--- a/src/cybergarage/http/chttp_authentication.c
+++ b/src/cybergarage/http/chttp_authentication.c
@@ -560,6 +560,7 @@ void cg_http_auth_header_parse(CgHttpPac
 void initDigestInfo(CgHttpAuth **digest)
 {
 	*digest = (CgHttpAuth *)malloc(sizeof(CgHttpAuth));
+	memset(*digest, '\0', sizeof(CgHttpAuth));
 	(*digest)->realm 		= NULL;
 	(*digest)->algorithm 	= NULL;
 	(*digest)->qop 		= NULL;
@@ -716,7 +717,7 @@ authRet_t cg_http_request_check_digest_a
 			tmp 				= cg_http_request_getqop(httpReq);
 			if(!tmp){
 				auth->qop		= NULL;
-				return HTTP_AUTH_ERROR;
+				/*qop can be unspecified*/
 			}
 			else{
 				auth->qop		= tmp;
@@ -729,7 +730,7 @@ authRet_t cg_http_request_check_digest_a
 			tmp 				= cg_http_request_getalgorithm(httpReq);
 			if(!tmp){
 				auth->algorithm	= NULL;
-				return HTTP_AUTH_ERROR;
+				/*algorithm can be unspecified*/
 			}
 			else{
 				auth->algorithm	= tmp;
@@ -742,6 +743,7 @@ authRet_t cg_http_request_check_digest_a
 			tmp 				= cg_http_request_getopaque(httpReq);
 			if(!tmp){
 				auth->opaque	= NULL;
+				printf("error: can not get opaque");
 				return HTTP_AUTH_ERROR;
 			}
 			else{
@@ -761,7 +763,7 @@ authRet_t cg_http_request_check_digest_a
 		if(!tmp)
 			auth->nc		= 0;
 		else
-			auth->nc		= tmp;
+			sscanf(tmp, "%08x", &auth->nc);
 
 		method				= cg_http_request_getmethod(httpReq);
 		uripath				= cg_http_request_geturi(httpReq);
@@ -773,8 +775,10 @@ authRet_t cg_http_request_check_digest_a
 	if the qop is "auth" or unspecified
 		ha2 = MD5( Method:digest-uri )
 */
+		memset(md5Input, "\0", sizeof(md5Input));
 		snprintf(md5Input, sizeof(md5Input), "%s:%s:%s", user, auth->realm, passwd);
 		cg_str2md5(md5Input,ha1);
+		memset(md5Input, "\0", sizeof(md5Input));
 		snprintf(md5Input, sizeof(md5Input), "%s:%s", method, uripath);
 		cg_str2md5(md5Input,ha2);
 
@@ -827,7 +831,8 @@ authRet_t cg_http_request_check_digest_a
 				cg_str2md5(md5Input, ha1);
 			}
 
-			snprintf(md5Input, sizeof(md5Input), "%s:%s:%s:%s:%s:%s",
+			memset(md5Input, '\0', sizeof(md5Input));
+			snprintf(md5Input, sizeof(md5Input), "%s:%s:%08x:%s:%s:%s",
 											ha1,
 											auth->nonce,
 											auth->nc,