Example of Using RSA Primitive Functions¶

The following example illustrates the use of RSA primitives. The example uses the BigNumber class and functions creating some cryptographic contexts, whose source code can be found in Appendix B.
Use of RSA Primitives
// P prime factor
BigNumber    P("0xEECFAE81B1B9B3C908810B10A1B5600199EB9F44AEF4FDA493B81A9E3D84F632"
                 "124EF0236E5D1E3B7E28FAE7AA040A2D5B252176459D1F397541BA2A58FB6599");
// Q prime factor
BigNumber    Q("0xC97FB1F027F453F6341233EAAAD1D9353F6C42D08866B1D05A0F2035028B9D86"
                 "9840B41666B42E92EA0DA3B43204B5CFCE3352524D0416A5A441E700AF461503");
// P's CRT exponent
BigNumber   dP("0x54494CA63EBA0337E4E24023FCD69A5AEB07DDDC0183A4D0AC9B54B051F2B13E"
                 "D9490975EAB77414FF59C1F7692E9A2E202B38FC910A474174ADC93C1F67C981");
// Q's CRT exponent
BigNumber   dQ("0x471E0290FF0AF0750351B7F878864CA961ADBD3A8A7E991C5C0556A94C3146A7"
                 "F9803F8F6F8AE342E931FD8AE47A220D1B99A495849807FE39F9245A9836DA3D");
// CRT coefficient
BigNumber invQ("0xB06C4FDABB6301198D265BDBAE9423B380F271F73453885093077FCD39E2119F"
                 "C98632154F5883B167A967BF402B4E9E2E0F9656E698EA3666EDFB25798039F7");
// rsa modulus N = P*Q
BigNumber    N("0xBBF82F090682CE9C2338AC2B9DA871F7368D07EED41043A440D6B6F07454F51F"
                 "B8DFBAAF035C02AB61EA48CEEB6FCD4876ED520D60E1EC4619719D8A5B8B807F"
                 "AFB8E0A3DFC737723EE6B4B7D93A2584EE6A649D060953748834B2454598394E"
                 "E0AAB12D7B61A51F527A9A41F6C1687FE2537298CA2A8F5946F8E5FD091DBDCB");
// private exponent
BigNumber    D("0xA5DAFC5341FAF289C4B988DB30C1CDF83F31251E0668B42784813801579641B2"
                 "9410B3C7998D6BC465745E5C392669D6870DA2C082A939E37FDCB82EC93EDAC9"
                 "7FF3AD5950ACCFBC111C76F1A9529444E56AAF68C56C092CD38DC3BEF5D20A93"
                 "9926ED4F74A13EDDFBE1A1CECC4894AF9428C2B7B8883FE4463A4BC85B1CB3C1");
// public exponent
BigNumber    E("0x11");


int RSA_sample(void)
{
   int keyCtxSize;


   // (bit) size of key components
   int bitsN = N.BitSize();
   int bitsE = E.BitSize();
   int bitsP = P.BitSize();
   int bitsQ = Q.BitSize();


   // define and setup public key
   ippsRSA_GetSizePublicKey(bitsN, bitsE, &keyCtxSize);
   IppsRSAPublicKeyState* pPub = (IppsRSAPublicKeyState*)( new Ipp8u [keyCtxSize] );
   ippsRSA_InitPublicKey(bitsN, bitsE, pPub, keyCtxSize);
   ippsRSA_SetPublicKey(N, E, pPub);


   // define and setup (type2) private key
   ippsRSA_GetSizePrivateKeyType2(bitsP, bitsQ, &keyCtxSize);
   IppsRSAPrivateKeyState* pPrv = (IppsRSAPrivateKeyState*)( new Ipp8u [keyCtxSize] );
   ippsRSA_InitPrivateKeyType2(bitsP, bitsQ, pPrv, keyCtxSize);
   ippsRSA_SetPrivateKeyType2(P, Q, dP, dQ, invQ, pPrv);


   // allocate scratch buffer
   int buffSizePublic;
   ippsRSA_GetBufferSizePublicKey(&buffSizePublic, pPub);
   int buffSizePrivate;
   ippsRSA_GetBufferSizePrivateKey(&buffSizePrivate, pPrv);
   int buffSize = max(buffSizePublic, buffSizePrivate);
   Ipp8u* scratchBuffer = NULL;
   scratchBuffer = new Ipp8u [buffSize];


   // error flag
   int error = 0;


   do {
      //
      // validate keys
      //


      // random generator
      IppsPRNGState* pRand = newPRNG();
      // prime generator
      IppsPrimeState* pPrimeG = newPrimeGen(P.BitSize());


      int validateRes = IPP_IS_INVALID;
      ippsRSA_ValidateKeys(&validateRes,
                           pPub, pPrv, NULL, scratchBuffer,
                           10, pPrimeG, ippsPRNGen, pRand);


      // delete geterators
      deletePrimeGen(pPrimeG);
      deletePRNG(pRand);


      if(IPP_IS_VALID!=validateRes) {
         cout <<"validation fail" << endl;
         error = 1;
         break;
      }


      // known plain- and ciper-texts
      BigNumber kat_PT("0x00EB7A19ACE9E3006350E329504B45E2CA82310B26DCD87D5C68F1EEA8F55267"
                         "C31B2E8BB4251F84D7E0B2C04626F5AFF93EDCFB25C9C2B3FF8AE10E839A2DDB"
                         "4CDCFE4FF47728B4A1B7C1362BAAD29AB48D2869D5024121435811591BE392F9"
                         "82FB3E87D095AEB40448DB972F3AC14F7BC275195281CE32D2F1B76D4D353E2D");
      BigNumber kat_CT("0x1253E04DC0A5397BB44A7AB87E9BF2A039A33D1E996FC82A94CCD30074C95DF7"
                         "63722017069E5268DA5D1C0B4F872CF653C11DF82314A67968DFEAE28DEF04BB"
                         "6D84B1C31D654A1970E5783BD6EB96A024C2CA2F4A90FE9F2EF5C9C140E5BB48"
                         "DA9536AD8700C84FC9130ADEA74E558D51A74DDF85D8B50DE96838D6063E0955");


      //
      // encrypt  message
      //
      BigNumber ct(0, N.DwordSize());
      ippsRSA_Encrypt(kat_PT, ct, pPub, scratchBuffer);
      if(ct!=kat_CT) {
         cout <<"encryption fail" << endl;
         error = 1;
         break;
      }


      //
      // decrypt message
      //
      BigNumber rt(0, N.DwordSize());
      ippsRSA_Decrypt(kat_CT, rt, pPrv, scratchBuffer);
      if(rt!=kat_PT) {
         cout <<"decryption fail" << endl;
         error = 1;
         break;
      }
   } while(0);


   delete [] scratchBuffer;


   delete [] (Ipp8u*) pPub;


   // remove sensitive data before release
   ippsRSA_InitPrivateKeyType2(bitsP, bitsQ, pPrv, keyCtxSize);
   delete [] (Ipp8u*) pPrv;


   return error==0;
}
Intel® Integrated Performance Primitives Cryptography documentation

Example of Using RSA Primitive Functions¶
