is just interpreted as a list of ciphers to be appended to the current preference list. If the list includes any ciphers already present they will be ignored: that is they will not moved to the end of the list.

Additionally the cipher string @STRENGTH can be used at any point to sort the current cipher list in order of encryption algorithm key length.


CIPHER STRINGS

The following is a list of all permitted cipher strings and their meanings.

DEFAULT

the default cipher list. This is determined at compile time and is normally ALL:!ADH:RC4+RSA:+SSLv2:@STRENGTH. This must be the first cipher string specified.

COMPLEMENTOFDEFAULT

the ciphers included in ALL, but not enabled by default. Currently this is ADH. Note that this rule does not cover eNULL, which is not included by ALL (use COMPLEMENTOFALL if necessary).

ALL

all ciphers suites except the eNULL ciphers which must be explicitly enabled.

COMPLEMENTOFALL

the cipher suites not enabled by ALL, currently being eNULL.

HIGH

``high'' encryption cipher suites. This currently means those with key lengths larger than 128 bits, and some cipher suites with 128-bit keys.

MEDIUM

``medium'' encryption cipher suites, currently some of those using 128 bit encryption.

LOW

``low'' encryption cipher suites, currently those using 64 or 56 bit encryption algorithms but excluding export cipher suites.

EXP, EXPORT

export encryption algorithms. Including 40 and 56 bits algorithms.

EXPORT40

40 bit export encryption algorithms

EXPORT56

56 bit export encryption algorithms. In OpenSSL 0.9.8c and later the set of 56 bit export ciphers is empty unless OpenSSL has been explicitly configured with support for experimental ciphers.

eNULL, NULL

the ``NULL'' ciphers that is those offering no encryption. Because these offer no encryption at all and are a security risk they are disabled unless explicitly included.

aNULL

the cipher suites offering no authentication. This is currently the anonymous DH algorithms. These cipher suites are vulnerable to a ``man in the middle'' attack and so their use is normally discouraged.

kRSA, RSA

cipher suites using RSA key exchange.

kEDH

cipher suites using ephemeral DH key agreement.

kDHr, kDHd

cipher suites using DH key agreement and DH certificates signed by CAs with RSA and DSS keys respectively. Not implemented.

aRSA

cipher suites using RSA authentication, i.e. the certificates carry RSA keys.

aDSS, DSS

cipher suites using DSS authentication, i.e. the certificates carry DSS keys.

aDH

cipher suites effectively using DH authentication, i.e. the certificates carry DH keys. Not implemented.

kFZA, aFZA, eFZA, FZA

ciphers suites using FORTEZZA key exchange, authentication, encryption or all FORTEZZA algorithms. Not implemented.

TLSv1, SSLv3, SSLv2

TLS v1.0, SSL v3.0 or SSL v2.0 cipher suites respectively.

DH

cipher suites using DH, including anonymous DH.

ADH

anonymous DH cipher suites.

AES

cipher suites using AES.

3DES

cipher suites using triple DES.

DES

cipher suites using DES (not triple DES).

RC4

cipher suites using RC4.

RC2

cipher suites using RC2.

IDEA

cipher suites using IDEA.

MD5

cipher suites using MD5.

SHA1, SHA

cipher suites using SHA1.

Camellia

cipher suites using Camellia.


CIPHER SUITE NAMES

The following lists give the SSL or TLS cipher suites names from the relevant specification and their OpenSSL equivalents. It should be noted, that several cipher suite names do not include the authentication used, e.g. DES-CBC3-SHA. In these cases, RSA authentication is used.


SSL v3.0 cipher suites.

 SSL_RSA_WITH_NULL_MD5                   NULL-MD5
 SSL_RSA_WITH_NULL_SHA                   NULL-SHA
 SSL_RSA_EXPORT_WITH_RC4_40_MD5          EXP-RC4-MD5
 SSL_RSA_WITH_RC4_128_MD5                RC4-MD5
 SSL_RSA_WITH_RC4_128_SHA                RC4-SHA
 SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5      EXP-RC2-CBC-MD5
 SSL_RSA_WITH_IDEA_CBC_SHA               IDEA-CBC-SHA
 SSL_RSA_EXPORT_WITH_DES40_CBC_SHA       EXP-DES-CBC-SHA
 SSL_RSA_WITH_DES_CBC_SHA                DES-CBC-SHA
 SSL_RSA_WITH_3DES_EDE_CBC_SHA           DES-CBC3-SHA
 SSL_DH_DSS_EXPORT_WITH_DES40_CBC_SHA    Not implemented.
 SSL_DH_DSS_WITH_DES_CBC_SHA             Not implemented.
 SSL_DH_DSS_WITH_3DES_EDE_CBC_SHA        Not implemented.
 SSL_DH_RSA_EXPORT_WITH_DES40_CBC_SHA    Not implemented.
 SSL_DH_RSA_WITH_DES_CBC_SHA             Not implemented.
 SSL_DH_RSA_WITH_3DES_EDE_CBC_SHA        Not implemented.
 SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA   EXP-EDH-DSS-DES-CBC-SHA
 SSL_DHE_DSS_WITH_DES_CBC_SHA            EDH-DSS-CBC-SHA
 SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA       EDH-DSS-DES-CBC3-SHA
 SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA   EXP-EDH-RSA-DES-CBC-SHA
 SSL_DHE_RSA_WITH_DES_CBC_SHA            EDH-RSA-DES-CBC-SHA
 SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA       EDH-RSA-DES-CBC3-SHA
 SSL_DH_anon_EXPORT_WITH_RC4_40_MD5      EXP-ADH-RC4-MD5
 SSL_DH_anon_WITH_RC4_128_MD5            ADH-RC4-MD5
 SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA   EXP-ADH-DES-CBC-SHA
 SSL_DH_anon_WITH_DES_CBC_SHA            ADH-DES-CBC-SHA
 SSL_DH_anon_WITH_3DES_EDE_CBC_SHA       ADH-DES-CBC3-SHA
 SSL_FORTEZZA_KEA_WITH_NULL_SHA          Not implemented.
 SSL_FORTEZZA_KEA_WITH_FORTEZZA_CBC_SHA  Not implemented.
 SSL_FORTEZZA_KEA_WITH_RC4_128_SHA       Not implemented.


TLS v1.0 cipher suites.

 TLS_RSA_WITH_NULL_MD5                   NULL-MD5
 TLS_RSA_WITH_NULL_SHA                   NULL-SHA
 TLS_RSA_EXPORT_WITH_RC4_40_MD5          EXP-RC4-MD5
 TLS_RSA_WITH_RC4_128_MD5                RC4-MD5
 TLS_RSA_WITH_RC4_128_SHA                RC4-SHA
 TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5      EXP-RC2-CBC-MD5
 TLS_RSA_WITH_IDEA_CBC_SHA               IDEA-CBC-SHA
 TLS_RSA_EXPORT_WITH_DES40_CBC_SHA       EXP-DES-CBC-SHA
 TLS_RSA_WITH_DES_CBC_SHA                DES-CBC-SHA
 TLS_RSA_WITH_3DES_EDE_CBC_SHA           DES-CBC3-SHA
 TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA    Not implemented.
 TLS_DH_DSS_WITH_DES_CBC_SHA             Not implemented.
 TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA        Not implemented.
 TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA    Not implemented.
 TLS_DH_RSA_WITH_DES_CBC_SHA             Not implemented.
 TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA        Not implemented.
 TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA   EXP-EDH-DSS-DES-CBC-SHA
 TLS_DHE_DSS_WITH_DES_CBC_SHA            EDH-DSS-CBC-SHA
 TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA       EDH-DSS-DES-CBC3-SHA
 TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA   EXP-EDH-RSA-DES-CBC-SHA
 TLS_DHE_RSA_WITH_DES_CBC_SHA            EDH-RSA-DES-CBC-SHA
 TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA       EDH-RSA-DES-CBC3-SHA
 TLS_DH_anon_EXPORT_WITH_RC4_40_MD5      EXP-ADH-RC4-MD5
 TLS_DH_anon_WITH_RC4_128_MD5            ADH-RC4-MD5
 TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA   EXP-ADH-DES-CBC-SHA
 TLS_DH_anon_WITH_DES_CBC_SHA            ADH-DES-CBC-SHA
 TLS_DH_anon_WITH_3DES_EDE_CBC_SHA       ADH-DES-CBC3-SHA


AES ciphersuites from RFC3268, extending TLS v1.0

 TLS_RSA_WITH_AES_128_CBC_SHA            AES128-SHA
 TLS_RSA_WITH_AES_256_CBC_SHA            AES256-SHA
 TLS_DH_DSS_WITH_AES_128_CBC_SHA         DH-DSS-AES128-SHA
 TLS_DH_DSS_WITH_AES_256_CBC_SHA         DH-DSS-AES256-SHA
 TLS_DH_RSA_WITH_AES_128_CBC_SHA         DH-RSA-AES128-SHA
 TLS_DH_RSA_WITH_AES_256_CBC_SHA         DH-RSA-AES256-SHA
 TLS_DHE_DSS_WITH_AES_128_CBC_SHA        DHE-DSS-AES128-SHA
 TLS_DHE_DSS_WITH_AES_256_CBC_SHA        DHE-DSS-AES256-SHA
 TLS_DHE_RSA_WITH_AES_128_CBC_SHA        DHE-RSA-AES128-SHA
 TLS_DHE_RSA_WITH_AES_256_CBC_SHA        DHE-RSA-AES256-SHA
 TLS_DH_anon_WITH_AES_128_CBC_SHA        ADH-AES128-SHA
 TLS_DH_anon_WITH_AES_256_CBC_SHA        ADH-AES256-SHA


Camellia ciphersuites from RFC4132, extending TLS v1.0

 TLS_RSA_WITH_CAMELLIA_128_CBC_SHA      CAMELLIA128-SHA
 TLS_RSA_WITH_CAMELLIA_256_CBC_SHA      CAMELLIA256-SHA
 TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA   Not implemented.
 TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA   Not implemented.
 TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA   Not implemented.
 TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA   Not implemented.
 TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA  DHE-DSS-CAMELLIA128-SHA
 TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA  DHE-DSS-CAMELLIA256-SHA
 TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA  DHE-RSA-CAMELLIA128-SHA
 TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA  DHE-RSA-CAMELLIA256-SHA
 TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA  ADH-CAMELLIA128-SHA
 TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA  ADH-CAMELLIA256-SHA


Additional Export 1024 and other cipher suites

Note: these ciphers can also be used in SSL v3.

 TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA     EXP1024-DES-CBC-SHA
 TLS_RSA_EXPORT1024_WITH_RC4_56_SHA      EXP1024-RC4-SHA
 TLS_DHE_DSS_EXPORT1024_WITH_DES_CBC_SHA EXP1024-DHE-DSS-DES-CBC-SHA
 TLS_DHE_DSS_EXPORT1024_WITH_RC4_56_SHA  EXP1024-DHE-DSS-RC4-SHA
 TLS_DHE_DSS_WITH_RC4_128_SHA            DHE-DSS-RC4-SHA


SSL v2.0 cipher suites.

 SSL_CK_RC4_128_WITH_MD5                 RC4-MD5
 SSL_CK_RC4_128_EXPORT40_WITH_MD5        EXP-RC4-MD5
 SSL_CK_RC2_128_CBC_WITH_MD5             RC2-MD5
 SSL_CK_RC2_128_CBC_EXPORT40_WITH_MD5    EXP-RC2-MD5
 SSL_CK_IDEA_128_CBC_WITH_MD5            IDEA-CBC-MD5
 SSL_CK_DES_64_CBC_WITH_MD5              DES-CBC-MD5
 SSL_CK_DES_192_EDE3_CBC_WITH_MD5        DES-CBC3-MD5


NOTES

The non-ephemeral DH modes are currently unimplemented in OpenSSL because there is no support for DH certificates.

Some compiled versions of OpenSSL may not include all the ciphers listed here because some ciphers were excluded at compile time.


EXAMPLES

Verbose listing of all OpenSSL ciphers including NULL ciphers:

 openssl ciphers -v 'ALL:eNULL'

Include all ciphers except NULL and anonymous DH then sort by strength:

 openssl ciphers -v 'ALL:!ADH:@STRENGTH'

Include only 3DES ciphers and then place RSA ciphers last:

 openssl ciphers -v '3DES:+RSA'

Include all RC4 ciphers but leave out those without authentication:

 openssl ciphers -v 'RC4:!COMPLEMENTOFDEFAULT'

Include all chiphers with RSA authentication but leave out ciphers without encryption.

 openssl ciphers -v 'RSA:!COMPLEMENTOFALL'


SEE ALSO

s_client(1), s_server(1), ssl(3)


HISTORY

The COMPLENTOFALL and COMPLEMENTOFDEFAULT selection options for cipherlist strings were added in OpenSSL 0.9.7. The -V option for the ciphers command was added in OpenSSL 0.9.9.