swaroop: store whole signer/decryption chains and private keys encrypted by machine UUID.

4 files changed, 172 insertions, 37 deletions

diff --git a/src/lib/config.cc b/src/lib/config.cc
index 9dd6f638e..04cf6dd9b 100644
--- a/src/lib/config.cc
+++ b/src/lib/config.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2018 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2019 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -179,6 +179,8 @@ Config::set_defaults ()
 	_player_watermark_period = 1;
 	_player_watermark_duration = 50;
 	_player_lock_file = boost::none;
+	_signer_chain_path = "signer";
+	_decryption_chain_path = "decryption";
 #endif
 
 	_allowed_dcp_frame_rates.clear ();
@@ -394,6 +396,21 @@ try
 	}
 
 	cxml::NodePtr signer = f.optional_node_child ("Signer");
+#ifdef DCPOMATIC_VARIANT_SWAROOP
+	if (signer && signer->node_children().size() == 1) {
+		/* The content of <Signer> is a path to a file; if it's relative it's in the same
+		   directory as .config. */
+		_signer_chain_path = signer->content();
+		if (_signer_chain_path.is_relative()) {
+			_signer_chain = read_swaroop_chain (path(_signer_chain_path.string()));
+		} else {
+			_signer_chain = read_swaroop_chain (_signer_chain_path);
+		}
+	} else {
+		/* <Signer> is not present or has children: ignore it and remake. */
+		_signer_chain = create_certificate_chain ();
+	}
+#else
 	if (signer) {
 		shared_ptr<dcp::CertificateChain> c (new dcp::CertificateChain ());
 		/* Read the signing certificates and private key in from the config file */
@@ -406,6 +423,7 @@ try
 		/* Make a new set of signing certificates and key */
 		_signer_chain = create_certificate_chain ();
 	}
+#endif
 
 	/* These must be done before we call BadSignerChain as that might set one
 	   of the nags.
@@ -432,29 +450,32 @@ try
 	}
 
 	cxml::NodePtr decryption = f.optional_node_child ("Decryption");
+#ifdef DCPOMATIC_VARIANT_SWAROOP
+	if (decryption && decryption->node_children().size() == 1) {
+		/* The content of <Decryption> is a path to a file; if it's relative, it's in the same
+		   directory as .config. */
+		_decryption_chain_path = decryption->content();
+		if (_decryption_chain_path.is_relative()) {
+			_decryption_chain = read_swaroop_chain (path(_decryption_chain_path.string()));
+		} else {
+			_decryption_chain = read_swaroop_chain (_decryption_chain_path);
+		}
+	} else {
+		/* <Decryption> is not present or has more children: ignore it and remake. */
+		_decryption_chain = create_certificate_chain ();
+	}
+#else
 	if (decryption) {
 		shared_ptr<dcp::CertificateChain> c (new dcp::CertificateChain ());
 		BOOST_FOREACH (cxml::NodePtr i, decryption->node_children ("Certificate")) {
 			c->add (dcp::Certificate (i->content ()));
 		}
-		optional<string> key = decryption->optional_string_child ("PrivateKey");
-#ifdef DCPOMATIC_VARIANT_SWAROOP
-		if (key) {
-			c->set_key (*key);
-		} else {
-			dcp::Data encrypted_key (path("private"));
-			dcp::Data iv (path("iv"));
-			c->set_key (dcpomatic::decrypt (encrypted_key, key_from_uuid(), iv));
-		}
-#else
-		DCPOMATIC_ASSERT (key);
-		c->set_key (*key);
-#endif
+		c->set_key (decryption->string_child ("PrivateKey"));
 		_decryption_chain = c;
 	} else {
 		_decryption_chain = create_certificate_chain ();
 	}
-
+#endif
 	if (f.optional_node_child("DKDMGroup")) {
 		/* New-style: all DKDMs in a group */
 		_dkdms = dynamic_pointer_cast<DKDMGroup> (DKDMBase::read (f.node_child("DKDMGroup")));
@@ -613,19 +634,6 @@ Config::write () const
 	write_cinemas ();
 }
 
-#ifdef DCPOMATIC_VARIANT_SWAROOP
-/* Make up a key from the machine UUID */
-dcp::Data
-Config::key_from_uuid () const
-{
-	dcp::Data key (dcpomatic::crypto_key_length());
-	memset (key.data().get(), 0, key.size());
-	string const magic = command_and_read ("dcpomatic2_uuid");
-	strncpy ((char *) key.data().get(), magic.c_str(), dcpomatic::crypto_key_length());
-	return key;
-}
-#endif
-
 void
 Config::write_config () const
 {
@@ -793,25 +801,36 @@ Config::write_config () const
 	/* [XML] Signer Certificate chain and private key to use when signing DCPs and KDMs.  Should contain <code>&lt;Certificate&gt;</code>
 	   tags in order and a <code>&lt;PrivateKey&gt;</code> tag all containing PEM-encoded certificates or private keys as appropriate.
 	*/
+#ifdef DCPOMATIC_VARIANT_SWAROOP
+	if (_signer_chain_path.is_relative()) {
+		write_swaroop_chain (_signer_chain, path(_signer_chain_path.string()));
+	} else {
+		write_swaroop_chain (_signer_chain, _signer_chain_path);
+	}
+	root->add_child("Signer")->add_child_text(_signer_chain_path.string());
+#else
 	xmlpp::Element* signer = root->add_child ("Signer");
 	DCPOMATIC_ASSERT (_signer_chain);
 	BOOST_FOREACH (dcp::Certificate const & i, _signer_chain->unordered()) {
 		signer->add_child("Certificate")->add_child_text (i.certificate (true));
 	}
 	signer->add_child("PrivateKey")->add_child_text (_signer_chain->key().get ());
+#endif
 
 	/* [XML] Decryption Certificate chain and private key to use when decrypting KDMs */
+#ifdef DCPOMATIC_VARIANT_SWAROOP
+	if (_decryption_chain_path.is_relative()) {
+		write_swaroop_chain (_decryption_chain, path(_decryption_chain_path.string()));
+	} else {
+		write_swaroop_chain (_decryption_chain, _decryption_chain_path);
+	}
+	root->add_child("Decryption")->add_child_text(_decryption_chain_path.string());
+#else
 	xmlpp::Element* decryption = root->add_child ("Decryption");
 	DCPOMATIC_ASSERT (_decryption_chain);
 	BOOST_FOREACH (dcp::Certificate const & i, _decryption_chain->unordered()) {
 		decryption->add_child("Certificate")->add_child_text (i.certificate (true));
 	}
-#ifdef DCPOMATIC_VARIANT_SWAROOP
-	dcp::Data iv = dcpomatic::random_iv ();
-	dcp::Data encrypted_key = dcpomatic::encrypt (_decryption_chain->key().get(), key_from_uuid(), iv);
-	encrypted_key.write (path("private"));
-	iv.write (path("iv"));
-#else
 	decryption->add_child("PrivateKey")->add_child_text (_decryption_chain->key().get ());
 #endif
 
diff --git a/src/lib/config.h b/src/lib/config.h
index e28928226..70d8f9200 100644
--- a/src/lib/config.h
+++ b/src/lib/config.h
@@ -1083,9 +1083,6 @@ private:
 	boost::filesystem::path directory_or (boost::optional<boost::filesystem::path> dir, boost::filesystem::path a) const;
 	void add_to_history_internal (std::vector<boost::filesystem::path>& h, boost::filesystem::path p);
 	void backup ();
-#ifdef DCPOMATIC_VARIANT_SWAROOP
-	dcp::Data key_from_uuid () const;
-#endif
 
 	template <class T>
 	void maybe_set (T& member, T new_value, Property prop = OTHER) {
@@ -1175,10 +1172,16 @@ private:
 	std::string _notification_bcc;
 	std::string _notification_email;
 	boost::shared_ptr<const dcp::CertificateChain> _signer_chain;
+#ifdef DCPOMATIC_VARIANT_SWAROOP
+	boost::filesystem::path _signer_chain_path;
+#endif
 	/** Chain used to decrypt KDMs; the leaf of this chain is the target
 	 *  certificate for making KDMs given to DCP-o-matic.
 	 */
 	boost::shared_ptr<const dcp::CertificateChain> _decryption_chain;
+#ifdef DCPOMATIC_VARIANT_SWAROOP
+	boost::filesystem::path _decryption_chain_path;
+#endif
 	/** true to check for updates on startup */
 	bool _check_for_updates;
 	bool _check_for_test_updates;
diff --git a/src/lib/util.cc b/src/lib/util.cc
index 595c7e76e..a1ea8f9f1 100644
--- a/src/lib/util.cc
+++ b/src/lib/util.cc
@@ -35,6 +35,7 @@
 #include "rect.h"
 #include "digester.h"
 #include "audio_processor.h"
+#include "crypto.h"
 #include "compose.hpp"
 #include "audio_buffers.h"
 #include <dcp/locale_convert.h>
@@ -93,6 +94,7 @@ using boost::thread;
 using boost::optional;
 using boost::lexical_cast;
 using boost::bad_lexical_cast;
+using boost::scoped_array;
 using dcp::Size;
 using dcp::raw_convert;
 using dcp::locale_convert;
@@ -812,3 +814,110 @@ checked_fread (void* ptr, size_t size, FILE* stream, boost::filesystem::path pat
 		}
 	}
 }
+
+#ifdef DCPOMATIC_VARIANT_SWAROOP
+
+/* Make up a key from the machine UUID */
+dcp::Data
+key_from_uuid ()
+{
+	dcp::Data key (dcpomatic::crypto_key_length());
+	memset (key.data().get(), 0, key.size());
+	string const magic = command_and_read ("dcpomatic2_uuid");
+	strncpy ((char *) key.data().get(), magic.c_str(), dcpomatic::crypto_key_length());
+	return key;
+}
+
+/* swaroop chain file format:
+ *
+ *  0 [int16_t] IV length
+ *  2 [int16_t] cert #1 length, or 0 for none
+ *  4 [int16_t] cert #2 length, or 0 for none
+ *  6 [int16_t] cert #3 length, or 0 for none
+ *  8 [int16_t] cert #4 length, or 0 for none
+ * 10 [int16_t] cert #5 length, or 0 for none
+ * 12 [int16_t] cert #6 length, or 0 for none
+ * 14 [int16_t] cert #7 length, or 0 for none
+ * 16 [int16_t] cert #8 length, or 0 for none
+ * 16 [int16_t] private key length
+ * 20 IV
+ *    cert #1
+ *    cert #2
+ *    cert #3
+ *    cert #4
+ *    cert #5
+ *    cert #6
+ *    cert #7
+ *    cert #8
+ *    private key
+ */
+
+struct __attribute__ ((packed)) Header_ {
+	int16_t iv_length;
+	int16_t cert_length[8];
+	int16_t private_key_length;
+};
+
+typedef struct Header_ Header;
+
+shared_ptr<dcp::CertificateChain>
+read_swaroop_chain (boost::filesystem::path path)
+{
+	dcp::Data data (path);
+	Header* header = (Header *) data.data().get();
+	uint8_t* p = data.data().get() + sizeof(Header);
+
+	dcp::Data iv (p, header->iv_length);
+	p += iv.size();
+
+	shared_ptr<dcp::CertificateChain> cc (new dcp::CertificateChain());
+	for (int i = 0; i < 8; ++i) {
+		if (header->cert_length[i] == 0) {
+			break;
+		}
+		dcp::Data c(p, header->cert_length[i]);
+		p += c.size();
+		cc->add (dcp::Certificate(dcpomatic::decrypt(c, key_from_uuid(), iv)));
+	}
+
+	dcp::Data k (p, header->private_key_length);
+	cc->set_key (dcpomatic::decrypt(k, key_from_uuid(), iv));
+	return cc;
+}
+
+void
+write_swaroop_chain (shared_ptr<const dcp::CertificateChain> chain, boost::filesystem::path output)
+{
+	cout << "write " << output.string() << "\n";
+
+	scoped_array<uint8_t> buffer (new uint8_t[65536]);
+	Header* header = (Header *) buffer.get();
+	memset (header, 0, sizeof(Header));
+	uint8_t* p = buffer.get() + sizeof(Header);
+
+	dcp::Data iv = dcpomatic::random_iv ();
+	header->iv_length = iv.size ();
+	memcpy (p, iv.data().get(), iv.size());
+	p += iv.size();
+
+	int N = 0;
+	BOOST_FOREACH (dcp::Certificate i, chain->root_to_leaf()) {
+		dcp::Data e = dcpomatic::encrypt (i.certificate(true), key_from_uuid(), iv);
+		memcpy (p, e.data().get(), e.size());
+		p += e.size();
+		DCPOMATIC_ASSERT (N < 8);
+		header->cert_length[N] = e.size ();
+		++N;
+	}
+
+	dcp::Data k = dcpomatic::encrypt (chain->key().get(), key_from_uuid(), iv);
+	memcpy (p, k.data().get(), k.size());
+	p += k.size();
+	header->private_key_length = k.size ();
+
+	FILE* f = fopen_boost (output, "wb");
+	checked_fwrite (buffer.get(), p - buffer.get(), f, output);
+	fclose (f);
+}
+
+#endif
diff --git a/src/lib/util.h b/src/lib/util.h
index 94e9e3761..bdf2480fc 100644
--- a/src/lib/util.h
+++ b/src/lib/util.h
@@ -100,5 +100,9 @@ extern boost::shared_ptr<AudioBuffers> remap (boost::shared_ptr<const AudioBuffe
 extern Eyes increment_eyes (Eyes e);
 extern void checked_fread (void* ptr, size_t size, FILE* stream, boost::filesystem::path path);
 extern void checked_fwrite (void const * ptr, size_t size, FILE* stream, boost::filesystem::path path);
+#ifdef DCPOMATIC_VARIANT_SWAROOP
+extern boost::shared_ptr<dcp::CertificateChain> read_swaroop_chain (boost::filesystem::path path);
+extern void write_swaroop_chain (boost::shared_ptr<const dcp::CertificateChain> chain, boost::filesystem::path output);
+#endif
 
 #endif