Allow changing cipher suites offered in SSL/TLS handshake #19914
Description
Some servers require clients to use specific suite of ciphers, that is different from the one netcore offers by default.
This is the list that netcore on Windows 10 defaults to (on my PC)
Handshake Protocol: Client Hello
Handshake Type: Client Hello (1)
Length: 165
Version: TLS 1.2 (0x0303)
Random
Session ID Length: 0
Cipher Suites Length: 46
Cipher Suites (23 suites)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (0xc02c)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02b)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (0xc030)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xc02f)
Cipher Suite: TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (0x009f)
Cipher Suite: TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (0x009e)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 (0xc024)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (0xc023)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (0xc028)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (0xc027)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (0xc00a)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (0xc009)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (0xc014)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (0xc013)
Cipher Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x0039)
Cipher Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x0033)
Cipher Suite: TLS_RSA_WITH_AES_256_GCM_SHA384 (0x009d)
Cipher Suite: TLS_RSA_WITH_AES_128_GCM_SHA256 (0x009c)
Cipher Suite: TLS_RSA_WITH_AES_256_CBC_SHA256 (0x003d)
Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA256 (0x003c)
Cipher Suite: TLS_RSA_WITH_AES_256_CBC_SHA (0x0035)
Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA (0x002f)
Cipher Suite: TLS_RSA_WITH_3DES_EDE_CBC_SHA (0x000a)
For comparison, here's the list netcore offers on OS X Sierra
Cipher Suites Length: 202
Cipher Suites (101 suites)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (0xc030)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (0xc02c)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (0xc028)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 (0xc024)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (0xc014)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (0xc00a)
Cipher Suite: TLS_DH_DSS_WITH_AES_256_GCM_SHA384 (0x00a5)
Cipher Suite: TLS_DHE_DSS_WITH_AES_256_GCM_SHA384 (0x00a3)
Cipher Suite: TLS_DH_RSA_WITH_AES_256_GCM_SHA384 (0x00a1)
Cipher Suite: TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (0x009f)
Cipher Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 (0x006b)
Cipher Suite: TLS_DHE_DSS_WITH_AES_256_CBC_SHA256 (0x006a)
Cipher Suite: TLS_DH_RSA_WITH_AES_256_CBC_SHA256 (0x0069)
Cipher Suite: TLS_DH_DSS_WITH_AES_256_CBC_SHA256 (0x0068)
Cipher Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x0039)
Cipher Suite: TLS_DHE_DSS_WITH_AES_256_CBC_SHA (0x0038)
Cipher Suite: TLS_DH_RSA_WITH_AES_256_CBC_SHA (0x0037)
Cipher Suite: TLS_DH_DSS_WITH_AES_256_CBC_SHA (0x0036)
Cipher Suite: TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA (0x0088)
Cipher Suite: TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA (0x0087)
Cipher Suite: TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA (0x0086)
Cipher Suite: TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA (0x0085)
Cipher Suite: TLS_ECDH_anon_WITH_AES_256_CBC_SHA (0xc019)
Cipher Suite: TLS_DH_anon_WITH_AES_256_GCM_SHA384 (0x00a7)
Cipher Suite: TLS_DH_anon_WITH_AES_256_CBC_SHA256 (0x006d)
Cipher Suite: TLS_DH_anon_WITH_AES_256_CBC_SHA (0x003a)
Cipher Suite: TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA (0x0089)
Cipher Suite: TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 (0xc032)
Cipher Suite: TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 (0xc02e)
Cipher Suite: TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 (0xc02a)
Cipher Suite: TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 (0xc026)
Cipher Suite: TLS_ECDH_RSA_WITH_AES_256_CBC_SHA (0xc00f)
Cipher Suite: TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA (0xc005)
Cipher Suite: TLS_RSA_WITH_AES_256_GCM_SHA384 (0x009d)
Cipher Suite: TLS_RSA_WITH_AES_256_CBC_SHA256 (0x003d)
Cipher Suite: TLS_RSA_WITH_AES_256_CBC_SHA (0x0035)
Cipher Suite: TLS_RSA_WITH_CAMELLIA_256_CBC_SHA (0x0084)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xc02f)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02b)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (0xc027)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (0xc023)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (0xc013)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (0xc009)
Cipher Suite: TLS_DH_DSS_WITH_AES_128_GCM_SHA256 (0x00a4)
Cipher Suite: TLS_DHE_DSS_WITH_AES_128_GCM_SHA256 (0x00a2)
Cipher Suite: TLS_DH_RSA_WITH_AES_128_GCM_SHA256 (0x00a0)
Cipher Suite: TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (0x009e)
Cipher Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 (0x0067)
Cipher Suite: TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 (0x0040)
Cipher Suite: TLS_DH_RSA_WITH_AES_128_CBC_SHA256 (0x003f)
Cipher Suite: TLS_DH_DSS_WITH_AES_128_CBC_SHA256 (0x003e)
Cipher Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x0033)
Cipher Suite: TLS_DHE_DSS_WITH_AES_128_CBC_SHA (0x0032)
Cipher Suite: TLS_DH_RSA_WITH_AES_128_CBC_SHA (0x0031)
Cipher Suite: TLS_DH_DSS_WITH_AES_128_CBC_SHA (0x0030)
Cipher Suite: TLS_DHE_RSA_WITH_SEED_CBC_SHA (0x009a)
Cipher Suite: TLS_DHE_DSS_WITH_SEED_CBC_SHA (0x0099)
Cipher Suite: TLS_DH_RSA_WITH_SEED_CBC_SHA (0x0098)
Cipher Suite: TLS_DH_DSS_WITH_SEED_CBC_SHA (0x0097)
Cipher Suite: TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA (0x0045)
Cipher Suite: TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA (0x0044)
Cipher Suite: TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA (0x0043)
Cipher Suite: TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA (0x0042)
Cipher Suite: TLS_ECDH_anon_WITH_AES_128_CBC_SHA (0xc018)
Cipher Suite: TLS_DH_anon_WITH_AES_128_GCM_SHA256 (0x00a6)
Cipher Suite: TLS_DH_anon_WITH_AES_128_CBC_SHA256 (0x006c)
Cipher Suite: TLS_DH_anon_WITH_AES_128_CBC_SHA (0x0034)
Cipher Suite: TLS_DH_anon_WITH_SEED_CBC_SHA (0x009b)
Cipher Suite: TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA (0x0046)
Cipher Suite: TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 (0xc031)
Cipher Suite: TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02d)
Cipher Suite: TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 (0xc029)
Cipher Suite: TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 (0xc025)
Cipher Suite: TLS_ECDH_RSA_WITH_AES_128_CBC_SHA (0xc00e)
Cipher Suite: TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA (0xc004)
Cipher Suite: TLS_RSA_WITH_AES_128_GCM_SHA256 (0x009c)
Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA256 (0x003c)
Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA (0x002f)
Cipher Suite: TLS_RSA_WITH_SEED_CBC_SHA (0x0096)
Cipher Suite: TLS_RSA_WITH_CAMELLIA_128_CBC_SHA (0x0041)
Cipher Suite: TLS_RSA_WITH_IDEA_CBC_SHA (0x0007)
Cipher Suite: TLS_ECDHE_RSA_WITH_RC4_128_SHA (0xc011)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_RC4_128_SHA (0xc007)
Cipher Suite: TLS_ECDH_anon_WITH_RC4_128_SHA (0xc016)
Cipher Suite: TLS_DH_anon_WITH_RC4_128_MD5 (0x0018)
Cipher Suite: TLS_ECDH_RSA_WITH_RC4_128_SHA (0xc00c)
Cipher Suite: TLS_ECDH_ECDSA_WITH_RC4_128_SHA (0xc002)
Cipher Suite: TLS_RSA_WITH_RC4_128_SHA (0x0005)
Cipher Suite: TLS_RSA_WITH_RC4_128_MD5 (0x0004)
Cipher Suite: TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA (0xc012)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA (0xc008)
Cipher Suite: TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA (0x0016)
Cipher Suite: TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA (0x0013)
Cipher Suite: TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA (0x0010)
Cipher Suite: TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA (0x000d)
Cipher Suite: TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA (0xc017)
Cipher Suite: TLS_DH_anon_WITH_3DES_EDE_CBC_SHA (0x001b)
Cipher Suite: TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA (0xc00d)
Cipher Suite: TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA (0xc003)
Cipher Suite: TLS_RSA_WITH_3DES_EDE_CBC_SHA (0x000a)
Cipher Suite: TLS_EMPTY_RENEGOTIATION_INFO_SCSV (0x00ff)
Here's the cipher suites offered by .NET for Windows (TLS 1.0 is default unless different SslProtocol specified in call to AuthenticateAsClient)
Handshake Protocol: Client Hello
Handshake Type: Client Hello (1)
Length: 107
Version: TLS 1.0 (0x0301)
Random
Session ID Length: 0
Cipher Suites Length: 22
Cipher Suites (11 suites)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (0xc00a)
Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (0xc009)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (0xc014)
Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (0xc013)
Cipher Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x0039)
Cipher Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x0033)
Cipher Suite: TLS_RSA_WITH_AES_256_CBC_SHA (0x0035)
Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA (0x002f)
Cipher Suite: TLS_RSA_WITH_3DES_EDE_CBC_SHA (0x000a)
Cipher Suite: TLS_RSA_WITH_RC4_128_SHA (0x0005)
Cipher Suite: TLS_RSA_WITH_RC4_128_MD5 (0x0004)
One way to solve this in corefx would be to add something akin to Xamarin's ClientCipherSuitesCallback to the ServicePointManager.
Possible workarounds:
-
See workaround posted in Add SmtpClient support #14288.
-
See Microsoft knowledge base article on how to restrict the use of certain cryptographic algorithms and protocols in Schannel.dll (applicable to Windows only).