1 files changed, 15 insertions, 3 deletions
diff --git a/Swiften/SASL/SCRAMSHA1ClientAuthenticator.cpp b/Swiften/SASL/SCRAMSHA1ClientAuthenticator.cpp
index ab61ef5..b55e5e4 100644
--- a/Swiften/SASL/SCRAMSHA1ClientAuthenticator.cpp
+++ b/Swiften/SASL/SCRAMSHA1ClientAuthenticator.cpp
@@ -1,101 +1,113 @@
 #include "Swiften/SASL/SCRAMSHA1ClientAuthenticator.h"
 
 #include <cassert>
 #include <map>
 #include <boost/lexical_cast.hpp>
 
 #include "Swiften/StringCodecs/SHA1.h"
 #include "Swiften/StringCodecs/Base64.h"
 #include "Swiften/StringCodecs/HMACSHA1.h"
 #include "Swiften/StringCodecs/PBKDF2.h"
 #include "Swiften/StringPrep/StringPrep.h"
 
 namespace Swift {
 
 SCRAMSHA1ClientAuthenticator::SCRAMSHA1ClientAuthenticator(const String& nonce) : ClientAuthenticator("SCRAM-SHA-1"), step(Initial), clientnonce(nonce) {
 }
 
 ByteArray SCRAMSHA1ClientAuthenticator::getResponse() const {
 	if (step == Initial) {
 		return "n,," + getInitialBareClientMessage();
 	}
 	else {
 		ByteArray clientKey = HMACSHA1::getResult(saltedPassword, "Client Key");
 		ByteArray storedKey = SHA1::getBinaryHash(clientKey);
 		ByteArray clientSignature = HMACSHA1::getResult(storedKey, authMessage);
 		ByteArray clientProof = clientKey;
 		for (unsigned int i = 0; i < clientProof.getSize(); ++i) {
 			clientProof[i] ^= clientSignature[i];
 		}
 		ByteArray result = ByteArray("c=biwsCg==,r=") + clientnonce + serverNonce + ",p=" + Base64::encode(clientProof);
 		return result;
 	}
 }
 
 bool SCRAMSHA1ClientAuthenticator::setChallenge(const ByteArray& challenge) {
 	if (step == Initial) {
 		initialServerMessage = challenge;
 
-		// TODO: Check if this is correct
 		std::map<char, String> keys = parseMap(String(initialServerMessage.getData(), initialServerMessage.getSize()));
+
+		// Extract the salt
 		ByteArray salt = Base64::decode(keys['s']);
-		String clientServerNonce = keys['r'];
 
 		// Extract the server nonce
+		String clientServerNonce = keys['r'];
 		if (clientServerNonce.getUTF8Size() <= clientnonce.getUTF8Size()) {
 			return false;
 		}
 		String receivedClientNonce = clientServerNonce.getSubstring(0, clientnonce.getUTF8Size());
 		if (receivedClientNonce != clientnonce) {
 			return false;
 		}
 		serverNonce = clientServerNonce.getSubstring(clientnonce.getUTF8Size(), clientServerNonce.npos());
-		int iterations = boost::lexical_cast<int>(keys['i'].getUTF8String());
+
+		// Extract the number of iterations
+		int iterations = 0;
+		try {
+			iterations = boost::lexical_cast<int>(keys['i'].getUTF8String());
+		}
+		catch (const boost::bad_lexical_cast&) {
+			return false;
+		}
+		if (iterations <= 0) {
+			return false;
+		}
 
 		// Compute all the values needed for the server signature
 		saltedPassword = PBKDF2::encode(StringPrep::getPrepared(getPassword(), StringPrep::SASLPrep), salt, iterations);
 		authMessage = getInitialBareClientMessage() + "," + initialServerMessage + "," + "c=biwsCg==," + "r=" + clientnonce + serverNonce;
 		ByteArray serverKey = HMACSHA1::getResult(saltedPassword, "Server Key");
 		serverSignature = HMACSHA1::getResult(serverKey, authMessage);
 
 		step = Proof;
 		return true;
 	}
 	else {
 		ByteArray result = ByteArray("v=") + ByteArray(Base64::encode(serverSignature));
 		return challenge == result;
 	}
 }
 
 std::map<char, String> SCRAMSHA1ClientAuthenticator::parseMap(const String& s) {
 	std::map<char, String> result;
 	if (s.getUTF8Size() > 0) {
 		char key;
 		String value;
 		size_t i = 0;
 		bool expectKey = true;
 		while (i < s.getUTF8Size()) {
 			if (expectKey) {
 				key = s[i];
 				expectKey = false;
 				i++;
 			}
 			else if (s[i] == ',') {
 				result[key] = value;
 				value = "";
 				expectKey = true;
 			}
 			else {
 				value += s[i];
 			}
 			i++;
 		}
 		result[key] = value;
 	}
 	return result;
 }
 
 ByteArray SCRAMSHA1ClientAuthenticator::getInitialBareClientMessage() const {
 	String authenticationID = StringPrep::getPrepared(getAuthenticationID(), StringPrep::SASLPrep);
 	String escapedAuthenticationID;
 	for (size_t i = 0; i < authenticationID.getUTF8Size(); ++i) {