To support testing specific client configurations, you can specify a version or range of versions of SSL/TLS that are allowed for a connection. You can as also specify which cipher suites are allowed for that connection.
⚠️ Reg. ciphers and TLS 1.3
Due to limitations in the underlying go implementation, changing the ciphers for TLS 1.3 is not supported and will do nothing.
Limiting SSL/TLS version
To limit the k6 to a specific SSL/TLS version, use a global configuration option:
Versions available to choose from
Here's the list of available SSL/TLS versions that you can choose from, ordered from oldest version to latest.
- http.SSL_3_0
- http.TLS_1_0
- http.TLS_1_1
- http.TLS_1_2
- http.TLS_1_3
Limiting cipher suites
To limit the cipher suites that k6 is allowed to use, there's a global configuration option. You choose a list of allowed ciphers:
Checking SSL/TLS version and cipher suite used in requests
You can also check which SSL/TLS version and ciphers were used. To do so, look at the tls_version and tls_cipher_suite response object properties.
Cipher suites available to choose from
Here's a list of available SSL/TLS cipher suites:
- TLS_RSA_WITH_RC4_128_SHA
- TLS_RSA_WITH_3DES_EDE_CBC_SHA
- TLS_RSA_WITH_AES_128_CBC_SHA
- TLS_RSA_WITH_AES_256_CBC_SHA
- TLS_RSA_WITH_AES_128_GCM_SHA256
- TLS_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDHE_ECDSA_WITH_RC4_128_SHA
- TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
- TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
- TLS_ECDHE_RSA_WITH_RC4_128_SHA
- TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
⚠️ Differences depending on k6 build
This list reflects the available cipher suites in the latest official build. If you are using a custom-built k6, the available cipher suites will depend on the Go version you compiled it with, see https://golang.org/pkg/crypto/tls/#pkg-constants.