empty trust_root is no trust root.

work around some thoughtful and considerate RPs that take the pain of sending
the trust_root parameter, but do not go into as much trouble as setting it to
anything but an empty string.

Signed-off-by: Michael Krelin <hacker@klever.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/basic_op.cc b/lib/basic_op.cc
index fa659ac..511b51a 100644
--- a/lib/basic_op.cc
+++ b/lib/basic_op.cc
@@ -123,77 +123,83 @@ namespace opkele {
 	oum.reset_fields();
 	oum.set_field("ns",OIURI_OPENID20);
 	oum.set_field("error",u.what());
 	oum.set_field("error_code","unsupported-type");
 	oum.set_field("session_type","DH-SHA256");
 	oum.set_field("assoc_type","HMAC-SHA256");
 	return oum;
     }
 
     void basic_OP::checkid_(const basic_openid_message& inm,
 	    extension_t *ext) {
 	reset_vars();
 	string modestr = inm.get_field("mode");
 	if(modestr=="checkid_setup")
 	    mode = mode_checkid_setup;
 	else if(modestr=="checkid_immediate")
 	    mode = mode_checkid_immediate;
 	else
 	    throw bad_input(OPKELE_CP_ "Invalid checkid_* mode");
 	try {
 	    assoc = retrieve_assoc(invalidate_handle=inm.get_field("assoc_handle"));
 	    invalidate_handle.clear();
 	}catch(failed_lookup&) { }
 	try {
 	    openid2 = (inm.get_field("ns")==OIURI_OPENID20);
 	}catch(failed_lookup&) { openid2 = false; }
 	try {
 	    return_to = inm.get_field("return_to");
 	}catch(failed_lookup&) { }
 	if(openid2) {
 	    try {
 		realm = inm.get_field("realm");
+		if(realm.empty())
+		    throw failed_lookup(OPKELE_CP_ "Empty realm doesn't count");
 	    }catch(failed_lookup&) {
 		try {
 		    realm = inm.get_field("trust_root");
+		    if(realm.empty())
+			throw failed_lookup(OPKELE_CP_ "Empty trust_root doesn't count");
 		}catch(failed_lookup&) {
 		    if(return_to.empty())
 			throw bad_input(OPKELE_CP_
 				"Both realm and return_to are unset");
 		    realm = return_to;
 		}
 	    }
 	}else{
 	    try {
 		realm = inm.get_field("trust_root");
+		if(realm.empty())
+		    throw failed_lookup(OPKELE_CP_ "Empty trust_root doesn't count");
 	    }catch(failed_lookup&) {
 		if(return_to.empty())
 		    throw bad_input(OPKELE_CP_
 			    "Both realm and return_to are unset");
 		realm = return_to;
 	    }
 	}
 	try {
 	    identity = inm.get_field("identity");
 	    try {
 		claimed_id = inm.get_field("claimed_id");
 	    }catch(failed_lookup&) {
 		if(openid2)
 		    throw bad_input(OPKELE_CP_
 			    "claimed_id and identity must be either both present or both absent");
 		claimed_id = identity;
 	    }
 	}catch(failed_lookup&) {
 	    if(openid2 && inm.has_field("claimed_id"))
 		throw bad_input(OPKELE_CP_
 		    "claimed_id and identity must be either both present or both absent");
 	}
 	verify_return_to();
 	if(ext) ext->op_checkid_hook(inm);
     }
 
     basic_openid_message& basic_OP::id_res(basic_openid_message& om,
 	    extension_t *ext) {
 	assert(!return_to.empty());
 	assert(!is_id_select());
 	if(!assoc) {
 	    assoc = alloc_assoc("HMAC-SHA256",SHA256_DIGEST_LENGTH,true);