diff -r f18401adf8e1 -r 641f389e9157 crypto/weakcrypto/source/asymmetric/dsakeys.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/crypto/weakcrypto/source/asymmetric/dsakeys.cpp Tue Aug 31 17:00:08 2010 +0300 @@ -0,0 +1,468 @@ +/* +* Copyright (c) 2003-2009 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: +* +*/ + + +#include +#include +#include +#include +#include "../common/inlines.h" +#include "../bigint/mont.h" + +const TUint SHASIZE = 20; +const TUint KMinPrimeLength = 512; +const TUint KMaxPrimeLength = 1024; +const TUint KPrimeLengthMultiple = 64; + +/* CDSAParameters */ + +EXPORT_C const TInteger& CDSAParameters::P(void) const + { + return iP; + } + +EXPORT_C const TInteger& CDSAParameters::Q(void) const + { + return iQ; + } + +EXPORT_C const TInteger& CDSAParameters::G(void) const + { + return iG; + } + +EXPORT_C CDSAParameters::~CDSAParameters(void) + { + iP.Close(); + iQ.Close(); + iG.Close(); + } + +EXPORT_C CDSAParameters* CDSAParameters::NewL(RInteger& aP, RInteger& aQ, + RInteger& aG) + { + CDSAParameters* me = new (ELeave) CDSAParameters(aP, aQ, aG); + return (me); + } + +EXPORT_C TBool CDSAParameters::ValidatePrimesL(const CDSAPrimeCertificate& aCert) + const + { + TBool result = EFalse; + RInteger p; + RInteger q; + //Regenerate primes using aCert's seed and counter + TUint counter = aCert.Counter(); + if(!CDSAParameters::GeneratePrimesL(aCert.Seed(), counter, p, + P().BitCount(), q, ETrue)) + { + return result; + } + //this doesn't leave, no need to push p and q + if(p == P() && q == Q() && counter == aCert.Counter()) + { + result = ETrue; + } + p.Close(); + q.Close(); + return result; + } + +EXPORT_C TBool CDSAParameters::ValidPrimeLength(TUint aPrimeBits) + { + return (aPrimeBits >= KMinPrimeLength && + aPrimeBits <= KMaxPrimeLength && + aPrimeBits % KPrimeLengthMultiple == 0); + } + +EXPORT_C CDSAParameters::CDSAParameters(RInteger& aP, RInteger& aQ, + RInteger& aG) : iP(aP), iQ(aQ), iG(aG) + { + } + +EXPORT_C CDSAParameters::CDSAParameters(void) + { + } + +TBool CDSAParameters::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(!CDSAParameters::ValidPrimeLength(aL)) + { + User::Leave(KErrNotSupported); + } + + CSHA1* sha1 = CSHA1::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 U; + TBuf8 temp; + const TUint n = (aL-1)/160; + const TUint b = (aL-1)%160; + HBufC8* Wbuf = HBufC8::NewMaxLC((n+1) * SHASIZE); + TUint8* W = const_cast(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(U.Ptr()), temp.Ptr(), SHASIZE); + + //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[SHASIZE-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(&aQ); + CleanupStack::PopAndDestroy(Wbuf); + CleanupStack::PopAndDestroy(seedBuf); + CleanupStack::PopAndDestroy(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)*SHASIZE, 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((*Wbuf)[SHASIZE - 1 - b/8]) |= 0x80; + TPtr8 Wptr(W + SHASIZE - 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(&aP); + CleanupStack::Pop(&aQ); + CleanupStack::PopAndDestroy(Wbuf); + CleanupStack::PopAndDestroy(seedBuf); + CleanupStack::PopAndDestroy(sha1); + return ETrue; + } + CleanupStack::PopAndDestroy(&aP); + } + } + CleanupStack::PopAndDestroy(&aQ); + CleanupStack::PopAndDestroy(Wbuf); + CleanupStack::PopAndDestroy(seedBuf); + CleanupStack::PopAndDestroy(sha1); + return EFalse; + } + +/* CDSAPublicKey */ + +EXPORT_C CDSAPublicKey* CDSAPublicKey::NewL(RInteger& aP, RInteger& aQ, + RInteger& aG, RInteger& aY) + { + CDSAPublicKey* self = new(ELeave) CDSAPublicKey(aP, aQ, aG, aY); + return self; + } + +EXPORT_C CDSAPublicKey* CDSAPublicKey::NewLC(RInteger& aP, RInteger& aQ, + RInteger& aG, RInteger& aY) + { + CDSAPublicKey* self = NewL(aP, aQ, aG, aY); + CleanupStack::PushL(self); + return self; + } + +EXPORT_C const TInteger& CDSAPublicKey::Y(void) const + { + return iY; + } + +EXPORT_C CDSAPublicKey::CDSAPublicKey(void) + { + } + +EXPORT_C CDSAPublicKey::CDSAPublicKey(RInteger& aP, RInteger& aQ, RInteger& aG, + RInteger& aY) : CDSAParameters(aP, aQ, aG), iY(aY) + { + } + +EXPORT_C CDSAPublicKey::~CDSAPublicKey(void) + { + iY.Close(); + } + +/* CDSAPrivateKey */ + +EXPORT_C CDSAPrivateKey* CDSAPrivateKey::NewL(RInteger& aP, RInteger& aQ, + RInteger& aG, RInteger& aX) + { + CDSAPrivateKey* self = new(ELeave) CDSAPrivateKey(aP, aQ, aG, aX); + return self; + } + +EXPORT_C CDSAPrivateKey* CDSAPrivateKey::NewLC(RInteger& aP, RInteger& aQ, + RInteger& aG, RInteger& aX) + { + CDSAPrivateKey* self = NewL(aP, aQ, aG, aX); + CleanupStack::PushL(self); + return self; + } + +EXPORT_C const TInteger& CDSAPrivateKey::X(void) const + { + return iX; + } + +CDSAPrivateKey::CDSAPrivateKey(RInteger& aP, RInteger& aQ, RInteger& aG, + RInteger& aX) : CDSAParameters(aP, aQ, aG), iX(aX) + { + } + +EXPORT_C CDSAPrivateKey::CDSAPrivateKey(void) + { + } + +EXPORT_C CDSAPrivateKey::~CDSAPrivateKey(void) + { + iX.Close(); + } + +/* CDSAKeyPair */ + +EXPORT_C CDSAKeyPair* CDSAKeyPair::NewL(TUint aKeyBits) + { + CDSAKeyPair* self = NewLC(aKeyBits); + CleanupStack::Pop(); + return self; + } + +EXPORT_C CDSAKeyPair* CDSAKeyPair::NewLC(TUint aKeyBits) + { + CDSAKeyPair* self = new(ELeave) CDSAKeyPair(); + CleanupStack::PushL(self); + self->ConstructL(aKeyBits); + return self; + } + +EXPORT_C const CDSAPublicKey& CDSAKeyPair::PublicKey(void) const + { + return *iPublic; + } + +EXPORT_C const CDSAPrivateKey& CDSAKeyPair::PrivateKey(void) const + { + return *iPrivate; + } + +EXPORT_C CDSAKeyPair::~CDSAKeyPair(void) + { + delete iPublic; + delete iPrivate; + delete iPrimeCertificate; + } + +EXPORT_C CDSAKeyPair::CDSAKeyPair(void) + { + } + +EXPORT_C const CDSAPrimeCertificate& CDSAKeyPair::PrimeCertificate(void) const + { + return *iPrimeCertificate; + } + +void CDSAKeyPair::ConstructL(TUint aPBits) + { + //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 seed(SHASIZE); + TUint c; + RInteger p; + RInteger q; + do + { + GenerateRandomBytesL(seed); + } + while(!CDSAParameters::GeneratePrimesL(seed, c, p, aPBits, 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); + + 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); + RInteger p1 = RInteger::NewL(p); + CleanupStack::PushL(p1); + RInteger q1 = RInteger::NewL(q); + CleanupStack::PushL(q1); + + --q; + // select random x | 0 < x < q + RInteger x = RInteger::NewRandomL(TInteger::One(), q); + CleanupStack::PushL(x); + ++q; + + iPrivate = CDSAPrivateKey::NewL(p1, q1, g1, x); + CleanupStack::Pop(4, &g1); //x,q1,p1,g1 -- all owned by iPrivate + + RInteger y = RInteger::NewL(montP->ExponentiateL(*g, iPrivate->X())); + CleanupStack::PushL(y); + RInteger g2 = RInteger::NewL(iPrivate->G()); + CleanupStack::PushL(g2); + iPublic = CDSAPublicKey::NewL(p, q, g2, y); + CleanupStack::Pop(2, &y); //g2, y + CleanupStack::PopAndDestroy(montP); + CleanupStack::Pop(2, &p); //q, p + } + + +/* CDSAPrimeCertificate */ + +EXPORT_C CDSAPrimeCertificate* CDSAPrimeCertificate::NewL(const TDesC8& aSeed, + TUint aCounter) + { + CDSAPrimeCertificate* self = NewLC(aSeed, aCounter); + CleanupStack::Pop(); + return self; + } + +EXPORT_C CDSAPrimeCertificate* CDSAPrimeCertificate::NewLC(const TDesC8& aSeed, + TUint aCounter) + { + CDSAPrimeCertificate* self = new(ELeave) CDSAPrimeCertificate(aCounter); + CleanupStack::PushL(self); + self->ConstructL(aSeed); + return self; + } + +EXPORT_C const TDesC8& CDSAPrimeCertificate::Seed(void) const + { + return *iSeed; + } + +EXPORT_C TUint CDSAPrimeCertificate::Counter(void) const + { + return iCounter; + } + +EXPORT_C CDSAPrimeCertificate::~CDSAPrimeCertificate(void) + { + delete const_cast(iSeed); + } + +void CDSAPrimeCertificate::ConstructL(const TDesC8& aSeed) + { + iSeed = aSeed.AllocL(); + } + +EXPORT_C CDSAPrimeCertificate::CDSAPrimeCertificate(TUint aCounter) + : iCounter(aCounter) + { + } + +EXPORT_C CDSAPrimeCertificate::CDSAPrimeCertificate(void) + { + }