Developer Reference


Example of Using Discrete-logarithm Based Primitive Functions

Use of DLPSignDSA and DLPVerifyDSA
// // known domain parameters // static const int M = 512; // DSA system bitsize static const int L = 160; // DSA order bitsize static BigNumber P("0x8DF2A494492276AA3D25759BB06869CBEAC0D83AFB8D0CF7" \ "CBB8324F0D7882E5D0762FC5B7210EAFC2E9ADAC32AB7AAC" \ "49693DFBF83724C2EC0736EE31C80291");   static BigNumber Q("0xC773218C737EC8EE993B4F2DED30F48EDACE915F");   static BigNumber G("0x626D027839EA0A13413163A55B4CB500299D5522956CEFCB" \ "3BFF10F399CE2C2E71CB9DE5FA24BABF58E5B79521925C9C" \ "C42E9F6F464B088CC572AF53E6D78802");   // // known DSA regular key pair // static BigNumber X("0x2070B3223DBA372FDE1C0FFC7B2E3B498B260614");     static BigNumber Y("0x19131871D75B1612A819F29D78D1B0D7346F7AA77BB62A85" \ "9BFD6C5675DA9D212D3A36EF1672EF660B8C7C255CC0EC74" \ "858FBA33F44C06699630A76B030EE333");     int DSAsign_verify_sample(void) { // DLP context IppsDLPState *DLPState = newDLP(M, L);   // set up DLP crypto system ippsDLPSet(P, Q, G, DLPState);   // message Ipp8u message[] = "abc";   // compute message digest to be signed Ipp8u md[SHA1_DIGEST_LENGTH/8]; ippsSHA1MessageDigest(message, sizeof(message)-1, md); BigNumber digest(0, BITS_2_WORDS(SHA1_DIGEST_LENGTH)); ippsSetOctString_BN(md, SHA1_DIGEST_LENGTH/8, digest);   // generate ephemeral key pair (ephX,ephY) BigNumber ephX(0, BITS_2_WORDS(L)); BigNumber ephY(0, BITS_2_WORDS(M));     IppsPRNGState* pRand = newPRNG(); ippsDLPGenKeyPair(ephX, ephY, DLPState, ippsPRNGen, pRand); deletePRNG(pRand); // // generate signature // BigNumber signR(0, BITS_2_WORDS(L)); // R and S signature's component BigNumber signS(0, BITS_2_WORDS(L)); ippsDLPSetKeyPair(ephX, ephY, DLPState); // set up ephemeral keys ippsDLPSignDSA(digest, X, // sign digest signR, signS, DLPState);     // // verify signature // ippsDLPSetKeyPair(0, Y, DLPState); // set up regular public key IppDLResult result; ippsDLPVerifyDSA(digest, signR,signS, // verify &result, DLPState);   // remove actual keys from context and release resource ippsDLPInit(M, L, DLPState); deleteDLP(DLPState); return result==ippDLValid; }  

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