ctx_dh.c

cryptlib安全工具包

/****************************************************************************
*																			*
*					cryptlib Diffie-Hellman Key Exchange Routines			*
*						Copyright Peter Gutmann 1995-2005					*
*																			*
****************************************************************************/

#define PKC_CONTEXT		/* Indicate that we're working with PKC context */
#if defined( INC_ALL )
  #include "crypt.h"
  #include "context.h"
#else
  #include "crypt.h"
  #include "context/context.h"
#endif /* Compiler-specific includes */

/* The DH key exchange process is somewhat complex because there are two
   phases involved for both sides, an "export" and an "import" phase, and
   they have to be performed in the correct order.  The sequence of
   operations is:

	A.load:		set p, g from fixed or external values
				x(A) = rand, x s.t. 0 < x < q-1

	A.export	y(A) = g^x(A) mod p		error if y != 0 at start
				output = y(A)

	B.load		read p, g / set p, g from external values
				x(B) = rand, x s.t. 0 < x < q-1

	B.import	y(A) = input
				z = y(A)^x(B) mod p

	B.export	y(B) = g^x(B) mod p		error if y != 0 at start
				output = y(B)

	A.import	y(B) = input
				z = y(B)^x(A) mod p

   Note that we have to set x when we load p and g because otherwise we'd
   have to set x(A) on export and x(B) on import, which is tricky since the
   DH code doesn't know whether it's working with A or B */

#ifdef USE_DH

/****************************************************************************
*																			*
*								Algorithm Self-test							*
*																			*
****************************************************************************/

/* Test the Diffie-Hellman implementation using a sample key.  Because a lot 
   of the high-level encryption routines don't exist yet, we cheat a bit and 
   set up a dummy encryption context with just enough information for the 
   following code to work */

typedef struct {
	const int pLen; const BYTE p[ 128 ];
	const int qLen; const BYTE q[ 20 ];
	const int gLen; const BYTE g[ 128 ];
	const int xLen; const BYTE x[ 20 ];
	const int yLen; const BYTE y[ 128 ];
	} DLP_KEY;

static const DLP_KEY FAR_BSS dlpTestKey = {
	/* p */
	128,
	{ 0x04, 0x4C, 0xDD, 0x5D, 0xB6, 0xED, 0x23, 0xAE, 
	  0xB2, 0xA7, 0x59, 0xE6, 0xF8, 0x3D, 0xA6, 0x27, 
	  0x85, 0xF2, 0xFE, 0xE2, 0xE8, 0xF3, 0xDA, 0xA3, 
	  0x7B, 0xD6, 0x48, 0xD4, 0x44, 0xCA, 0x6E, 0x10, 
	  0x97, 0x6C, 0x1D, 0x6C, 0x39, 0xA7, 0x0C, 0x88, 
	  0x8E, 0x1F, 0xDD, 0xF7, 0x59, 0x69, 0xDA, 0x36, 
	  0xDD, 0xB8, 0x3E, 0x1A, 0xD2, 0x91, 0x3E, 0x30, 
	  0xB1, 0xB5, 0xC2, 0xBC, 0xA9, 0xA3, 0xA5, 0xDE, 
	  0xC7, 0xCF, 0x51, 0x2C, 0x1B, 0x89, 0xD0, 0x71, 
	  0xE3, 0x71, 0xBB, 0x50, 0x86, 0x26, 0x32, 0x9F, 
	  0xF5, 0x4A, 0x9C, 0xB1, 0x78, 0x7B, 0x47, 0x1F, 
	  0x19, 0xC7, 0x26, 0x22, 0x15, 0x62, 0x71, 0xAB, 
	  0xD7, 0x25, 0xA5, 0xE4, 0x68, 0x71, 0x93, 0x5D, 
	  0x1F, 0x29, 0x01, 0x05, 0x9C, 0x57, 0x3A, 0x09, 
	  0xB0, 0xB8, 0xE4, 0xD2, 0x37, 0x90, 0x36, 0x2F, 
	  0xBF, 0x1E, 0x74, 0xB4, 0x6B, 0xE4, 0x66, 0x07 }, 

	/* q */
	20,
	{ 0xFD, 0xD9, 0xC8, 0x5F, 0x73, 0x62, 0xC9, 0x79, 
	  0xEF, 0xD5, 0x09, 0x07, 0x02, 0xE7, 0xF2, 0x90, 
	  0x97, 0x13, 0x26, 0x1D }, 

	/* g */
	128,
	{ 0x02, 0x4E, 0xDD, 0x0D, 0x7F, 0x4D, 0xB1, 0x42, 
	  0x01, 0x50, 0xE7, 0x9A, 0x65, 0x73, 0x8B, 0x31, 
	  0x24, 0x6B, 0xC6, 0x74, 0xA7, 0x68, 0x26, 0x11, 
	  0x06, 0x3C, 0x96, 0xA9, 0xA6, 0x23, 0x12, 0x79, 
	  0xC4, 0xEE, 0x21, 0x88, 0xDD, 0xE3, 0xF0, 0x37, 
	  0xCE, 0x3E, 0x54, 0x53, 0x57, 0x03, 0x30, 0xE4, 
	  0xD3, 0xAB, 0x39, 0x4E, 0x39, 0xDC, 0xA2, 0x88, 
	  0x82, 0xF6, 0xE8, 0xBA, 0xAC, 0xF5, 0x7D, 0x2F, 
	  0x23, 0x9A, 0x09, 0x94, 0xB2, 0x89, 0xA2, 0xC9, 
	  0x7C, 0xBE, 0x4D, 0x48, 0x0E, 0x59, 0x51, 0xB8, 
	  0x7D, 0x99, 0x88, 0x79, 0xA8, 0x13, 0x0E, 0x12, 
	  0x56, 0x9D, 0x4B, 0x2E, 0xE0, 0xE1, 0x37, 0x78, 
	  0x6F, 0xCC, 0x4D, 0x97, 0xA9, 0x02, 0x0E, 0xD2, 
	  0x43, 0x83, 0xEC, 0x4F, 0xC2, 0x70, 0xEF, 0x16, 
	  0xDE, 0xBF, 0xBA, 0xD1, 0x6C, 0x8A, 0x36, 0xEE, 
	  0x42, 0x41, 0xE9, 0xE7, 0x66, 0xAE, 0x46, 0x3B }, 

	/* x */
	20,
	{ 0xD9, 0x41, 0x29, 0xF7, 0x40, 0x32, 0x09, 0x71, 
	  0xB8, 0xE2, 0xB8, 0xCB, 0x74, 0x46, 0x0B, 0xD4, 
	  0xF2, 0xAB, 0x54, 0xA1 }, 

	/* y */
	128,
	{ 0x01, 0x7E, 0x16, 0x5B, 0x65, 0x51, 0x0A, 0xDA, 
	  0x82, 0x1A, 0xD9, 0xF4, 0x1E, 0x66, 0x6D, 0x7D, 
	  0x23, 0xA6, 0x28, 0x2F, 0xE6, 0xC2, 0x03, 0x8E, 
	  0x8C, 0xAB, 0xC2, 0x08, 0x87, 0xC9, 0xE8, 0x51, 
	  0x0A, 0x37, 0x1E, 0xD4, 0x41, 0x7F, 0xA2, 0xC5, 
	  0x48, 0x26, 0xB7, 0xF6, 0xC2, 0x6F, 0xB2, 0xF8, 
	  0xF9, 0x43, 0x43, 0xF9, 0xDA, 0xAB, 0xA2, 0x59, 
	  0x27, 0xBA, 0xC9, 0x1C, 0x8C, 0xAB, 0xC4, 0x90, 
	  0x27, 0xE1, 0x10, 0x39, 0x6F, 0xD2, 0xCD, 0x7C, 
	  0xD1, 0x0B, 0xFA, 0x28, 0xD2, 0x7A, 0x7B, 0x52, 
	  0x8A, 0xA0, 0x5A, 0x0F, 0x10, 0xF7, 0xBA, 0xFD, 
	  0x33, 0x0C, 0x3C, 0xCE, 0xE5, 0xF2, 0xF6, 0x92, 
	  0xED, 0x04, 0xBF, 0xD3, 0xF8, 0x3D, 0x39, 0xCC, 
	  0xAA, 0xCC, 0x0B, 0xB2, 0x6B, 0xD8, 0xB2, 0x8A, 
	  0x5C, 0xCE, 0xDA, 0xF9, 0xE1, 0xA7, 0x23, 0x50, 
	  0xDC, 0xCE, 0xA4, 0xD5, 0xA5, 0x4F, 0x08, 0x0F }
	};

static BOOLEAN pairwiseConsistencyTest( CONTEXT_INFO *contextInfoPtr,
										const BOOLEAN isGeneratedKey )
	{
	CONTEXT_INFO checkContextInfo;
	PKC_INFO contextData, *pkcInfo = &contextData;
	KEYAGREE_PARAMS keyAgreeParams1, keyAgreeParams2;
	const CAPABILITY_INFO *capabilityInfoPtr;
	int status;

	/* The DH pairwise check is a bit more complex than the one for the
	   other algorithms because there's no matched public/private key pair,
	   so we have to load a second DH key to use for key agreement with
	   the first one */
	status = staticInitContext( &checkContextInfo, CONTEXT_PKC, 
								getDHCapability(), &contextData, 
								sizeof( PKC_INFO ), NULL );
	if( cryptStatusError( status ) )
		return( FALSE );
	if( isGeneratedKey )
		{
		PKC_INFO *sourcePkcInfo = contextInfoPtr->ctxPKC;
		int bnStatus = BN_STATUS;

		/* If it's a generated key with random p and g parameters rather
		   than the fixed test values, we have to make the parameters for
		   the check context match the ones for the generated key */
		CKPTR( BN_copy( &pkcInfo->dlpParam_p, &sourcePkcInfo->dlpParam_p ) );
		CKPTR( BN_copy( &pkcInfo->dlpParam_g, &sourcePkcInfo->dlpParam_g ) );
		CKPTR( BN_copy( &pkcInfo->dlpParam_q, &sourcePkcInfo->dlpParam_q ) );
		CKPTR( BN_copy( &pkcInfo->dlpParam_y, &sourcePkcInfo->dlpParam_y ) );
		if( bnStatusError( bnStatus ) )
			return( getBnStatus( bnStatus ) );
		}
	else
		{
		status = extractBignum( &pkcInfo->dlpParam_p, dlpTestKey.p, 
								dlpTestKey.pLen, DLPPARAM_MIN_P, 
								DLPPARAM_MAX_P, NULL, TRUE );
		if( cryptStatusOK( status ) )
			status = extractBignum( &pkcInfo->dlpParam_g, dlpTestKey.g, 
									dlpTestKey.gLen, DLPPARAM_MIN_G, 
									DLPPARAM_MAX_G, &pkcInfo->dlpParam_p, 
									FALSE );
		if( cryptStatusOK( status ) )
			status = extractBignum( &pkcInfo->dlpParam_q, dlpTestKey.q, 
									dlpTestKey.qLen, DLPPARAM_MIN_Q, 
									DLPPARAM_MAX_Q, &pkcInfo->dlpParam_p,
									FALSE );
		if( cryptStatusOK( status ) )
			status = extractBignum( &pkcInfo->dlpParam_y, dlpTestKey.y, 
									dlpTestKey.yLen, DLPPARAM_MIN_Y, 
									DLPPARAM_MAX_Y, &pkcInfo->dlpParam_p,
									FALSE );
		if( cryptStatusOK( status ) )
			status = extractBignum( &pkcInfo->dlpParam_x, dlpTestKey.x, 
									dlpTestKey.xLen, DLPPARAM_MIN_X, 
									DLPPARAM_MAX_X, &pkcInfo->dlpParam_p,
									FALSE );
		if( cryptStatusError( status ) )
			return( status );
		}

	/* Perform the pairwise test using the check key */
	capabilityInfoPtr = checkContextInfo.capabilityInfo;
	status = capabilityInfoPtr->initKeyFunction( &checkContextInfo, NULL, 0 );
	if( cryptStatusOK( status ) )
		{
		memset( &keyAgreeParams1, 0, sizeof( KEYAGREE_PARAMS ) );
		status = capabilityInfoPtr->encryptFunction( contextInfoPtr,
					( BYTE * ) &keyAgreeParams1, sizeof( KEYAGREE_PARAMS ) );
		}
	if( cryptStatusOK( status ) )
		{
		memset( &keyAgreeParams2, 0, sizeof( KEYAGREE_PARAMS ) );
		status = capabilityInfoPtr->encryptFunction( &checkContextInfo,
					( BYTE * ) &keyAgreeParams2, sizeof( KEYAGREE_PARAMS ) );
		}
	if( cryptStatusOK( status ) )
		status = capabilityInfoPtr->decryptFunction( contextInfoPtr,
					( BYTE * ) &keyAgreeParams2, sizeof( KEYAGREE_PARAMS ) );
	if( cryptStatusOK( status ) )
		status = capabilityInfoPtr->decryptFunction( &checkContextInfo,
					( BYTE * ) &keyAgreeParams1, sizeof( KEYAGREE_PARAMS ) );
	if( cryptStatusError( status ) || \
		memcmp( keyAgreeParams1.wrappedKey, keyAgreeParams2.wrappedKey, 
				dlpTestKey.pLen ) )
		status = CRYPT_ERROR_FAILED;

	/* Clean up */
	staticDestroyContext( &checkContextInfo );

	return( cryptStatusOK( status ) ? TRUE : FALSE );