10 KiB
Ciphers
With curl's options
CURLOPT_SSL_CIPHER_LIST
and
--ciphers
users can control which ciphers to consider when negotiating TLS connections.
TLS 1.3 ciphers are supported since curl 7.61 for OpenSSL 1.1.1+, and since
curl 7.85 for Schannel with options
CURLOPT_TLS13_CIPHERS
and
--tls13-ciphers
. If you are using a different SSL backend you can try setting TLS 1.3 cipher
suites by using the respective regular cipher option.
The names of the known ciphers differ depending on which TLS backend that libcurl was built to use. This is an attempt to list known cipher names.
OpenSSL
(based on OpenSSL docs)
When specifying multiple cipher names, separate them with colon (:).
SSL3 cipher suites
NULL-MD5
NULL-SHA
RC4-MD5
RC4-SHA
IDEA-CBC-SHA
DES-CBC3-SHA
DH-DSS-DES-CBC3-SHA
DH-RSA-DES-CBC3-SHA
DHE-DSS-DES-CBC3-SHA
DHE-RSA-DES-CBC3-SHA
ADH-RC4-MD5
ADH-DES-CBC3-SHA
TLS v1.0 cipher suites
NULL-MD5
NULL-SHA
RC4-MD5
RC4-SHA
IDEA-CBC-SHA
DES-CBC3-SHA
DHE-DSS-DES-CBC3-SHA
DHE-RSA-DES-CBC3-SHA
ADH-RC4-MD5
ADH-DES-CBC3-SHA
AES cipher suites from RFC 3268, extending TLS v1.0
AES128-SHA
AES256-SHA
DH-DSS-AES128-SHA
DH-DSS-AES256-SHA
DH-RSA-AES128-SHA
DH-RSA-AES256-SHA
DHE-DSS-AES128-SHA
DHE-DSS-AES256-SHA
DHE-RSA-AES128-SHA
DHE-RSA-AES256-SHA
ADH-AES128-SHA
ADH-AES256-SHA
SEED cipher suites from RFC 4162, extending TLS v1.0
SEED-SHA
DH-DSS-SEED-SHA
DH-RSA-SEED-SHA
DHE-DSS-SEED-SHA
DHE-RSA-SEED-SHA
ADH-SEED-SHA
GOST cipher suites, extending TLS v1.0
GOST94-GOST89-GOST89
GOST2001-GOST89-GOST89
GOST94-NULL-GOST94
GOST2001-NULL-GOST94
Elliptic curve cipher suites
ECDHE-RSA-NULL-SHA
ECDHE-RSA-RC4-SHA
ECDHE-RSA-DES-CBC3-SHA
ECDHE-RSA-AES128-SHA
ECDHE-RSA-AES256-SHA
ECDHE-ECDSA-NULL-SHA
ECDHE-ECDSA-RC4-SHA
ECDHE-ECDSA-DES-CBC3-SHA
ECDHE-ECDSA-AES128-SHA
ECDHE-ECDSA-AES256-SHA
AECDH-NULL-SHA
AECDH-RC4-SHA
AECDH-DES-CBC3-SHA
AECDH-AES128-SHA
AECDH-AES256-SHA
TLS v1.2 cipher suites
NULL-SHA256
AES128-SHA256
AES256-SHA256
AES128-GCM-SHA256
AES256-GCM-SHA384
DH-RSA-AES128-SHA256
DH-RSA-AES256-SHA256
DH-RSA-AES128-GCM-SHA256
DH-RSA-AES256-GCM-SHA384
DH-DSS-AES128-SHA256
DH-DSS-AES256-SHA256
DH-DSS-AES128-GCM-SHA256
DH-DSS-AES256-GCM-SHA384
DHE-RSA-AES128-SHA256
DHE-RSA-AES256-SHA256
DHE-RSA-AES128-GCM-SHA256
DHE-RSA-AES256-GCM-SHA384
DHE-DSS-AES128-SHA256
DHE-DSS-AES256-SHA256
DHE-DSS-AES128-GCM-SHA256
DHE-DSS-AES256-GCM-SHA384
ECDHE-RSA-AES128-SHA256
ECDHE-RSA-AES256-SHA384
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-RSA-AES256-GCM-SHA384
ECDHE-ECDSA-AES128-SHA256
ECDHE-ECDSA-AES256-SHA384
ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-ECDSA-AES256-GCM-SHA384
ADH-AES128-SHA256
ADH-AES256-SHA256
ADH-AES128-GCM-SHA256
ADH-AES256-GCM-SHA384
AES128-CCM
AES256-CCM
DHE-RSA-AES128-CCM
DHE-RSA-AES256-CCM
AES128-CCM8
AES256-CCM8
DHE-RSA-AES128-CCM8
DHE-RSA-AES256-CCM8
ECDHE-ECDSA-AES128-CCM
ECDHE-ECDSA-AES256-CCM
ECDHE-ECDSA-AES128-CCM8
ECDHE-ECDSA-AES256-CCM8
Camellia HMAC-Based cipher suites from RFC 6367, extending TLS v1.2
ECDHE-ECDSA-CAMELLIA128-SHA256
ECDHE-ECDSA-CAMELLIA256-SHA384
ECDHE-RSA-CAMELLIA128-SHA256
ECDHE-RSA-CAMELLIA256-SHA384
TLS 1.3 cipher suites
(Note these ciphers are set with CURLOPT_TLS13_CIPHERS and --tls13-ciphers)
TLS_AES_256_GCM_SHA384
TLS_CHACHA20_POLY1305_SHA256
TLS_AES_128_GCM_SHA256
TLS_AES_128_CCM_8_SHA256
TLS_AES_128_CCM_SHA256
WolfSSL
RC4-SHA,
RC4-MD5,
DES-CBC3-SHA,
AES128-SHA,
AES256-SHA,
NULL-SHA,
NULL-SHA256,
DHE-RSA-AES128-SHA,
DHE-RSA-AES256-SHA,
DHE-PSK-AES256-GCM-SHA384,
DHE-PSK-AES128-GCM-SHA256,
PSK-AES256-GCM-SHA384,
PSK-AES128-GCM-SHA256,
DHE-PSK-AES256-CBC-SHA384,
DHE-PSK-AES128-CBC-SHA256,
PSK-AES256-CBC-SHA384,
PSK-AES128-CBC-SHA256,
PSK-AES128-CBC-SHA,
PSK-AES256-CBC-SHA,
DHE-PSK-AES128-CCM,
DHE-PSK-AES256-CCM,
PSK-AES128-CCM,
PSK-AES256-CCM,
PSK-AES128-CCM-8,
PSK-AES256-CCM-8,
DHE-PSK-NULL-SHA384,
DHE-PSK-NULL-SHA256,
PSK-NULL-SHA384,
PSK-NULL-SHA256,
PSK-NULL-SHA,
HC128-MD5,
HC128-SHA,
HC128-B2B256,
AES128-B2B256,
AES256-B2B256,
RABBIT-SHA,
NTRU-RC4-SHA,
NTRU-DES-CBC3-SHA,
NTRU-AES128-SHA,
NTRU-AES256-SHA,
AES128-CCM-8,
AES256-CCM-8,
ECDHE-ECDSA-AES128-CCM,
ECDHE-ECDSA-AES128-CCM-8,
ECDHE-ECDSA-AES256-CCM-8,
ECDHE-RSA-AES128-SHA,
ECDHE-RSA-AES256-SHA,
ECDHE-ECDSA-AES128-SHA,
ECDHE-ECDSA-AES256-SHA,
ECDHE-RSA-RC4-SHA,
ECDHE-RSA-DES-CBC3-SHA,
ECDHE-ECDSA-RC4-SHA,
ECDHE-ECDSA-DES-CBC3-SHA,
AES128-SHA256,
AES256-SHA256,
DHE-RSA-AES128-SHA256,
DHE-RSA-AES256-SHA256,
ECDH-RSA-AES128-SHA,
ECDH-RSA-AES256-SHA,
ECDH-ECDSA-AES128-SHA,
ECDH-ECDSA-AES256-SHA,
ECDH-RSA-RC4-SHA,
ECDH-RSA-DES-CBC3-SHA,
ECDH-ECDSA-RC4-SHA,
ECDH-ECDSA-DES-CBC3-SHA,
AES128-GCM-SHA256,
AES256-GCM-SHA384,
DHE-RSA-AES128-GCM-SHA256,
DHE-RSA-AES256-GCM-SHA384,
ECDHE-RSA-AES128-GCM-SHA256,
ECDHE-RSA-AES256-GCM-SHA384,
ECDHE-ECDSA-AES128-GCM-SHA256,
ECDHE-ECDSA-AES256-GCM-SHA384,
ECDH-RSA-AES128-GCM-SHA256,
ECDH-RSA-AES256-GCM-SHA384,
ECDH-ECDSA-AES128-GCM-SHA256,
ECDH-ECDSA-AES256-GCM-SHA384,
CAMELLIA128-SHA,
DHE-RSA-CAMELLIA128-SHA,
CAMELLIA256-SHA,
DHE-RSA-CAMELLIA256-SHA,
CAMELLIA128-SHA256,
DHE-RSA-CAMELLIA128-SHA256,
CAMELLIA256-SHA256,
DHE-RSA-CAMELLIA256-SHA256,
ECDHE-RSA-AES128-SHA256,
ECDHE-ECDSA-AES128-SHA256,
ECDH-RSA-AES128-SHA256,
ECDH-ECDSA-AES128-SHA256,
ECDHE-RSA-AES256-SHA384,
ECDHE-ECDSA-AES256-SHA384,
ECDH-RSA-AES256-SHA384,
ECDH-ECDSA-AES256-SHA384,
ECDHE-RSA-CHACHA20-POLY1305,
ECDHE-ECDSA-CHACHA20-POLY1305,
DHE-RSA-CHACHA20-POLY1305,
ECDHE-RSA-CHACHA20-POLY1305-OLD,
ECDHE-ECDSA-CHACHA20-POLY1305-OLD,
DHE-RSA-CHACHA20-POLY1305-OLD,
ADH-AES128-SHA,
QSH,
RENEGOTIATION-INFO,
IDEA-CBC-SHA,
ECDHE-ECDSA-NULL-SHA,
ECDHE-PSK-NULL-SHA256,
ECDHE-PSK-AES128-CBC-SHA256,
PSK-CHACHA20-POLY1305,
ECDHE-PSK-CHACHA20-POLY1305,
DHE-PSK-CHACHA20-POLY1305,
EDH-RSA-DES-CBC3-SHA,
Schannel
Schannel allows the enabling and disabling of encryption algorithms, but not specific cipher suites, prior to TLS 1.3. The algorithms are defined by Microsoft.
The algorithms below are for TLS 1.2 and earlier. TLS 1.3 is covered in the next section.
There is also the case that the selected algorithm is not supported by the
protocol or does not match the ciphers offered by the server during the SSL
negotiation. In this case curl will return error
CURLE_SSL_CONNECT_ERROR (35) SEC_E_ALGORITHM_MISMATCH
and the request will fail.
CALG_MD2,
CALG_MD4,
CALG_MD5,
CALG_SHA,
CALG_SHA1,
CALG_MAC,
CALG_RSA_SIGN,
CALG_DSS_SIGN,
CALG_NO_SIGN,
CALG_RSA_KEYX,
CALG_DES,
CALG_3DES_112,
CALG_3DES,
CALG_DESX,
CALG_RC2,
CALG_RC4,
CALG_SEAL,
CALG_DH_SF,
CALG_DH_EPHEM,
CALG_AGREEDKEY_ANY,
CALG_HUGHES_MD5,
CALG_SKIPJACK,
CALG_TEK,
CALG_CYLINK_MEK,
CALG_SSL3_SHAMD5,
CALG_SSL3_MASTER,
CALG_SCHANNEL_MASTER_HASH,
CALG_SCHANNEL_MAC_KEY,
CALG_SCHANNEL_ENC_KEY,
CALG_PCT1_MASTER,
CALG_SSL2_MASTER,
CALG_TLS1_MASTER,
CALG_RC5,
CALG_HMAC,
CALG_TLS1PRF,
CALG_HASH_REPLACE_OWF,
CALG_AES_128,
CALG_AES_192,
CALG_AES_256,
CALG_AES,
CALG_SHA_256,
CALG_SHA_384,
CALG_SHA_512,
CALG_ECDH,
CALG_ECMQV,
CALG_ECDSA,
CALG_ECDH_EPHEM,
As of curl 7.77.0, you can also pass SCH_USE_STRONG_CRYPTO as a cipher name
to constrain the set of available ciphers as specified in the Schannel
documentation.
Note that the supported ciphers in this case follow the OS version, so if you
are running an outdated OS you might still be supporting weak ciphers.
TLS 1.3 cipher suites
You can set TLS 1.3 ciphers for Schannel by using CURLOPT_TLS13_CIPHERS or
--tls13-ciphers with the names below.
If TLS 1.3 cipher suites are set then libcurl will add or restrict Schannel TLS 1.3 algorithms automatically. Essentially, libcurl is emulating support for individual TLS 1.3 cipher suites since Schannel does not support it directly.
TLS_AES_256_GCM_SHA384
TLS_AES_128_GCM_SHA256
TLS_CHACHA20_POLY1305_SHA256
TLS_AES_128_CCM_8_SHA256
TLS_AES_128_CCM_SHA256
Note if you set TLS 1.3 ciphers without also setting the minimum TLS version to
1.3 then it's possible Schannel may negotiate an earlier TLS version and cipher
suite if your libcurl and OS settings allow it. You can set the minimum TLS
version by using CURLOPT_SSLVERSION or --tlsv1.3.
BearSSL
BearSSL ciphers can be specified by either the OpenSSL name (ECDHE-RSA-AES128-GCM-SHA256) or the IANA name (TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256).
Since BearSSL 0.1:
DES-CBC3-SHA
AES128-SHA
AES256-SHA
AES128-SHA256
AES256-SHA256
AES128-GCM-SHA256
AES256-GCM-SHA384
ECDH-ECDSA-DES-CBC3-SHA
ECDH-ECDSA-AES128-SHA
ECDH-ECDSA-AES256-SHA
ECDHE-ECDSA-DES-CBC3-SHA
ECDHE-ECDSA-AES128-SHA
ECDHE-ECDSA-AES256-SHA
ECDH-RSA-DES-CBC3-SHA
ECDH-RSA-AES128-SHA
ECDH-RSA-AES256-SHA
ECDHE-RSA-DES-CBC3-SHA
ECDHE-RSA-AES128-SHA
ECDHE-RSA-AES256-SHA
ECDHE-ECDSA-AES128-SHA256
ECDHE-ECDSA-AES256-SHA384
ECDH-ECDSA-AES128-SHA256
ECDH-ECDSA-AES256-SHA384
ECDHE-RSA-AES128-SHA256
ECDHE-RSA-AES256-SHA384
ECDH-RSA-AES128-SHA256
ECDH-RSA-AES256-SHA384
ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-ECDSA-AES256-GCM-SHA384
ECDH-ECDSA-AES128-GCM-SHA256
ECDH-ECDSA-AES256-GCM-SHA384
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-RSA-AES256-GCM-SHA384
ECDH-RSA-AES128-GCM-SHA256
ECDH-RSA-AES256-GCM-SHA384
Since BearSSL 0.2:
ECDHE-RSA-CHACHA20-POLY1305
ECDHE-ECDSA-CHACHA20-POLY1305
Since BearSSL 0.6:
AES128-CCM
AES256-CCM
AES128-CCM8
AES256-CCM8
ECDHE-ECDSA-AES128-CCM
ECDHE-ECDSA-AES256-CCM
ECDHE-ECDSA-AES128-CCM8
ECDHE-ECDSA-AES256-CCM8