eckey.c File Reference

#include "precomp.h"

Include dependency graph for eckey.c:

Go to the source code of this file.

Macros
#define	SYMCRYPT_FLAG_ECKEY_PUBLIC_KEY_ORDER_VALIDATION   (0x1)
#define	SYMCRYPT_ECPOINT_SET_RANDOM_MAX_TRIES   (1000)

Functions
PSYMCRYPT_ECKEY SYMCRYPT_CALL	SymCryptEckeyAllocate (_In_ PCSYMCRYPT_ECURVE pCurve)
VOID SYMCRYPT_CALL	SymCryptEckeyFree (_Out_ PSYMCRYPT_ECKEY pkObj)
UINT32 SYMCRYPT_CALL	SymCryptSizeofEckeyFromCurve (_In_ PCSYMCRYPT_ECURVE pCurve)
PSYMCRYPT_ECKEY SYMCRYPT_CALL	SymCryptEckeyCreate (_Out_writes_bytes_(cbBuffer) PBYTE pbBuffer, SIZE_T cbBuffer, PCSYMCRYPT_ECURVE pCurve)
VOID SYMCRYPT_CALL	SymCryptEckeyWipePrivateState (_Inout_ PSYMCRYPT_ECKEY pkEckey)
VOID SYMCRYPT_CALL	SymCryptEckeyWipe (_Out_ PSYMCRYPT_ECKEY pkDst)
VOID	SymCryptEckeyCopy (_In_ PCSYMCRYPT_ECKEY pkSrc, _Out_ PSYMCRYPT_ECKEY pkDst)
UINT32 SYMCRYPT_CALL	SymCryptEckeySizeofPublicKey (_In_ PCSYMCRYPT_ECKEY pkEckey, _In_ SYMCRYPT_ECPOINT_FORMAT ecPointFormat)
UINT32 SYMCRYPT_CALL	SymCryptEckeySizeofPrivateKey (_In_ PCSYMCRYPT_ECKEY pkEckey)
BOOLEAN SYMCRYPT_CALL	SymCryptEckeyHasPrivateKey (_In_ PCSYMCRYPT_ECKEY pkEckey)
SYMCRYPT_ERROR SYMCRYPT_CALL	SymCryptEckeyPerformPublicKeyValidation (_In_ PCSYMCRYPT_ECKEY pEckey, _In_ UINT32 flags, _Out_writes_bytes_(cbScratch) PBYTE pbScratch, SIZE_T cbScratch)
SYMCRYPT_ERROR SYMCRYPT_CALL	SymCryptEckeySetValue (_In_reads_bytes_(cbPrivateKey) PCBYTE pbPrivateKey, SIZE_T cbPrivateKey, _In_reads_bytes_(cbPublicKey) PCBYTE pbPublicKey, SIZE_T cbPublicKey, SYMCRYPT_NUMBER_FORMAT numFormat, SYMCRYPT_ECPOINT_FORMAT ecPointFormat, UINT32 flags, _Inout_ PSYMCRYPT_ECKEY pEckey)
SYMCRYPT_ERROR SYMCRYPT_CALL	SymCryptEckeyGetValue (_In_ PCSYMCRYPT_ECKEY pEckey, _Out_writes_bytes_(cbPrivateKey) PBYTE pbPrivateKey, SIZE_T cbPrivateKey, _Out_writes_bytes_(cbPublicKey) PBYTE pbPublicKey, SIZE_T cbPublicKey, SYMCRYPT_NUMBER_FORMAT numFormat, SYMCRYPT_ECPOINT_FORMAT ecPointFormat, UINT32 flags)
SYMCRYPT_ERROR SYMCRYPT_CALL	SymCryptEckeySetRandom (_In_ UINT32 flags, _Inout_ PSYMCRYPT_ECKEY pEckey)
SYMCRYPT_ERROR SYMCRYPT_CALL	SymCryptEckeyExtendKeyUsage (_Inout_ PSYMCRYPT_ECKEY pEckey, UINT32 flags)

Macro Definition Documentation

SYMCRYPT_ECPOINT_SET_RANDOM_MAX_TRIES

#define SYMCRYPT_ECPOINT_SET_RANDOM_MAX_TRIES   (1000)

Definition at line 729 of file eckey.c.

SYMCRYPT_FLAG_ECKEY_PUBLIC_KEY_ORDER_VALIDATION

#define SYMCRYPT_FLAG_ECKEY_PUBLIC_KEY_ORDER_VALIDATION   (0x1)

Definition at line 176 of file eckey.c.

Function Documentation

SymCryptEckeyAllocate()

PSYMCRYPT_ECKEY SYMCRYPT_CALL SymCryptEckeyAllocate

(

_In_ PCSYMCRYPT_ECURVE

pCurve

)

Definition at line 12 of file eckey.c.

{
    PVOID               p;
    SIZE_T              cb;
    PSYMCRYPT_ECKEY     res = NULL;
 
    cb = SymCryptSizeofEckeyFromCurve( pCurve );
 
    p = SymCryptCallbackAlloc( cb );
 
    if ( p==NULL )
    {
        goto cleanup;
    }
 
    res = SymCryptEckeyCreate( p, cb, pCurve );
 
cleanup:
    return res;
}

Referenced by alloc_ecc_key().

SymCryptEckeyCopy()

VOID SymCryptEckeyCopy	(	_In_ PCSYMCRYPT_ECKEY	pkSrc,
		_Out_ PSYMCRYPT_ECKEY	pkDst
	)

Definition at line 122 of file eckey.c.

{
    //
    // in-place copy is somewhat common...
    //
    if( pkSrc != pkDst )
    {
        // Copy the fAlgorithmInfo flags
        pkDst->fAlgorithmInfo = pkSrc->fAlgorithmInfo;
 
        // Copy the hasPrivateKey flag
        pkDst->hasPrivateKey = pkSrc->hasPrivateKey;
 
        // Copy the public key
        SymCryptEcpointCopy( pkSrc->pCurve, pkSrc->poPublicKey, pkDst->poPublicKey );
 
        // Copy the private key
        SymCryptIntCopy( pkSrc->piPrivateKey, pkDst->piPrivateKey );
    }
}

SymCryptEckeyCreate()

PSYMCRYPT_ECKEY SYMCRYPT_CALL SymCryptEckeyCreate	(	_Out_writes_bytes_(cbBuffer) PBYTE	pbBuffer,
		SIZE_T	cbBuffer,
		PCSYMCRYPT_ECURVE	pCurve
	)

Definition at line 58 of file eckey.c.

{
    PSYMCRYPT_ECKEY         pkObj = NULL;
    UINT32 privateKeyDigits = SymCryptEcurveDigitsofScalarMultiplier(pCurve);
 
    SIZE_T cbPublicKey = SymCryptSizeofEcpointFromCurve( pCurve );
    SIZE_T cbPrivateKey = SymCryptSizeofIntFromDigits( privateKeyDigits );
 
    UNREFERENCED_PARAMETER( cbBuffer );     // only referenced in ASSERTs...
 
    SYMCRYPT_ASSERT( pCurve != NULL );
    SYMCRYPT_ASSERT( cbBuffer >= SymCryptSizeofEckeyFromCurve( pCurve ) );
 
    SYMCRYPT_ASSERT( cbBuffer >= sizeof(SYMCRYPT_ECKEY) +
                            cbPublicKey +
                            cbPrivateKey );
 
    SYMCRYPT_ASSERT_ASYM_ALIGNED( pbBuffer );
 
    pkObj = (PSYMCRYPT_ECKEY) pbBuffer;
 
    pkObj->fAlgorithmInfo = 0;
    pkObj->hasPrivateKey = FALSE;
    pkObj->pCurve = pCurve;
 
    pkObj->poPublicKey = SymCryptEcpointCreate(
                        pbBuffer + sizeof(SYMCRYPT_ECKEY),
                        cbPublicKey,
                        pCurve );
    SYMCRYPT_ASSERT( pkObj->poPublicKey != NULL );
 
    pkObj->piPrivateKey = SymCryptIntCreate(
                        pbBuffer + sizeof(SYMCRYPT_ECKEY) + cbPublicKey,
                        cbPrivateKey,
                        privateKeyDigits );
    SYMCRYPT_ASSERT( pkObj->piPrivateKey );
 
    // Setting the magic
    SYMCRYPT_SET_MAGIC( pkObj );
 
    return pkObj;
}

Referenced by SymCryptEckeyAllocate().

SymCryptEckeyExtendKeyUsage()

SYMCRYPT_ERROR SYMCRYPT_CALL SymCryptEckeyExtendKeyUsage	(	_Inout_ PSYMCRYPT_ECKEY	pEckey,
		UINT32	flags
	)

Definition at line 976 of file eckey.c.

{
    SYMCRYPT_ERROR scError = SYMCRYPT_NO_ERROR;
 
    // Ensure caller has specified what algorithm(s) the key will be used with
    UINT32 algorithmFlags = SYMCRYPT_FLAG_ECKEY_ECDSA | SYMCRYPT_FLAG_ECKEY_ECDH;
 
    if ( ( ( flags & ~algorithmFlags ) != 0 ) ||
         ( ( flags & algorithmFlags ) == 0) )
    {
        scError = SYMCRYPT_INVALID_ARGUMENT;
        goto cleanup;
    }
 
    pEckey->fAlgorithmInfo |= flags;
 
cleanup:
    return scError;
}

SymCryptEckeyFree()

VOID SYMCRYPT_CALL SymCryptEckeyFree

(

_Out_ PSYMCRYPT_ECKEY

pkObj

)

Definition at line 35 of file eckey.c.

{
    SYMCRYPT_CHECK_MAGIC( pkObj );
    SymCryptEckeyWipe( pkObj );
    SymCryptCallbackFree( pkObj );
}

Referenced by destroy_key().

SymCryptEckeyGetValue()

SYMCRYPT_ERROR SYMCRYPT_CALL SymCryptEckeyGetValue	(	_In_ PCSYMCRYPT_ECKEY	pEckey,
		_Out_writes_bytes_(cbPrivateKey) PBYTE	pbPrivateKey,
		SIZE_T	cbPrivateKey,
		_Out_writes_bytes_(cbPublicKey) PBYTE	pbPublicKey,
		SIZE_T	cbPublicKey,
		SYMCRYPT_NUMBER_FORMAT	numFormat,
		SYMCRYPT_ECPOINT_FORMAT	ecPointFormat,
		UINT32	flags
	)

Definition at line 581 of file eckey.c.

{
    SYMCRYPT_ERROR      scError = SYMCRYPT_NO_ERROR;
    PBYTE               pbScratch = NULL;
    UINT32              cbScratch = 0;
    PBYTE               pbScratchInternal = NULL;
    UINT32              cbScratchInternal = 0;
 
    PCSYMCRYPT_ECURVE   pCurve = pEckey->pCurve;
 
    PSYMCRYPT_INT           piTmpInteger = NULL;
    UINT32                  cbTmpInteger = 0;
    PSYMCRYPT_MODELEMENT    peTmpModElement = NULL;
    UINT32                  cbTmpModElement = pCurve->cbModElement;
 
    UINT32 privateKeyDigits = SymCryptEcurveDigitsofScalarMultiplier(pCurve);
 
    SYMCRYPT_ASSERT( (cbPrivateKey==0) || (cbPrivateKey == SymCryptEcurveSizeofScalarMultiplier( pEckey->pCurve )) );
    SYMCRYPT_ASSERT( (cbPublicKey==0) || (cbPublicKey == SymCryptEckeySizeofPublicKey( pEckey, ecPointFormat)) );
 
    // Make sure we only specify the correct flags
    if (flags != 0)
    {
        scError = SYMCRYPT_INVALID_ARGUMENT;
        goto cleanup;
    }
 
    // Allocate scratch space
    cbScratch = SYMCRYPT_INTERNAL_SCRATCH_BYTES_FOR_ECKEY_ECURVE_OPERATIONS( pCurve );
    pbScratch = SymCryptCallbackAlloc( cbScratch );
    if ( pbScratch == NULL )
    {
        scError = SYMCRYPT_MEMORY_ALLOCATION_FAILURE;
        goto cleanup;
    }
 
    pbScratchInternal = pbScratch;
    cbScratchInternal = cbScratch;
 
    // Allocate the integer
    cbTmpInteger = SymCryptSizeofIntFromDigits( privateKeyDigits );
    piTmpInteger = SymCryptIntCreate( pbScratchInternal, cbTmpInteger, privateKeyDigits );
    SYMCRYPT_ASSERT( piTmpInteger != NULL );
 
    pbScratchInternal += cbTmpInteger;
    cbScratchInternal -= cbTmpInteger;
 
    // Allocate the modelement
    peTmpModElement = SymCryptModElementCreate( pbScratchInternal, cbTmpModElement, pCurve->GOrd );
    SYMCRYPT_ASSERT( peTmpModElement != NULL );
 
    pbScratchInternal += cbTmpModElement;
    cbScratchInternal -= cbTmpModElement;
 
    if ((cbPrivateKey == 0) && (cbPublicKey == 0))
    {
        scError = SYMCRYPT_INVALID_ARGUMENT;
        goto cleanup;
    }
 
    if (cbPrivateKey != 0)
    {
        if (!pEckey->hasPrivateKey)
        {
            scError = SYMCRYPT_INVALID_BLOB;
            goto cleanup;
        }
 
        // If this keypair may be used in ECDSA, and does not have the no FIPS flag, run the PCT if
        // it has not already been run
        if ( ((pEckey->fAlgorithmInfo & SYMCRYPT_FLAG_ECKEY_ECDSA) != 0) &&
             ((pEckey->fAlgorithmInfo & SYMCRYPT_FLAG_KEY_NO_FIPS) == 0) )
        {
            SYMCRYPT_RUN_KEY_GEN_PCT(
                SymCryptEcDsaPct,
                pEckey,
                SYMCRYPT_PCT_ECDSA );
        }
 
        // Copy the key into the temporary integer
        SymCryptIntCopy( pEckey->piPrivateKey, piTmpInteger );
 
        // Convert the "DivH" format into the external format
        if (pCurve->coFactorPower>0)
        {
            // For the "Canonical" format: Multiply the integer by h
            // and then take the result modulo GOrd
            if (pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_CANONICAL)
            {
                SymCryptIntMulPow2( piTmpInteger, pCurve->coFactorPower, piTmpInteger );
                SymCryptIntDivMod(
                    piTmpInteger,
                    SymCryptDivisorFromModulus(pCurve->GOrd),
                    NULL,
                    piTmpInteger,
                    pbScratchInternal,
                    cbScratchInternal );
            }
 
            // For the "TimesH" format: Multiply the integer by h again by shifting
            if (pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_DIVH_TIMESH)
            {
                SymCryptIntMulPow2( piTmpInteger, pCurve->coFactorPower, piTmpInteger );
            }
        }
 
        scError = SymCryptIntGetValue( piTmpInteger, pbPrivateKey, cbPrivateKey, numFormat );
        if (scError != SYMCRYPT_NO_ERROR)
        {
            goto cleanup;
        }
    }
 
    if (cbPublicKey != 0)
    {
        scError = SymCryptEcpointGetValue(
                            pCurve,
                            pEckey->poPublicKey,
                            numFormat,
                            ecPointFormat,
                            pbPublicKey,
                            cbPublicKey,
                            SYMCRYPT_FLAG_DATA_PUBLIC,
                            pbScratch,
                            cbScratch );
    }
 
cleanup:
 
    if ( pbScratch != NULL )
    {
        SymCryptWipe( pbScratch, cbScratch );
        SymCryptCallbackFree( pbScratch );
    }
 
    return scError;
}

Referenced by export_ecc_key().

SymCryptEckeyHasPrivateKey()

BOOLEAN SYMCRYPT_CALL SymCryptEckeyHasPrivateKey

(

_In_ PCSYMCRYPT_ECKEY

pkEckey

)

Definition at line 171 of file eckey.c.

{
    return pkEckey->hasPrivateKey;
}

SymCryptEckeyPerformPublicKeyValidation()

SYMCRYPT_ERROR SYMCRYPT_CALL SymCryptEckeyPerformPublicKeyValidation	(	_In_ PCSYMCRYPT_ECKEY	pEckey,
		_In_ UINT32	flags,
		_Out_writes_bytes_(cbScratch) PBYTE	pbScratch,
		SIZE_T	cbScratch
	)

Definition at line 180 of file eckey.c.

{
    SYMCRYPT_ERROR scError = SYMCRYPT_NO_ERROR;
 
    PCSYMCRYPT_ECURVE   pCurve = pEckey->pCurve;
 
    PSYMCRYPT_ECPOINT   poNPub = NULL;
    UINT32              cbNPub = SymCryptSizeofEcpointFromCurve( pCurve );
 
    // This is an excessive amount of space to require, but all callers can currently provide it, and it's easy to phrase
    SYMCRYPT_ASSERT( cbScratch >= SYMCRYPT_INTERNAL_SCRATCH_BYTES_FOR_ECKEY_ECURVE_OPERATIONS( pCurve ) );
 
    SYMCRYPT_ASSERT( cbScratch >= cbNPub );
 
    // Check if Public key is O
    if ( SymCryptEcpointIsZero( pCurve, pEckey->poPublicKey, pbScratch, cbScratch ) )
    {
        return SYMCRYPT_INVALID_ARGUMENT;
    }
 
    // Public key is represented by Modelements of the underlying finite field for the curve
    // If we have reached this point we have either:
    // Constructed the Public key to have coordinates in the field (Generate case), or
    // Verified the Public key has coordinates in the field (SetValue case)
 
    // Check that Public key is on the curve
    // Skip check for Montgomery curves as we do not have an EcpointOnCurve function for them
    if ( !SYMCRYPT_CURVE_IS_MONTGOMERY_TYPE(pCurve) &&
        !SymCryptEcpointOnCurve( pCurve, pEckey->poPublicKey, pbScratch, cbScratch ) )
    {
        return SYMCRYPT_INVALID_ARGUMENT;
    }
 
    // Perform validation that Public key is in a subgroup of order GOrd.
    if ( (flags & SYMCRYPT_FLAG_ECKEY_PUBLIC_KEY_ORDER_VALIDATION) != 0 )
    {
        if ( SymCryptIntIsEqualUint32( pCurve->H, 1 ) )
        {
            // If cofactor is 1 then to validate that Public key has order GOrd
            // it is sufficient to validate Public key is on the curve
            // We just performed this check - so we are done.
        }
        else
        {
            // Ensure GOrd*(Public key) == O
            poNPub = SymCryptEcpointCreate( pbScratch, cbNPub, pCurve );
            pbScratch += cbNPub;
            cbScratch -= cbNPub;
 
            SYMCRYPT_ASSERT( poNPub != NULL );
 
            // Do the multiplication
            scError = SymCryptEcpointScalarMul(
                pCurve,
                SymCryptIntFromModulus( pCurve->GOrd ),
                pEckey->poPublicKey,
                0, // Do not multiply by cofactor!
                poNPub,
                pbScratch,
                cbScratch );
            if ( scError != SYMCRYPT_NO_ERROR )
            {
                return scError;
            }
 
            if ( !SymCryptEcpointIsZero( pCurve, poNPub, pbScratch, cbScratch ) )
            {
                return SYMCRYPT_INVALID_ARGUMENT;
            }
        }
    }
 
    return SYMCRYPT_NO_ERROR;
}

Referenced by SymCryptEckeySetRandom(), and SymCryptEckeySetValue().

SymCryptEckeySetRandom()

SYMCRYPT_ERROR SYMCRYPT_CALL SymCryptEckeySetRandom	(	_In_ UINT32	flags,
		_Inout_ PSYMCRYPT_ECKEY	pEckey
	)

Definition at line 733 of file eckey.c.

{
    SYMCRYPT_ERROR      scError = SYMCRYPT_NO_ERROR;
    PBYTE               pbScratch = NULL;
    UINT32              cbScratch = 0;
    PBYTE               pbScratchInternal = NULL;
    UINT32              cbScratchInternal = 0;
 
    PCSYMCRYPT_ECURVE   pCurve = pEckey->pCurve;
 
    PSYMCRYPT_ECPOINT   poTmp = NULL;
    UINT32              cbTmp = 0;
 
    INT32 cntr = SYMCRYPT_ECPOINT_SET_RANDOM_MAX_TRIES;
 
    PSYMCRYPT_MODELEMENT peScalar = NULL;
    PSYMCRYPT_INT        piScalar = NULL;
    UINT32               cbScalar = 0;
 
    UINT32 highBitRestrictionPosition = pCurve->HighBitRestrictionPosition;
 
    // Ensure caller has specified what algorithm(s) the key will be used with
    UINT32 algorithmFlags = SYMCRYPT_FLAG_ECKEY_ECDSA | SYMCRYPT_FLAG_ECKEY_ECDH;
    // Make sure only allowed flags are specified
    UINT32 allowedFlags = SYMCRYPT_FLAG_KEY_NO_FIPS | algorithmFlags;
 
    if ( ( ( flags & ~allowedFlags ) != 0 ) ||
         ( ( flags & algorithmFlags ) == 0 ) )
    {
        scError = SYMCRYPT_INVALID_ARGUMENT;
        goto cleanup;
    }
 
    //
    // From symcrypt_internal.h we have:
    //      - sizeof results are upper bounded by 2^19
    //      - SYMCRYPT_SCRATCH_BYTES results are upper bounded by 2^27 (including RSA and ECURVE)
    // Thus the following calculation does not overflow cbScratch.
    //
    cbScratch = SYMCRYPT_INTERNAL_SCRATCH_BYTES_FOR_ECKEY_ECURVE_OPERATIONS( pCurve );
    pbScratch = SymCryptCallbackAlloc( cbScratch );
    if ( pbScratch == NULL )
    {
        scError = SYMCRYPT_MEMORY_ALLOCATION_FAILURE;
        goto cleanup;
    }
 
    // Allocating temporaries
    pbScratchInternal = pbScratch;
    cbScratchInternal = cbScratch;
 
    peScalar = SymCryptModElementCreate( pbScratchInternal, pCurve->cbModElement, pCurve->GOrd );
    SYMCRYPT_ASSERT( peScalar != NULL );
 
    pbScratchInternal += pCurve->cbModElement;
    cbScratchInternal -= pCurve->cbModElement;
 
    cbScalar = SymCryptSizeofIntFromDigits( SymCryptEcurveDigitsofScalarMultiplier(pCurve) );
    piScalar = SymCryptIntCreate( pbScratchInternal, cbScalar, SymCryptEcurveDigitsofScalarMultiplier(pCurve) );
 
    pbScratchInternal += cbScalar;
    cbScratchInternal -= cbScalar;
 
    // Shift the high bit position if the format is "TIMESH"
    //  Note:   Do not actually multiply the integer as we will check if it is
    //          less than the group order
    if (pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_DIVH_TIMESH)
    {
        highBitRestrictionPosition -= pCurve->coFactorPower;
    }
 
    // Main loop
    do
    {
        // We perform Private key range validation by construction
        // Setting a random mod element in the [1, SubgroupOrder-1] set
        // This will be the "DivH" format of the private key. This means
        // that PublicKey = h * PrivateKey * G
        SymCryptModSetRandom(
            pCurve->GOrd,
            peScalar,
            (SYMCRYPT_FLAG_MODRANDOM_ALLOW_ONE|SYMCRYPT_FLAG_MODRANDOM_ALLOW_MINUSONE),
            pbScratchInternal,
            cbScratchInternal );
 
        // Converting to "canonical" format
        if (pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_CANONICAL)
        {
            for (UINT32 i=0; i<pCurve->coFactorPower; i++)
            {
                SymCryptModAdd( pCurve->GOrd, peScalar, peScalar, peScalar, pbScratchInternal, cbScratchInternal );
            }
        }
 
        // Set the temporary scalar to verify the format
        SymCryptModElementToInt( pCurve->GOrd, peScalar, piScalar, pbScratchInternal, cbScratchInternal );
 
        if (pCurve->HighBitRestrictionNumOfBits > 0)
        {
            // Set the desired bits
            SymCryptIntSetBits(
                    piScalar,
                    pCurve->HighBitRestrictionValue,
                    highBitRestrictionPosition,
                    pCurve->HighBitRestrictionNumOfBits );
 
            // Make sure we didn't exceed the group order
            if ( SymCryptIntIsLessThan(
                    piScalar,
                    SymCryptIntFromModulus( pCurve->GOrd )) )
            {
                break;
            }
        }
        else
        {
            // No high bit restriction was specified
            break;
        }
 
        cntr--;
    }
    while (cntr>0);
 
    if (cntr <= 0)
    {
        scError = SYMCRYPT_INVALID_ARGUMENT;
        goto cleanup;
    }
 
    // Here piScalar has a private key that satisfies the restriction(s)
    // Move it to the modelement
    SymCryptIntToModElement( piScalar, pCurve->GOrd, peScalar, pbScratchInternal, cbScratchInternal );
 
    // Convert the private key back to "DIVH" format
    if (pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_CANONICAL)
    {
        SymCryptModDivPow2( pCurve->GOrd, peScalar, pCurve->coFactorPower, peScalar, pbScratchInternal, cbScratchInternal );
    }
 
    // Set the private key
    SymCryptModElementToInt( pCurve->GOrd, peScalar, pEckey->piPrivateKey, pbScratchInternal, cbScratchInternal );
 
    // Do the multiplication (pass over the entire scratch space as it is not needed anymore)
    scError = SymCryptEcpointScalarMul(
        pCurve,
        pEckey->piPrivateKey,
        NULL,
        SYMCRYPT_FLAG_ECC_LL_COFACTOR_MUL,
        pEckey->poPublicKey,
        pbScratch,
        cbScratch );
    if ( scError != SYMCRYPT_NO_ERROR )
    {
        goto cleanup;
    }
 
    // Perform range and public key order validation on generated Public key.
    if ( (flags & SYMCRYPT_FLAG_KEY_NO_FIPS) == 0 )
    {
        // Perform Public key validation.
        // Always perform range validation and validation that Public key is in subgroup of order GOrd
        scError = SymCryptEckeyPerformPublicKeyValidation(
            pEckey,
            SYMCRYPT_FLAG_ECKEY_PUBLIC_KEY_ORDER_VALIDATION,
            pbScratch,
            cbScratch );
        if ( scError != SYMCRYPT_NO_ERROR )
        {
            goto cleanup;
        }
    }
 
    pEckey->hasPrivateKey = TRUE;
 
    pEckey->fAlgorithmInfo = flags; // We want to track all of the flags in the Eckey
 
    if ( (flags & SYMCRYPT_FLAG_KEY_NO_FIPS) == 0 )
    {
        if( ( flags & SYMCRYPT_FLAG_ECKEY_ECDSA ) != 0 )
        {
            // Ensure ECDSA algorithm selftest is run before first use of ECDSA algorithm
            SYMCRYPT_RUN_SELFTEST_ONCE(
                SymCryptEcDsaSelftest,
                SYMCRYPT_SELFTEST_ALGORITHM_ECDSA );
        }
 
        if( ( flags & SYMCRYPT_FLAG_ECKEY_ECDH ) != 0 )
        {
            // Ensure we have run the algorithm selftest at least once.
            SYMCRYPT_RUN_SELFTEST_ONCE(
                SymCryptEcDhSecretAgreementSelftest,
                SYMCRYPT_SELFTEST_ALGORITHM_ECDH );
 
            // Run PCT eagerly so it only needs to be defined here
            // The important case for performance is ECDH key generation
 
            // ECDH PCT per SP80056a-rev3 5.6.2.1.4 b)
            // Recompute the public key from the private key
            // Option a) appears to be explicitly overruled by 140-3 IG
            pbScratchInternal = pbScratch;
            cbScratchInternal = cbScratch;
 
            cbTmp = SymCryptSizeofEcpointFromCurve( pCurve );
            poTmp = SymCryptEcpointCreate( pbScratchInternal, cbTmp, pCurve );
            pbScratchInternal += cbTmp;
            cbScratchInternal -= cbTmp;
 
            SYMCRYPT_ASSERT( poTmp != NULL );
 
            // Always multiply by the cofactor since the internal format is "DIVH"
            scError = SymCryptEcpointScalarMul(
                pCurve,
                pEckey->piPrivateKey,
                NULL,
                SYMCRYPT_FLAG_ECC_LL_COFACTOR_MUL,
                poTmp,
                pbScratchInternal,
                cbScratchInternal );
            if ( scError != SYMCRYPT_NO_ERROR )
            {
                goto cleanup;
            }
 
            SYMCRYPT_FIPS_ASSERT( SymCryptEcpointIsEqual( pCurve, poTmp, pEckey->poPublicKey, 0, pbScratchInternal, cbScratchInternal ) );
        }
    }
 
cleanup:
 
    if ( pbScratch != NULL )
    {
        SymCryptWipe( pbScratch, cbScratch );
        SymCryptCallbackFree( pbScratch );
    }
 
    return scError;
}

Referenced by finalize_key_pair().

SymCryptEckeySetValue()

SYMCRYPT_ERROR SYMCRYPT_CALL SymCryptEckeySetValue	(	_In_reads_bytes_(cbPrivateKey) PCBYTE	pbPrivateKey,
		SIZE_T	cbPrivateKey,
		_In_reads_bytes_(cbPublicKey) PCBYTE	pbPublicKey,
		SIZE_T	cbPublicKey,
		SYMCRYPT_NUMBER_FORMAT	numFormat,
		SYMCRYPT_ECPOINT_FORMAT	ecPointFormat,
		UINT32	flags,
		_Inout_ PSYMCRYPT_ECKEY	pEckey
	)

Definition at line 261 of file eckey.c.

{
    SYMCRYPT_ERROR      scError = SYMCRYPT_NO_ERROR;
    PBYTE               pbScratch = NULL;
    UINT32              cbScratch = 0;
    PBYTE               pbScratchInternal = NULL;
    UINT32              cbScratchInternal = 0;
 
    PCSYMCRYPT_ECURVE   pCurve = pEckey->pCurve;
 
    PSYMCRYPT_ECPOINT   poTmp = NULL;
    UINT32              cbTmp = 0;
 
    PSYMCRYPT_INT           piTmpInteger = NULL;
    UINT32                  cbTmpInteger = 0;
    PSYMCRYPT_MODELEMENT    peTmpModElement = NULL;
    UINT32                  cbTmpModElement = pCurve->cbModElement;
 
    UINT32 privateKeyDigits = SymCryptEcurveDigitsofScalarMultiplier(pCurve);
 
    UINT32 fValidatePublicKeyOrder = SYMCRYPT_FLAG_ECKEY_PUBLIC_KEY_ORDER_VALIDATION;
 
    // Ensure caller has specified what algorithm(s) the key will be used with
    UINT32 algorithmFlags = SYMCRYPT_FLAG_ECKEY_ECDSA | SYMCRYPT_FLAG_ECKEY_ECDH;
    // Make sure only allowed flags are specified
    UINT32 allowedFlags = SYMCRYPT_FLAG_KEY_NO_FIPS | SYMCRYPT_FLAG_KEY_MINIMAL_VALIDATION | algorithmFlags;
 
    if ( ( ( flags & ~allowedFlags ) != 0 ) ||
         ( ( flags & algorithmFlags ) == 0 ) )
    {
        scError = SYMCRYPT_INVALID_ARGUMENT;
        goto cleanup;
    }
 
    // Check that minimal validation flag only specified with no fips
    if ( ( ( flags & SYMCRYPT_FLAG_KEY_NO_FIPS ) == 0 ) &&
         ( ( flags & SYMCRYPT_FLAG_KEY_MINIMAL_VALIDATION ) != 0 ) )
    {
        scError = SYMCRYPT_INVALID_ARGUMENT;
        goto cleanup;
    }
 
    if ( ( flags & SYMCRYPT_FLAG_KEY_NO_FIPS ) != 0 )
    {
        fValidatePublicKeyOrder = 0;
    }
 
    if ( ( ( cbPrivateKey == 0 ) && ( cbPublicKey == 0 ) ) ||
         ( ( cbPrivateKey != 0 ) && ( cbPrivateKey != SymCryptEcurveSizeofScalarMultiplier( pEckey->pCurve ) ) ) ||
         ( ( cbPublicKey != 0 )  && ( cbPublicKey != SymCryptEckeySizeofPublicKey( pEckey, ecPointFormat ) ) ) )
    {
        scError = SYMCRYPT_INVALID_ARGUMENT;
        goto cleanup;
    }
 
    // Allocate scratch space
    cbScratch = SYMCRYPT_INTERNAL_SCRATCH_BYTES_FOR_ECKEY_ECURVE_OPERATIONS( pCurve );
    pbScratch = SymCryptCallbackAlloc( cbScratch );
    if ( pbScratch == NULL )
    {
        scError = SYMCRYPT_MEMORY_ALLOCATION_FAILURE;
        goto cleanup;
    }
 
    if ( pbPrivateKey != NULL )
    {
        //
        // Private key calculations
        //
 
        pbScratchInternal = pbScratch;
        cbScratchInternal = cbScratch;
 
        // Allocate the integer
        cbTmpInteger = SymCryptSizeofIntFromDigits( privateKeyDigits );
        piTmpInteger = SymCryptIntCreate( pbScratchInternal, cbTmpInteger, privateKeyDigits );
        SYMCRYPT_ASSERT( piTmpInteger != NULL );
 
        pbScratchInternal += cbTmpInteger;
        cbScratchInternal -= cbTmpInteger;
 
        // Allocate the modelement
        peTmpModElement = SymCryptModElementCreate( pbScratchInternal, cbTmpModElement, pCurve->GOrd );
        SYMCRYPT_ASSERT( peTmpModElement != NULL );
 
        pbScratchInternal += cbTmpModElement;
        cbScratchInternal -= cbTmpModElement;
 
        // Get the "raw" private key
        scError = SymCryptIntSetValue( pbPrivateKey, cbPrivateKey, numFormat, piTmpInteger );
        if (scError != SYMCRYPT_NO_ERROR)
        {
            goto cleanup;
        }
 
        // Validation steps
        if ( ( flags & SYMCRYPT_FLAG_KEY_MINIMAL_VALIDATION ) == 0 )
        {
            // Perform range validation on imported Private key if it is in canonical format
            if ( pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_CANONICAL )
            {
                // Check if Private key is greater than or equal to GOrd
                if ( !SymCryptIntIsLessThan( piTmpInteger, SymCryptIntFromModulus( pCurve->GOrd ) ) )
                {
                    scError = SYMCRYPT_INVALID_ARGUMENT;
                    goto cleanup;
                }
            }
 
            // "TimesH" formats
            // IntGetBits requirements:
            //      We know that coFactorPower is up to SYMCRYPT_ECURVE_MAX_COFACTOR_POWER. Thus
            //      less than 32 and less than the digits size in bits.
            if ( (pCurve->coFactorPower>0) &&
                (pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_DIVH_TIMESH) &&
                (SymCryptIntGetBits( piTmpInteger, 0, pCurve->coFactorPower) != 0) )
            {
                scError = SYMCRYPT_INVALID_ARGUMENT;
                goto cleanup;
            }
 
 
            // High bit restrictions
            // IntGetBits requirements:
            //      Satisfied by asserting that
            //      HighBitRestrictionPosition + HighBitRestrictionNumOfBits <= GOrdBitsize + coFactorPower
            //      during EcurveAllocate.
            if ( (pCurve->HighBitRestrictionNumOfBits>0) &&
                (SymCryptIntGetBits(
                    piTmpInteger,
                    pCurve->HighBitRestrictionPosition,
                    pCurve->HighBitRestrictionNumOfBits) != pCurve->HighBitRestrictionValue) )
            {
                scError = SYMCRYPT_INVALID_ARGUMENT;
                goto cleanup;
            }
        }
 
        // Convert the private key to "DivH" format
        if (pCurve->coFactorPower>0)
        {
            // "TimesH" format: Divide the input private key with the cofactor
            // by shifting right the appropriate number of bits
            if (pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_DIVH_TIMESH)
            {
                SymCryptIntDivPow2( piTmpInteger, pCurve->coFactorPower, piTmpInteger );
            }
 
            // "Canonical" format: Divide by h modulo GOrd
            if (pCurve->PrivateKeyDefaultFormat == SYMCRYPT_ECKEY_PRIVATE_FORMAT_CANONICAL)
            {
                SymCryptIntToModElement( piTmpInteger, pCurve->GOrd, peTmpModElement, pbScratchInternal, cbScratchInternal );
                SymCryptModDivPow2( pCurve->GOrd, peTmpModElement, pCurve->coFactorPower, peTmpModElement, pbScratchInternal, cbScratchInternal );
                SymCryptModElementToInt( pCurve->GOrd, peTmpModElement, piTmpInteger, pbScratchInternal, cbScratchInternal );
            }
        }
 
        // Divide the input private key since it could be larger than subgroup order
        SymCryptIntDivMod(
            piTmpInteger,
            SymCryptDivisorFromModulus(pCurve->GOrd),
            NULL,
            piTmpInteger,
            pbScratchInternal,
            cbScratchInternal );
 
        // Check if Private key is 0 after dividing it by the subgroup order
        // Other part of range validation - perform unconditionally as it is cheap
        // and it never makes sense for private key to be 0 intentionally
        if (SymCryptIntIsEqualUint32( piTmpInteger, 0 ))
        {
            scError = SYMCRYPT_INVALID_ARGUMENT;
            goto cleanup;
        }
 
        // Copy into the ECKEY
        SymCryptIntCopy( piTmpInteger, pEckey->piPrivateKey );
 
        pEckey->hasPrivateKey = TRUE;
    }
 
    if ( pbPublicKey != NULL )
    {
        scError = SymCryptEcpointSetValue(
                            pCurve,
                            pbPublicKey,
                            cbPublicKey,
                            numFormat,
                            ecPointFormat,
                            pEckey->poPublicKey,
                            SYMCRYPT_FLAG_DATA_PUBLIC,
                            pbScratch,
                            cbScratch );
        if ( scError != SYMCRYPT_NO_ERROR )
        {
            goto cleanup;
        }
 
        // Perform Public key validation on imported Public key.
        if ( ( flags & SYMCRYPT_FLAG_KEY_MINIMAL_VALIDATION ) == 0 )
        {
            scError = SymCryptEckeyPerformPublicKeyValidation(
                pEckey,
                fValidatePublicKeyOrder,
                pbScratch,
                cbScratch );
            if ( scError != SYMCRYPT_NO_ERROR )
            {
                goto cleanup;
            }
        }
    }
 
    // Calculating the public key if no key was provided
    // or if needed for keypair regeneration validation
    if ( (pbPublicKey==NULL) ||
         ( ( ( flags & SYMCRYPT_FLAG_KEY_NO_FIPS ) == 0 ) &&
          (pbPrivateKey!=NULL) && (pbPublicKey!=NULL) ) )
    {
        // Calculate the public key from the private key
        pbScratchInternal = pbScratch;
        cbScratchInternal = cbScratch;
 
        // By default calculate the Public key directly where it will be persisted
        poTmp = pEckey->poPublicKey;
 
        if ( pbPublicKey != NULL )
        {
            // If doing regeneration validation calculate the Public key in scratch
            cbTmp = SymCryptSizeofEcpointFromCurve( pCurve );
            poTmp = SymCryptEcpointCreate( pbScratchInternal, cbTmp, pCurve );
            pbScratchInternal += cbTmp;
            cbScratchInternal -= cbTmp;
        }
 
        SYMCRYPT_ASSERT( poTmp != NULL );
 
        // Always multiply by the cofactor since the internal format is "DIVH"
        scError = SymCryptEcpointScalarMul(
            pCurve,
            pEckey->piPrivateKey,
            NULL,
            SYMCRYPT_FLAG_ECC_LL_COFACTOR_MUL,
            poTmp,
            pbScratchInternal,
            cbScratchInternal );
        if ( scError != SYMCRYPT_NO_ERROR )
        {
            goto cleanup;
        }
 
        if ( pbPublicKey != NULL )
        {
            if ( !SymCryptEcpointIsEqual( pCurve, poTmp, pEckey->poPublicKey, 0, pbScratchInternal, cbScratchInternal ) )
            {
                scError = SYMCRYPT_INVALID_ARGUMENT;
                goto cleanup;
            }
        }
        else if ( ( flags & SYMCRYPT_FLAG_KEY_MINIMAL_VALIDATION ) == 0 )
        {
            // Perform Public key validation on generated Public key.
            scError = SymCryptEckeyPerformPublicKeyValidation(
                pEckey,
                fValidatePublicKeyOrder,
                pbScratch,
                cbScratch );
            if ( scError != SYMCRYPT_NO_ERROR )
            {
                goto cleanup;
            }
        }
    }
 
    pEckey->fAlgorithmInfo = flags; // We want to track all of the flags in the Eckey
 
    if ( ( flags & SYMCRYPT_FLAG_KEY_NO_FIPS ) == 0 )
    {
        if ( ( flags & SYMCRYPT_FLAG_ECKEY_ECDSA ) != 0 )
        {
            // Ensure ECDSA algorithm selftest is run before first use of ECDSA algorithm
            SYMCRYPT_RUN_SELFTEST_ONCE(
                SymCryptEcDsaSelftest,
                SYMCRYPT_SELFTEST_ALGORITHM_ECDSA );
 
            // PCT does not need to be run on import - mark it as done
            pEckey->fAlgorithmInfo |= SYMCRYPT_PCT_ECDSA;
        }
 
        if ( ( flags & SYMCRYPT_FLAG_ECKEY_ECDH ) != 0 )
        {
            SYMCRYPT_RUN_SELFTEST_ONCE(
                SymCryptEcDhSecretAgreementSelftest,
                SYMCRYPT_SELFTEST_ALGORITHM_ECDH );
        }
    }
 
cleanup:
 
    if ( pbScratch != NULL )
    {
        SymCryptWipe( pbScratch, cbScratch );
        SymCryptCallbackFree( pbScratch );
    }
 
    return scError;
}

Referenced by import_ecc_key().

SymCryptEckeySizeofPrivateKey()

UINT32 SYMCRYPT_CALL SymCryptEckeySizeofPrivateKey

(

_In_ PCSYMCRYPT_ECKEY

pkEckey

)

Definition at line 164 of file eckey.c.

{
    return SymCryptEcurveSizeofScalarMultiplier( pkEckey->pCurve );
}

Referenced by export_ecc_key(), and import_ecc_key().

SymCryptEckeySizeofPublicKey()

UINT32 SYMCRYPT_CALL SymCryptEckeySizeofPublicKey	(	_In_ PCSYMCRYPT_ECKEY	pkEckey,
		_In_ SYMCRYPT_ECPOINT_FORMAT	ecPointFormat
	)

Definition at line 147 of file eckey.c.

{
    //
    // From symcrypt_internal.h we have:
    //      - sizeof results are upper bounded by 2^19
    //      - SYMCRYPT_SCRATCH_BYTES results are upper bounded by 2^27 (including RSA and ECURVE)
    //      - SymCryptEcpointFormatNumberofElements returns up to 4 elements.
    //
    // Thus the following calculation does not overflow cbScratch.
    //
    return SymCryptEcpointFormatNumberofElements[ecPointFormat] * SymCryptEcurveSizeofFieldElement( pkEckey->pCurve );
}

Referenced by export_ecc_key(), import_ecc_key(), SymCryptEckeyGetValue(), and SymCryptEckeySetValue().

SymCryptEckeyWipe()

VOID SYMCRYPT_CALL SymCryptEckeyWipe

(

_Out_ PSYMCRYPT_ECKEY

pkDst

)

Definition at line 115 of file eckey.c.

{
    // Wipe the whole structure in one go.
    SymCryptWipe( pkDst, SymCryptSizeofEckeyFromCurve( pkDst->pCurve ) );
}

Referenced by SymCryptEckeyFree().

SymCryptEckeyWipePrivateState()

VOID SYMCRYPT_CALL SymCryptEckeyWipePrivateState

(

_Inout_ PSYMCRYPT_ECKEY

pkEckey

)

Definition at line 106 of file eckey.c.

{
    SymCryptIntSetValueUint32( 0, pkEckey->piPrivateKey );
    pkEckey->hasPrivateKey = FALSE;
}

SymCryptSizeofEckeyFromCurve()

UINT32 SYMCRYPT_CALL SymCryptSizeofEckeyFromCurve

(

_In_ PCSYMCRYPT_ECURVE

pCurve

)

Definition at line 44 of file eckey.c.

{
    //
    // From symcrypt_internal.h we have:
    //      - sizeof results are upper bounded by 2^19
    //      - SYMCRYPT_SCRATCH_BYTES results are upper bounded by 2^27 (including RSA and ECURVE)
    //      - SymCryptSizeofEcpointFromCurve outputs the size of up to 4 modelements + some overhead
    // Thus the following calculation does not overflow the result.
    //
    return sizeof(SYMCRYPT_ECKEY) + SymCryptSizeofEcpointFromCurve( pCurve ) + SymCryptSizeofIntFromDigits(SymCryptEcurveDigitsofScalarMultiplier(pCurve));
}

Referenced by SymCryptEckeyAllocate(), SymCryptEckeyCreate(), and SymCryptEckeyWipe().