int nIn = sqlite3_value_bytes(argv[0]);
  char *zOut, *zTemp;
  if( 0==zIn ) return;
  if( 0==(zOut = sqlite3_malloc64( nIn * 2 + 3 )) ){
    sqlite3_result_error_nomem(context);
    return;
  }
  if( sqlite3_user_data(context)==0 ){
    zTemp = obscure((char*)zIn);
  }else{
    zTemp = unobscure((char*)zIn);
  }
  strcpy(zOut, zTemp);
  fossil_free(zTemp);
  sqlite3_result_text(context, zOut, strlen(zOut), sqlite3_free);
}

/*
** Return True if zName is a protected (a.k.a. "sensitive") setting.
*/

    zPw = 0;
  }else{
    /* Password failure while doing a sync from the command-line interface */
    url_prompt_for_password();
    zPw = g.url.passwd;
  }

  /* The login card wants the SHA1 hash of the password (as computed by
  ** sha1_shared_secret()), not the original password.  So convert the
  ** password to its SHA1 encoding if it isn't already a SHA1 hash.
  **
  ** We assume that a hexadecimal string of exactly 40 characters is a
  ** SHA1 hash, not an original password.  If a user has a password which
  ** just happens to be a 40-character hex string, then this routine won't
  ** be able to distinguish it from a hash, the translation will not be
  ** performed, and the sync won't work.  
  */

  if( zPw && zPw[0] && (strlen(zPw)!=40 || !validate16(zPw,40)) ){
    const char *zProjectCode = 0;
    if( g.url.flags & URL_USE_PARENT ){
      zProjectCode = db_get("parent-project-code", 0);
    }else{
      zProjectCode = db_get("project-code", 0);
    }
    zPw = sha1_shared_secret(zPw, zLogin, zProjectCode);
    if( g.url.pwConfig!=0 ){
      char *x = obscure(zPw);
      db_set(g.url.pwConfig/*works-like:"x"*/, x, 0);
      fossil_free(x);
    }
    fossil_free(g.url.passwd);
    g.url.passwd = fossil_strdup(zPw);
  }

  blob_append(&pw, zPw, -1);
  sha1sum_blob(&pw, &sig);
  blob_appendf(pLogin, "login %F %b %b\n", zLogin, &nonce, &sig);
  blob_reset(&pw);
  blob_reset(&sig);
  blob_reset(&nonce);

  db_protect_only(PROTECT_NONE);
  sqlite3_set_authorizer(db, db_top_authorizer, db);
  if( local_bSqlCmdTest ){
    sqlite3_create_function(db, "db_protect", 1, SQLITE_UTF8, 0,
                            sqlcmd_db_protect, 0, 0);
    sqlite3_create_function(db, "db_protect_pop", 0, SQLITE_UTF8, 0,
                            sqlcmd_db_protect_pop, 0, 0);
    sqlite3_create_function(db, "shared_secret", 2, SQLITE_UTF8, 0,
                            sha1_shared_secret_sql_function, 0, 0);
  }
  return SQLITE_OK;
}

/*
** atexit() handler that cleans up global state modified by this module.
*/

**
**     Make REF the new default URL, replacing the prior default.
**     REF may be a URL or a NAME from a prior "add".
*/
void remote_url_cmd(void){
  char *zUrl, *zArg;
  int nArg;
  int showPw;
  db_find_and_open_repository(0, 0);
  showPw = find_option("show-passwords",0,0)!=0;

  /* We should be done with options.. */
  verify_all_options();

  /* 2021-10-25: A note about data structures.
  **
  ** The remote URLs are stored in the CONFIG table.  The URL is stored

    db_multi_exec("DELETE FROM config WHERE name glob 'sync-pw:*'");
    db_multi_exec("DELETE FROM config WHERE name = 'last-sync-pw'");
    db_protect_pop();
    db_commit_transaction();
    return;
  }
  if( strncmp(zArg, "config-data", nArg)==0 ){
    /* Undocumented command:  "fossil remote config-data [-show-passwords]"
    **
    ** Show the CONFIG table entries that relate to remembering remote URLs
    */
    Stmt q;
    int n;
    sqlite3_create_function(g.db, "unobscure", 1, SQLITE_UTF8, &g.db,
                            db_obscure, 0, 0);
    n = db_int(13,
       "SELECT max(length(name))"
       "  FROM config"
       " WHERE name GLOB 'sync-*:*'"
          " OR name GLOB 'last-sync-*'"
          " OR name GLOB 'parent-project-*'"
    );
    db_prepare(&q,
      "SELECT name,"
      "  CASE WHEN name NOT LIKE '%%sync-pw%%' AND name<>'parent-project-pw'"
      "       THEN value"
      "       WHEN %d THEN unobscure(value)"
      "       ELSE printf('%%.*c',length(value)/2-1,'*') END"
      "  FROM config"
      " WHERE name GLOB 'sync-*:*'"
         " OR name GLOB 'last-sync-*'"
         " OR name GLOB 'parent-project-*'"
      " ORDER BY name LIKE '%%sync-pw%%' OR name='parent-project-pw', name",
      showPw
    );
    while( db_step(&q)==SQLITE_ROW ){
      fossil_print("%-*s  %s\n",
        n, db_column_text(&q,0),
        db_column_text(&q,1)
      );
    }

** Check the signature on an application/x-fossil payload received by
** the HTTP server.  The signature is a line of the following form:
**
**        login LOGIN NONCE SIGNATURE
**
** The NONCE is the SHA1 hash of the remainder of the input.
** SIGNATURE is the SHA1 checksum of the NONCE concatenated
** with the sha1_shared_secret() encoding of the users password.
**
**   SIGNATURE = sha1_sum( NONCE + sha1_shared_secret(PASSWORD) );
**
** The parameters to this routine are ephemeral blobs holding the
** LOGIN, NONCE and SIGNATURE.
**
** This routine attempts to locate the user and verify the signature.
** If everything checks out, the USER.CAP column for the USER table
** is consulted to set privileges in the global g variable.