diff options
Diffstat (limited to 'caddyhttp/httpserver/mitm.go')
| -rw-r--r-- | caddyhttp/httpserver/mitm.go | 104 |
1 files changed, 103 insertions, 1 deletions
diff --git a/caddyhttp/httpserver/mitm.go b/caddyhttp/httpserver/mitm.go index ae5a05967..5d9f0d170 100644 --- a/caddyhttp/httpserver/mitm.go +++ b/caddyhttp/httpserver/mitm.go @@ -65,7 +65,16 @@ func (h *tlsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { mitm = !info.looksLikeChrome() && !info.looksLikeSafari() } else if strings.Contains(ua, "Firefox") { checked = true - mitm = !info.looksLikeFirefox() + if strings.Contains(ua, "Windows") { + ver := getVersion(ua, "Firefox") + if ver == 45.0 || ver == 52.0 { + mitm = !info.looksLikeTor() + } else { + mitm = !info.looksLikeFirefox() + } + } else { + mitm = !info.looksLikeFirefox() + } } else if strings.Contains(ua, "Safari") { checked = true mitm = !info.looksLikeSafari() @@ -87,6 +96,34 @@ func (h *tlsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { h.next.ServeHTTP(w, r) } +// getVersion returns a (possibly simplified) representation of the version string +// from a UserAgent string. It returns a float, so it can represent major and minor +// versions; the rest of the version is just tacked on behind the decimal point. +// The purpose of this is to stay simple while allowing for basic, fast comparisons. +// If the version for softwareName is not found in ua, -1 is returned. +func getVersion(ua, softwareName string) float64 { + search := softwareName + "/" + start := strings.Index(ua, search) + if start < 0 { + return -1 + } + start += len(search) + end := strings.Index(ua[start:], " ") + if end < 0 { + end = len(ua) + } + strVer := strings.Replace(ua[start:end], "-", "", -1) + firstDot := strings.Index(strVer, ".") + if firstDot >= 0 { + strVer = strVer[:firstDot+1] + strings.Replace(strVer[firstDot+1:], ".", "", -1) + } + ver, err := strconv.ParseFloat(strVer, 64) + if err != nil { + return -1 + } + return ver +} + // clientHelloConn reads the ClientHello // and stores it in the attached listener. type clientHelloConn struct { @@ -330,6 +367,7 @@ func (info rawHelloInfo) looksLikeFirefox() bool { // Note: Firefox 51+ does not advertise 0x3374 (13172, NPN). // Note: Firefox doesn't advertise 0x0 (0, SNI) when connecting to IP addresses. // Note: Firefox 55+ doesn't appear to advertise 0xFF03 (65283, short headers). It used to be between 5 and 13. + // Note: Firefox on Fedora (or RedHat) doesn't include ECC suites because of patent liability. requiredExtensionsOrder := []uint16{23, 65281, 10, 11, 35, 16, 5, 13} if !assertPresenceAndOrdering(requiredExtensionsOrder, info.extensions, true) { return false @@ -543,6 +581,70 @@ func (info rawHelloInfo) looksLikeSafari() bool { return assertPresenceAndOrdering(expectedCipherSuiteOrder, info.cipherSuites, true) } +// looksLikeTor returns true if the info looks like a ClientHello from Tor browser +// (based on Firefox). +func (info rawHelloInfo) looksLikeTor() bool { + requiredExtensionsOrder := []uint16{10, 11, 16, 5, 13} + if !assertPresenceAndOrdering(requiredExtensionsOrder, info.extensions, true) { + return false + } + + // check for session tickets support; Tor doesn't support them to prevent tracking + for _, ext := range info.extensions { + if ext == 35 { + return false + } + } + + // We check for both presence of curves and their ordering, including + // an optional curve at the beginning (for Tor based on Firefox 52) + infoCurves := info.curves + if len(info.curves) == 4 { + if info.curves[0] != 29 { + return false + } + infoCurves = info.curves[1:] + } + requiredCurves := []tls.CurveID{23, 24, 25} + if len(infoCurves) < len(requiredCurves) { + return false + } + for i := range requiredCurves { + if infoCurves[i] != requiredCurves[i] { + return false + } + } + + if hasGreaseCiphers(info.cipherSuites) { + return false + } + + // We check for order of cipher suites but not presence, since + // according to the paper, cipher suites may be not be added + // or reordered by the user, but they may be disabled. + expectedCipherSuiteOrder := []uint16{ + TLS_AES_128_GCM_SHA256, // 0x1301 + TLS_CHACHA20_POLY1305_SHA256, // 0x1303 + TLS_AES_256_GCM_SHA384, // 0x1302 + tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, // 0xc02b + tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, // 0xc02f + tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, // 0xcca9 + tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, // 0xcca8 + tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, // 0xc02c + tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, // 0xc030 + tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, // 0xc00a + tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, // 0xc009 + tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, // 0xc013 + tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, // 0xc014 + TLS_DHE_RSA_WITH_AES_128_CBC_SHA, // 0x33 + TLS_DHE_RSA_WITH_AES_256_CBC_SHA, // 0x39 + tls.TLS_RSA_WITH_AES_128_CBC_SHA, // 0x2f + tls.TLS_RSA_WITH_AES_256_CBC_SHA, // 0x35 + tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA, // 0xa + } + return assertPresenceAndOrdering(expectedCipherSuiteOrder, info.cipherSuites, false) +} + // assertPresenceAndOrdering will return true if candidateList contains // the items in requiredItems in the same order as requiredItems. // |