1 files changed, 4 insertions, 0 deletions
diff --git a/Swiften/SASL/DIGESTMD5ClientAuthenticator.cpp b/Swiften/SASL/DIGESTMD5ClientAuthenticator.cpp
index 5e78ee2..249a538 100644
--- a/Swiften/SASL/DIGESTMD5ClientAuthenticator.cpp
+++ b/Swiften/SASL/DIGESTMD5ClientAuthenticator.cpp
@@ -1,55 +1,59 @@
 /*
  * Copyright (c) 2010 Remko Tronçon
  * Licensed under the GNU General Public License v3.
  * See Documentation/Licenses/GPLv3.txt for more information.
  */
 
 #include <Swiften/SASL/DIGESTMD5ClientAuthenticator.h>
 
 #include <cassert>
 
 #include <Swiften/StringCodecs/MD5.h>
 #include <Swiften/StringCodecs/Hexify.h>
 #include <Swiften/Base/Concat.h>
 #include <Swiften/Base/Algorithm.h>
 
 namespace Swift {
 
 DIGESTMD5ClientAuthenticator::DIGESTMD5ClientAuthenticator(const std::string& host, const std::string& nonce) : ClientAuthenticator("DIGEST-MD5"), step(Initial), host(host), cnonce(nonce) {
 }
 
+bool DIGESTMD5ClientAuthenticator::canBeUsed() {
+	return MD5::isAllowedForCrypto();
+}
+
 boost::optional<SafeByteArray> DIGESTMD5ClientAuthenticator::getResponse() const {
 	if (step == Initial) {
 		return boost::optional<SafeByteArray>();
 	}
 	else if (step == Response) {
 		std::string realm;
 		if (challenge.getValue("realm")) {
 			realm = *challenge.getValue("realm");
 		}
 		std::string qop = "auth";
 		std::string digestURI = "xmpp/" + host;
 		std::string nc = "00000001";
 
 		// Compute the response value
 		ByteArray A1 = concat(
 				MD5::getHash(
 					concat(createSafeByteArray(getAuthenticationID().c_str()), createSafeByteArray(":"), createSafeByteArray(realm.c_str()), createSafeByteArray(":"), getPassword())),
 				createByteArray(":"), createByteArray(*challenge.getValue("nonce")), createByteArray(":"), createByteArray(cnonce));
 		if (!getAuthorizationID().empty()) {
 			append(A1, createByteArray(":" + getAuthenticationID()));
 		}
 		ByteArray A2 = createByteArray("AUTHENTICATE:" + digestURI);
 
 		std::string responseValue = Hexify::hexify(MD5::getHash(createByteArray(
 			Hexify::hexify(MD5::getHash(A1)) + ":"
 			+ *challenge.getValue("nonce") + ":" + nc + ":" + cnonce + ":" + qop + ":"
 			+ Hexify::hexify(MD5::getHash(A2)))));
 
 
 		DIGESTMD5Properties response;
 		response.setValue("username", getAuthenticationID());
 		if (!realm.empty()) {
 			response.setValue("realm", realm);
 		}
 		response.setValue("nonce", *challenge.getValue("nonce"));