C4InputValidation.cpp

Go to the documentation of this file.

/*
 * OpenClonk, http://www.openclonk.org
 *
 * Copyright (c) 2007-2009, RedWolf Design GmbH, http://www.clonk.de/
 * Copyright (c) 2009-2016, The OpenClonk Team and contributors
 *
 * Distributed under the terms of the ISC license; see accompanying file
 * "COPYING" for details.
 *
 * "Clonk" is a registered trademark of Matthes Bender, used with permission.
 * See accompanying file "TRADEMARK" for details.
 *
 * To redistribute this file separately, substitute the full license texts
 * for the above references.
 */
// user input validation functions
 
#include "C4Include.h"
#include "lib/C4InputValidation.h"
 
#include "lib/C4Markup.h"
 
namespace C4InVal
{
    bool ValidateString(char *szString, ValidationOption eOption, size_t iMaxSize)
    {
        // validate in a StdStrBuf. Does one alloc and copy :(
        StdStrBuf buf; buf.Copy(szString);
        bool fInvalid = ValidateString(buf, eOption);
        if (fInvalid) SCopy(buf.getData(), szString, iMaxSize);
        return fInvalid;
    }
 
    bool ValidateString(StdStrBuf &rsString, ValidationOption eOption)
    {
        bool fValid = true;
        // validation depending on option
        // check min length
        if (!rsString.getLength())
        {
            // empty if not allowed?
            if (eOption != VAL_NameAllowEmpty && eOption != VAL_NameExAllowEmpty && eOption != VAL_Comment)
            {
                rsString.Copy("empty");
                fValid = false;
            }
        }
        switch (eOption)
        {
        case VAL_Filename: // regular filenames only
            // absolutely no directory traversal
            if (rsString.ReplaceChar('/', '_')) fValid = false;
            if (rsString.ReplaceChar('\\', '_')) fValid = false;
 
            // fallthrough to general file name validation
        case VAL_SubPathFilename: // filenames and optional subpath
            // do not traverse upwards in file hierarchy
            if (rsString.Replace("..", "__")) fValid = false;
            if (*rsString.getData() == '/' || *rsString.getData() == '\\') { *rsString.getMData() = '_'; fValid = false; }
 
            // fallthrough to general file name validation
        case VAL_FullPath:        // full filename paths
            // some characters are prohibited in filenames in general
            if (rsString.ReplaceChar('*', '_')) fValid = false;
            if (rsString.ReplaceChar('?', '_')) fValid = false;
            if (rsString.ReplaceChar('<', '_')) fValid = false;
            if (rsString.ReplaceChar('>', '_')) fValid = false;
            // ';' and '|' is never allowed in filenames, because it would cause problems in many engine internal file lists
            if (rsString.ReplaceChar(';', '_')) fValid = false;
            if (rsString.ReplaceChar('|', '_')) fValid = false;
            // the colon is generally prohibited except at pos 2 (C:\...), because it could lead to creation of (invisible) streams on NTFS
            if (rsString.ReplaceChar(':', '_')) fValid = false;
            if (*rsString.getData() == ':') { *rsString.getMData() = '_'; fValid = false; }
            // validate drive letter
            if (rsString.getLength()>=2 && *rsString.getPtr(1) == ':')
            {
                if (eOption != VAL_FullPath)
                {
                    *rsString.getMPtr(1)='_'; fValid = false;
                }
                else if (!isalpha((unsigned char)*rsString.getData()) || (*rsString.getPtr(2)!='\\' && *rsString.getPtr(2)!='/'))
                {
                    *rsString.getMData()=*rsString.getMPtr(1)='_'; fValid = false;
                }
            }
            break;
 
        case VAL_NameNoEmpty:
        case VAL_NameAllowEmpty:
            // no markup
            if (C4Markup::StripMarkup(&rsString)) { fValid = false; }
            // trim spaces
            if (rsString.TrimSpaces()) fValid = false;
            // min length
            if (eOption == VAL_NameNoEmpty) if (!rsString.getLength()) { fValid = false; rsString.Copy("Unknown"); }
            // max length
            if (rsString.getLength() > C4MaxName) { fValid = false; rsString.SetLength(C4MaxName); }
            break;
 
        case VAL_NameExNoEmpty:
        case VAL_NameExAllowEmpty:
            // trim spaces
            if (rsString.TrimSpaces()) fValid = false;
            // min length
            if (eOption == VAL_NameExNoEmpty) if (!rsString.getLength()) { fValid = false; rsString.Copy("Unknown"); }
            // max length
            if (rsString.getLength() > C4MaxLongName) { fValid = false; rsString.SetLength(C4MaxLongName); }
            break;
 
        case VAL_IRCName: // nickname for IRC. a-z, A-Z, _^{[]} only; 0-9|- inbetween; max 30 characters
            if (rsString.getLength() > 30) fValid = false;
            if (rsString.getLength() < 2) fValid = false;
            if (!rsString.ValidateChars("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_^{[]}", "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_^{[]}0123456789|-")) { fValid = false; rsString.Copy("Guest"); }
            if (SEqualNoCase(rsString.getData(), "NickServ")
                || SEqualNoCase(rsString.getData(), "ChanServ")
                || SEqualNoCase(rsString.getData(), "MemoServ")
                || SEqualNoCase(rsString.getData(), "OperServ")
                || SEqualNoCase(rsString.getData(), "HelpServ")) fValid = false;
            if (!fValid) rsString.Copy("Guest");
            break;
 
        case VAL_IRCPass: // password for IRC; max 31 characters
            // max length; no spaces
            if (rsString.getLength() > 31) { fValid = false; rsString.SetLength(31); }
            if (rsString.getLength() < 2) { fValid = false; rsString.Copy("secret"); }
            if (rsString.ReplaceChar(' ', '_')) fValid = false;
            break;
 
        case VAL_IRCChannel: // IRC channel name
        { // needed for the vector
            std::vector<StdCopyStrBuf> chans;
            StdStrBuf SplitPart;
            StdCopyStrBuf tmp; tmp.Copy(rsString);
            while(tmp.SplitAtChar(',', &SplitPart)) // Split
            {
                chans.push_back(tmp);
                tmp.Copy(SplitPart);
            }
            chans.push_back(tmp);
            rsString.Clear();
            for(std::vector<StdCopyStrBuf>::iterator it = chans.begin(); it < chans.end(); ++it) // Reassemble clean
            {
                if (it->getLength() > 32) { fValid = false; it->SetLength(32); }
                else if (it->getLength() < 2) { fValid = false; it->Clear(); }
                else if (*it->getData() != '#' && *it->getData() != '+') { fValid = false; it->InsertChar('#', 0); }
                if (it->ReplaceChar(' ', '_')) fValid = false;
                rsString.Append(*it);
                if(it+1 < chans.end() && it->getLength() > 0) rsString.Append(",");
            }
            if(rsString.getLength() < 2) rsString.Copy("#openclonk");
            break;
        }
 
        case VAL_Comment: // comment - just limit length
            if (rsString.getLength() > C4MaxComment) { fValid = false; rsString.SetLength(C4MaxComment); }
            break;
 
        default:
            assert(!"not yet implemented");
        }
        // issue warning for invalid adjustments
        if (false) if (!fValid)
        {
            const char *szOption = "unknown";
            switch (eOption)
            {
            case VAL_Filename:         szOption = "filename";         break;
            case VAL_SubPathFilename:  szOption = "(sub-)filename";   break;
            case VAL_FullPath:         szOption = "free filename";    break;
            case VAL_NameNoEmpty:      szOption = "strict name";      break;
            case VAL_NameExNoEmpty:    szOption = "name";             break;
            case VAL_NameAllowEmpty:   szOption = "strict name*";     break;
            case VAL_NameExAllowEmpty: szOption = "name*";            break;
            case VAL_IRCName:          szOption = "IRC nick";         break;
            case VAL_IRCPass:          szOption = "IRC password";     break;
            case VAL_IRCChannel:       szOption = "IRC channel";      break;
            case VAL_Comment:          szOption = "Comment";          break;
            }
            LogF(R"(WARNING: Adjusted invalid user input for "%s" to "%s")", szOption, rsString.getData());
        }
        return !fValid;
    }
 
    bool ValidateInt(int32_t &riVal, int32_t iMinVal, int32_t iMaxVal)
    {
        if (riVal < iMinVal) { riVal = iMinVal; return false; }
        else if (riVal > iMaxVal) { riVal = iMaxVal; return false; }
        else return true;
    }
}