Man1 - ciphers.1ssl

openssl-ciphers, ciphers - SSL cipher display and cipher list tool

openssl ciphers [*-help*] [*-s*] [*-v*] [*-V*] [*-ssl3*] [*-tls1*] [*-tls1_1*] [*-tls1_2*] [*-tls1_3*] [*-s*] [*-psk*] [*-srp*] [*-stdname*] [*-convert name*] [*-ciphersuites val*] [*cipherlist*]

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.

-help

Print a usage message.

-s

Only list supported ciphers: those consistent with the security level, and minimum and maximum protocol version. This is closer to the actual cipher list an application will support. PSK and SRP ciphers are not enabled by default: they require -psk or -srp to enable them. It also does not change the default list of supported signature algorithms. On a server the list of supported ciphers might also exclude other ciphers depending on the configured certificates and presence of DH parameters. If this option is not used then all ciphers that match the cipherlist will be listed.

-psk

When combined with -s includes cipher suites which require PSK.

-srp

When combined with -s includes cipher suites which require SRP.

-v

Verbose output: For each cipher suite, list details as provided by SSL_CIPHER_description (3).

-V

Like -v, but include the official cipher suite values in hex.

-tls1_3, -tls1_2, -tls1_1, -tls1, -ssl3

In combination with the -s option, list the ciphers which could be used if the specified protocol were negotiated. Note that not all protocols and flags may be available, depending on how OpenSSL was built.

-stdname

Precede each cipher suite by its standard name.

-convert name

Convert a standard cipher name to its OpenSSL name.

-ciphersuites val

Sets the list of TLSv1.3 ciphersuites. This list will be combined with any TLSv1.2 and below ciphersuites that have been configured. The format for this list is a simple colon (:) separated list of TLSv1.3 ciphersuite names. By default this value is: TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256

cipherlist

A cipher list of TLSv1.2 and below ciphersuites to convert to a cipher preference list. This list will be combined with any TLSv1.3 ciphersuites that have been configured. If it is not included then the default cipher list will be used. The format is described below.

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.

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

The cipher string =@SECLEVEL==n can be used at any point to set the security level to n, which should be a number between zero and five, inclusive. See SSL_CTX_set_security_level for a description of what each level means.

The cipher list can be prefixed with the DEFAULT keyword, which enables the default cipher list as defined below. Unlike cipher strings, this prefix may not be combined with other strings using + character. For example, DEFAULT+DES is not valid.

The content of the default list is determined at compile time and normally corresponds to ALL:!COMPLEMENTOFDEFAULT:!eNULL.

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

COMPLEMENTOFDEFAULT

The ciphers included in ALL, but not enabled by default. Currently this includes all RC4 and anonymous ciphers. Note that this rule does not cover eNULL, which is not included by ALL (use COMPLEMENTOFALL if necessary). Note that RC4 based cipher suites are not built into OpenSSL by default (see the enable-weak-ssl-ciphers option to Configure).

ALL

All cipher suites except the eNULL ciphers (which must be explicitly enabled if needed). As of OpenSSL 1.0.0, the ALL cipher suites are sensibly ordered by default.

COMPLEMENTOFALL

The cipher suites not enabled by ALL, currently 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. All these cipher suites have been removed as of OpenSSL 1.1.0.

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 not enabled via either the DEFAULT or ALL cipher strings. Be careful when building cipherlists out of lower-level primitives such as kRSA or aECDSA as these do overlap with the eNULL ciphers. When in doubt, include !eNULL in your cipherlist.

aNULL

The cipher suites offering no authentication. This is currently the anonymous DH algorithms and anonymous ECDH algorithms. These cipher suites are vulnerable to man in the middle attacks and so their use is discouraged. These are excluded from the DEFAULT ciphers, but included in the ALL ciphers. Be careful when building cipherlists out of lower-level primitives such as kDHE or AES as these do overlap with the aNULL ciphers. When in doubt, include !aNULL in your cipherlist.

kRSA, aRSA, RSA

Cipher suites using RSA key exchange or authentication. RSA is an alias for kRSA.

kDHr, kDHd, kDH

Cipher suites using static DH key agreement and DH certificates signed by CAs with RSA and DSS keys or either respectively. All these cipher suites have been removed in OpenSSL 1.1.0.

kDHE, kEDH, DH

Cipher suites using ephemeral DH key agreement, including anonymous cipher suites.

DHE, EDH

Cipher suites using authenticated ephemeral DH key agreement.

ADH

Anonymous DH cipher suites, note that this does not include anonymous Elliptic Curve DH (ECDH) cipher suites.

kEECDH, kECDHE, ECDH

Cipher suites using ephemeral ECDH key agreement, including anonymous cipher suites.

ECDHE, EECDH

Cipher suites using authenticated ephemeral ECDH key agreement.

AECDH

Anonymous Elliptic Curve Diffie-Hellman cipher suites.

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. All these cipher suites have been removed in OpenSSL 1.1.0.

aECDSA, ECDSA

Cipher suites using ECDSA authentication, i.e. the certificates carry ECDSA keys.

TLSv1.2, TLSv1.0, SSLv3

Lists cipher suites which are only supported in at least TLS v1.2, TLS v1.0 or SSL v3.0 respectively. Note: there are no cipher suites specific to TLS v1.1. Since this is only the minimum version, if, for example, TLSv1.0 is negotiated then both TLSv1.0 and SSLv3.0 cipher suites are available. Note: these cipher strings do not change the negotiated version of SSL or TLS, they only affect the list of available cipher suites.

AES128, AES256, AES

cipher suites using 128 bit AES, 256 bit AES or either 128 or 256 bit AES.

AESGCM

AES in Galois Counter Mode (GCM): these cipher suites are only supported in TLS v1.2.

AESCCM, AESCCM8

AES in Cipher Block Chaining - Message Authentication Mode (CCM): these cipher suites are only supported in TLS v1.2. AESCCM references CCM cipher suites using both 16 and 8 octet Integrity Check Value (ICV) while AESCCM8 only references 8 octet ICV.

ARIA128, ARIA256, ARIA

Cipher suites using 128 bit ARIA, 256 bit ARIA or either 128 or 256 bit ARIA.

CAMELLIA128, CAMELLIA256, CAMELLIA

Cipher suites using 128 bit CAMELLIA, 256 bit CAMELLIA or either 128 or 256 bit CAMELLIA.

CHACHA20

Cipher suites using ChaCha20.

3DES

Cipher suites using triple DES.

DES

Cipher suites using DES (not triple DES). All these cipher suites have been removed in OpenSSL 1.1.0.

RC4

Cipher suites using RC4.

RC2

Cipher suites using RC2.

IDEA

Cipher suites using IDEA.

SEED

Cipher suites using SEED.

MD5

Cipher suites using MD5.

SHA1, SHA

Cipher suites using SHA1.

SHA256, SHA384

Cipher suites using SHA256 or SHA384.

aGOST

Cipher suites using GOST R 34.10 (either 2001 or 94) for authentication (needs an engine supporting GOST algorithms).

aGOST01

Cipher suites using GOST R 34.10-2001 authentication.

kGOST

Cipher suites, using VKO 34.10 key exchange, specified in the RFC 4357.

GOST94

Cipher suites, using HMAC based on GOST R 34.11-94.

GOST89MAC

Cipher suites using GOST 28147-89 MAC instead of HMAC.

PSK

All cipher suites using pre-shared keys (PSK).

kPSK, kECDHEPSK, kDHEPSK, kRSAPSK

Cipher suites using PSK key exchange, ECDHE_PSK, DHE_PSK or RSA_PSK.

aPSK

Cipher suites using PSK authentication (currently all PSK modes apart from RSA_PSK).

SUITEB128, SUITEB128ONLY, SUITEB192

Enables suite B mode of operation using 128 (permitting 192 bit mode by peer) 128 bit (not permitting 192 bit by peer) or 192 bit level of security respectively. If used these cipherstrings should appear first in the cipher list and anything after them is ignored. Setting Suite B mode has additional consequences required to comply with RFC6460. In particular the supported signature algorithms is reduced to support only ECDSA and SHA256 or SHA384, only the elliptic curves P-256 and P-384 can be used and only the two suite B compliant cipher suites (ECDHE-ECDSA-AES128-GCM-SHA256 and ECDHE-ECDSA-AES256-GCM-SHA384) are permissible.

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.

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

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 all ciphers except ones with no encryption (eNULL) or no authentication (aNULL):

openssl ciphers -v ALL:!aNULL

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 ciphers with RSA authentication but leave out ciphers without encryption.

openssl ciphers -v RSA:!COMPLEMENTOFALL

Set security level to 2 and display all ciphers consistent with level 2:

openssl ciphers -s -v ALL:@SECLEVEL=2

s_client (1), s_server (1), ssl (7)

The -V option for the ciphers command was added in OpenSSL 1.0.0.

The -stdname is only available if OpenSSL is built with tracing enabled (enable-ssl-trace argument to Configure) before OpenSSL 1.1.1.

The -convert option was added in OpenSSL 1.1.1.

Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (the License). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at https://www.openssl.org/source/license.html.