--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/cryptoplugins/cryptospiplugins/source/softwarecrypto/dsakeypairgenimpl.cpp Fri Nov 06 13:21:00 2009 +0200
@@ -0,0 +1,383 @@
+/*
+* Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of the License "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+* DSA Keypair implementation
+* DSA keypair generation implementation
+*
+*/
+
+
+/**
+ @file
+*/
+
+#include "dsakeypairgenimpl.h"
+#include "pluginconfig.h"
+#include "keypair.h"
+#include "common/inlines.h" // For TClassSwap
+#include "mont.h"
+#include "sha1impl.h"
+#include <random.h>
+
+
+const TUint KShaSize = 20;
+const TUint KMinPrimeLength = 512;
+const TUint KMaxPrimeLength = 1024;
+const TUint KPrimeLengthMultiple = 64;
+
+using namespace SoftwareCrypto;
+
+
+/* CDSAPrimeCertificate */
+
+CDSAPrimeCertificate* CDSAPrimeCertificate::NewL(const TDesC8& aSeed, TUint aCounter)
+ {
+ CDSAPrimeCertificate* self = NewLC(aSeed, aCounter);
+ CleanupStack::Pop();
+ return self;
+ }
+
+CDSAPrimeCertificate* CDSAPrimeCertificate::NewLC(const TDesC8& aSeed, TUint aCounter)
+ {
+ CDSAPrimeCertificate* self = new(ELeave) CDSAPrimeCertificate(aCounter);
+ CleanupStack::PushL(self);
+ self->ConstructL(aSeed);
+ return self;
+ }
+
+const TDesC8& CDSAPrimeCertificate::Seed() const
+ {
+ return *iSeed;
+ }
+
+TUint CDSAPrimeCertificate::Counter() const
+ {
+ return iCounter;
+ }
+
+CDSAPrimeCertificate::~CDSAPrimeCertificate()
+ {
+ delete const_cast<HBufC8*>(iSeed);
+ }
+
+void CDSAPrimeCertificate::ConstructL(const TDesC8& aSeed)
+ {
+ iSeed = aSeed.AllocL();
+ }
+
+CDSAPrimeCertificate::CDSAPrimeCertificate(TUint aCounter)
+ : iCounter(aCounter)
+ {
+ }
+
+CDSAPrimeCertificate::CDSAPrimeCertificate()
+ {
+ }
+
+
+/* CDSAKeyPairGenImpl */
+CDSAKeyPairGenImpl::CDSAKeyPairGenImpl()
+ {
+ }
+
+CDSAKeyPairGenImpl::~CDSAKeyPairGenImpl()
+ {
+ delete iPrimeCertificate;
+ }
+
+CDSAKeyPairGenImpl* CDSAKeyPairGenImpl::NewL()
+ {
+ CDSAKeyPairGenImpl* self = CDSAKeyPairGenImpl::NewLC();
+ CleanupStack::Pop(self);
+ return self;
+ }
+
+CDSAKeyPairGenImpl* CDSAKeyPairGenImpl::NewLC()
+ {
+ CDSAKeyPairGenImpl* self = new(ELeave) CDSAKeyPairGenImpl();
+ CleanupStack::PushL(self);
+ self->ConstructL();
+ return self;
+ }
+
+void CDSAKeyPairGenImpl::ConstructL(void)
+ {
+ CKeyPairGenImpl::ConstructL();
+ }
+
+CExtendedCharacteristics* CDSAKeyPairGenImpl::CreateExtendedCharacteristicsL()
+ {
+ // All Symbian software plug-ins have unlimited concurrency, cannot be reserved
+ // for exclusive use and are not CERTIFIED to be standards compliant.
+ return CExtendedCharacteristics::NewL(KMaxTInt, EFalse);
+ }
+
+const CExtendedCharacteristics* CDSAKeyPairGenImpl::GetExtendedCharacteristicsL()
+ {
+ return CDSAKeyPairGenImpl::CreateExtendedCharacteristicsL();
+ }
+
+TUid CDSAKeyPairGenImpl::ImplementationUid() const
+ {
+ return KCryptoPluginDsaKeyPairGenUid;
+ }
+
+void CDSAKeyPairGenImpl::Reset()
+ {
+ // does nothing in this plugin
+ }
+
+TBool CDSAKeyPairGenImpl::ValidPrimeLength(TUint aPrimeBits)
+ {
+ return (aPrimeBits >= KMinPrimeLength &&
+ aPrimeBits <= KMaxPrimeLength &&
+ aPrimeBits % KPrimeLengthMultiple == 0);
+ }
+
+TBool CDSAKeyPairGenImpl::GeneratePrimesL(const TDesC8& aSeed,
+ TUint& aCounter,
+ RInteger& aP,
+ TUint aL,
+ RInteger& aQ,
+ TBool aUseInputCounter)
+ {
+ //This follows the steps in FIPS 186-2
+ //See DSS Appendix 2.2
+ //Note. Step 1 is performed prior to calling GeneratePrimesL, so that this
+ //routine can be used for both generation and validation.
+ //Step 1. Choose an arbitrary sequence of at least 160 bits and call it
+ //SEED. Let g be the length of SEED in bits.
+
+ if(!ValidPrimeLength(aL))
+ {
+ User::Leave(KErrNotSupported);
+ }
+
+ CSHA1Impl* sha1 = CSHA1Impl::NewL();
+ CleanupStack::PushL(sha1);
+
+ HBufC8* seedBuf = aSeed.AllocLC();
+ TPtr8 seed = seedBuf->Des();
+ TUint gBytes = aSeed.Size();
+
+ //Note that the DSS's g = BytesToBits(gBytes) ie. the number of random bits
+ //in the seed.
+ //This function has made the assumption (for ease of computation) that g%8
+ //is 0. Ie the seed is a whole number of random bytes.
+ TBuf8<KShaSize> U;
+ TBuf8<KShaSize> temp;
+ const TUint n = (aL-1)/160;
+ const TUint b = (aL-1)%160;
+ HBufC8* Wbuf = HBufC8::NewMaxLC((n+1) * KShaSize);
+ TUint8* W = const_cast<TUint8*>(Wbuf->Ptr());
+
+ U.Copy(sha1->Final(seed));
+
+ //Step 2. U = SHA-1[SEED] XOR SHA-1[(SEED+1) mod 2^g]
+ for(TInt i=gBytes - 1, carry=ETrue; i>=0 && carry; i--)
+ {
+ //!++(TUint) adds one to the current word which if it overflows to zero
+ //sets carry to 1 thus letting the loop continue. It's a poor man's
+ //multi-word addition. Swift eh?
+ carry = !++(seed[i]);
+ }
+
+ temp.Copy(sha1->Final(seed));
+ XorBuf(const_cast<TUint8*>(U.Ptr()), temp.Ptr(), KShaSize);
+
+ //Step 3. Form q from U by setting the most significant bit (2^159)
+ //and the least significant bit to 1.
+ U[0] |= 0x80;
+ U[KShaSize-1] |= 1;
+
+ aQ = RInteger::NewL(U);
+ CleanupStack::PushL(aQ);
+
+ //Step 4. Use a robust primality testing algo to test if q is prime
+ //The robust part is the calling codes problem. This will use whatever
+ //random number generator you set for the thread. To attempt FIPS 186-2
+ //compliance, set a FIPS 186-2 compliant RNG.
+ if( !aQ.IsPrimeL() )
+ {
+ //Step 5. If not exit and get a new seed
+ CleanupStack::PopAndDestroy(4, sha1);
+ return EFalse;
+ }
+
+ TUint counterEnd = aUseInputCounter ? aCounter+1 : 4096;
+
+ //Step 6. Let counter = 0 and offset = 2
+ //Note 1. that the DSS speaks of SEED + offset + k because they always
+ //refer to a constant SEED. We update our seed as we go so the offset
+ //variable has already been added to seed in the previous iterations.
+ //Note 2. We've already added 1 to our seed, so the first time through this
+ //the offset in DSS speak will be 2.
+ for(TUint counter=0; counter < counterEnd; counter++)
+ {
+ //Step 7. For k=0, ..., n let
+ // Vk = SHA-1[(SEED + offset + k) mod 2^g]
+ //I'm storing the Vk's inside of a big W buffer.
+ for(TUint k=0; k<=n; k++)
+ {
+ for(TInt i=gBytes-1, carry=ETrue; i>=0 && carry; i--)
+ {
+ carry = !++(seed[i]);
+ }
+ if(!aUseInputCounter || counter == aCounter)
+ {
+ TPtr8 Wptr(W+(n-k)*KShaSize, gBytes);
+ Wptr.Copy(sha1->Final(seed));
+ }
+ }
+ if(!aUseInputCounter || counter == aCounter)
+ {
+ //Step 8. Let W be the integer... and let X = W + 2^(L-1)
+ const_cast<TUint8&>((*Wbuf)[KShaSize - 1 - b/8]) |= 0x80;
+ TPtr8 Wptr(W + KShaSize - 1 - b/8, aL/8, aL/8);
+ RInteger X = RInteger::NewL(Wptr);
+ CleanupStack::PushL(X);
+ //Step 9. Let c = X mod 2q and set p = X - (c-1)
+ RInteger twoQ = aQ.TimesL(TInteger::Two());
+ CleanupStack::PushL(twoQ);
+ RInteger c = X.ModuloL(twoQ);
+ CleanupStack::PushL(c);
+ --c;
+ aP = X.MinusL(c);
+ CleanupStack::PopAndDestroy(3, &X); //twoQ, c, X
+ CleanupStack::PushL(aP);
+
+ //Step 10 and 11: if p >= 2^(L-1) and p is prime
+ if( aP.Bit(aL-1) && aP.IsPrimeL() )
+ {
+ aCounter = counter;
+ CleanupStack::Pop(2, &aQ);
+ CleanupStack::PopAndDestroy(3, sha1);
+ return ETrue;
+ }
+ CleanupStack::PopAndDestroy(&aP);
+ }
+ }
+ CleanupStack::PopAndDestroy(4, &sha1);
+ return EFalse;
+ }
+
+void CDSAKeyPairGenImpl::GenerateKeyPairL(TInt aKeySize,
+ const CCryptoParams& aKeyParameters,
+ CKeyPair*& aKeyPair)
+ {
+ //This is the first step of DSA prime generation. The remaining steps are
+ //performed in CDSAParameters::GeneratePrimesL
+ //Step 1. Choose an arbitrary sequence of at least 160 bits and call it
+ //SEED. Let g be the length of SEED in bits.
+ TBuf8<KShaSize> seed(KShaSize);
+ TUint c;
+ RInteger p;
+ RInteger q;
+
+ do
+ {
+ GenerateRandomBytesL(seed);
+ }
+ while(!GeneratePrimesL(seed, c, p, aKeySize, q));
+
+ //Double PushL will not fail as GeneratePrimesL uses the CleanupStack
+ //(at least one push and pop ;)
+ CleanupStack::PushL(p);
+ CleanupStack::PushL(q);
+
+ iPrimeCertificate = CDSAPrimeCertificate::NewL(seed, c);
+
+ // aKeyParameters isn't const here anymore
+ CCryptoParams& paramRef=const_cast<CCryptoParams&>(aKeyParameters);
+ paramRef.AddL(c, KDsaKeyGenerationCounterUid);
+ paramRef.AddL(seed, KDsaKeyGenerationSeedUid);
+
+ CMontgomeryStructure* montP = CMontgomeryStructure::NewLC(p);
+
+ --p;
+
+ // e = (p-1)/q
+ RInteger e = p.DividedByL(q);
+ CleanupStack::PushL(e);
+
+ --p; //now it's p-2 :)
+
+ RInteger h;
+ const TInteger* g = 0;
+ do
+ {
+ // find a random h | 1 < h < p-1
+ h = RInteger::NewRandomL(TInteger::Two(), p);
+ CleanupStack::PushL(h);
+ // g = h^e mod p
+ g = &(montP->ExponentiateL(h, e));
+ CleanupStack::PopAndDestroy(&h);
+ }
+ while( *g <= TInteger::One() );
+ CleanupStack::PopAndDestroy(&e);
+
+ ++p; //reincrement p to original value
+ ++p;
+
+
+ RInteger g1 = RInteger::NewL(*g); //take a copy of montP's g
+ CleanupStack::PushL(g1);
+ --q;
+ // select random x | 0 < x < q
+ RInteger x = RInteger::NewRandomL(TInteger::One(), q);
+ CleanupStack::PushL(x);
+ ++q;
+
+ //
+ // create the keys parameters
+ CCryptoParams* privateKeyParameters = CCryptoParams::NewLC();
+ privateKeyParameters->AddL(p, KDsaKeyParameterPUid);
+ privateKeyParameters->AddL(q, KDsaKeyParameterQUid);
+ privateKeyParameters->AddL(g1, KDsaKeyParameterGUid);
+ privateKeyParameters->AddL(x, KDsaKeyParameterXUid);
+ TKeyProperty privateKeyProperties = {KDSAKeyPairGeneratorUid,
+ KCryptoPluginDsaKeyPairGenUid,
+ KDsaPrivateKeyUid,
+ KNonEmbeddedKeyUid};
+
+ CCryptoParams* publicKeyParameters = CCryptoParams::NewLC();
+ publicKeyParameters->AddL(p, KDsaKeyParameterPUid);
+ publicKeyParameters->AddL(q, KDsaKeyParameterQUid);
+ publicKeyParameters->AddL(g1, KDsaKeyParameterGUid);
+ RInteger y = RInteger::NewL(montP->ExponentiateL(*g, x));
+ CleanupStack::PushL(y);
+ publicKeyParameters->AddL(y, KDsaKeyParameterYUid);
+ TKeyProperty publicKeyProperties = {KDSAKeyPairGeneratorUid,
+ KCryptoPluginDsaKeyPairGenUid,
+ KDsaPublicKeyUid,
+ KNonEmbeddedKeyUid};
+
+ //
+ // create the private key
+ //
+ CKey* privateKey = CKey::NewL(privateKeyProperties, *privateKeyParameters);
+ CleanupStack::PushL(privateKey);
+
+ //
+ // create the public key
+ //
+ CKey* publicKey = CKey::NewL(publicKeyProperties, *publicKeyParameters);
+ CleanupStack::PushL(publicKey);
+
+ aKeyPair = CKeyPair::NewL(publicKey, privateKey);
+
+ //publicKey, publicKeyParameters, y, privateKey, privateKeyParameters, x, g1, montP, q, p
+ CleanupStack::Pop(2, privateKey);
+ CleanupStack::PopAndDestroy(8, &p);
+ }