zRef = P("HTTP_REFERER");
  if( zRef==0 ) return 0;
  nBase = (int)strlen(g.zBaseURL);
  if( fossil_strncmp(g.zBaseURL,zRef,nBase)!=0 ) return 0;
  if( zRef[nBase]!=0 && zRef[nBase]!='/' ) return 0;
  return 1;
}

/*
** Return true if the current CGI request is a POST request
*/
static int cgi_is_post_request(void){
  const char *zMethod = P("REQUEST_METHOD");
  if( zMethod==0 ) return 0;
  if( strcmp(zMethod,"POST")!=0 ) return 0;
  return  1;
}

/*
** Return true if the current request appears to be safe from a
** Cross-Site Request Forgery (CSRF) attack.  The level of checking
** is determined by the parameter.  The higher the number, the more
** secure we are:
**
**    0:     Request must come from the same origin
**    1:     Same origin and must be a POST request
**    2:     All of the above plus must have a valid CSRF token
**
** Results are cached in the g.okCsrf variable.  The g.okCsrf value
** has meaning as follows:
**
**    -1:   Not a secure request
**     0:   Status unknown
**     1:   Request comes from the same origin
**     2:   (1) plus it is a POST request
**     3:   (2) plus there is a valid "csrf" token in the request
*/
int cgi_csrf_safe(int securityLevel){


  if( g.okCsrf<0 ) return 0;
  if( g.okCsrf==0 ){
    if( !cgi_same_origin() ){
      g.okCsrf = -1;
    }else{
      g.okCsrf = 1;
      if( cgi_is_post_request() ){
        g.okCsrf = 2;
        if( fossil_strcmp(P("csrf"), g.zCsrfToken)==0 ){
          g.okCsrf = 3;
        }
      }
    }
  }
  return g.okCsrf >= (securityLevel+1);
}

/*
** Verify that CSRF defenses are maximal - that the request comes from
** the same origin, that it is a POST request, and that there is a valid
** "csrf" token.  If this is not the case, fail immediately.



*/
void cgi_csrf_verify(void){



  if( !cgi_csrf_safe(2) ){
    fossil_fatal("Cross-site Request Forgery detected");
  }
}

/*
** Information about all query parameters, post parameter, cookies and
** CGI environment variables are stored in a hash table as follows:
*/

        "   AND tagxref.tagid=tag.tagid"
        "   AND tag.tagname GLOB 'sym-*'",
        rid
      );
    }
  }
  zETime = db_text(0, "SELECT coalesce(datetime(%Q),datetime('now'))", zETime);
  if( P("submit")!=0 && (zBody!=0 && zComment!=0) && cgi_csrf_safe(2) ){

    if ( !event_commit_common(rid, zId, zBody, zETime,
                              zMimetype, zComment, zTags,
                              zClrFlag[0] ? zClr : 0) ){
      style_header("Error");
      @ Internal error:  Fossil tried to make an invalid artifact for
      @ the edited technote.
      style_finish_page();

  int fpid;

  login_check_credentials();
  if( forumpost_may_close()==0 ){
    login_needed(g.anon.Admin);
    return;
  }
  cgi_csrf_verify();
  fpid = symbolic_name_to_rid(zFpid, "f");
  if( fpid<=0 ){
    webpage_error("Missing or invalid fpid query parameter");
  }
  fClose = sqlite3_strglob("*_close*", g.zPath)==0;
  if( fClose ) zReason = PD("reason",0);
  forumpost_close(fpid, fClose, zReason);

    }else{
      @ %d(nRows) moderator(s)
    }
  }

  @ <h2>Settings</h2>
  @ <p>Configuration settings specific to the forum.</p>
  if( P("submit") && cgi_csrf_safe(2) ){
    int i = 0;
    const char *zSetting;

    db_begin_transaction();
    while( (zSetting = zSettingsBool[i++]) ){
      const char *z = P(zSetting);
      if( !z || !z[0] ) z = "off";
      db_set(zSetting/*works-like:"x"*/, z, 0);
    }
    db_end_transaction(0);

  zNewColorFlag = P("newclr") ? " checked" : "";
  zNewTagFlag = P("newtag") ? " checked" : "";
  zNewTag = PDT("tagname","");
  zNewBrFlag = P("newbr") ? " checked" : "";
  zNewBranch = PDT("brname","");
  zCloseFlag = P("close") ? " checked" : "";
  zHideFlag = P("hide") ? " checked" : "";
  if( P("apply") && cgi_csrf_safe(2) ){
    Blob ctrl;
    char *zNow;


    blob_zero(&ctrl);
    zNow = date_in_standard_format(zChngTime ? zChngTime : "now");
    blob_appendf(&ctrl, "D %s\n", zNow);
    init_newtags();
    if( zNewColorFlag[0]
     && zNewColor[0]
     && (fPropagateColor!=fNewPropagateColor

    @ </blockquote>
    @ <hr>
    blob_reset(&suffix);
  }
  @ <p>Make changes to attributes of check-in
  @ [%z(href("%R/ci/%!S",zUuid))%s(zUuid)</a>]:</p>
  form_begin(0, "%R/ci_edit");

  @ <div><input type="hidden" name="r" value="%s(zUuid)">
  @ <table border="0" cellspacing="10">

  @ <tr><th align="right" valign="top">User:</th>
  @ <td valign="top">
  @   <input type="text" name="u" size="20" value="%h(zNewUser)">
  @ </td></tr>

  fossil_redirect_to_https_if_needed(1);
  sqlite3_create_function(g.db, "constant_time_cmp", 2, SQLITE_UTF8, 0,
                  constant_time_cmp_function, 0, 0);
  zUsername = P("u");
  zPasswd = P("p");
  anonFlag = g.zLogin==0 && PB("anon");
  /* Handle log-out requests */
  if( P("out") && cgi_csrf_safe(2) ){
    login_clear_login_data();
    redirect_to_g();
    return;
  }

  /* Redirect for create-new-account requests */
  if( P("self") ){
    cgi_redirectf("%R/register");
    return;
  }

  /* Deal with password-change requests */
  if( g.perm.Password && zPasswd
   && (zNew1 = P("n1"))!=0 && (zNew2 = P("n2"))!=0
   && cgi_csrf_safe(2)
  ){
    /* If there is not a "real" login, we cannot change any password. */
    if( g.zLogin ){
      /* The user requests a password change */
      zSha1Pw = sha1_shared_secret(zPasswd, g.zLogin, 0);
      if( db_int(1, "SELECT 0 FROM user"
                    " WHERE uid=%d"

** While rendering a form, call this routine to add the Anti-CSRF token
** as a hidden element of the form.
*/
void login_insert_csrf_secret(void){
  @ <input type="hidden" name="csrf" value="%s(g.zCsrfToken)">
}

















/*
** Check to see if the candidate username zUserID is already used.
** Return 1 if it is already in use.  Return 0 if the name is 
** available for a self-registeration.
*/
static int login_self_choosen_userid_already_exists(const char *zUserID){
  int rc = db_exists(

#ifdef FOSSIL_ENABLE_TCL
  /* all Tcl related context necessary for integration */
  struct TclContext tcl;
#endif

  /* For defense against Cross-site Request Forgery attacks */
  char zCsrfToken[12];    /* Value of the anti-CSRF token */
  int okCsrf;             /* -1:  unsafe
                          **  0:  unknown
                          **  1:  same origin
                          **  2:  same origin + is POST
                          **  3:  same origin, POST, valid csrf token */

  int parseCnt[10];       /* Counts of artifacts parsed */
  FILE *fDebug;           /* Write debug information here, if the file exists */
#ifdef FOSSIL_ENABLE_TH1_HOOKS
  int fNoThHook;          /* Disable all TH1 command/webpage hooks */
#endif
  int thTrace;            /* True to enable TH1 debugging output */

  z = P("s");
  zSQL = z ? trim_string(z) : 0;
  zClrKey = trim_string(PD("k",""));
  zDesc = trim_string(PD("d",""));
  zMimetype = P("m");
  zTag = P("x");
  report_update_reportfmt_table();
  if( rn>0 && P("del2") && cgi_csrf_safe(2) ){

    db_multi_exec("DELETE FROM reportfmt WHERE rn=%d", rn);
    cgi_redirect("reportlist");
    return;
  }else if( rn>0 && P("del1") && cgi_csrf_safe(2) ){
    zTitle = db_text(0, "SELECT title FROM reportfmt "
                         "WHERE rn=%d", rn);
    if( zTitle==0 ) cgi_redirect("reportlist");

    style_header("Are You Sure?");
    @ <form action="rptedit" method="post">
    @ <p>You are about to delete all traces of the report

    }
    if( zErr==0
     && db_exists("SELECT 1 FROM reportfmt WHERE title=%Q and rn<>%d",
                  zTitle, rn)
    ){
      zErr = mprintf("There is already another report named \"%h\"", zTitle);
    }
    if( zErr==0 && cgi_csrf_safe(2) ){

      if( zTag && zTag[0]==0 ) zTag = 0;
      if( zDesc && zDesc[0]==0 ){ zDesc = 0; zMimetype = 0; }
      if( zMimetype && zMimetype[0]==0 ){ zDesc = 0; zMimetype = 0; }
      if( rn>0 ){
        db_multi_exec(
            "UPDATE reportfmt SET title=%Q, sqlcode=%Q,"
            " owner=%Q, cols=%Q, mtime=now(), "

  const char *zQ = P(zQParm);
  int iVal = db_get_boolean(zVar, dfltVal);
  if( zQ==0 && !disabled && P("submit") ){
    zQ = "off";
  }
  if( zQ ){
    int iQ = fossil_strcmp(zQ,"on")==0 || atoi(zQ);
    if( iQ!=iVal && cgi_csrf_safe(2) ){

      db_protect_only(PROTECT_NONE);
      db_set(zVar/*works-like:"x"*/, iQ ? "1" : "0", 0);
      db_protect_pop();
      setup_incr_cfgcnt();
      admin_log("Set option [%q] to [%q].",
                zVar, iQ ? "on" : "off");
      iVal = iQ;

  const char *zVar,     /* The corresponding row in the CONFIG table */
  const char *zQParm,   /* The query parameter */
  const char *zDflt,    /* Default value if CONFIG table entry does not exist */
  int disabled          /* 1 if disabled */
){
  const char *zVal = db_get(zVar, zDflt);
  const char *zQ = P(zQParm);
  if( zQ && fossil_strcmp(zQ,zVal)!=0 && cgi_csrf_safe(2) ){
    const int nZQ = (int)strlen(zQ);

    setup_incr_cfgcnt();
    db_protect_only(PROTECT_NONE);
    db_set(zVar/*works-like:"x"*/, zQ, 0);
    db_protect_pop();
    admin_log("Set entry_attribute %Q to: %.*s%s",
              zVar, 20, zQ, (nZQ>20 ? "..." : ""));
    zVal = zQ;

  const char *zVar,     /* The corresponding row in the CONFIG table */
  const char *zQP,      /* The query parameter */
  const char *zDflt,    /* Default value if CONFIG table entry does not exist */
  int disabled          /* 1 if the textarea should  not be editable */
){
  const char *z = db_get(zVar, zDflt);
  const char *zQ = P(zQP);
  if( zQ && !disabled && fossil_strcmp(zQ,z)!=0 && cgi_csrf_safe(2) ){
    const int nZQ = (int)strlen(zQ);

    db_protect_only(PROTECT_NONE);
    db_set(zVar/*works-like:"x"*/, zQ, 0);
    db_protect_pop();
    setup_incr_cfgcnt();
    admin_log("Set textarea_attribute %Q to: %.*s%s",
              zVar, 20, zQ, (nZQ>20 ? "..." : ""));
    z = zQ;

  const char *zDflt,    /* Default value if CONFIG table entry does not exist */
  int nChoice,          /* Number of choices */
  const char *const *azChoice /* Choices in pairs (VAR value, Display) */
){
  const char *z = db_get(zVar, zDflt);
  const char *zQ = P(zQP);
  int i;
  if( zQ && fossil_strcmp(zQ,z)!=0 && cgi_csrf_safe(2) ){
    const int nZQ = (int)strlen(zQ);

    db_unprotect(PROTECT_ALL);
    db_set(zVar/*works-like:"x"*/, zQ, 0);
    setup_incr_cfgcnt();
    db_protect_pop();
    admin_log("Set multiple_choice_attribute %Q to: %.*s%s",
              zVar, 20, zQ, (nZQ>20 ? "..." : ""));
    z = zQ;

            "SELECT sql FROM repository.sqlite_schema"
            " WHERE sql IS NOT NULL ORDER BY name");
    go = 1;
  }else if( P("tablelist") ){
    zQ = sqlite3_mprintf("SELECT*FROM pragma_table_list ORDER BY schema, name");
    go = 1;
  }
  if( go && cgi_csrf_safe(2) ){
    sqlite3_stmt *pStmt;
    int rc;
    const char *zTail;
    int nCol;
    int nRow = 0;
    int i;
    @ <hr>

    sqlite3_set_authorizer(g.db, raw_sql_query_authorizer, 0);
    search_sql_setup(g.db);
    rc = sqlite3_prepare_v2(g.db, zQ, -1, &pStmt, &zTail);
    if( rc!=SQLITE_OK ){
      @ <div class="generalError">%h(sqlite3_errmsg(g.db))</div>
      sqlite3_finalize(pStmt);
    }else if( pStmt==0 ){

  }
  style_set_current_feature("setup");
  style_header("Raw TH1 Commands");
  @ <p><b>Caution:</b> There are no restrictions on the TH1 that can be
  @ run by this page.  If Tcl integration was enabled at compile-time and
  @ the "tcl" setting is enabled, Tcl commands may be run as well.</p>
  @
  form_begin(0, "%R/admin_th1");

  @ TH1:<br>
  @ <textarea name="q" rows="5" cols="80">%h(zQ)</textarea><br>
  @ <input type="submit" name="go" value="Run TH1">
  @ </form>
  if( go && cgi_csrf_safe(2) ){
    const char *zR;
    int rc;
    int n;
    @ <hr>

    rc = Th_Eval(g.interp, 0, zQ, -1);
    zR = Th_GetResult(g.interp, &n);
    if( rc==TH_OK ){
      @ <pre class="th1result">%h(zR)</pre>
    }else{
      @ <pre class="th1error">%h(zR)</pre>
    }

  login_check_credentials();
  if( !g.perm.Admin ){
    login_needed(0);
    return;
  }
  style_set_current_feature("setup");
  style_header("URL Alias Configuration");
  if( P("submit")!=0 && cgi_csrf_safe(2) ){
    Blob token;
    Blob sql;
    const char *zNewName;
    const char *zValue;
    char zCnt[10];

    blob_init(&namelist, PD("namelist",""), -1);
    blob_init(&sql, 0, 0);
    while( blob_token(&namelist, &token) ){
      const char *zOldName = blob_str(&token);
      sqlite3_snprintf(sizeof(zCnt), zCnt, "n%d", cnt);
      zNewName = PD(zCnt, "");
      sqlite3_snprintf(sizeof(zCnt), zCnt, "v%d", cnt);

  if( !cgi_all("login","info","pw","apply") ){
    /* need all of the above properties to make a change.  Since one or
    ** more are missing, no-op */
  }else if( higherUser ){
    /* An Admin (a) user cannot edit a Superuser (s) */
  }else if( zDeleteVerify!=0 ){
    /* Need to verify a delete request */
  }else if( !cgi_csrf_safe(2) ){
    /* This might be a cross-site request forgery, so ignore it */
  }else{
    /* We have all the information we need to make the change to the user */
    char c;
    char zCap[70], zNm[4];
    zNm[0] = 'a';
    zNm[2] = 0;

      @ a different user.</span>
      @
      @ <p><a href="setup_uedit?id=%d(uid)&referer=%T(zRef)">
      @ [Bummer]</a></p>
      style_finish_page();
      return;
    }
    cgi_csrf_verify();
    db_unprotect(PROTECT_USER);
    db_multi_exec(
       "REPLACE INTO user(uid,login,info,pw,cap,mtime) "
       "VALUES(nullif(%d,0),%Q,%Q,%Q,%Q,now())",
      uid, zLogin, P("info"), zPw, zCap
    );
    if( zOldLogin && fossil_strcmp(zLogin, zOldLogin)!=0 ){

        canonical16(p, nUuid);
        p += nUuid+1;
      }
    }
    zUuid = zCanonical;
  }
  style_header("Shunned Artifacts");
  if( zUuid && P("sub") && cgi_csrf_safe(2) ){
    const char *p = zUuid;
    int allExist = 1;

    while( *p ){
      db_multi_exec("DELETE FROM shun WHERE uuid=%Q", p);
      if( !db_exists("SELECT 1 FROM blob WHERE uuid=%Q", p) ){
        allExist = 0;
      }
      admin_log("Unshunned %Q", p);
      p += strlen(p)+1;

      }
      @ will no longer be shunned.  But they may not exist in the repository.
      @ It may be necessary to rebuild the repository using the
      @ <b>fossil rebuild</b> command-line before the artifact content
      @ can pulled in from other repositories.</p>
    }
  }
  if( zUuid && P("add") && cgi_csrf_safe(2) ){
    const char *p = zUuid;
    int rid, tagid;

    while( *p ){
      db_multi_exec(
        "INSERT OR IGNORE INTO shun(uuid,mtime)"
        " VALUES(%Q, now())", p);
      db_multi_exec("DELETE FROM attachment WHERE src=%Q", p);
      rid = db_int(0, "SELECT rid FROM blob WHERE uuid=%Q", p);
      if( rid ){

  if( g.perm.Hyperlink ){
    @ <form method="POST" action="%z(zLink)" %s(zOtherArgs)>
  }else{
    needHrefJs = 1;
    @ <form method="POST" data-action='%s(zLink)' action='%R/login' \
    @ %s(zOtherArgs)>
  }
  login_insert_csrf_secret();
}

/*
** Add a new element to the submenu
*/
void style_submenu_element(
  const char *zLabel,

  int argc,
  const char **argv,
  int *argl
){
  if( argc!=1 ){
    return Th_WrongNumArgs(interp, "verifyCsrf");
  }
  if( !cgi_csrf_safe(2) ){
    fossil_fatal("possible CSRF attack");
  }
  return TH_OK;
}

/*
** TH1 command: verifyLogin
**
** Returns non-zero if the specified user name and password represent a

  char *zDate, *aUsed;
  const char *zUuid;
  int i;
  int nJ = 0, rc = TH_OK;
  Blob tktchng, cksum;
  int needMod;

  if( !cgi_csrf_safe(2) ){
    @ <p class="generalError">Error: Invalid CSRF token.</p>
    return TH_OK;
  }
  if( !captcha_is_correct(0) ){
    @ <p class="generalError">Error: Incorrect security code.</p>
    return TH_OK;
  }
  zUuid = (const char *)pUuid;
  blob_zero(&tktchng);
  zDate = date_in_standard_format("now");

  if( g.thTrace ) Th_Trace("BEGIN_TKTNEW<br>\n", -1);
  ticket_init();
  initializeVariablesFromCGI();
  getAllTicketFields();
  initializeVariablesFromDb();
  if( g.zPath[0]=='d' ) showAllFields();
  form_begin(0, "%R/%s", g.zPath);

  if( P("date_override") && g.perm.Setup ){
    @ <input type="hidden" name="date_override" value="%h(P("date_override"))">
  }
  zScript = ticket_newpage_code();
  if( g.zLogin && g.zLogin[0] ){
    int nEmail = 0;
    (void)Th_MaybeGetVar(g.interp, "private_contact", &nEmail);

  ticket_init();
  getAllTicketFields();
  initializeVariablesFromCGI();
  initializeVariablesFromDb();
  if( g.zPath[0]=='d' ) showAllFields();
  form_begin(0, "%R/%s", g.zPath);
  @ <input type="hidden" name="name" value="%s(zName)">

  zScript = ticket_editpage_code();
  Th_Store("login", login_name());
  Th_Store("date", db_text(0, "SELECT datetime('now')"));
  Th_CreateCommand(g.interp, "append_field", appendRemarkCmd, 0, 0);
  Th_CreateCommand(g.interp, "submit_ticket", submitTicketCmd, (void*)&zName,0);
  if( g.thTrace ) Th_Trace("BEGIN_TKTEDIT_SCRIPT<br>\n", -1);
  if( Th_Render(zScript)==TH_RETURN && !g.thTrace && zName ){

  isSubmit = P("submit")!=0;
  z = P("x");
  if( z==0 ){
    z = db_get(zDbField, zDfltValue);
  }
  style_set_current_feature("tktsetup");
  style_header("Edit %s", zTitle);
  if( P("clear")!=0 && cgi_csrf_safe(2) ){

    db_unset(zDbField/*works-like:"x"*/, 0);
    if( xRebuild ) xRebuild();
    cgi_redirect("tktsetup");
  }else if( isSubmit && cgi_csrf_safe(2) ){
    char *zErr = 0;

    if( xText && (zErr = xText(z))!=0 ){
      @ <p class="tktsetupError">ERROR: %h(zErr)</p>
    }else{
      db_set(zDbField/*works-like:"x"*/, z, 0);
      if( xRebuild ) xRebuild();
      cgi_redirect("tktsetup");
    }

      return;
    }
    zMimetype = wiki_filter_mimetypes(pWiki->zMimetype)
      /* see https://fossil-scm.org/forum/forumpost/0acfdaac80 */;
  }
  if( !isSandbox && P("submit")!=0 && P("r")!=0 && P("u")!=0
   && (goodCaptcha = captcha_is_correct(0))
   && cgi_csrf_safe(2)
  ){
    char *zDate;
    Blob cksum;
    Blob body;
    Blob wiki;

    blob_zero(&body);

    blob_append(&body, pWiki->zWiki, -1);
    blob_zero(&wiki);
    db_begin_transaction();
    zDate = date_in_standard_format("now");
    blob_appendf(&wiki, "D %s\n", zDate);
    blob_appendf(&wiki, "L %F\n", zPageName);
    if( fossil_strcmp(zMimetype, "text/x-fossil-wiki")!=0 ){

    safe_html_context(DOCSRC_WIKI);
    wiki_render_by_mimetype(&preview, zMimetype);
    @ <hr>
    blob_reset(&preview);
  }
  zUser = PD("u", g.zLogin);
  form_begin(0, "%R/wikiappend");

  @ <input type="hidden" name="name" value="%h(zPageName)">
  @ <input type="hidden" name="mimetype" value="%h(zMimetype)">
  @ Your Name:
  @ <input type="text" name="u" size="20" value="%h(zUser)"><br>
  zFormat = mimetype_common_name(zMimetype);
  @ Comment to append (formatted as %s(zFormat)):<br>
  @ <textarea name="r" class="wikiedit" cols="80"

  isSubmit = P("submit")!=0;
  z = P("x");
  if( z==0 ){
    z = db_get(zDbField, zDfltValue);
  }
  style_set_current_feature("xfersetup");
  style_header("Edit %s", zTitle);
  if( P("clear")!=0 && cgi_csrf_safe(2) ){

    db_unset(zDbField/*works-like:"x"*/, 0);
    if( xRebuild ) xRebuild();
    z = zDfltValue;
  }else if( isSubmit && cgi_csrf_safe(2) ){
    char *zErr = 0;

    if( xText && (zErr = xText(z))!=0 ){
      @ <p class="xfersetupError">ERROR: %h(zErr)</p>
    }else{
      db_set(zDbField/*works-like:"x"*/, z, 0);
      if( xRebuild ) xRebuild();
      cgi_redirect("xfersetup");
    }