Fix various issues in TLS found using BoGo

 - BoGo sends unparseable OCSP responses, so we have to accomodate for
   this by delaying decoding until verification and simply ignoring
   OCSP responses that we can't parse.
 - Check that there is no trailing garbage at the end of various messages.
 - Don't send empty SNI
 - Check the TLS record header versions (previously ignored)
 - For CBC 1/n-1 splitting split every record instead of just first.
   I think this is not a problem but it is what BoGo expects.
 - New Channel::application_protocol virtual (previously was
   implemented on both Client and Server but not shared).
 - Changes to resumption version handling.
 - Fix server version selection when newer versions are disabled.

New policy hooks added in service of BoGo:
 - maximum_certificate_chain_size gives the maximum cert chain in bytes
   that we'll accept.
 - allow_resumption_for_renegotiation specifies if a renegotiation
   attempt can be simply (re-)resumed instead.
 - abort_handshake_on_undesired_renegotiation - previously we just
   ignored it with a warning alert. Now behavior is configurable.
 - request_client_certificate_authentication
 - require_client_certificate_authentication

1 files changed, 20 insertions, 18 deletions

diff --git a/src/lib/tls/tls_policy.cpp b/src/lib/tls/tls_policy.cpp
index 4caaf623a..58ba73ade 100644
--- a/src/lib/tls/tls_policy.cpp
+++ b/src/lib/tls/tls_policy.cpp
@@ -25,6 +25,8 @@ std::vector<Signature_Scheme> Policy::allowed_signature_schemes() const
 
    for(Signature_Scheme scheme : all_signature_schemes())
       {
+      if(signature_scheme_is_known(scheme) == false)
+         continue;
       const bool sig_allowed = allowed_signature_method(signature_algorithm_of_scheme(scheme));
       const bool hash_allowed = allowed_signature_hash(hash_function_of_scheme(scheme));
 
@@ -57,7 +59,7 @@ std::vector<std::string> Policy::allowed_ciphers() const
       //"AES-128",
       //"Camellia-256",
       //"Camellia-128",
-      //"SEED"
+      //"SEED",
       //"3DES",
       };
    }
@@ -292,19 +294,19 @@ Protocol_Version Policy::latest_supported_version(bool datagram) const
    {
    if(datagram)
       {
-      if(allow_dtls12())
+      if(acceptable_protocol_version(Protocol_Version::DTLS_V12))
          return Protocol_Version::DTLS_V12;
-      if(allow_dtls10())
+      if(acceptable_protocol_version(Protocol_Version::DTLS_V10))
          return Protocol_Version::DTLS_V10;
       throw Invalid_State("Policy forbids all available DTLS version");
       }
    else
       {
-      if(allow_tls12())
+      if(acceptable_protocol_version(Protocol_Version::TLS_V12))
          return Protocol_Version::TLS_V12;
-      if(allow_tls11())
+      if(acceptable_protocol_version(Protocol_Version::TLS_V11))
          return Protocol_Version::TLS_V11;
-      if(allow_tls10())
+      if(acceptable_protocol_version(Protocol_Version::TLS_V10))
          return Protocol_Version::TLS_V10;
       throw Invalid_State("Policy forbids all available TLS version");
       }
@@ -329,6 +331,13 @@ bool Policy::hide_unknown_users() const { return false; }
 bool Policy::server_uses_own_ciphersuite_preferences() const { return true; }
 bool Policy::negotiate_encrypt_then_mac() const { return true; }
 bool Policy::support_cert_status_message() const { return true; }
+bool Policy::allow_resumption_for_renegotiation() const { return true; }
+bool Policy::only_resume_with_exact_version() const { return true; }
+bool Policy::require_client_certificate_authentication() const { return false; }
+bool Policy::request_client_certificate_authentication() const { return require_client_certificate_authentication(); }
+bool Policy::abort_connection_on_undesired_renegotiation() const { return false; }
+
+size_t Policy::maximum_certificate_chain_size() const { return 0; }
 
 // 1 second initial timeout, 60 second max - see RFC 6347 sec 4.2.4.1
 size_t Policy::dtls_initial_timeout() const { return 1*1000; }
@@ -431,7 +440,11 @@ std::vector<uint16_t> Policy::ciphersuite_list(Protocol_Version version,
    for(auto&& suite : Ciphersuite::all_known_ciphersuites())
       {
       // Can we use it?
-      if(suite.valid() == false)
+      if(!suite.valid())
+         continue;
+
+      // Can we use it in this version?
+      if(!suite.usable_in_version(version))
          continue;
 
       // Is it acceptable to the policy?
@@ -442,17 +455,6 @@ std::vector<uint16_t> Policy::ciphersuite_list(Protocol_Version version,
       if(!have_srp && suite.kex_method() == Kex_Algo::SRP_SHA)
          continue;
 
-      if(!version.supports_aead_modes())
-         {
-         // Are we doing AEAD in a non-AEAD version?
-         if(suite.mac_algo() == "AEAD")
-            continue;
-
-         // Older (v1.0/v1.1) versions also do not support any hash but SHA-1
-         if(suite.mac_algo() != "SHA-1")
-            continue;
-         }
-
       if(!value_exists(kex, suite.kex_algo()))
          continue; // unsupported key exchange