static Matrix_t *makekernel(const Poly_t *pol) { Matrix_t *materg; PTR rowptr; FEL *xbuf, *pbuf = pol->Data; long pdeg = pol->Degree; int k, xshift; long fl = pol->Field; materg = MatAlloc(fl,pdeg,pdeg); rowptr = materg->Data; xbuf = NALLOC(FEL,pdeg+1); for (k = 0; k <= pdeg; ++k) xbuf[k] = FF_ZERO; xbuf[0] = FF_ONE; for (k = 0; k < pdeg; ++k) { int l; for (l = 0; l < pdeg; ++l) FfInsert(rowptr,l,xbuf[l]); FfInsert(rowptr,k,FfSub(xbuf[k],FF_ONE)); FfStepPtr(&rowptr); for (xshift = (int) fl; xshift > 0; ) { FEL f; int d; /* Find leading pos */ for (l = pdeg-1; xbuf[l] == FF_ZERO && l >= 0; --l); /* Shift left as much as possible */ if ((d = pdeg - l) > xshift) d = xshift; for (; l >= 0; l--) xbuf[l+d] = xbuf[l]; for (l = d-1; l >= 0; --l) xbuf[l] = FF_ZERO; xshift -= d; if (xbuf[pdeg] == FF_ZERO) continue; /* Reduce with pol */ f = FfNeg(FfDiv(xbuf[pdeg],pbuf[pdeg])); for (l = pdeg-1; l >= 0; --l) xbuf[l] = FfAdd(xbuf[l],FfMul(pbuf[l],f)); xbuf[pdeg] = FF_ZERO; } } SysFree(xbuf); return MatNullSpace__(materg); }
static void TestScalarProduct1(PTR a, PTR b, int size) { int count; for (count = 0; count < 10; ++count) { int i; FEL expected = FF_ZERO; FfMulRow(a,FF_ZERO); FfMulRow(b,FF_ZERO); for (i = 0; i < size; ++i) { FEL f1 = FTab[MtxRandomInt(FfOrder)]; FEL f2 = FTab[MtxRandomInt(FfOrder)]; FfInsert(a,i,f1); FfInsert(b,i,f2); expected = FfAdd(expected,FfMul(f1,f2)); } ASSERT_EQ_INT(FfScalarProduct(a,b), expected); } }
void FfAddMulRow(PTR row1, PTR row2, FEL f) { register long i; register FEL *p1, *p2; CHECKFEL(f); if (f == FF_ZERO) return; if (f == FF_ONE) { FfAddRow(row1,row2); return; } p1 = row1; p2 = row2; for (i = FfNoc; i != 0; --i) { *p1 = FfAdd(*p1,FfMul(*p2,f)); ++p1; ++p2; } }
EpidStatus EpidSignBasic(MemberCtx const* ctx, void const* msg, size_t msg_len, void const* basename, size_t basename_len, BasicSignature* sig, BigNumStr* rnd_bsn) { EpidStatus sts = kEpidErr; EcPoint* B = NULL; EcPoint* t = NULL; // temp value in G1 EcPoint* k = NULL; EcPoint* e = NULL; FfElement* R2 = NULL; FfElement* p2y = NULL; FfElement* t1 = NULL; FfElement* t2 = NULL; FfElement* a = NULL; FfElement* b = NULL; FfElement* rx = NULL; FfElement* ra = NULL; FfElement* rb = NULL; struct p2x_t { uint32_t i; uint8_t bsn[1]; }* p2x = NULL; FfElement* t3 = NULL; // temporary for multiplication FfElement* c = NULL; uint8_t* digest = NULL; PreComputedSignature curr_presig = {0}; if (!ctx || !sig) { return kEpidBadArgErr; } if (!msg && (0 != msg_len)) { // if message is non-empty it must have both length and content return kEpidBadArgErr; } if (!basename && (0 != basename_len)) { // if basename is non-empty it must have both length and content return kEpidBadArgErr; } if (!ctx->epid2_params) { return kEpidBadArgErr; } do { FiniteField* Fp = ctx->epid2_params->Fp; SignCommitOutput commit_out = {0}; FpElemStr c_str = {0}; EcGroup* G1 = ctx->epid2_params->G1; FiniteField* GT = ctx->epid2_params->GT; FiniteField* Fq = ctx->epid2_params->Fq; PairingState* ps_ctx = ctx->epid2_params->pairing_state; const BigNumStr kOne = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}; BigNumStr t1_str = {0}; BigNumStr t2_str = {0}; size_t digest_size = 0; uint16_t* rf_ctr = (uint16_t*)&ctx->rf_ctr; FfElement const* x = ctx->x; if (basename) { if (!IsBasenameAllowed(ctx->allowed_basenames, basename, basename_len)) { sts = kEpidBadArgErr; BREAK_ON_EPID_ERROR(sts); } } sts = NewEcPoint(G1, &B); BREAK_ON_EPID_ERROR(sts); sts = NewEcPoint(G1, &k); BREAK_ON_EPID_ERROR(sts); sts = NewEcPoint(G1, &t); BREAK_ON_EPID_ERROR(sts); sts = NewEcPoint(G1, &e); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(GT, &R2); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(Fq, &p2y); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(Fp, &t1); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(Fp, &t2); BREAK_ON_EPID_ERROR(sts); p2x = (struct p2x_t*)SAFE_ALLOC(sizeof(struct p2x_t) + basename_len - 1); if (!p2x) { sts = kEpidMemAllocErr; break; } sts = NewFfElement(Fp, &a); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(Fp, &b); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(Fp, &rx); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(Fp, &ra); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(Fp, &rb); BREAK_ON_EPID_ERROR(sts); sts = MemberGetPreSig((MemberCtx*)ctx, &curr_presig); BREAK_ON_EPID_ERROR(sts); // 3. If the pre-computed signature pre-sigma exists, the member // loads (B, K, T, a, b, rx, rf, ra, rb, R1, R2) from // pre-sigma. Refer to Section 4.4 for the computation of // these values. sts = ReadFfElement(Fp, &curr_presig.a, sizeof(curr_presig.a), a); BREAK_ON_EPID_ERROR(sts); sts = ReadFfElement(Fp, &curr_presig.b, sizeof(curr_presig.b), b); BREAK_ON_EPID_ERROR(sts); sts = ReadFfElement(Fp, &curr_presig.rx, sizeof(curr_presig.rx), rx); BREAK_ON_EPID_ERROR(sts); sts = ReadFfElement(Fp, &curr_presig.ra, sizeof(curr_presig.ra), ra); BREAK_ON_EPID_ERROR(sts); sts = ReadFfElement(Fp, &curr_presig.rb, sizeof(curr_presig.rb), rb); BREAK_ON_EPID_ERROR(sts); // If the basename is provided, use it, otherwise use presig B if (basename) { // 3.a. The member computes (B, i2, y2) = G1.tpmHash(bsn). sts = EcHash(G1, basename, basename_len, ctx->hash_alg, B, &p2x->i); BREAK_ON_EPID_ERROR(sts); p2x->i = htonl(p2x->i); sts = WriteEcPoint(G1, B, &commit_out.B, sizeof(commit_out.B)); BREAK_ON_EPID_ERROR(sts); sts = ReadFfElement(Fq, &commit_out.B.y, sizeof(commit_out.B.y), p2y); BREAK_ON_EPID_ERROR(sts); // b.i. (KTPM, LTPM, ETPM, counterTPM) = TPM2_Commit(P1=h1,(s2, y2) = (i2 // || bsn, y2)). // b.ii.K = KTPM. if (0 != memcpy_S((void*)p2x->bsn, basename_len, basename, basename_len)) { sts = kEpidBadArgErr; break; } sts = Tpm2Commit(ctx->tpm2_ctx, ctx->h1, p2x, sizeof(p2x->i) + basename_len, p2y, k, t, e, (uint16_t*)&ctx->rf_ctr); BREAK_ON_EPID_ERROR(sts); sts = WriteEcPoint(G1, k, &commit_out.K, sizeof(commit_out.K)); BREAK_ON_EPID_ERROR(sts); // c.i. The member computes R1 = LTPM. sts = WriteEcPoint(G1, t, &commit_out.R1, sizeof(commit_out.R1)); BREAK_ON_EPID_ERROR(sts); // c.ii. e12rf = pairing(ETPM, g2) sts = Pairing(ps_ctx, e, ctx->epid2_params->g2, R2); BREAK_ON_EPID_ERROR(sts); // c.iii. R2 = GT.sscmMultiExp(ea2, t1, e12rf, 1, e22, t2, e2w,ra). // 4.i. The member computes t1 = (- rx) mod p. sts = FfNeg(Fp, rx, t1); BREAK_ON_EPID_ERROR(sts); // 4.j. The member computes t2 = (rb - a * rx) mod p. sts = FfMul(Fp, a, rx, t2); BREAK_ON_EPID_ERROR(sts); sts = FfNeg(Fp, t2, t2); BREAK_ON_EPID_ERROR(sts); sts = FfAdd(Fp, rb, t2, t2); BREAK_ON_EPID_ERROR(sts); sts = WriteFfElement(Fp, t1, &t1_str, sizeof(t1_str)); BREAK_ON_EPID_ERROR(sts); sts = WriteFfElement(Fp, t2, &t2_str, sizeof(t2_str)); BREAK_ON_EPID_ERROR(sts); { FfElement const* points[4]; BigNumStr const* exponents[4]; points[0] = ctx->ea2; points[1] = R2; points[2] = ctx->e22; points[3] = ctx->e2w; exponents[0] = &t1_str; exponents[1] = &kOne; exponents[2] = &t2_str; exponents[3] = (BigNumStr*)&curr_presig.ra; sts = FfMultiExp(GT, points, exponents, COUNT_OF(points), R2); BREAK_ON_EPID_ERROR(sts); } sts = WriteFfElement(GT, R2, &commit_out.R2, sizeof(commit_out.R2)); BREAK_ON_EPID_ERROR(sts); // d. The member over-writes the counterTPM, B, K, R1 and R2 values. } else { if (!rnd_bsn) { sts = kEpidBadArgErr; break; } sts = ReadEcPoint(G1, &curr_presig.B, sizeof(curr_presig.B), B); BREAK_ON_EPID_ERROR(sts); commit_out.B = curr_presig.B; commit_out.K = curr_presig.K; commit_out.R1 = curr_presig.R1; ((MemberCtx*)ctx)->rf_ctr = curr_presig.rf_ctr; commit_out.R2 = curr_presig.R2; *rnd_bsn = curr_presig.rnd_bsn; } commit_out.T = curr_presig.T; sts = HashSignCommitment(Fp, ctx->hash_alg, &ctx->pub_key, &commit_out, msg, msg_len, &c_str); BREAK_ON_EPID_ERROR(sts); digest_size = EpidGetHashSize(ctx->hash_alg); digest = (uint8_t*)SAFE_ALLOC(digest_size); if (!digest) { sts = kEpidNoMemErr; break; } memcpy_S(digest + digest_size - sizeof(c_str), sizeof(c_str), &c_str, sizeof(c_str)); sts = NewFfElement(Fp, &t3); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(Fp, &c); BREAK_ON_EPID_ERROR(sts); sts = ReadFfElement(Fp, &c_str, sizeof(c_str), c); BREAK_ON_EPID_ERROR(sts); // 7. The member computes sx = (rx + c * x) mod p. sts = FfMul(Fp, c, x, t3); BREAK_ON_EPID_ERROR(sts); sts = FfAdd(Fp, rx, t3, t3); BREAK_ON_EPID_ERROR(sts); sts = WriteFfElement(Fp, t3, &sig->sx, sizeof(sig->sx)); BREAK_ON_EPID_ERROR(sts); // 8. The member computes sf = (rf + c * f) mod p. sts = Tpm2Sign(ctx->tpm2_ctx, digest, digest_size, *rf_ctr, NULL, t3); BREAK_ON_EPID_ERROR(sts); sts = WriteFfElement(Fp, t3, &sig->sf, sizeof(sig->sf)); BREAK_ON_EPID_ERROR(sts); // 9. The member computes sa = (ra + c * a) mod p. sts = FfMul(Fp, c, a, t3); BREAK_ON_EPID_ERROR(sts); sts = FfAdd(Fp, ra, t3, t3); BREAK_ON_EPID_ERROR(sts); sts = WriteFfElement(Fp, t3, &sig->sa, sizeof(sig->sa)); BREAK_ON_EPID_ERROR(sts); // 10. The member computes sb = (rb + c * b) mod p. sts = FfMul(Fp, c, b, t3); BREAK_ON_EPID_ERROR(sts); sts = FfAdd(Fp, rb, t3, t3); BREAK_ON_EPID_ERROR(sts); sts = WriteFfElement(Fp, t3, &sig->sb, sizeof(sig->sb)); BREAK_ON_EPID_ERROR(sts); sig->B = commit_out.B; sig->K = commit_out.K; sig->T = commit_out.T; sig->c = c_str; sts = kEpidNoErr; } while (0); if (sts != kEpidNoErr) { (void)Tpm2ReleaseCounter(ctx->tpm2_ctx, (uint16_t)ctx->rf_ctr); (void)Tpm2ReleaseCounter(ctx->tpm2_ctx, curr_presig.rf_ctr); } else if (basename) { (void)Tpm2ReleaseCounter(ctx->tpm2_ctx, curr_presig.rf_ctr); } EpidZeroMemory(&curr_presig, sizeof(curr_presig)); DeleteEcPoint(&B); DeleteEcPoint(&k); DeleteEcPoint(&t); DeleteEcPoint(&e); DeleteFfElement(&R2); DeleteFfElement(&p2y); DeleteFfElement(&t1); DeleteFfElement(&t2); DeleteFfElement(&a); DeleteFfElement(&b); DeleteFfElement(&rx); DeleteFfElement(&ra); DeleteFfElement(&rb); SAFE_FREE(p2x); DeleteFfElement(&t3); DeleteFfElement(&c); SAFE_FREE(digest); return sts; }
static factor_t *factorsquarefree(const Poly_t *pol) { long int e,j,k,ltmp,tdeg,exp; Poly_t *t0, *t, *w, *v; FEL *tbuf, *t0buf; factor_t *list; int nfactors = 0; /* Initialize variables -------------------- */ FfSetField(pol->Field); for (exp = 0, ltmp = FfOrder; ltmp % FfChar == 0; ++exp, ltmp /= FfChar); t0 = PolDup(pol); e = 1; /* Allocate the list of factors. The can be at most <pol->Degree> factors, but we need one extra entry to terminate the list. ----------------------------------------------------------- */ list = NALLOC(factor_t,pol->Degree + 1); /* Main loop --------- */ while (t0->Degree > 0) { Poly_t *der = PolDerive(PolDup(t0)); t = PolGcd(t0,der); PolFree(der); v = PolDivMod(t0,t); PolFree(t0); for (k = 0; v->Degree > 0; ) { Poly_t *tmp; if ( ++k % FfChar == 0 ) { tmp = PolDivMod(t,v); PolFree(t); t = tmp; k++; } w = PolGcd(t,v); list[nfactors].p = PolDivMod(v,w); list[nfactors].n = e * k; if (list[nfactors].p->Degree > 0) ++nfactors; /* add to output */ else PolFree(list[nfactors].p); /* discard const. */ PolFree(v); v = w; tmp = PolDivMod(t,v); PolFree(t); t = tmp; } PolFree(v); /* shrink the polynomial */ tdeg = t->Degree; e *= FfChar; if ( tdeg % FfChar != 0 ) printf("error in t, degree not div. by prime \n"); t0 = PolAlloc(FfOrder,tdeg/FfChar); t0buf = t0->Data; tbuf = t->Data; for (j = t0->Degree; j >= 0; --j) { FEL el, el1; long lexp; el = *tbuf; tbuf += FfChar; el1 = el; /* this is a bug, it should apply the e-1 power of the frobenius K. Lux 16th 11 1996 */ /* replace el1 by el1^(FfChar^(exp-1)) */ for ( lexp = 0; lexp < exp-1; lexp++ ) { long n; /* replace el1 by el1^FfChar */ el = el1; for ( n = FfChar-1; 0 < n; n-- ) { el1 = FfMul(el1,el); } } *t0buf = el1; ++t0buf; } PolFree(t); } PolFree(t0); /* Terminate the list ------------------ */ list[nfactors].p = NULL; list[nfactors].n = 0; return list; }
EpidStatus EpidComputePreSig(MemberCtx const* ctx, PreComputedSignature* precompsig) { EpidStatus res = kEpidNotImpl; EcPoint* B = NULL; EcPoint* K = NULL; EcPoint* T = NULL; EcPoint* R1 = NULL; FfElement* R2 = NULL; FfElement* a = NULL; FfElement* b = NULL; FfElement* rx = NULL; FfElement* rf = NULL; FfElement* ra = NULL; FfElement* rb = NULL; FfElement* t1 = NULL; FfElement* t2 = NULL; FfElement* f = NULL; if (!ctx || !precompsig) return kEpidBadArgErr; if (!ctx->epid2_params || !ctx->pub_key || !ctx->priv_key) return kEpidBadArgErr; do { // handy shorthands: EcGroup* G1 = ctx->epid2_params->G1; FiniteField* GT = ctx->epid2_params->GT; FiniteField* Fp = ctx->epid2_params->Fp; EcPoint* h2 = ctx->pub_key->h2; EcPoint* A = ctx->priv_key->A; FfElement* x = ctx->priv_key->x; BigNumStr f_str = {0}; BigNumStr a_str = {0}; BigNumStr t1_str = {0}; BigNumStr rf_str = {0}; BigNumStr t2_str = {0}; BigNumStr ra_str = {0}; static const BigNumStr one = { {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}}}; if (!G1 || !GT || !Fp || !h2 || !A || !x || !ctx->priv_key->f || !ctx->e12 || !ctx->e22 || !ctx->e2w || !ctx->ea2) { res = kEpidBadArgErr; BREAK_ON_EPID_ERROR(res); } f = ctx->priv_key->f; // The following variables B, K, T, R1 (elements of G1), R2 // (elements of GT), a, b, rx, rf, ra, rb, t1, t2 (256-bit // integers) are used. res = NewEcPoint(G1, &B); BREAK_ON_EPID_ERROR(res); res = NewEcPoint(G1, &K); BREAK_ON_EPID_ERROR(res); res = NewEcPoint(G1, &T); BREAK_ON_EPID_ERROR(res); res = NewEcPoint(G1, &R1); BREAK_ON_EPID_ERROR(res); res = NewFfElement(GT, &R2); BREAK_ON_EPID_ERROR(res); res = NewFfElement(Fp, &a); BREAK_ON_EPID_ERROR(res); res = NewFfElement(Fp, &b); BREAK_ON_EPID_ERROR(res); res = NewFfElement(Fp, &rx); BREAK_ON_EPID_ERROR(res); res = NewFfElement(Fp, &rf); BREAK_ON_EPID_ERROR(res); res = NewFfElement(Fp, &ra); BREAK_ON_EPID_ERROR(res); res = NewFfElement(Fp, &rb); BREAK_ON_EPID_ERROR(res); res = NewFfElement(Fp, &t1); BREAK_ON_EPID_ERROR(res); res = NewFfElement(Fp, &t2); BREAK_ON_EPID_ERROR(res); // 1. The member expects the pre-computation is done (e12, e22, e2w, // ea2). Refer to Section 3.5 for the computation of these // values. // 2. The member verifies gid in public key matches gid in private // key. // 3. The member computes B = G1.getRandom(). res = EcGetRandom(G1, ctx->rnd_func, ctx->rnd_param, B); BREAK_ON_EPID_ERROR(res); // 4. The member computes K = G1.sscmExp(B, f). res = WriteFfElement(Fp, f, &f_str, sizeof(f_str)); BREAK_ON_EPID_ERROR(res); res = EcExp(G1, B, &f_str, K); BREAK_ON_EPID_ERROR(res); // 5. The member chooses randomly an integers a from [1, p-1]. res = FfGetRandom(Fp, &one, ctx->rnd_func, ctx->rnd_param, a); BREAK_ON_EPID_ERROR(res); // 6. The member computes T = G1.sscmExp(h2, a). res = WriteFfElement(Fp, a, &a_str, sizeof(a_str)); BREAK_ON_EPID_ERROR(res); res = EcExp(G1, h2, &a_str, T); BREAK_ON_EPID_ERROR(res); // 7. The member computes T = G1.mul(T, A). res = EcMul(G1, T, A, T); BREAK_ON_EPID_ERROR(res); // 8. The member computes b = (a * x) mod p. res = FfMul(Fp, a, x, b); BREAK_ON_EPID_ERROR(res); // 9. The member chooses rx, rf, ra, rb randomly from [1, p-1]. res = FfGetRandom(Fp, &one, ctx->rnd_func, ctx->rnd_param, rx); BREAK_ON_EPID_ERROR(res); res = FfGetRandom(Fp, &one, ctx->rnd_func, ctx->rnd_param, rf); BREAK_ON_EPID_ERROR(res); res = FfGetRandom(Fp, &one, ctx->rnd_func, ctx->rnd_param, ra); BREAK_ON_EPID_ERROR(res); res = FfGetRandom(Fp, &one, ctx->rnd_func, ctx->rnd_param, rb); BREAK_ON_EPID_ERROR(res); // 10. The member computes t1 = (- rx) mod p. res = FfNeg(Fp, rx, t1); BREAK_ON_EPID_ERROR(res); // 11. The member computes t2 = (rb - a * rx) mod p. res = FfMul(Fp, a, rx, t2); BREAK_ON_EPID_ERROR(res); res = FfNeg(Fp, t2, t2); BREAK_ON_EPID_ERROR(res); res = FfAdd(Fp, rb, t2, t2); BREAK_ON_EPID_ERROR(res); // 12. The member computes R1 = G1.sscmExp(B, rf). res = WriteFfElement(Fp, rf, &rf_str, sizeof(rf_str)); BREAK_ON_EPID_ERROR(res); res = EcExp(G1, B, &rf_str, R1); BREAK_ON_EPID_ERROR(res); // 13. The member computes R2 = GT.sscmMultiExp(ea2, t1, e12, rf, // e22, t2, e2w, ra). res = WriteFfElement(Fp, t1, &t1_str, sizeof(t1_str)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(Fp, t2, &t2_str, sizeof(t2_str)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(Fp, ra, &ra_str, sizeof(ra_str)); BREAK_ON_EPID_ERROR(res); { FfElement const* points[4]; BigNumStr const* exponents[4]; points[0] = ctx->ea2; points[1] = ctx->e12; points[2] = ctx->e22; points[3] = ctx->e2w; exponents[0] = &t1_str; exponents[1] = &rf_str; exponents[2] = &t2_str; exponents[3] = &ra_str; res = FfMultiExp(GT, points, exponents, COUNT_OF(points), R2); BREAK_ON_EPID_ERROR(res); } // 14. The member sets and outputs pre-sigma = (B, K, T, a, b, rx, // rf, ra, rb, R1, R2). res = WriteEcPoint(G1, B, &precompsig->B, sizeof(precompsig->B)); BREAK_ON_EPID_ERROR(res); res = WriteEcPoint(G1, K, &precompsig->K, sizeof(precompsig->K)); BREAK_ON_EPID_ERROR(res); res = WriteEcPoint(G1, T, &precompsig->T, sizeof(precompsig->T)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(Fp, a, &precompsig->a, sizeof(precompsig->a)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(Fp, b, &precompsig->b, sizeof(precompsig->b)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(Fp, rx, &precompsig->rx, sizeof(precompsig->rx)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(Fp, rf, &precompsig->rf, sizeof(precompsig->rf)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(Fp, ra, &precompsig->ra, sizeof(precompsig->ra)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(Fp, rb, &precompsig->rb, sizeof(precompsig->rb)); BREAK_ON_EPID_ERROR(res); res = WriteEcPoint(G1, R1, &precompsig->R1, sizeof(precompsig->R1)); BREAK_ON_EPID_ERROR(res); res = WriteFfElement(GT, R2, &precompsig->R2, sizeof(precompsig->R2)); BREAK_ON_EPID_ERROR(res); // 15. The member stores pre-sigma in the secure storage of the // member. res = kEpidNoErr; } while (0); f = NULL; DeleteEcPoint(&B); DeleteEcPoint(&K); DeleteEcPoint(&T); DeleteEcPoint(&R1); DeleteFfElement(&R2); DeleteFfElement(&a); DeleteFfElement(&b); DeleteFfElement(&rx); DeleteFfElement(&rf); DeleteFfElement(&ra); DeleteFfElement(&rb); DeleteFfElement(&t1); DeleteFfElement(&t2); return (res); }
EpidStatus EpidRequestJoin(GroupPubKey const* pub_key, IssuerNonce const* ni, FpElemStr const* f, BitSupplier rnd_func, void* rnd_param, HashAlg hash_alg, JoinRequest* join_request) { EpidStatus sts; static const BigNumStr one = { {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}}}; BigNumStr r_str; JoinPCommitValues commit_values; Epid2Params_* params = NULL; FfElement* r_el = NULL; FfElement* f_el = NULL; FfElement* c_el = NULL; FfElement* cf_el = NULL; FfElement* s_el = NULL; EcPoint* f_pt = NULL; EcPoint* r_pt = NULL; EcPoint* h1_pt = NULL; if (!pub_key || !ni || !f || !rnd_func || !join_request) { return kEpidBadArgErr; } if (kSha256 != hash_alg && kSha384 != hash_alg && kSha512 != hash_alg) { return kEpidBadArgErr; } do { sts = CreateEpid2Params(¶ms); BREAK_ON_EPID_ERROR(sts); if (!params->Fp || !params->G1) { sts = kEpidBadArgErr; break; } sts = NewFfElement(params->Fp, &r_el); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(params->Fp, &f_el); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(params->Fp, &c_el); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(params->Fp, &cf_el); BREAK_ON_EPID_ERROR(sts); sts = NewFfElement(params->Fp, &s_el); BREAK_ON_EPID_ERROR(sts); sts = NewEcPoint(params->G1, &f_pt); BREAK_ON_EPID_ERROR(sts); sts = NewEcPoint(params->G1, &h1_pt); BREAK_ON_EPID_ERROR(sts); sts = NewEcPoint(params->G1, &r_pt); BREAK_ON_EPID_ERROR(sts); sts = ReadFfElement(params->Fp, (uint8_t const*)f, sizeof(*f), f_el); BREAK_ON_EPID_ERROR(sts); sts = ReadEcPoint(params->G1, (uint8_t*)&pub_key->h1, sizeof(pub_key->h1), h1_pt); BREAK_ON_EPID_ERROR(sts); // Step 1. The member chooses a random integer r from [1, p-1]. sts = FfGetRandom(params->Fp, &one, rnd_func, rnd_param, r_el); BREAK_ON_EPID_ERROR(sts); sts = WriteFfElement(params->Fp, r_el, (uint8_t*)&r_str, sizeof(r_str)); // Step 2. The member computes F = G1.sscmExp(h1, f). sts = EcExp(params->G1, h1_pt, (BigNumStr const*)f, f_pt); BREAK_ON_EPID_ERROR(sts); // Step 3. The member computes R = G1.sscmExp(h1, r). sts = EcExp(params->G1, h1_pt, (BigNumStr const*)&r_str, r_pt); BREAK_ON_EPID_ERROR(sts); // Step 4. The member computes c = Fp.hash(p || g1 || g2 || h1 || h2 || w || // F || R || NI). Refer to Section 7.1 for hash operation over a prime // field. sts = WriteBigNum(params->p, sizeof(commit_values.p), (uint8_t*)&commit_values.p); BREAK_ON_EPID_ERROR(sts); sts = WriteEcPoint(params->G1, params->g1, (uint8_t*)&commit_values.g1, sizeof(commit_values.g1)); BREAK_ON_EPID_ERROR(sts); sts = WriteEcPoint(params->G2, params->g2, (uint8_t*)&commit_values.g2, sizeof(commit_values.g2)); BREAK_ON_EPID_ERROR(sts); commit_values.h1 = pub_key->h1; commit_values.h2 = pub_key->h2; commit_values.w = pub_key->w; sts = WriteEcPoint(params->G1, f_pt, (uint8_t*)&commit_values.F, sizeof(commit_values.F)); BREAK_ON_EPID_ERROR(sts); sts = WriteEcPoint(params->G1, r_pt, (uint8_t*)&commit_values.R, sizeof(commit_values.R)); BREAK_ON_EPID_ERROR(sts); commit_values.NI = *ni; sts = FfHash(params->Fp, (uint8_t*)&commit_values, sizeof(commit_values), hash_alg, c_el); BREAK_ON_EPID_ERROR(sts); // Step 5. The member computes s = (r + c * f) mod p. sts = FfMul(params->Fp, c_el, f_el, cf_el); BREAK_ON_EPID_ERROR(sts); sts = FfAdd(params->Fp, r_el, cf_el, s_el); BREAK_ON_EPID_ERROR(sts); // Step 6. The output join request is (F, c, s). sts = WriteFfElement(params->Fp, c_el, (uint8_t*)&join_request->c, sizeof(join_request->c)); BREAK_ON_EPID_ERROR(sts); sts = WriteFfElement(params->Fp, s_el, (uint8_t*)&join_request->s, sizeof(join_request->s)); BREAK_ON_EPID_ERROR(sts); sts = WriteEcPoint(params->G1, f_pt, (uint8_t*)&join_request->F, sizeof(join_request->F)); BREAK_ON_EPID_ERROR(sts); sts = kEpidNoErr; } while (0); DeleteEcPoint(&h1_pt); DeleteEcPoint(&r_pt); DeleteEcPoint(&f_pt); DeleteFfElement(&s_el); DeleteFfElement(&cf_el); DeleteFfElement(&c_el); DeleteFfElement(&f_el); DeleteFfElement(&r_el); DeleteEpid2Params(¶ms); return sts; }
EpidStatus NewG2(Epid2Params const* param, BigNum* p, BigNum* q, FiniteField* Fq, FiniteField* Fq2, EcGroup** G2) { EpidStatus result = kEpidErr; EcGroup* ec = NULL; FfElement* a = NULL; FfElement* b = NULL; FfElement* fq_param_b = NULL; FfElement* x = NULL; FfElement* y = NULL; BigNum* order = NULL; BigNum* cofactor = NULL; if (!param || !Fq || !Fq2 || !G2) { return kEpidBadArgErr; } do { // 2. Set xi = (xi0, xi1) an element of Fq2. // 3. Let b', xi' be a temporary variable in Fq2. // 4. Compute xi' = Fq2.inverse(xi). // 5. Compute b' = Fq2.mul(xi', b). result = NewFfElement(Fq2, &b); if (kEpidNoErr != result) { break; } result = ReadFfElement(Fq2, ¶m->xi, sizeof(param->xi), b); if (kEpidNoErr != result) { break; } result = FfInv(Fq2, b, b); if (kEpidNoErr != result) { break; } result = NewFfElement(Fq, &fq_param_b); if (kEpidNoErr != result) { break; } result = ReadFfElement(Fq, ¶m->b, sizeof(param->b), fq_param_b); if (kEpidNoErr != result) { break; } result = FfMul(Fq2, b, fq_param_b, b); // ??? overflow fq2*fq if (kEpidNoErr != result) { break; } // 6. Set g2.x = (g2.x[0], g2.x[1]) an element of Fq2. // 7. Set g2.y = (g2.y[0], g2.y[1]) an element of Fq2. result = NewFfElement(Fq2, &x); if (kEpidNoErr != result) { break; } result = ReadFfElement(Fq2, ¶m->g2.x, sizeof(param->g2.x), x); if (kEpidNoErr != result) { break; } result = NewFfElement(Fq2, &y); if (kEpidNoErr != result) { break; } result = ReadFfElement(Fq2, ¶m->g2.y, sizeof(param->g2.y), y); if (kEpidNoErr != result) { break; } // 8. set h = 2q - p, aka cofactor result = NewBigNum(2 * sizeof(param->q), &cofactor); if (kEpidNoErr != result) { break; } result = BigNumAdd(q, q, cofactor); if (kEpidNoErr != result) { break; } result = BigNumSub(cofactor, p, cofactor); if (kEpidNoErr != result) { break; } // 9. set n = p * h, AKA order result = NewBigNum(2 * sizeof(param->q), &order); if (kEpidNoErr != result) { break; } result = BigNumMul(p, cofactor, order); if (kEpidNoErr != result) { break; } // set a to identity, NewFfElement does it by default result = NewFfElement(Fq2, &a); if (kEpidNoErr != result) { break; } // 10. Set G2 = E(Fq2).init(p, param(Fq2), n, h, 0, b', g2.x, g2.y) result = NewEcGroup(Fq2, a, b, x, y, order, cofactor, &ec); if (kEpidNoErr != result) { break; } *G2 = ec; result = kEpidNoErr; } while (0); DeleteBigNum(&cofactor); DeleteBigNum(&order); DeleteFfElement(&y); DeleteFfElement(&x); DeleteFfElement(&b); DeleteFfElement(&a); DeleteFfElement(&fq_param_b); return result; }