ECDSAWithSHA1,
}

var tlsrsakex = godebug.New("tlsrsakex")
var tls3des = godebug.New("tls3des")

func defaultCipherSuites() []uint16 {
	suites := slices.Clone(cipherSuitesPreferenceOrder)
	return slices.DeleteFunc(suites, func(c uint16) bool {
		return disabledCipherSuites[c] ||
			tlsrsakex.Value() != "1" && rsaKexCiphers[c] ||
			tls3des.Value() != "1" && tdesCiphers[c]
	})
}

3DES cipher suites were removed from the default list used when
[Config.CipherSuites] is nil. The default can be reverted adding `tls3des=1` to

	{Name: "randautoseed", Package: "math/rand"},
	{Name: "tarinsecurepath", Package: "archive/tar"},
	{Name: "tls10server", Package: "crypto/tls", Changed: 22, Old: "1"},
	{Name: "tls3des", Package: "crypto/tls", Changed: 23, Old: "1"},
	{Name: "tlskyber", Package: "crypto/tls", Changed: 23, Old: "0", Opaque: true},
	{Name: "tlsmaxrsasize", Package: "crypto/tls"},

		tlsrsakex.Value() // ensure godebug is initialized
		tlsrsakex.IncNonDefault()
	}
	if c.config.CipherSuites == nil && !needFIPS() && tdesCiphers[hs.suite.id] {
		tls3des.Value() // ensure godebug is initialized
		tls3des.IncNonDefault()
	}

	for _, id := range hs.clientHello.cipherSuites {
		if id == TLS_FALLBACK_SCSV {
			// The client is doing a fallback connection. See RFC 7507.

		tlsrsakex.Value() // ensure godebug is initialized
		tlsrsakex.IncNonDefault()
	}
	if hs.c.config.CipherSuites == nil && !needFIPS() && tdesCiphers[hs.suite.id] {
		tls3des.Value() // ensure godebug is initialized
		tls3des.IncNonDefault()
	}

	hs.c.cipherSuite = hs.suite.id
	return nil
}

func (hs *clientHandshakeState) doFullHandshake() error {
	c := hs.c

any effect.

Go 1.23 changed the default TLS cipher suites used by clients and servers when
not explicitly configured, removing 3DES cipher suites. The default can be reverted
using the [`tls3des` setting](/pkg/crypto/tls/#Config.CipherSuites).

Go 1.23 changed the behavior of [`tls.X509KeyPair`](/pkg/crypto/tls#X509KeyPair)
and [`tls.LoadX509KeyPair`](/pkg/crypto/tls#LoadX509KeyPair) to populate the

		package due to a non-default GODEBUG=tls10server=... setting.

	/godebug/non-default-behavior/tls3des:events
		The number of non-default behaviors executed by the crypto/tls
		package due to a non-default GODEBUG=tls3des=... setting.

	/godebug/non-default-behavior/tlsmaxrsasize:events
		The number of non-default behaviors executed by the crypto/tls
		package due to a non-default GODEBUG=tlsmaxrsasize=... setting.

	// suites were removed from the default list, but can be re-added with the
	// GODEBUG setting tlsrsakex=1. In Go 1.23 3DES cipher suites were removed
	// from the default list, but can be re-added with the GODEBUG setting
	// tls3des=1.
	CipherSuites []uint16

	// PreferServerCipherSuites is a legacy field and has no effect.
	//
	// It used to control whether the server would follow the client's or the