epee: add SSL support

RPC connections now have optional tranparent SSL.

An optional private key and certificate file can be passed,
using the --{rpc,daemon}-ssl-private-key and
--{rpc,daemon}-ssl-certificate options. Those have as
argument a path to a PEM format private private key and
certificate, respectively.
If not given, a temporary self signed certificate will be used.

SSL can be enabled or disabled using --{rpc}-ssl, which
accepts autodetect (default), disabled or enabled.

Access can be restricted to particular certificates using the
--rpc-ssl-allowed-certificates, which takes a list of
paths to PEM encoded certificates. This can allow a wallet to
connect to only the daemon they think they're connected to,
by forcing SSL and listing the paths to the known good
certificates.

To generate long term certificates:

openssl genrsa -out /tmp/KEY 4096
openssl req -new -key /tmp/KEY -out /tmp/REQ
openssl x509 -req -days 999999 -sha256 -in /tmp/REQ -signkey /tmp/KEY -out /tmp/CERT

/tmp/KEY is the private key, and /tmp/CERT is the certificate,
both in PEM format. /tmp/REQ can be removed. Adjust the last
command to set expiration date, etc, as needed. It doesn't
make a whole lot of sense for monero anyway, since most servers
will run with one time temporary self signed certificates anyway.

SSL support is transparent, so all communication is done on the
existing ports, with SSL autodetection. This means you can start
using an SSL daemon now, but you should not enforce SSL yet or
nothing will talk to you.

5 files changed, 29 insertions, 6 deletions

diff --git a/src/rpc/core_rpc_server.cpp b/src/rpc/core_rpc_server.cpp
index d18774149..fa27c259d 100644
--- a/src/rpc/core_rpc_server.cpp
+++ b/src/rpc/core_rpc_server.cpp
@@ -80,6 +80,7 @@ namespace cryptonote
     command_line::add_arg(desc, arg_rpc_ssl_private_key);
     command_line::add_arg(desc, arg_rpc_ssl_certificate);
     command_line::add_arg(desc, arg_rpc_ssl_allowed_certificates);
+    command_line::add_arg(desc, arg_rpc_ssl_allowed_fingerprints);
     command_line::add_arg(desc, arg_rpc_ssl_allow_any_cert);
     command_line::add_arg(desc, arg_bootstrap_daemon_address);
     command_line::add_arg(desc, arg_bootstrap_daemon_login);
@@ -156,12 +157,16 @@ namespace cryptonote
         ssl_allowed_certificates.back() = std::string();
       }
     }
+
+    const std::vector<std::string> ssl_allowed_fingerprint_strings = command_line::get_arg(vm, arg_rpc_ssl_allowed_fingerprints);
+    std::vector<std::vector<uint8_t>> ssl_allowed_fingerprints{ ssl_allowed_fingerprint_strings.size() };
+    std::transform(ssl_allowed_fingerprint_strings.begin(), ssl_allowed_fingerprint_strings.end(), ssl_allowed_fingerprints.begin(), epee::from_hex::vector);
     const bool ssl_allow_any_cert = command_line::get_arg(vm, arg_rpc_ssl_allow_any_cert);
 
     auto rng = [](size_t len, uint8_t *ptr){ return crypto::rand(len, ptr); };
     return epee::http_server_impl_base<core_rpc_server, connection_context>::init(
       rng, std::move(port), std::move(rpc_config->bind_ip), std::move(rpc_config->access_control_origins), std::move(http_login),
-      ssl_support, std::make_pair(ssl_private_key, ssl_certificate), ssl_allowed_certificates, ssl_allow_any_cert
+      ssl_support, std::make_pair(ssl_private_key, ssl_certificate), std::move(ssl_allowed_certificates), std::move(ssl_allowed_fingerprints), ssl_allow_any_cert
     );
   }
   //------------------------------------------------------------------------------------------------------------------------------
@@ -2369,6 +2374,11 @@ namespace cryptonote
     , "List of paths to PEM format certificates of allowed peers (all allowed if empty)"
     };
 
+  const command_line::arg_descriptor<std::vector<std::string>> core_rpc_server::arg_rpc_ssl_allowed_fingerprints = {
+      "rpc-ssl-allowed-fingerprints"
+    , "List of certificate fingerprints to allow"
+  };
+
   const command_line::arg_descriptor<bool> core_rpc_server::arg_rpc_ssl_allow_any_cert = {
       "rpc-ssl-allow-any-cert"
     , "Allow any peer certificate, rather than just those on the allowed list"
diff --git a/src/rpc/core_rpc_server.h b/src/rpc/core_rpc_server.h
index da1907af2..54fce3cd9 100644
--- a/src/rpc/core_rpc_server.h
+++ b/src/rpc/core_rpc_server.h
@@ -60,6 +60,7 @@ namespace cryptonote
     static const command_line::arg_descriptor<std::string> arg_rpc_ssl_private_key;
     static const command_line::arg_descriptor<std::string> arg_rpc_ssl_certificate;
     static const command_line::arg_descriptor<std::vector<std::string>> arg_rpc_ssl_allowed_certificates;
+    static const command_line::arg_descriptor<std::vector<std::string>> arg_rpc_ssl_allowed_fingerprints;
     static const command_line::arg_descriptor<bool> arg_rpc_ssl_allow_any_cert;
     static const command_line::arg_descriptor<std::string> arg_bootstrap_daemon_address;
     static const command_line::arg_descriptor<std::string> arg_bootstrap_daemon_login;
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index f2c0a7ba9..99b07a2b0 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -241,6 +241,7 @@ struct options {
   const command_line::arg_descriptor<std::string> daemon_ssl_private_key = {"daemon-ssl-private-key", tools::wallet2::tr("Path to a PEM format private key"), ""};
   const command_line::arg_descriptor<std::string> daemon_ssl_certificate = {"daemon-ssl-certificate", tools::wallet2::tr("Path to a PEM format certificate"), ""};
   const command_line::arg_descriptor<std::vector<std::string>> daemon_ssl_allowed_certificates = {"daemon-ssl-allowed-certificates", tools::wallet2::tr("List of paths to PEM format certificates of allowed RPC servers")};
+  const command_line::arg_descriptor<std::vector<std::string>> daemon_ssl_allowed_fingerprints = {"daemon-ssl-allowed-fingerprints", tools::wallet2::tr("List of valid fingerprints of allowed RPC servers")};
   const command_line::arg_descriptor<bool> daemon_ssl_allow_any_cert = {"daemon-ssl-allow-any-cert", tools::wallet2::tr("Allow any SSL certificate from the daemon"), false};
   const command_line::arg_descriptor<bool> testnet = {"testnet", tools::wallet2::tr("For testnet. Daemon must also be launched with --testnet flag"), false};
   const command_line::arg_descriptor<bool> stagenet = {"stagenet", tools::wallet2::tr("For stagenet. Daemon must also be launched with --stagenet flag"), false};
@@ -316,6 +317,7 @@ std::unique_ptr<tools::wallet2> make_basic(const boost::program_options::variabl
   auto daemon_ssl_private_key = command_line::get_arg(vm, opts.daemon_ssl_private_key);
   auto daemon_ssl_certificate = command_line::get_arg(vm, opts.daemon_ssl_certificate);
   auto daemon_ssl_allowed_certificates = command_line::get_arg(vm, opts.daemon_ssl_allowed_certificates);
+  auto daemon_ssl_allowed_fingerprints = command_line::get_arg(vm, opts.daemon_ssl_allowed_fingerprints);
   auto daemon_ssl_allow_any_cert = command_line::get_arg(vm, opts.daemon_ssl_allow_any_cert);
   auto daemon_ssl = command_line::get_arg(vm, opts.daemon_ssl);
   epee::net_utils::ssl_support_t ssl_support;
@@ -382,8 +384,11 @@ std::unique_ptr<tools::wallet2> make_basic(const boost::program_options::variabl
       }
   }
 
+  std::vector<std::vector<uint8_t>> ssl_allowed_fingerprints{ daemon_ssl_allowed_fingerprints.size() };
+  std::transform(daemon_ssl_allowed_fingerprints.begin(), daemon_ssl_allowed_fingerprints.end(), ssl_allowed_fingerprints.begin(), epee::from_hex::vector);
+
   std::unique_ptr<tools::wallet2> wallet(new tools::wallet2(nettype, kdf_rounds, unattended));
-  wallet->init(std::move(daemon_address), std::move(login), 0, *trusted_daemon, ssl_support, std::make_pair(daemon_ssl_private_key, daemon_ssl_certificate), ssl_allowed_certificates, daemon_ssl_allow_any_cert);
+  wallet->init(std::move(daemon_address), std::move(login), 0, *trusted_daemon, ssl_support, std::make_pair(daemon_ssl_private_key, daemon_ssl_certificate), ssl_allowed_certificates, ssl_allowed_fingerprints, daemon_ssl_allow_any_cert);
 
   boost::filesystem::path ringdb_path = command_line::get_arg(vm, opts.shared_ringdb_dir);
   wallet->set_ring_database(ringdb_path.string());
@@ -1044,6 +1049,7 @@ void wallet2::init_options(boost::program_options::options_description& desc_par
   command_line::add_arg(desc_params, opts.daemon_ssl_private_key);
   command_line::add_arg(desc_params, opts.daemon_ssl_certificate);
   command_line::add_arg(desc_params, opts.daemon_ssl_allowed_certificates);
+  command_line::add_arg(desc_params, opts.daemon_ssl_allowed_fingerprints);
   command_line::add_arg(desc_params, opts.daemon_ssl_allow_any_cert);
   command_line::add_arg(desc_params, opts.testnet);
   command_line::add_arg(desc_params, opts.stagenet);
@@ -1096,7 +1102,7 @@ std::unique_ptr<wallet2> wallet2::make_dummy(const boost::program_options::varia
 }
 
 //----------------------------------------------------------------------------------------------------
-bool wallet2::init(std::string daemon_address, boost::optional<epee::net_utils::http::login> daemon_login, uint64_t upper_transaction_weight_limit, bool trusted_daemon, epee::net_utils::ssl_support_t ssl_support, const std::pair<std::string, std::string> &private_key_and_certificate_path, const std::list<std::string> &allowed_certificates, bool allow_any_cert)
+bool wallet2::init(std::string daemon_address, boost::optional<epee::net_utils::http::login> daemon_login, uint64_t upper_transaction_weight_limit, bool trusted_daemon, epee::net_utils::ssl_support_t ssl_support, const std::pair<std::string, std::string> &private_key_and_certificate_path, const std::list<std::string> &allowed_certificates, const std::vector<std::vector<uint8_t>> &allowed_fingerprints, bool allow_any_cert)
 {
   m_checkpoints.init_default_checkpoints(m_nettype);
   if(m_http_client.is_connected())
@@ -1106,7 +1112,7 @@ bool wallet2::init(std::string daemon_address, boost::optional<epee::net_utils::
   m_daemon_address = std::move(daemon_address);
   m_daemon_login = std::move(daemon_login);
   m_trusted_daemon = trusted_daemon;
-  return m_http_client.set_server(get_daemon_address(), get_daemon_login(), ssl_support, private_key_and_certificate_path, allowed_certificates, allow_any_cert);
+  return m_http_client.set_server(get_daemon_address(), get_daemon_login(), ssl_support, private_key_and_certificate_path, allowed_certificates, allowed_fingerprints, allow_any_cert);
 }
 //----------------------------------------------------------------------------------------------------
 bool wallet2::is_deterministic() const
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index ea1172f40..b7ebe03d9 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -680,7 +680,8 @@ namespace tools
       bool trusted_daemon = true,
       epee::net_utils::ssl_support_t ssl_support = epee::net_utils::ssl_support_t::e_ssl_support_autodetect,
       const std::pair<std::string, std::string> &private_key_and_certificate_path = {},
-      const std::list<std::string> &allowed_certificates = {}, bool allow_any_cert = false);
+      const std::list<std::string> &allowed_certificates = {}, const std::vector<std::vector<uint8_t>> &allowed_fingerprints = {},
+      bool allow_any_cert = false);
 
     void stop() { m_run.store(false, std::memory_order_relaxed); m_message_store.stop(); }
 
diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 9adfb06c8..43b074c69 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -67,6 +67,7 @@ namespace
   const command_line::arg_descriptor<std::string> arg_rpc_ssl_private_key = {"rpc-ssl-private-key", tools::wallet2::tr("Path to a PEM format private key"), ""};
   const command_line::arg_descriptor<std::string> arg_rpc_ssl_certificate = {"rpc-ssl-certificate", tools::wallet2::tr("Path to a PEM format certificate"), ""};
   const command_line::arg_descriptor<std::vector<std::string>> arg_rpc_ssl_allowed_certificates = {"rpc-ssl-allowed-certificates", tools::wallet2::tr("List of paths to PEM format certificates of allowed RPC servers (all allowed if empty)")};
+  const command_line::arg_descriptor<std::vector<std::string>> arg_rpc_ssl_allowed_fingerprints = {"rpc-ssl-allowed-fingerprints", tools::wallet2::tr("List of certificate fingerprints to allow")};
 
   constexpr const char default_rpc_username[] = "monero";
 
@@ -240,6 +241,7 @@ namespace tools
     auto rpc_ssl_private_key = command_line::get_arg(vm, arg_rpc_ssl_private_key);
     auto rpc_ssl_certificate = command_line::get_arg(vm, arg_rpc_ssl_certificate);
     auto rpc_ssl_allowed_certificates = command_line::get_arg(vm, arg_rpc_ssl_allowed_certificates);
+    auto rpc_ssl_allowed_fingerprints = command_line::get_arg(vm, arg_rpc_ssl_allowed_fingerprints);
     auto rpc_ssl = command_line::get_arg(vm, arg_rpc_ssl);
     epee::net_utils::ssl_support_t rpc_ssl_support;
     if (!epee::net_utils::ssl_support_from_string(rpc_ssl_support, rpc_ssl))
@@ -258,11 +260,14 @@ namespace tools
         }
     }
 
+    std::vector<std::vector<uint8_t>> allowed_fingerprints{ rpc_ssl_allowed_fingerprints.size() };
+    std::transform(rpc_ssl_allowed_fingerprints.begin(), rpc_ssl_allowed_fingerprints.end(), allowed_fingerprints.begin(), epee::from_hex::vector);
+
     m_net_server.set_threads_prefix("RPC");
     auto rng = [](size_t len, uint8_t *ptr) { return crypto::rand(len, ptr); };
     return epee::http_server_impl_base<wallet_rpc_server, connection_context>::init(
       rng, std::move(bind_port), std::move(rpc_config->bind_ip), std::move(rpc_config->access_control_origins), std::move(http_login),
-      rpc_ssl_support, std::make_pair(rpc_ssl_private_key, rpc_ssl_certificate), allowed_certificates
+      rpc_ssl_support, std::make_pair(rpc_ssl_private_key, rpc_ssl_certificate), std::move(allowed_certificates), std::move(allowed_fingerprints)
     );
   }
   //------------------------------------------------------------------------------------------------------------------------------