TNL::ClientPuzzleManager class Reference

TNL::ClientPuzzleManager Class Reference

#include <tnlClientPuzzle.h>

Detailed Description

The ClientPuzzleManager class issues, solves and validates client puzzles for connection authentication.

Public Types

enum ErrorCode {
  Success,
  InvalidSolution,
  InvalidServerNonce,
  InvalidClientNonce,
  InvalidPuzzleDifficulty,
  ErrorCodeCount
}

Error codes that can be returned by checkSolution. More...

enum {
  PuzzleRefreshTime = 30000,
  InitialPuzzleDifficulty = 17,
  MaxPuzzleDifficulty = 26,
  MaxSolutionComputeFragment = 30,
  SolutionFragmentIterations = 50000
}

Difficulty levels of puzzles. More...

Public Member Functions

ClientPuzzleManager ()

~ClientPuzzleManager ()

void tick (U32 currentTime)

Checks to see if a new nonce needs to be created, and if so generates one and tosses out the current list of accepted nonces.

ErrorCode checkSolution (U32 solution, Nonce &clientNonce, Nonce &serverNonce, U32 puzzleDifficulty, U32 clientIdentity)

Checks a puzzle solution submitted by a client to see if it is a valid solution for the current or previous puzzle nonces.

Nonce getCurrentNonce ()

Returns the current server nonce.

U32 getCurrentDifficulty ()

Returns the current client puzzle difficulty.

Static Public Member Functions

bool solvePuzzle (U32 *solution, Nonce &clientNonce, Nonce &serverNonce, U32 puzzleDifficulty, U32 clientIdentity)

Computes a puzzle solution value for the given puzzle difficulty and server nonce.

Static Private Member Functions

bool checkOneSolution (U32 solution, Nonce &clientNonce, Nonce &serverNonce, U32 puzzleDifficulty, U32 clientIdentity)

Private Attributes

U32 mCurrentDifficulty

U32 mLastUpdateTime

U32 mLastTickTime

Nonce mCurrentNonce

Nonce mLastNonce

NonceTable * mCurrentNonceTable

NonceTable * mLastNonceTable

Member Enumeration Documentation

enum TNL::ClientPuzzleManager::ErrorCode

Error codes that can be returned by checkSolution.

Enumeration values:

Success

InvalidSolution

InvalidServerNonce

InvalidClientNonce

InvalidPuzzleDifficulty

ErrorCodeCount

anonymous enum

Difficulty levels of puzzles.

Enumeration values:

PuzzleRefreshTime Refresh the server puzzle every 30 seconds.

InitialPuzzleDifficulty Initial puzzle difficulty is set so clients do approx 2-3x the shared secret generation of the server.

MaxPuzzleDifficulty Maximum puzzle difficulty is approx 1 minute to solve on ~2004 hardware.

MaxSolutionComputeFragment Number of milliseconds spent computing solution per call to solvePuzzle.

SolutionFragmentIterations Number of attempts to spend on the client puzzle per call to solvePuzzle.

Constructor & Destructor Documentation

TNL::ClientPuzzleManager::ClientPuzzleManager ( )

TNL::ClientPuzzleManager::~ClientPuzzleManager ( )

Member Function Documentation

bool TNL::ClientPuzzleManager::checkOneSolution ( U32 solution,

Nonce & clientNonce,

Nonce & serverNonce,

U32 puzzleDifficulty,

U32 clientIdentity

) [static, private]

void TNL::ClientPuzzleManager::tick ( U32 currentTime )

Checks to see if a new nonce needs to be created, and if so generates one and tosses out the current list of accepted nonces.

ErrorCode TNL::ClientPuzzleManager::checkSolution ( U32 solution,

Nonce & clientNonce,

Nonce & serverNonce,

U32 puzzleDifficulty,

U32 clientIdentity

)

Checks a puzzle solution submitted by a client to see if it is a valid solution for the current or previous puzzle nonces.

bool TNL::ClientPuzzleManager::solvePuzzle ( U32 * solution,

Nonce & clientNonce,

Nonce & serverNonce,

U32 puzzleDifficulty,

U32 clientIdentity

) [static]

Computes a puzzle solution value for the given puzzle difficulty and server nonce.
If the execution time of this function exceeds MaxSolutionComputeFragment milliseconds, it will return the current trail solution in the solution variable and a return value of false.

Note:
Although the behavior of this function can be tweaked using MaxSolutionComputeFragment and SolutionFragmentIterations, it's important to bias these settings in favor of rapid puzzle completion. A client puzzle is only valid for two times PuzzleRefreshTime, so for about a minute, maximum. Most of the time the puzzle can be solved in only a few hundred milliseconds. It's better to solve the puzzle fast than to let it drag out, (ie, it's better to let your application hitch for a moment whilst calculating than to make the user endure many seconds of lag) so reducing the timeout or iterations should be done only if you know what you're doing.

Nonce TNL::ClientPuzzleManager::getCurrentNonce ( ) [inline]

Returns the current server nonce.

U32 TNL::ClientPuzzleManager::getCurrentDifficulty ( ) [inline]

Returns the current client puzzle difficulty.

Field Documentation

U32 TNL::ClientPuzzleManager::mCurrentDifficulty [private]

U32 TNL::ClientPuzzleManager::mLastUpdateTime [private]

U32 TNL::ClientPuzzleManager::mLastTickTime [private]

Nonce TNL::ClientPuzzleManager::mCurrentNonce [private]

Nonce TNL::ClientPuzzleManager::mLastNonce [private]

NonceTable* TNL::ClientPuzzleManager::mCurrentNonceTable [private]

NonceTable* TNL::ClientPuzzleManager::mLastNonceTable [private]


Public Types
enum	ErrorCode { Success, InvalidSolution, InvalidServerNonce, InvalidClientNonce, InvalidPuzzleDifficulty, ErrorCodeCount }
	Error codes that can be returned by checkSolution. More...
enum	{ PuzzleRefreshTime = 30000, InitialPuzzleDifficulty = 17, MaxPuzzleDifficulty = 26, MaxSolutionComputeFragment = 30, SolutionFragmentIterations = 50000 }
	Difficulty levels of puzzles. More...
Public Member Functions
	ClientPuzzleManager ()
	~ClientPuzzleManager ()
void	tick (U32 currentTime)
	Checks to see if a new nonce needs to be created, and if so generates one and tosses out the current list of accepted nonces.
ErrorCode	checkSolution (U32 solution, Nonce &clientNonce, Nonce &serverNonce, U32 puzzleDifficulty, U32 clientIdentity)
	Checks a puzzle solution submitted by a client to see if it is a valid solution for the current or previous puzzle nonces.
Nonce	getCurrentNonce ()
	Returns the current server nonce.
U32	getCurrentDifficulty ()
	Returns the current client puzzle difficulty.
Static Public Member Functions
bool	solvePuzzle (U32 *solution, Nonce &clientNonce, Nonce &serverNonce, U32 puzzleDifficulty, U32 clientIdentity)
	Computes a puzzle solution value for the given puzzle difficulty and server nonce.
Static Private Member Functions
bool	checkOneSolution (U32 solution, Nonce &clientNonce, Nonce &serverNonce, U32 puzzleDifficulty, U32 clientIdentity)
Private Attributes
U32	mCurrentDifficulty
U32	mLastUpdateTime
U32	mLastTickTime
Nonce	mCurrentNonce
Nonce	mLastNonce
NonceTable *	mCurrentNonceTable
NonceTable *	mLastNonceTable