feat: HTTP add TLS fingerprint fallback (#1444)

internal/httpclient/httpclienttest/fingerprint_server.go

@@ -0,0 +1,100 @@
+package httpclienttest
+
+import (
+	"crypto/tls"
+	"errors"
+	"io"
+	"log"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"testing"
+)
+
+type Profile string
+
+const (
+	ProfileNative     Profile = "native"
+	ProfileChrome     Profile = "chrome"
+	ProfileFirefox    Profile = "firefox"
+	ProfileSafari     Profile = "safari"
+	ProfileAnyBrowser Profile = "browser"
+)
+
+type FingerprintServerOptions struct {
+	RequiredProfile Profile
+	Handler         http.Handler
+}
+
+type FingerprintServer struct {
+	*httptest.Server
+
+	mu       sync.Mutex
+	profiles []Profile
+}
+
+func NewFingerprintServer(t testing.TB, options FingerprintServerOptions) *FingerprintServer {
+	t.Helper()
+
+	handler := options.Handler
+	if handler == nil {
+		handler = http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		})
+	}
+	server := &FingerprintServer{
+		Server: httptest.NewUnstartedServer(handler),
+	}
+	server.EnableHTTP2 = true
+	server.Config.ErrorLog = log.New(io.Discard, "", 0)
+	server.TLS = &tls.Config{
+		GetConfigForClient: func(hello *tls.ClientHelloInfo) (*tls.Config, error) {
+			profile := classifyProfile(hello.CipherSuites)
+			server.mu.Lock()
+			server.profiles = append(server.profiles, profile)
+			server.mu.Unlock()
+			if profileMatches(profile, options.RequiredProfile) {
+				return nil, nil
+			}
+			return nil, errors.New("required TLS fingerprint was not presented")
+		},
+	}
+	server.StartTLS()
+	t.Cleanup(server.Close)
+	return server
+}
+
+func (s *FingerprintServer) Profiles() []Profile {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return append([]Profile(nil), s.profiles...)
+}
+
+func profileMatches(actual, required Profile) bool {
+	if required == ProfileAnyBrowser {
+		return actual != ProfileNative
+	}
+	return actual == required
+}
+
+func classifyProfile(cipherSuites []uint16) Profile {
+	if len(cipherSuites) >= 5 && isGREASE(cipherSuites[0]) {
+		switch cipherSuites[4] {
+		case tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256:
+			return ProfileChrome
+		case tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384:
+			return ProfileSafari
+		}
+	}
+	if len(cipherSuites) >= 3 &&
+		cipherSuites[0] == tls.TLS_AES_128_GCM_SHA256 &&
+		cipherSuites[1] == tls.TLS_CHACHA20_POLY1305_SHA256 &&
+		cipherSuites[2] == tls.TLS_AES_256_GCM_SHA384 {
+		return ProfileFirefox
+	}
+	return ProfileNative
+}
+
+func isGREASE(value uint16) bool {
+	return value&0x0f0f == 0x0a0a && byte(value) == byte(value>>8)
+}