Add signatures to Dictionary, and fix unhex() API in Utils to be a little safer.

node/Dictionary.cpp

@@ -0,0 +1,154 @@
+/*
+ * ZeroTier One - Global Peer to Peer Ethernet
+ * Copyright (C) 2011-2014  ZeroTier Networks LLC
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ * --
+ *
+ * ZeroTier may be used and distributed under the terms of the GPLv3, which
+ * are available at: http://www.gnu.org/licenses/gpl-3.0.html
+ *
+ * If you would like to embed ZeroTier into a commercial application or
+ * redistribute it in a modified binary form, please contact ZeroTier Networks
+ * LLC. Start here: http://www.zerotier.com/
+ */
+
+#include "Dictionary.hpp"
+#include "C25519.hpp"
+#include "Identity.hpp"
+#include "Utils.hpp"
+
+namespace ZeroTier {
+
+void Dictionary::fromString(const char *s)
+{
+	clear();
+	bool escapeState = false;
+	std::string keyBuf;
+	std::string *element = &keyBuf;
+	while (*s) {
+		if (escapeState) {
+			escapeState = false;
+			switch(*s) {
+				case '0':
+					element->push_back((char)0);
+					break;
+				case 'r':
+					element->push_back('\r');
+					break;
+				case 'n':
+					element->push_back('\n');
+					break;
+				default:
+					element->push_back(*s);
+					break;
+			}
+		} else {
+			if (*s == '\\') {
+				escapeState = true;
+			} else if (*s == '=') {
+				if (element == &keyBuf)
+					element = &((*this)[keyBuf]);
+			} else if ((*s == '\r')||(*s == '\n')) {
+				if ((element == &keyBuf)&&(keyBuf.length() > 0))
+					(*this)[keyBuf];
+				keyBuf = "";
+				element = &keyBuf;
+			} else element->push_back(*s);
+		}
+		++s;
+	}
+	if ((element == &keyBuf)&&(keyBuf.length() > 0))
+		(*this)[keyBuf];
+}
+
+bool Dictionary::sign(const Identity &id)
+{
+	try {
+		std::string buf;
+		_mkSigBuf(buf);
+		char nows[32];
+		Utils::snprintf(nows,sizeof(nows),"%llx",(unsigned long long)Utils::now());
+		C25519::Signature sig(id.sign(buf.data(),buf.length()));
+		(*this)[ZT_DICTIONARY_SIGNATURE] = Utils::hex(sig.data,sig.size());
+		(*this)[ZT_DICTIONARY_SIGNATURE_IDENTITY] = id.toString(false);
+		(*this)[ZT_DICTIONARY_SIGNATURE_TIMESTAMP] = nows;
+		return true;
+	} catch ( ... ) {
+		return false;
+	}
+}
+
+bool Dictionary::verify(const Identity &id) const
+{
+	try {
+		std::string buf;
+		_mkSigBuf(buf);
+		const_iterator sig(find(ZT_DICTIONARY_SIGNATURE));
+		if (sig == end())
+			return false;
+		std::string sigbin(Utils::unhex(sig->second));
+		return id.verify(buf.data(),buf.length(),sigbin.data(),sigbin.length());
+	} catch ( ... ) {
+		return false;
+	}
+}
+
+void Dictionary::_mkSigBuf(std::string &buf) const
+{
+	unsigned long pairs = 0;
+	for(const_iterator i(begin());i!=end();++i) {
+		if ((i->first.length() < 2)||( (i->first[0] != '~')&&(i->first[1] != '!') )) {
+			buf.append(i->first);
+			buf.push_back('=');
+			buf.append(i->second);
+			buf.push_back('\0');
+			++pairs;
+		}
+	}
+	buf.push_back((char)0xff);
+	buf.push_back((char)((pairs >> 24) & 0xff)); // pad with number of key/value pairs at end
+	buf.push_back((char)((pairs >> 16) & 0xff));
+	buf.push_back((char)((pairs >> 8) & 0xff));
+	buf.push_back((char)(pairs & 0xff));
+}
+
+void Dictionary::_appendEsc(const char *data,unsigned int len,std::string &to)
+{
+	for(unsigned int i=0;i<len;++i) {
+		switch(data[i]) {
+			case 0:
+				to.append("\\0");
+				break;
+			case '\r':
+				to.append("\\r");
+				break;
+			case '\n':
+				to.append("\\n");
+				break;
+			case '\\':
+				to.append("\\\\");
+				break;
+			case '=':
+				to.append("\\=");
+				break;
+			default:
+				to.push_back(data[i]);
+				break;
+		}
+	}
+}
+
+} // namespace ZeroTier