From 7fc0940fe6448fdce1525e3b7640763e2a1008de Mon Sep 17 00:00:00 2001 From: Matthew Holt Date: Tue, 23 May 2017 14:49:10 -0600 Subject: [PATCH] mitm: Fix false positive for Firefox 55 nightly --- caddyhttp/httpserver/mitm.go | 55 +++++++++++++++++++++---------- caddyhttp/httpserver/mitm_test.go | 6 ++++ 2 files changed, 43 insertions(+), 18 deletions(-) diff --git a/caddyhttp/httpserver/mitm.go b/caddyhttp/httpserver/mitm.go index 1f3d456f0..ae5a05967 100644 --- a/caddyhttp/httpserver/mitm.go +++ b/caddyhttp/httpserver/mitm.go @@ -326,24 +326,34 @@ func (info rawHelloInfo) looksLikeFirefox() bool { // EC point formats, and handshake compression methods." // We check for the presence and order of the extensions. - // Note: Sometimes padding (21) is present, sometimes not. + // Note: Sometimes 0x15 (21, padding) is present, sometimes not. // Note: Firefox 51+ does not advertise 0x3374 (13172, NPN). // Note: Firefox doesn't advertise 0x0 (0, SNI) when connecting to IP addresses. - requiredExtensionsOrder := []uint16{23, 65281, 10, 11, 35, 16, 5, 65283, 13} + // Note: Firefox 55+ doesn't appear to advertise 0xFF03 (65283, short headers). It used to be between 5 and 13. + requiredExtensionsOrder := []uint16{23, 65281, 10, 11, 35, 16, 5, 13} if !assertPresenceAndOrdering(requiredExtensionsOrder, info.extensions, true) { return false } // We check for both presence of curves and their ordering. - expectedCurves := []tls.CurveID{29, 23, 24, 25} - if len(info.curves) != len(expectedCurves) { + requiredCurves := []tls.CurveID{29, 23, 24, 25} + if len(info.curves) < len(requiredCurves) { return false } - for i := range expectedCurves { - if info.curves[i] != expectedCurves[i] { + for i := range requiredCurves { + if info.curves[i] != requiredCurves[i] { return false } } + if len(info.curves) > len(requiredCurves) { + // newer Firefox (55 Nightly?) may have additional curves at end of list + allowedCurves := []tls.CurveID{256, 257} + for i := range allowedCurves { + if info.curves[len(requiredCurves)+i] != allowedCurves[i] { + return false + } + } + } if hasGreaseCiphers(info.cipherSuites) { return false @@ -353,6 +363,9 @@ func (info rawHelloInfo) looksLikeFirefox() bool { // 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 @@ -401,14 +414,14 @@ func (info rawHelloInfo) looksLikeChrome() bool { // 0xc00a, 0xc014, 0xc009, 0x9c, 0x9d, 0x2f, 0x35, 0xa chromeCipherExclusions := map[uint16]struct{}{ - TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384: {}, // 0xc024 - TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256: {}, // 0xc023 - TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384: {}, // 0xc028 - tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256: {}, // 0xc027 - TLS_RSA_WITH_AES_256_CBC_SHA256: {}, // 0x3d - tls.TLS_RSA_WITH_AES_128_CBC_SHA256: {}, // 0x3c - TLS_DHE_RSA_WITH_AES_128_CBC_SHA: {}, // 0x33 - TLS_DHE_RSA_WITH_AES_256_CBC_SHA: {}, // 0x39 + TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384: {}, // 0xc024 + tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256: {}, // 0xc023 + TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384: {}, // 0xc028 + tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256: {}, // 0xc027 + TLS_RSA_WITH_AES_256_CBC_SHA256: {}, // 0x3d + tls.TLS_RSA_WITH_AES_128_CBC_SHA256: {}, // 0x3c + TLS_DHE_RSA_WITH_AES_128_CBC_SHA: {}, // 0x33 + TLS_DHE_RSA_WITH_AES_256_CBC_SHA: {}, // 0x39 } for _, ext := range info.cipherSuites { if _, ok := chromeCipherExclusions[ext]; ok { @@ -511,7 +524,7 @@ func (info rawHelloInfo) looksLikeSafari() bool { tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, // 0xc02c tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, // 0xc02b TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384, // 0xc024 - TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, // 0xc023 + tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, // 0xc023 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_256_GCM_SHA384, // 0xc030 @@ -523,7 +536,7 @@ func (info rawHelloInfo) looksLikeSafari() bool { tls.TLS_RSA_WITH_AES_256_GCM_SHA384, // 0x9d tls.TLS_RSA_WITH_AES_128_GCM_SHA256, // 0x9c TLS_RSA_WITH_AES_256_CBC_SHA256, // 0x3d - TLS_RSA_WITH_AES_128_CBC_SHA256, // 0x3c + tls.TLS_RSA_WITH_AES_128_CBC_SHA256, // 0x3c tls.TLS_RSA_WITH_AES_256_CBC_SHA, // 0x35 tls.TLS_RSA_WITH_AES_128_CBC_SHA, // 0x2f } @@ -610,11 +623,17 @@ const ( // cipher suites missing from the crypto/tls package, // in no particular order here TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 = 0xc024 - TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 = 0xc023 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 = 0xc028 - TLS_RSA_WITH_AES_128_CBC_SHA256 = 0x3c TLS_RSA_WITH_AES_256_CBC_SHA256 = 0x3d TLS_DHE_RSA_WITH_AES_128_CBC_SHA = 0x33 TLS_DHE_RSA_WITH_AES_256_CBC_SHA = 0x39 TLS_RSA_WITH_RC4_128_MD5 = 0x4 + + // new PSK ciphers introduced by TLS 1.3, not (yet) in crypto/tls + // https://tlswg.github.io/tls13-spec/#rfc.appendix.A.4) + TLS_AES_128_GCM_SHA256 = 0x1301 + TLS_AES_256_GCM_SHA384 = 0x1302 + TLS_CHACHA20_POLY1305_SHA256 = 0x1303 + TLS_AES_128_CCM_SHA256 = 0x1304 + TLS_AES_128_CCM_8_SHA256 = 0x1305 ) diff --git a/caddyhttp/httpserver/mitm_test.go b/caddyhttp/httpserver/mitm_test.go index 669de707f..81c80606f 100644 --- a/caddyhttp/httpserver/mitm_test.go +++ b/caddyhttp/httpserver/mitm_test.go @@ -139,6 +139,12 @@ func TestHeuristicFunctionsAndHandler(t *testing.T) { helloHex: `010000bd030375f9022fc3a6562467f3540d68013b2d0b961979de6129e944efe0b35531323500001ec02bc02fcca9cca8c02cc030c00ac009c013c01400330039002f0035000a010000760000000e000c0000096c6f63616c686f737400170000ff01000100000a000a0008001d001700180019000b00020100002300000010000e000c02683208687474702f312e31000500050100000000ff030000000d0020001e040305030603020308040805080604010501060102010402050206020202`, interception: false, }, + { + // this was a Nightly release at the time + userAgent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:55.0) Gecko/20100101 Firefox/55.0", + helloHex: `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`, + interception: false, + }, }, "Edge": { {