Add ScOoxPasswordHash::verifyPassword(), tdf#104250 prep

Change-Id: Ife588fa0626b01336813e956a25e51541d1096e6

sc/inc/tabprotection.hxx

@@ -55,6 +55,7 @@ struct ScOoxPasswordHash
         maHashValue.clear();
         maSaltValue.clear();
     }
+    bool verifyPassword( const OUString& aPassText ) const;
 };
 
 namespace ScPassHashHelper

sc/source/core/data/tabprotection.cxx

@@ -20,6 +20,7 @@
 #include <tabprotection.hxx>
 #include <svl/PasswordHelper.hxx>
 #include <comphelper/docpasswordhelper.hxx>
+#include <comphelper/hash.hxx>
 #include <osl/diagnose.h>
 #include <document.hxx>
 
@@ -88,6 +89,19 @@ ScPasswordHash ScPassHashHelper::getHashTypeFromURI(const OUString& rURI)
     return PASSHASH_UNSPECIFIED;
 }
 
+bool ScOoxPasswordHash::verifyPassword( const OUString& aPassText ) const
+{
+    if (!hasPassword())
+        return false;
+
+    const OUString aHash( comphelper::Hash::calculateHashBase64( aPassText, maSaltValue, mnSpinCount, maAlgorithmName));
+    if (aHash.isEmpty())
+        // unsupported algorithm
+        return false;
+
+    return aHash == maHashValue;
+}
+
 ScPassHashProtectable::~ScPassHashProtectable()
 {
 }