[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [tor-talk] What is being detected to alert upon?



I didn't see an answer to this question, but I did compare the TLS Hello's
from Firefox and the Tor binary distributed by torproject.org and there are
lots of differences (see the two files attached), so I'm not sure this is
worth worrying about...


-----Original Message-----
From: Allen [mailto:allenpmd@gmail.com] 
Sent: Thursday, April 30, 2015 5:49 PM
To: tor-talk@lists.torproject.org
Subject: RE: [tor-talk] What is being detected to alert upon?

> a connection to a Tor bridge looks kind of like regular TLS traffic.

Question: I recompiled OpenSSL to remove a bunch of features that look
unnecessary and might present a security risk, such as SSL2, SSL3 and DTLS.
(In case it matters, it is OpenSSL v1.0.2a and the specific configure
options are no-ssl2 no-ssl3 no-idea no-dtls no-psk no-srp no-dso no-npn
no-hw no-engines -DOPENSSL_NO_HEARTBEATS -DOPENSSL_USE_IPV6=0).

I'm using this rebuilt DLL with Tor.  Does this compromise Tor's TLS
handshake so that it no longer looks like Firefox?  If so, what so I need to
do to allow Tor to mimic Firefox's TLS handshake?

FireFox 37.0.2

- TLS: TLS Rec Layer-1 HandShake: Client Hello.
  - TlsRecordLayer: TLS Rec Layer-1 HandShake:
     ContentType: HandShake:
   - Version: TLS 1.0
      Major: 3 (0x3)
      Minor: 1 (0x1)
     Length: 206 (0xCE)
   - SSLHandshake: SSL HandShake ClientHello(0x01)
      HandShakeType: ClientHello(0x01)
      Length: 202 (0xCA)
    - ClientHello: TLS 1.2
     - Version: TLS 1.2
        Major: 3 (0x3)
        Minor: 3 (0x3)
     - RandomBytes: 
        TimeStamp: 09/20/2025, 21:03:20 .0000 UTC 
        RandomBytes: Binary Large Object (28 Bytes)
       SessionIDLength: 0 (0x0)
       CipherSuitesLength: 24
     - TLSCipherSuites: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 { 0xC0,0x2B }
        Cipher: 49195 (0xC02B)
     - TLSCipherSuites: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256   { 0xC0,0x2F }
        Cipher: 49199 (0xC02F)
     - TLSCipherSuites: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA    { 0xC0,0x0A }
        Cipher: 49162 (0xC00A)
     - TLSCipherSuites: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA    { 0xC0,0x09 }
        Cipher: 49161 (0xC009)
     - TLSCipherSuites: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA      { 0xC0,0x13 }
        Cipher: 49171 (0xC013)
     - TLSCipherSuites: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA      { 0xC0,0x14 }
        Cipher: 49172 (0xC014)
     - TLSCipherSuites: TLS_DHE_RSA_WITH_AES_128_CBC_SHA        { 0x00, 0x33 }
        Cipher: 51 (0x33)
     - TLSCipherSuites: TLS_DHE_RSA_WITH_AES_256_CBC_SHA        { 0x00, 0x39 }
        Cipher: 57 (0x39)
     - TLSCipherSuites: TLS_RSA_WITH_AES_128_CBC_SHA            { 0x00, 0x2F }
        Cipher: 47 (0x2F)
     - TLSCipherSuites: TLS_RSA_WITH_AES_256_CBC_SHA            { 0x00, 0x35 }
        Cipher: 53 (0x35)
     - TLSCipherSuites: TLS_RSA_WITH_3DES_EDE_CBC_SHA           { 0x00,0x0A }
        Cipher: 10 (0xA)
     - TLSCipherSuites: Unknown Cipher
        Cipher: 255 (0xFF)
       CompressionMethodsLength: 1 (0x1)
       CompressionMethods: 0 (0x0)
       ExtensionsLength: 137 (0x89)
     - ClientHelloExtension: Server Name(0x0000)
        ExtensionType: Server Name(0x0000)
        ExtensionLength: 19 (0x13)
        NameListLength: 17 (0x11)
        NameType: Host Name (0)
        NameLength: 14 (0xE)
        ServerName: www.kernel.org
     - ClientHelloExtension: EC Point Formats(0x000B)
        ExtensionType: EC Point Formats(0x000B)
        ExtensionLength: 4 (0x4)
        ECPointLength: 3 (0x3)
        ECPointFormat: uncompressed(0x00)
        ECPointFormat: ansiX962_compressed_prime(0x01)
        ECPointFormat: ansiX962_compressed_char2(0x02)
     - ClientHelloExtension: Elliptic Curves(0x000A)
        ExtensionType: Elliptic Curves(0x000A)
        ExtensionLength: 8 (0x8)
        CurvesLength: 6 (0x6)
        NamedCurve: secp256r1(0x0017)
        NamedCurve: secp384r1(0x0018)
        NamedCurve: secp521r1(0x0019)
     - ClientHelloExtension: SessionTicket TLS(0x0023)
        ExtensionType: SessionTicket TLS(0x0023)
        ExtensionLength: 0 (0x0)
     - ClientHelloExtension: Signature Algorithms(0x000D)
        ExtensionType: Signature Algorithms(0x000D)
        ExtensionLength: 32 (0x20)
        Data: Binary Large Object (32 Bytes)
     - ClientHelloExtension: Unknown Extension Type
        ExtensionType: Unknown Extension Type
        ExtensionLength: 1 (0x1)
        Data: Binary Large Object (1 Bytes)
     - ClientHelloExtension: Unknown Extension Type
        ExtensionType: Unknown Extension Type
        ExtensionLength: 0 (0x0)
     - ClientHelloExtension: Unknown Extension Type
        ExtensionType: Unknown Extension Type
        ExtensionLength: 41 (0x29)
        Data: Binary Large Object (41 Bytes)
Tor win32 0.2.6.7

- TLS: TLS Rec Layer-1 HandShake: Client Hello.
  - TlsRecordLayer: TLS Rec Layer-1 HandShake:
     ContentType: HandShake:
   - Version: TLS 1.0
      Major: 3 (0x3)
      Minor: 1 (0x1)
     Length: 232 (0xE8)
   - SSLHandshake: SSL HandShake ClientHello(0x01)
      HandShakeType: ClientHello(0x01)
      Length: 228 (0xE4)
    - ClientHello: TLS 1.2
     - Version: TLS 1.2
        Major: 3 (0x3)
        Minor: 3 (0x3)
     - RandomBytes: 
        TimeStamp: 01/26/1978, 07:04:34 .0000 UTC 
        RandomBytes: Binary Large Object (28 Bytes)
       SessionIDLength: 0 (0x0)
       CipherSuitesLength: 48
     - TLSCipherSuites: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 { 0xC0,0x2B }
        Cipher: 49195 (0xC02B)
     - TLSCipherSuites: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256   { 0xC0,0x2F }
        Cipher: 49199 (0xC02F)
     - TLSCipherSuites: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA    { 0xC0,0x0A }
        Cipher: 49162 (0xC00A)
     - TLSCipherSuites: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA    { 0xC0,0x09 }
        Cipher: 49161 (0xC009)
     - TLSCipherSuites: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA      { 0xC0,0x13 }
        Cipher: 49171 (0xC013)
     - TLSCipherSuites: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA      { 0xC0,0x14 }
        Cipher: 49172 (0xC014)
     - TLSCipherSuites: TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA     { 0xC0,0x12 }
        Cipher: 49170 (0xC012)
     - TLSCipherSuites: TLS_ECDHE_ECDSA_WITH_RC4_128_SHA        { 0xC0,0x07 }
        Cipher: 49159 (0xC007)
     - TLSCipherSuites: TLS_ECDHE_RSA_WITH_RC4_128_SHA          { 0xC0,0x11 }
        Cipher: 49169 (0xC011)
     - TLSCipherSuites: TLS_DHE_RSA_WITH_AES_128_CBC_SHA        { 0x00, 0x33 }
        Cipher: 51 (0x33)
     - TLSCipherSuites: TLS_DHE_DSS_WITH_AES_128_CBC_SHA        { 0x00, 0x32 }
        Cipher: 50 (0x32)
     - TLSCipherSuites: TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA   { 0x00, 0x45 }
        Cipher: 69 (0x45)
     - TLSCipherSuites: TLS_DHE_RSA_WITH_AES_256_CBC_SHA        { 0x00, 0x39 }
        Cipher: 57 (0x39)
     - TLSCipherSuites: TLS_DHE_DSS_WITH_AES_256_CBC_SHA        { 0x00, 0x38 }
        Cipher: 56 (0x38)
     - TLSCipherSuites: TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA   { 0x00, 0x88 }
        Cipher: 136 (0x88)
     - TLSCipherSuites: TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA        { 0x00,0x16}
        Cipher: 22 (0x16)
     - TLSCipherSuites: TLS_RSA_WITH_AES_128_CBC_SHA            { 0x00, 0x2F }
        Cipher: 47 (0x2F)
     - TLSCipherSuites: TLS_RSA_WITH_CAMELLIA_128_CBC_SHA       { 0x00, 0x41 }
        Cipher: 65 (0x41)
     - TLSCipherSuites: TLS_RSA_WITH_AES_256_CBC_SHA            { 0x00, 0x35 }
        Cipher: 53 (0x35)
     - TLSCipherSuites: TLS_RSA_WITH_CAMELLIA_256_CBC_SHA       { 0x00, 0x84 }
        Cipher: 132 (0x84)
     - TLSCipherSuites: TLS_RSA_WITH_3DES_EDE_CBC_SHA           { 0x00,0x0A }
        Cipher: 10 (0xA)
     - TLSCipherSuites: TLS_RSA_WITH_RC4_128_SHA                { 0x00,0x05 }
        Cipher: 5 (0x5)
     - TLSCipherSuites: TLS_RSA_WITH_RC4_128_MD5                { 0x00,0x04 }
        Cipher: 4 (0x4)
     - TLSCipherSuites: Unknown Cipher
        Cipher: 255 (0xFF)
       CompressionMethodsLength: 1 (0x1)
       CompressionMethods: 0 (0x0)
       ExtensionsLength: 139 (0x8B)
     - ClientHelloExtension: Server Name(0x0000)
        ExtensionType: Server Name(0x0000)
        ExtensionLength: 26 (0x1A)
        NameListLength: 24 (0x18)
        NameType: Host Name (0)
        NameLength: 21 (0x15)
        ServerName: www.mqmaoa6ufwefd.com
     - ClientHelloExtension: EC Point Formats(0x000B)
        ExtensionType: EC Point Formats(0x000B)
        ExtensionLength: 4 (0x4)
        ECPointLength: 3 (0x3)
        ECPointFormat: uncompressed(0x00)
        ECPointFormat: ansiX962_compressed_prime(0x01)
        ECPointFormat: ansiX962_compressed_char2(0x02)
     - ClientHelloExtension: Elliptic Curves(0x000A)
        ExtensionType: Elliptic Curves(0x000A)
        ExtensionLength: 52 (0x34)
        CurvesLength: 50 (0x32)
        NamedCurve: sect571r1(0x000E)
        NamedCurve: sect571k1(0x000D)
        NamedCurve: secp521r1(0x0019)
        NamedCurve: sect409k1(0x000B)
        NamedCurve: sect409r1(0x000C)
        NamedCurve: secp384r1(0x0018)
        NamedCurve: sect283k1(0x0009)
        NamedCurve: sect283r1(0x000A)
        NamedCurve: secp256k1(0x0016)
        NamedCurve: secp256r1(0x0017)
        NamedCurve: sect239k1(0x0008)
        NamedCurve: sect233k1(0x0006)
        NamedCurve: sect233r1(0x0007)
        NamedCurve: secp224k1(0x0014)
        NamedCurve: secp224r1(0x0015)
        NamedCurve: sect193r1(0x0004)
        NamedCurve: sect193r2(0x0005)
        NamedCurve: secp192k1(0x0012)
        NamedCurve: secp192r1(0x0013)
        NamedCurve: sect163k1(0x0001)
        NamedCurve: sect163r1(0x0002)
        NamedCurve: sect163r2(0x0003)
        NamedCurve: secp160k1(0x000F)
        NamedCurve: secp160r1(0x0010)
        NamedCurve: secp160r2(0x0011)
     - ClientHelloExtension: SessionTicket TLS(0x0023)
        ExtensionType: SessionTicket TLS(0x0023)
        ExtensionLength: 0 (0x0)
     - ClientHelloExtension: Signature Algorithms(0x000D)
        ExtensionType: Signature Algorithms(0x000D)
        ExtensionLength: 32 (0x20)
        Data: Binary Large Object (32 Bytes)
     - ClientHelloExtension: Unknown Extension Type
        ExtensionType: Unknown Extension Type
        ExtensionLength: 1 (0x1)
        Data: Binary Large Object (1 Bytes)
-- 
tor-talk mailing list - tor-talk@lists.torproject.org
To unsubscribe or change other settings go to
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk