Quite large reworking of signer/cert handling.

1 files changed, 269 insertions, 0 deletions

diff --git a/src/certificate_chain.cc b/src/certificate_chain.cc
new file mode 100644
index 00000000..dbed590b
--- /dev/null
+++ b/src/certificate_chain.cc
@@ -0,0 +1,269 @@
+/*
+    Copyright (C) 2013-2014 Carl Hetherington <cth@carlh.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+/** @file  src/signer_chain.cc
+ *  @brief Functions to make signer chains.
+ */
+
+#include "certificate_chain.h"
+#include "exceptions.h"
+#include "util.h"
+#include "KM_util.h"
+#include <openssl/sha.h>
+#include <openssl/bio.h>
+#include <openssl/evp.h>
+#include <boost/filesystem.hpp>
+#include <boost/algorithm/string.hpp>
+#include <fstream>
+#include <sstream>
+
+using std::string;
+using std::ofstream;
+using std::ifstream;
+using std::stringstream;
+using std::cout;
+
+/** Run a shell command.
+ *  @param cmd Command to run (UTF8-encoded).
+ */
+static void
+command (string cmd)
+{
+#ifdef LIBDCP_WINDOWS
+	/* We need to use CreateProcessW on Windows so that the UTF-8/16 mess
+	   is handled correctly.
+	*/
+	int const wn = MultiByteToWideChar (CP_UTF8, 0, cmd.c_str(), -1, 0, 0);
+	wchar_t* buffer = new wchar_t[wn];
+	if (MultiByteToWideChar (CP_UTF8, 0, cmd.c_str(), -1, buffer, wn) == 0) {
+		delete[] buffer;
+		return;
+	}
+
+	int code = 1;
+
+	STARTUPINFOW startup_info;
+	memset (&startup_info, 0, sizeof (startup_info));
+	startup_info.cb = sizeof (startup_info);
+	PROCESS_INFORMATION process_info;
+
+	/* XXX: this doesn't actually seem to work; failing commands end up with
+	   a return code of 0
+	*/
+	if (CreateProcessW (0, buffer, 0, 0, FALSE, CREATE_NO_WINDOW, 0, 0, &startup_info, &process_info)) {
+		WaitForSingleObject (process_info.hProcess, INFINITE);
+		DWORD c;
+		if (GetExitCodeProcess (process_info.hProcess, &c)) {
+			code = c;
+		}
+		CloseHandle (process_info.hProcess);
+		CloseHandle (process_info.hThread);
+	}
+
+	delete[] buffer;
+#else
+	cmd += " 2> /dev/null";
+	int const r = system (cmd.c_str ());
+	int const code = WEXITSTATUS (r);
+#endif
+	if (code) {
+		stringstream s;
+		s << "error " << code << " in " << cmd << " within " << boost::filesystem::current_path();
+		throw dcp::MiscError (s.str());
+	}
+}
+
+/** Extract a public key from a private key and create a SHA1 digest of it.
+ *  @param private_key Private key
+ *  @param openssl openssl binary name (or full path if openssl is not on the system path).
+ *  @return SHA1 digest of corresponding public key, with escaped / characters.
+ */
+static string
+public_key_digest (boost::filesystem::path private_key, boost::filesystem::path openssl)
+{
+	boost::filesystem::path public_name = private_key.string() + ".public";
+
+	/* Create the public key from the private key */
+	stringstream s;
+	s << "\"" << openssl.string() << "\" rsa -outform PEM -pubout -in " << private_key.string() << " -out " << public_name.string ();
+	command (s.str().c_str ());
+
+	/* Read in the public key from the file */
+
+	string pub;
+	ifstream f (public_name.string().c_str ());
+	if (!f.good ()) {
+		throw dcp::MiscError ("public key not found");
+	}
+
+	bool read = false;
+	while (f.good ()) {
+		string line;
+		getline (f, line);
+		if (line.length() >= 10 && line.substr(0, 10) == "-----BEGIN") {
+			read = true;
+		} else if (line.length() >= 8 && line.substr(0, 8) == "-----END") {
+			break;
+		} else if (read) {
+			pub += line;
+		}
+	}
+
+	/* Decode the base64 of the public key */
+		
+	unsigned char buffer[512];
+	int const N = dcp::base64_decode (pub, buffer, 1024);
+
+	/* Hash it with SHA1 (without the first 24 bytes, for reasons that are not entirely clear) */
+
+	SHA_CTX context;
+	if (!SHA1_Init (&context)) {
+		throw dcp::MiscError ("could not init SHA1 context");
+	}
+
+	if (!SHA1_Update (&context, buffer + 24, N - 24)) {
+		throw dcp::MiscError ("could not update SHA1 digest");
+	}
+
+	unsigned char digest[SHA_DIGEST_LENGTH];
+	if (!SHA1_Final (digest, &context)) {
+		throw dcp::MiscError ("could not finish SHA1 digest");
+	}
+
+	char digest_base64[64];
+	string dig = Kumu::base64encode (digest, SHA_DIGEST_LENGTH, digest_base64, 64);
+#ifdef LIBDCP_WINDOWS
+	boost::replace_all (dig, "/", "\\/");
+#else	
+	boost::replace_all (dig, "/", "\\\\/");
+#endif	
+	return dig;
+}
+
+boost::filesystem::path
+dcp::make_certificate_chain (boost::filesystem::path openssl)
+{
+	boost::filesystem::path directory = boost::filesystem::unique_path ();
+	boost::filesystem::create_directories (directory);
+	
+	boost::filesystem::path const cwd = boost::filesystem::current_path ();
+	boost::filesystem::current_path (directory);
+
+	string quoted_openssl = "\"" + openssl.string() + "\"";
+
+	command (quoted_openssl + " genrsa -out ca.key 2048");
+
+	{
+		ofstream f ("ca.cnf");
+		f << "[ req ]\n"
+		  << "distinguished_name = req_distinguished_name\n"
+		  << "x509_extensions	= v3_ca\n"
+		  << "[ v3_ca ]\n"
+		  << "basicConstraints = critical,CA:true,pathlen:3\n"
+		  << "keyUsage = keyCertSign,cRLSign\n"
+		  << "subjectKeyIdentifier = hash\n"
+		  << "authorityKeyIdentifier = keyid:always,issuer:always\n"
+		  << "[ req_distinguished_name ]\n"
+		  << "O = Unique organization name\n"
+		  << "OU = Organization unit\n"
+		  << "CN = Entity and dnQualifier\n";
+	}
+
+	string const ca_subject = "/O=example.org/OU=example.org/CN=.smpte-430-2.ROOT.NOT_FOR_PRODUCTION/dnQualifier=" + public_key_digest ("ca.key", openssl);
+
+	{
+		stringstream c;
+		c << quoted_openssl
+		  << " req -new -x509 -sha256 -config ca.cnf -days 3650 -set_serial 5"
+		  << " -subj " << ca_subject << " -key ca.key -outform PEM -out ca.self-signed.pem";
+		command (c.str().c_str());
+	}
+
+	command (quoted_openssl + " genrsa -out intermediate.key 2048");
+
+	{
+		ofstream f ("intermediate.cnf");
+		f << "[ default ]\n"
+		  << "distinguished_name = req_distinguished_name\n"
+		  << "x509_extensions = v3_ca\n"
+		  << "[ v3_ca ]\n"
+		  << "basicConstraints = critical,CA:true,pathlen:2\n"
+		  << "keyUsage = keyCertSign,cRLSign\n"
+		  << "subjectKeyIdentifier = hash\n"
+		  << "authorityKeyIdentifier = keyid:always,issuer:always\n"
+		  << "[ req_distinguished_name ]\n"
+		  << "O = Unique organization name\n"
+		  << "OU = Organization unit\n"
+		  << "CN = Entity and dnQualifier\n";
+	}
+		
+	string const inter_subject = "/O=example.org/OU=example.org/CN=.smpte-430-2.INTERMEDIATE.NOT_FOR_PRODUCTION/dnQualifier="
+		+ public_key_digest ("intermediate.key", openssl);
+
+	{
+		stringstream s;
+		s << quoted_openssl
+		  << " req -new -config intermediate.cnf -days 3649 -subj " << inter_subject << " -key intermediate.key -out intermediate.csr";
+		command (s.str().c_str());
+	}
+
+	
+	command (
+		quoted_openssl +
+		" x509 -req -sha256 -days 3649 -CA ca.self-signed.pem -CAkey ca.key -set_serial 6"
+		" -in intermediate.csr -extfile intermediate.cnf -extensions v3_ca -out intermediate.signed.pem"
+		);
+
+	command (quoted_openssl + " genrsa -out leaf.key 2048");
+
+	{
+		ofstream f ("leaf.cnf");
+		f << "[ default ]\n"
+		  << "distinguished_name = req_distinguished_name\n"
+		  << "x509_extensions	= v3_ca\n"
+		  << "[ v3_ca ]\n"
+		  << "basicConstraints = critical,CA:false\n"
+		  << "keyUsage = digitalSignature,keyEncipherment\n"
+		  << "subjectKeyIdentifier = hash\n"
+		  << "authorityKeyIdentifier = keyid,issuer:always\n"
+		  << "[ req_distinguished_name ]\n"
+		  << "O = Unique organization name\n"
+		  << "OU = Organization unit\n"
+		  << "CN = Entity and dnQualifier\n";
+	}
+
+	string const leaf_subject = "/O=example.org/OU=example.org/CN=CS.smpte-430-2.LEAF.NOT_FOR_PRODUCTION/dnQualifier="
+		+ public_key_digest ("leaf.key", openssl);
+
+	{
+		stringstream s;
+		s << quoted_openssl << " req -new -config leaf.cnf -days 3648 -subj " << leaf_subject << " -key leaf.key -outform PEM -out leaf.csr";
+		command (s.str().c_str());
+	}
+
+	command (
+		quoted_openssl +
+		" x509 -req -sha256 -days 3648 -CA intermediate.signed.pem -CAkey intermediate.key"
+		" -set_serial 7 -in leaf.csr -extfile leaf.cnf -extensions v3_ca -out leaf.signed.pem"
+		);
+
+	boost::filesystem::current_path (cwd);
+
+	return directory;
+}