check if return_to matches realm

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

2 files changed, 45 insertions, 0 deletions

diff --git a/include/opkele/exception.h b/include/opkele/exception.h
index 5c8418e..33f89cc 100644
--- a/include/opkele/exception.h
+++ b/include/opkele/exception.h
@@ -359,2 +359,11 @@ namespace opkele {
 
+    /**
+     * thrown if return_to URL doesn't match realm
+     */
+    class bad_return_to : public exception {
+	public:
+	    bad_return_to(OPKELE_E_PARS)
+		: exception(OPKELE_E_CONS) { }
+    };
+
 }
diff --git a/lib/basic_op.cc b/lib/basic_op.cc
index 22012bc..f7573aa 100644
--- a/lib/basic_op.cc
+++ b/lib/basic_op.cc
@@ -2,2 +2,3 @@
 #include <cassert>
+#include <algorithm>
 #include <openssl/sha.h>
@@ -11,2 +12,4 @@
 namespace opkele {
+    using std::pair;
+    using std::mismatch;
 
@@ -319,2 +322,35 @@ namespace opkele {
 
+    void basic_op::verify_return_to() {
+	string nrealm = opkele::util::rfc_3986_normalize_uri(realm);
+	if(nrealm.find('#')!=string::npos)
+	    throw opkele::bad_realm(OPKELE_CP_ "authentication realm contains URI fragment");
+	string nrt = opkele::util::rfc_3986_normalize_uri(return_to);
+	string::size_type pr = nrealm.find("://");
+	string::size_type prt = nrt.find("://");
+	assert(!(pr==string::npos || prt==string::npos));
+	pr += sizeof("://")-1;
+	prt += sizeof("://")-1;
+	if(!strncmp(nrealm.c_str()+pr,"*.",2)) {
+	    pr = nrealm.find('.',pr);
+	    prt = nrt.find('.',prt);
+	    assert(pr!=string::npos);
+	    if(prt==string::npos)
+		throw bad_return_to(
+			OPKELE_CP_ "return_to URL doesn't match realm");
+	    // TODO: check for overgeneralized realm
+	}
+	string::size_type lr = nrealm.length();
+	string::size_type lrt = nrt.length();
+	if( (lrt-prt) < (lr-pr) )
+	    throw bad_return_to(
+		    OPKELE_CP_ "return_to URL doesn't match realm");
+	pair<const char*,const char*> mp = mismatch(
+		nrealm.c_str()+pr,nrealm.c_str()+lr,
+		nrt.c_str()+prt);
+	if( (*(mp.first-1))!='/'
+		&& !strchr("/?#",*mp.second) )
+	    throw bad_return_to(
+		    OPKELE_CP_ "return_to URL doesn't match realm");
+    }
+
 }