# Ciphers

With curl's options
[`CURLOPT_SSL_CIPHER_LIST`](https://curl.haxx.se/libcurl/c/CURLOPT_SSL_CIPHER_LIST.html)
and
[`--ciphers`](https://curl.haxx.se/docs/manpage.html#--ciphers)
users can control which ciphers to consider when negotiating TLS connections.

TLS 1.3 ciphers are supported since curl 7.61 with options
[`CURLOPT_TLS13_CIPHERS`](https://curl.haxx.se/libcurl/c/CURLOPT_TLS13_CIPHERS.html)
and
[`--tls13-ciphers`](https://curl.haxx.se/docs/manpage.html#--tls13-ciphers)
.

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](https://www.openssl.org/docs/man1.1.0/apps/ciphers.html))

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 ciphersuites from RFC3268, 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 ciphersuites from RFC4162, 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 ciphersuites, 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 ciphersuites from RFC6367, 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`

## NSS

### Totally insecure

`rc4`
`rc4-md5`
`rc4export`
`rc2`
`rc2export`
`des`
`desede3`

###  SSL3/TLS cipher suites

`rsa_rc4_128_md5`
`rsa_rc4_128_sha`
`rsa_3des_sha`
`rsa_des_sha`
`rsa_rc4_40_md5`
`rsa_rc2_40_md5`
`rsa_null_md5`
`rsa_null_sha`
`fips_3des_sha`
`fips_des_sha`
`fortezza`
`fortezza_rc4_128_sha`
`fortezza_null`

### TLS 1.0 Exportable 56-bit Cipher Suites

`rsa_des_56_sha`
`rsa_rc4_56_sha`

### AES ciphers

`dhe_dss_aes_128_cbc_sha`
`dhe_dss_aes_256_cbc_sha`
`dhe_rsa_aes_128_cbc_sha`
`dhe_rsa_aes_256_cbc_sha`
`rsa_aes_128_sha`
`rsa_aes_256_sha`

### ECC ciphers

`ecdh_ecdsa_null_sha`
`ecdh_ecdsa_rc4_128_sha`
`ecdh_ecdsa_3des_sha`
`ecdh_ecdsa_aes_128_sha`
`ecdh_ecdsa_aes_256_sha`
`ecdhe_ecdsa_null_sha`
`ecdhe_ecdsa_rc4_128_sha`
`ecdhe_ecdsa_3des_sha`
`ecdhe_ecdsa_aes_128_sha`
`ecdhe_ecdsa_aes_256_sha`
`ecdh_rsa_null_sha`
`ecdh_rsa_128_sha`
`ecdh_rsa_3des_sha`
`ecdh_rsa_aes_128_sha`
`ecdh_rsa_aes_256_sha`
`ecdhe_rsa_null`
`ecdhe_rsa_rc4_128_sha`
`ecdhe_rsa_3des_sha`
`ecdhe_rsa_aes_128_sha`
`ecdhe_rsa_aes_256_sha`
`ecdh_anon_null_sha`
`ecdh_anon_rc4_128sha`
`ecdh_anon_3des_sha`
`ecdh_anon_aes_128_sha`
`ecdh_anon_aes_256_sha`

### HMAC-SHA256 cipher suites

`rsa_null_sha_256`
`rsa_aes_128_cbc_sha_256`
`rsa_aes_256_cbc_sha_256`
`dhe_rsa_aes_128_cbc_sha_256`
`dhe_rsa_aes_256_cbc_sha_256`
`ecdhe_ecdsa_aes_128_cbc_sha_256`
`ecdhe_rsa_aes_128_cbc_sha_256`

### AES GCM cipher suites in RFC 5288 and RFC 5289

`rsa_aes_128_gcm_sha_256`
`dhe_rsa_aes_128_gcm_sha_256`
`dhe_dss_aes_128_gcm_sha_256`
`ecdhe_ecdsa_aes_128_gcm_sha_256`
`ecdh_ecdsa_aes_128_gcm_sha_256`
`ecdhe_rsa_aes_128_gcm_sha_256`
`ecdh_rsa_aes_128_gcm_sha_256`

### cipher suites using SHA384

`rsa_aes_256_gcm_sha_384`
`dhe_rsa_aes_256_gcm_sha_384`
`dhe_dss_aes_256_gcm_sha_384`
`ecdhe_ecdsa_aes_256_sha_384`
`ecdhe_rsa_aes_256_sha_384`
`ecdhe_ecdsa_aes_256_gcm_sha_384`
`ecdhe_rsa_aes_256_gcm_sha_384`

### chacha20-poly1305 cipher suites

`ecdhe_rsa_chacha20_poly1305_sha_256`
`ecdhe_ecdsa_chacha20_poly1305_sha_256`
`dhe_rsa_chacha20_poly1305_sha_256`

## GSKit

Ciphers are internally defined as
[numeric codes](https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_73/apis/gsk_attribute_set_buffer.htm),
but libcurl maps them to the following case-insensitive names.

### SSL2 cipher suites (insecure: disabled by default)

`rc2-md5`
`rc4-md5`
`exp-rc2-md5`
`exp-rc4-md5`
`des-cbc-md5`
`des-cbc3-md5`

### SSL3 cipher suites

`null-md5`
`null-sha`
`rc4-md5`
`rc4-sha`
`exp-rc2-cbc-md5`
`exp-rc4-md5`
`exp-des-cbc-sha`
`des-cbc3-sha`

### TLS v1.0 cipher suites

`null-md5`
`null-sha`
`rc4-md5`
`rc4-sha`
`exp-rc2-cbc-md5`
`exp-rc4-md5`
`exp-des-cbc-sha`
`des-cbc3-sha`
`aes128-sha`
`aes256-sha`

### TLS v1.1 cipher suites

`null-md5`
`null-sha`
`rc4-md5`
`rc4-sha`
`exp-des-cbc-sha`
`des-cbc3-sha`
`aes128-sha`
`aes256-sha`

### TLS v1.2 cipher suites

`null-md5`
`null-sha`
`null-sha256`
`rc4-md5`
`rc4-sha`
`des-cbc3-sha`
`aes128-sha`
`aes256-sha`
`aes128-sha256`
`aes256-sha256`
`aes128-gcm-sha256`
`aes256-gcm-sha384`

## 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 ciphersuites. They are
[defined](https://docs.microsoft.com/windows/desktop/SecCrypto/alg-id) by
Microsoft.

`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`,
