int bb_verify(unsigned char *sig, unsigned int hashlen, unsigned char *hash, bb_public_key_t pk)
{
element_t sigma, r;
element_t m;
element_t t0, t1, t2;
int res;
int len;
pairing_ptr pairing = pk->param->pairing;
element_init(m, pairing->Zr);
element_from_hash(m, hash, hashlen);
element_init(sigma, pairing->G1);
len = element_from_bytes_x_only(sigma, sig);
element_init(r, pairing->Zr);
element_from_bytes(r, sig + len);
element_init(t0, pairing->G2);
element_init(t1, pairing->G2);
element_init(t2, pairing->GT);
element_pow_zn(t0, pk->g2, m);
element_pow_zn(t1, pk->v, r);
element_mul(t0, t0, t1);
element_mul(t0, t0, pk->u);
element_pairing(t2, sigma, t0);
if (!element_cmp(t2, pk->z)) {
res = 1;
} else {
element_mul(t2, t2, pk->z);
res = element_is1(t2);
}
element_clear(t0);
element_clear(t1);
element_clear(t2);
element_clear(m);
element_clear(sigma);
element_clear(r);
return res;
}
// USER JOIN PHASE 2 - user key generation (Join)
int xsgs_user_join_phase2(XSGS_PUBLIC_KEY* gpk, XSGS_USER_DB_ENTRY* udbe,
XSGS_ISSUER_KEY* ik, XSGS_PAILLIER_PUBKEY* ppk, XSGS_JOIN_PHASE1* jpd1,
XSGS_JOIN_PHASE2* jpd2) {
int ret;
pairing_ptr pairing = gpk->pairing;
field_ptr Fp = pairing->Zr;
mpz_t r1, h; //, t;
element_t R1, R2, g1, B, D, zp, gt, hp;
mpz_init(h);
mpz_from_hash(h, jpd1->U.hash, JOIN_HASH_BITS / 8);
// 1. verify C e G1 and check U
// R1 = g^s * c^h mod n^2
mpz_init(r1);
mpz_powm2(r1, ppk->g, jpd1->U.s, jpd1->U.c, h, ppk->n_squared);
// R2 = H^s * C^h
element_init_G1(R2, pairing);
element_pow_naf2_mpz(R2, gpk->H, jpd1->U.s, jpd1->C, h);
mpz_clear(h);
// h = H(g, n, c, C, H, R1, R2)
DWORD data_len = mpz_length_in_bytes(ppk->g)
+ mpz_length_in_bytes(ppk->n_squared)
+ mpz_length_in_bytes(jpd1->U.c) + element_length_in_bytes(jpd1->C)
+ element_length_in_bytes(gpk->H) + mpz_length_in_bytes(r1)
+ element_length_in_bytes(R2);
BYTE* data_buf = (BYTE*) malloc(data_len);
data_buf += mpz_to_bytes(data_buf, ppk->g);
data_buf += mpz_to_bytes(data_buf, ppk->n_squared);
data_buf += mpz_to_bytes(data_buf, jpd1->U.c);
data_buf += element_to_bytes(data_buf, jpd1->C);
data_buf += element_to_bytes(data_buf, gpk->H);
data_buf += mpz_to_bytes(data_buf, r1);
data_buf += element_to_bytes(data_buf, R2);
data_buf -= data_len;
BYTE* hash = (BYTE*) malloc(JOIN_HASH_BITS / 8);
xsgs_hash(data_buf, data_len * 8, hash, JOIN_HASH_BITS);
free(data_buf);
mpz_clear(r1);
element_clear(R2);
// compare hashes
ret = memcmp(jpd1->U.hash, hash, JOIN_HASH_BITS / 8);
free(hash);
if (!ret) {
element_t r;
// initialization
element_init(udbe->UCert.x, Fp);
element_init_G1(udbe->UCert.A, pairing);
element_init_G1(udbe->C, pairing);
element_init_G1(jpd2->A, pairing);
element_init_G1(g1, pairing);
element_init_GT(B, pairing);
element_init_GT(gt, pairing);
element_init(zp, Fp);
// save jpd1->C to ubde->C
element_set(udbe->C, jpd1->C);
// 2. x eR Zp and
element_random(udbe->UCert.x);
// A <- (G1 * C)^{1/(gamma + x)}
element_add(zp, ik->gamma, udbe->UCert.x);
element_invert(zp, zp);
element_mul(jpd2->A, gpk->G1, jpd1->C);
element_pow_naf(jpd2->A, jpd2->A, zp);
element_set(udbe->UCert.A, jpd2->A);
// 3. B <- e(G1 * C, G2) / e(A, W) = e(G1 * C, G2) * e(A^-1, W)
element_mul(g1, gpk->G1, jpd1->C);
element_pairing(B, g1, gpk->G2);
element_invert(g1, jpd2->A);
element_pairing(gt, g1, gpk->W);
element_mul(B, B, gt);
element_clear(g1);
element_clear(zp);
element_clear(gt);
// 4. D <- e(A, G2)
element_init_GT(D, pairing);
element_pairing(D, jpd2->A, gpk->G2);
// 5. V <- NIZKPoKDL(B, D)
// T1 = B^gamma
element_init_GT(jpd2->V.T1, pairing);
element_pow_zn(jpd2->V.T1, B, ik->gamma);
// T2 = D^gamma
element_init_GT(jpd2->V.T2, pairing);
element_pow_zn(jpd2->V.T2, D, ik->gamma);
// r eR Zp
element_init(r, Fp);
element_random(r);
// R1 = B^r
element_init_GT(R1, pairing);
element_pow_zn(R1, B, r);
// R2 = D^r
element_init_GT(R2, pairing);
element_pow_zn(R2, D, r);
// h = H(B, D, T1, T2, R1, R2)
data_len = element_length_in_bytes(B) + element_length_in_bytes(D)
+ element_length_in_bytes(jpd2->V.T1)
+ element_length_in_bytes(jpd2->V.T2)
+ element_length_in_bytes(R1) + element_length_in_bytes(R2);
data_buf = (BYTE*) malloc(data_len);
data_buf += element_to_bytes(data_buf, B);
data_buf += element_to_bytes(data_buf, D);
data_buf += element_to_bytes(data_buf, jpd2->V.T1);
data_buf += element_to_bytes(data_buf, jpd2->V.T2);
data_buf += element_to_bytes(data_buf, R1);
data_buf += element_to_bytes(data_buf, R2);
data_buf -= data_len;
jpd2->V.hash = (BYTE*) malloc(JOIN_HASH_BITS / 8);
xsgs_hash(data_buf, data_len * 8, jpd2->V.hash, JOIN_HASH_BITS);
element_init(hp, Fp);
element_from_hash(hp, jpd1->U.hash, JOIN_HASH_BITS / 8);
free(data_buf);
element_clear(B);
element_clear(D);
element_clear(R1);
element_clear(R2);
// s = r - hash * gamma mod p
element_init(jpd2->V.s, Fp);
element_mul(jpd2->V.s, hp, ik->gamma);
element_add(jpd2->V.s, r, jpd2->V.s);
element_clear(r);
element_clear(hp);
}
// return (A, V = (T1, T2, hash, s) )
return ret;
}
// USER JOIN PHASE 3 - user key generation (Join)
int xsgs_user_join_phase3(XSGS_PUBLIC_KEY* gpk, XSGS_USER_CERT* ucert,
XSGS_JOIN_PHASE1* jpd1, XSGS_JOIN_PHASE2* jpd2, XSGS_JOIN_PHASE3* jpd3,
char* usk_pem_filename) {
int ret;
pairing_ptr pairing = gpk->pairing;
field_ptr Fp = pairing->Zr;
element_t B, D, R1, R2, h, g1, gt;
// B = e(G1 * C, G2) / e(A, W) = e(G1 * C, G2) * e(A^-1, W)
element_init_GT(B, pairing);
element_init_G1(g1, pairing);
element_init_GT(gt, pairing);
element_mul(g1, gpk->G1, jpd1->C);
element_pairing(B, g1, gpk->G2);
element_invert(g1, jpd2->A);
element_pairing(gt, g1, gpk->W);
element_mul(B, B, gt);
// D = e(A, G2)
element_init_GT(D, pairing);
element_pairing(D, jpd2->A, gpk->G2);
// verifies A e Group1, Checks V
element_init(h, Fp);
element_from_hash(h, jpd1->U.hash, JOIN_HASH_BITS / 8);
element_neg(h, h);
// R1 = B^s * T1^h
element_init_GT(R1, pairing);
element_pow_naf2(R1, B, jpd2->V.s, jpd2->V.T1, h);
// R2 = D^s * T2^h
element_init_GT(R2, pairing);
element_pow_naf2(R2, D, jpd2->V.s, jpd2->V.T2, h);
// clear tmp
element_clear(g1);
element_clear(gt);
element_clear(h);
// h = H(B, D, T1, T2, R1, R2)
DWORD data_len = element_length_in_bytes(B) + element_length_in_bytes(D)
+ element_length_in_bytes(jpd2->V.T1)
+ element_length_in_bytes(jpd2->V.T2) + element_length_in_bytes(R1)
+ element_length_in_bytes(R2);
BYTE* data_buf = (BYTE*) malloc(data_len);
data_buf += element_to_bytes(data_buf, B);
data_buf += element_to_bytes(data_buf, D);
data_buf += element_to_bytes(data_buf, jpd2->V.T1);
data_buf += element_to_bytes(data_buf, jpd2->V.T2);
data_buf += element_to_bytes(data_buf, R1);
data_buf += element_to_bytes(data_buf, R2);
data_buf -= data_len;
BYTE* hash = (BYTE*) malloc(JOIN_HASH_BITS / 8);
xsgs_hash(data_buf, data_len * 8, hash, JOIN_HASH_BITS);
free(data_buf);
element_clear(B);
element_clear(D);
element_clear(R1);
element_clear(R2);
// compare hashes
ret = memcmp(jpd2->V.hash, hash, JOIN_HASH_BITS / 8);
free(hash);
if (!ret) {
element_init_G1(ucert->A, pairing);
element_set(ucert->A, jpd2->A);
// S = sign(A)
DWORD msg_len = element_length_in_bytes(ucert->A);
BYTE* msg = (BYTE*) malloc(msg_len);
element_to_bytes(msg, ucert->A);
ret = xsgs_rsa_sign(usk_pem_filename, msg, msg_len, &(jpd3->S.sig), &(jpd3->S.len));
free(msg);
}
// return ( S = (rsa signature length, rsa signature) )
return ret;
}
int main(void)
{
pairing_t pairing;
char param[50000];
size_t count = fread(param, 1, 50000, stdin);
if (!count) pbc_die("input error");
pairing_init_set_buf(pairing, param, count);
// int cont = 0;
struct timeval tvBegin, tvEnd;
element_t g, h;
element_t public_key, secret_key;
element_t sig;
element_t temp1, temp2;
element_init_G2(g, pairing);
element_init_G2(public_key, pairing);
element_init_G1(h, pairing);
element_init_G1(sig, pairing);
element_init_GT(temp1, pairing);
element_init_GT(temp2, pairing);
element_init_Zr(secret_key, pairing);
// Generating key
element_random(g);
element_random(secret_key);
element_pow_zn(public_key, g, secret_key);
// Generating message
element_from_hash(h, "ABCDEF", 6);
element_pow_zn(sig, h, secret_key);
// RANDOM TESTS
/*
// Fp
element_t p1, p2;
element_init(p1, element_x(h)->field);
element_init(p2, p1->field);
element_random(p1);
element_random(p2);
// multiplication
element_t puntos[2000];
for(cont = 0; cont < 1000; cont++){
element_init(puntos[cont], element_x(h)->field);
element_init(puntos[2*cont], element_x(h)->field);
element_random(puntos[cont]);
element_random(puntos[2*cont]);
}
gettimeofday(&tvBegin, NULL);
for(cont = 0; cont < 1000; cont++){
element_mul(puntos[cont], puntos[cont], puntos[2*cont]);
}
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
//square
gettimeofday(&tvBegin, NULL);
for(cont = 0; cont < 1000; cont++) element_square(puntos[cont], puntos[2*cont]);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
// add
gettimeofday(&tvBegin, NULL);
for(cont = 0; cont < 1000; cont++) element_add(puntos[cont], puntos[cont], puntos[2*cont]);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
// invers
gettimeofday(&tvBegin, NULL);
for(cont = 0; cont < 1000; cont++) element_invert(puntos[cont], puntos[2*cont]);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
// Fpk
element_t q1, q2;
element_init_GT(q1, pairing);
element_init_GT(q2, pairing);
element_random(q1);
element_random(q2);
// multiplication
for(cont = 0; cont < 1000; cont++){
element_init_GT(puntos[cont], pairing);
element_init_GT(puntos[2*cont], pairing);
element_random(puntos[cont]);
element_random(puntos[2*cont]);
}
gettimeofday(&tvBegin, NULL);
for(cont = 0; cont < 1000; cont++) {
element_mul(puntos[cont], puntos[cont], puntos[2*cont]);
}
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
//square
gettimeofday(&tvBegin, NULL);
for(cont = 0; cont < 1000; cont++) element_square(puntos[cont], puntos[cont]);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
// add
gettimeofday(&tvBegin, NULL);
for(cont = 0; cont < 1000; cont++){
element_add(element_x(puntos[cont]), element_x(puntos[cont]), element_x(puntos[2*cont]));
element_add(element_y(puntos[cont]), element_y(puntos[cont]), element_y(puntos[2*cont]));
}
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
// invers
gettimeofday(&tvBegin, NULL);
for(cont = 0; cont < 1000; cont++) element_invert(puntos[cont], puntos[2*cont]);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
// CURVE OPERATIONS
element_t punto, punto2;
element_init(punto, h->field); element_random(punto);
element_init(punto2, h->field); element_random(punto2);
// add
gettimeofday(&tvBegin, NULL);
element_mul(punto, punto, punto2);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
// double
gettimeofday(&tvBegin, NULL);
element_double(punto, punto2);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1);
// SIZE GROUP
int m = mpz_sizeinbase(pairing->r, 2) - 2;
printf("%i\n", m);
int contador = 0;
for(;;){
if(!m) break;
if(mpz_tstbit(pairing->r,m)) contador++;
m--;
}
printf("%i\n", contador);
*/
// One pairing
gettimeofday(&tvBegin, NULL);
eval_miller(temp1, sig, g, pairing);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1000);
//print_contador();
// One pairing (with precomputed values)
// Original method
pairing_pp_t pp;
// Precomp
gettimeofday(&tvBegin, NULL);
pairing_pp_init(pp, sig, pairing);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1000);
// Eval
gettimeofday(&tvBegin, NULL);
pairing_pp_apply(temp1, g, pp);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1000);
pairing_pp_clear(pp);
void do_precomp(){
lpoly *list;
// precomputation
gettimeofday(&tvBegin, NULL);
list = lpoly_init();
precompute(list, pairing->r, sig, g);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1000);
// DMAX
printf("%i\n", list->MAXD);
// eval
gettimeofday(&tvBegin, NULL);
compute_miller(temp2, list, g, pairing);
gettimeofday(&tvEnd, NULL);
timeval_subtract(&tvEnd, &tvBegin, 1000);
lpoly_free(list);
}
static void fq_from_hash(element_ptr n, void *data, int len) {
eptr r = n->data;
int k = len / 2;
element_from_hash(r->x, data, k);
element_from_hash(r->y, (char *)data + k, len - k);
}
static void gt_from_hash(element_ptr e, void *data, int len) {
pairing_ptr pairing = e->field->pairing;
element_from_hash(e->data, data, len);
pairing->finalpow(e);
}
bool Manager::JoinMember(string request, string & respond)
{
//elements
element_t Pi1;
element_t Pi2;
element_t Sk;
element_t R;
element_init_G1(Pi1,pairing);
element_init_GT(Pi2, pairing);
element_init_Zr(Sk, pairing);
element_init_G1(R,pairing);
//read & check SoK
string hash;
string hash_check;
RequestFromString(request,hash,Sk,Pi1);
//check Pi1 is point of curve
if(element_item_count(Pi1)!=2)
{
element_clear(Pi1);
element_clear(Pi2);
element_clear(Sk);
element_clear(R);
return 1;//failure
}
element_t tmp1, tmp2;
element_t c_Hsok;
element_init_G1(tmp1, pairing);
element_init_G1(tmp2, pairing);
element_init_Zr(c_Hsok, pairing);
element_from_hash(c_Hsok,(void*)hash.c_str(),hash.length());
element_pow_zn(tmp1,g,Sk);
element_pow_zn(tmp2,Pi1,c_Hsok);
element_div(R,tmp1,tmp2);
hash_check=Helper::Hash_g_R(g,R);
if(hash.compare(hash_check))
{
element_clear(Pi1);
element_clear(Pi2);
element_clear(Sk);
element_clear(R);
element_clear(tmp1);
element_clear(tmp2);
element_clear(c_Hsok);
return 1;//failure
}
//generate r_issuer
element_t issuer_r;
element_init_Zr(issuer_r, pairing);
element_random(issuer_r);
//create a b c
element_t ai;
element_t bi;
element_t ci;
element_t temp_ci1;
element_t temp_ci2;
//init
element_init_G1(ai, pairing);
element_init_G1(bi, pairing);
element_init_G1(ci, pairing);
element_init_G1(temp_ci1, pairing);
element_init_G1(temp_ci2, pairing);
//compute ai bi ci
element_pow_zn(ai,g,issuer_r);//ai
element_pow_zn(bi,ai,y);//bi
element_pow_zn(temp_ci1,ai,x);
element_pow_zn(temp_ci2,Pi1,issuer_r);
element_pow_zn(temp_ci2,temp_ci2,x);
element_pow_zn(temp_ci2,temp_ci2,y);
element_mul(ci,temp_ci1,temp_ci2);//ci
//create RESPOND
respond=MemberSecretToString(ai,bi,ci);
//compute Pi2
element_pairing(Pi2,Pi1,g);
//Write_to_reg_list
AddToRegistrationList(Pi1, Pi2);
//clear elements
element_clear(issuer_r);
element_clear(Pi1);
element_clear(Pi2);
element_clear(temp_ci1);
element_clear(temp_ci2);
element_clear(tmp1);
element_clear(tmp2);
element_clear(c_Hsok);
element_clear(Sk);
element_clear(R);
element_clear(ai);
element_clear(bi);
element_clear(ci);
return 0;//success
}
int main(int argc, char **argv) {
pairing_t pairing;
pbc_demo_pairing_init(pairing, argc, argv);
if (!pairing_is_symmetric(pairing)) pbc_die("pairing must be symmetric");
double time1, time2;
element_t P, Ppub, x, S, H, t1, t2, t3, t4;
element_init_Zr(x, pairing);
element_init_Zr(H, pairing);
element_init_Zr(t1, pairing);
element_init_G1(S, pairing);
element_init_G1(P, pairing);
element_init_G1(Ppub, pairing);
element_init_G1(t2, pairing);
element_init_GT(t3, pairing);
element_init_GT(t4, pairing);
printf("ZSS short signature schema\n");
printf("KEYGEN\n");
time1 = pbc_get_time();
element_random(x);
element_random(P);
element_mul_zn(Ppub, P, x);
element_printf("P = %B\n", P);
element_printf("x = %B\n", x);
element_printf("Ppub = %B\n", Ppub);
printf("SIGN\n");
element_from_hash(H, "Message", 7);
element_add(t1, H, x);
element_invert(t1, t1);
element_mul_zn(S, P, t1);
printf("Signature of message \"Message\" is:\n");
element_printf("S = %B\n", S);
printf("VERIFY\n");
element_from_hash(H, "Message", 7);
element_mul_zn(t2, P, H);
element_add(t2, t2, Ppub);
element_pairing(t3, t2, S);
element_pairing(t4, P, P);
element_printf("e(H(m)P + Ppub, S) = %B\n", t3);
element_printf("e(P, P) = %B\n", t4);
if (!element_cmp(t3, t4)) printf("Signature is valid\n");
else printf("Signature is invalid\n");
time2 = pbc_get_time();
printf("All time = %fs\n", time2 - time1);
element_clear(P);
element_clear(Ppub);
element_clear(x);
element_clear(S);
element_clear(H);
element_clear(t1);
element_clear(t2);
element_clear(t3);
element_clear(t4);
pairing_clear(pairing);
return 0;
}
/**
* In this scheme every signer can aggregate a signature on a different message.
*
* This __cannot__ verify multiple messages from the same AS.
*
* We have __one__ signer -> __one__ message but as the message could be the same
* for every signer, we can aggregate on it.
*
* @param store here we insert all the messages and all the signers
* (as we __must__ verify every message of every signer)
*
* @return 0 if verify = success.
*
*/
int
pbgp_ibe_verify(setup_params_t *setup, ibe_signature_t *sign, store_t *store)
{
assert(sign && setup && store);
element_t sumID, sumCi, sumTot, Pubi0,
Pubi1, Pm, t1, p1, p2, e1, e2, ci;
pairing_pp_t pp1, pp2, pp3;
element_init_G1(sumID, setup->pairing);
element_init_G1(sumCi, setup->pairing);
element_init_G1(sumTot, setup->pairing);
element_init_G1(Pubi0, setup->pairing);
element_init_G1(Pubi1, setup->pairing);
element_init_G1(Pm, setup->pairing);
element_init_G1(t1, setup->pairing);
element_init_GT(p1, setup->pairing);
element_init_GT(p2, setup->pairing);
element_init_GT(e1, setup->pairing);
element_init_GT(e2, setup->pairing);
element_init_Zr(ci, setup->pairing);
element_set0(sumID);
element_set0(sumCi);
//
// For each ASNUM in the list
//
store_iterator_t *iterator = pbgp_store_iterator_open(store);
store_key_t key = STORE_KEY_INIT;
while (1)
{
uint32_t id = 0;
size_t ksize = 0, dsize = 0;
// This mess is to avoid __any__ malloc call >:/
int ret = pbgp_store_iterator_uget_next_size(iterator, &ksize, &dsize);
if (ret != 0) {
break ;
}
// compute key data size
ksize -= STORE_KEY_METADATA_LENGTH;
if (sizeof(id) != ksize) {
continue ;
}
// key buffer
unsigned char kbuf[ksize];
memset (kbuf, 0, ksize);
key.data = kbuf;
key.dsize = sizeof(kbuf);
// data buffer
unsigned char message[dsize];
memset (message, 0, dsize);
// get asnum + message
ret = pbgp_store_iterator_uget_next(iterator, &key, message, &dsize);
if (ret != 0) {
break ;
}
char id0[BUFSIZ],
id1[BUFSIZ];
memcpy(&id, kbuf, sizeof id);
_ibe_get_id_pair(id, id0, sizeof (id0), id1, sizeof (id1));
//
// Computes public keys for this AS from its identity
//
unsigned char hash[EVP_MAX_MD_SIZE + 1];
// hash(id0)
memset(hash, 0, sizeof (hash));
_element_from_hash(Pubi0, hash, pbgp_rsa_uhash((unsigned char *) id0, strlen(id0), hash));
// hash(id1)
memset(hash, 0, sizeof (hash));
_element_from_hash(Pubi1, hash, pbgp_rsa_uhash((unsigned char *) id1, strlen(id1), hash));
// ci = hash(m)
memset(hash, 0, sizeof (hash));
element_from_hash(ci, hash, pbgp_rsa_uhash(message, dsize, hash));
// Computes sum(Pi_0) sum(ci * Pi_1)
element_mul_zn(t1, Pubi1, ci);
element_add(sumID, sumID, Pubi0);
element_add(sumCi, sumCi, t1);
}
pbgp_store_iterator_close(iterator);
element_add(sumTot, sumID, sumCi);
pairing_pp_init(pp1, sumTot, setup->pairing);
pairing_pp_init(pp2, sign->v, setup->pairing);
pairing_pp_init(pp3, sign->u, setup->pairing);
// e(Q = ibePub, sumTot)
pairing_pp_apply(p1, setup->ibePub, pp1);
// e(Tn = v, Pw)
pairing_pp_apply(p2, sign->w, pp2);
// e(Q = ibePub, sumTot) * e(Tn = v, Pw)
element_mul(e2, p1, p2);
// e(Sn = u, P)
pairing_pp_apply(e1, setup->g, pp3);
int rv = element_cmp(e1, e2);
pairing_pp_clear(pp1);
pairing_pp_clear(pp2);
pairing_pp_clear(pp3);
element_clear(sumID);
element_clear(sumCi);
element_clear(sumTot);
element_clear(t1);
element_clear(ci);
element_clear(Pubi0);
element_clear(Pubi1);
element_clear(Pm);
element_clear(p1);
element_clear(p2);
element_clear(e1);
element_clear(e2);
return rv;
}
/**
* In this scheme every signer can aggregate a signature on a different message.
*
* @param sign the computated signature (param modified)
* @param m the message to sign
* @param mlen message length
*
* The __caller__ SHOULD add id:message to some storage as we need the aggregate signature
* signers id=asnum to vrfy @see pbgp_ibe_vrfy()
*
* ie. pbgp_store_uput(store, STORE_KEY_SET_DATA(key, ASLIST, signer_id), (void *) m, mlen)
*
*/
void
pbgp_ibe_sign(setup_params_t *setup,
ibe_keypair_t *key,
const unsigned char *m,
size_t mlen,
ibe_signature_t *sign)
{
element_t ri, t1, t2, t3, t4, ci;
//
// Check if this is the first signature
// "w must be an unique unseen value"
//
if (element_is0(sign->w)) {
#if HAVE_LIBUUID || HAVE_LIBE2FS_UUID
uuid_t uuid;
uuid_generate(uuid);
element_from_hash(sign->w, uuid, sizeof uuid);
#else
element_random(sign->w);
#endif
if (element_is0(sign->w)) {
pbgp_fatal("pbgp_ibe_sign :: random");
}
}
element_init_G1(t1, setup->pairing);
element_init_G1(t2, setup->pairing);
element_init_G1(t3, setup->pairing);
element_init_G1(t4, setup->pairing);
element_init_Zr(ri, setup->pairing);
element_init_Zr(ci, setup->pairing);
// ci = binary_hash(message)
unsigned char hash[EVP_MAX_MD_SIZE + 1];
memset(hash, 0, sizeof (hash));
unsigned int len = pbgp_rsa_uhash(m, mlen, hash);
element_from_hash(ci, hash, len);
// ri = random element
element_random(ri);
// ri * Pw
element_mul_zn(t1, sign->w, ri);
// Pi,0 = key->priv0
// Pi,1 = key->priv1
// ci * Pi,1
element_mul_zn(t2, key->priv1, ci);
// ri * Pi,0
// element_mul(t5, ri, key->pub0);
// ri * Pw + ci * sP(i,1) + sP(i,0)
element_add(t3, t1, t2);
// Si = ri * Pw + ci * Pi,1 + Pi,0
element_add(t3, t3, key->priv0);
// Ti = ri * P
element_mul_zn(t4, setup->g, ri);
// Sum(sign) for each signature
// w is the same for all signers
// u = sum(Si)
element_add(sign->u, sign->u, t3);
// v = sum(Ti)
element_add(sign->v, sign->v, t4);
element_clear(t1);
element_clear(t2);
element_clear(t3);
element_clear(t4);
element_clear(ri);
element_clear(ci);
}
void bbs_sign(unsigned char *sig, int hashlen, void *hash, bbs_group_public_key_ptr gpk, bbs_group_private_key_ptr gsk)
{
bbs_sys_param_ptr param = gpk->param;
pairing_ptr pairing = param->pairing;
field_ptr Fp = pairing->Zr;
element_t T1, T2, T3;
element_t R1, R2, R3, R4, R5;
element_t alpha, beta;
element_t c;
element_t ralpha, rbeta, rx, rdelta1, rdelta2;
element_t z0, z1;
element_t e10, et0;
unsigned char *writeptr = sig;
element_init_G1(T1, pairing);
element_init_G1(T2, pairing);
element_init_G1(T3, pairing);
element_init_G1(R1, pairing);
element_init_G1(R2, pairing);
element_init_GT(R3, pairing);
element_init_G1(R4, pairing);
element_init_G1(R5, pairing);
element_init(c, Fp);
element_init(alpha, Fp); element_random(alpha);
element_init(beta, Fp); element_random(beta);
//temp variables
element_init(z0, Fp);
element_init(z1, Fp);
element_init_GT(et0, pairing);
element_init_G1(e10, pairing);
element_init(ralpha, Fp); element_random(ralpha);
element_init(rbeta, Fp); element_random(rbeta);
element_init(rx, Fp); element_random(rx);
element_init(rdelta1, Fp); element_random(rdelta1);
element_init(rdelta2, Fp); element_random(rdelta2);
element_pow_zn(T1, gpk->u, alpha);
element_pow_zn(T2, gpk->v, beta);
element_add(z0, alpha, beta);
element_pow_zn(T3, gpk->h, z0);
element_mul(T3, T3, gsk->A);
element_pow_zn(R1, gpk->u, ralpha);
element_pow_zn(R2, gpk->v, rbeta);
/*
* rather than computing e(T3,g2), note that T3 = A h^{alpha+beta},
* use precomputed e(A,g2) and e(h,g2), and use appropriate
* exponentiations in GT.
*/
//pairing_apply(et0, T3, gpk->g2, pairing); /* precomputed */
element_pow_zn(et0, gpk->pr_h_g2, z0); /* NB. here z0 = alpha+beta */
element_mul(et0, et0, gsk->pr_A_g2);
//element_pow_zn(R3, et0, rx);
// pairing_apply(et0, gpk->h, gpk->w, pairing); /* precomputed */
element_add(z0, ralpha, rbeta);
element_neg(z0, z0);
//element_pow_zn(et0, gpk->pr_h_w, z0);
//element_mul(R3, R3, et0);
// pairing_apply(et0, gpk->h, gpk->g2, pairing); /* precomputed */
element_add(z1, rdelta1, rdelta2);
element_neg(z1, z1);
//element_pow_zn(et0, gpk->pr_h_g2, z1);
//element_mul(R3, R3, et0);
element_pow3_zn(R3, et0, rx, gpk->pr_h_w, z0, gpk->pr_h_g2, z1);
//element_pow_zn(R4, T1, rx);
element_neg(z0, rdelta1);
//element_pow_zn(e10, gpk->u, z0);
//element_mul(R4, R4, e10);
element_pow2_zn(R4, T1, rx, gpk->u, z0);
//element_pow_zn(R5, T2, rx);
element_neg(z0, rdelta2);
//element_pow_zn(e10, gpk->v, z0);
//element_mul(R5, R5, e10);
element_pow2_zn(R5, T2, rx, gpk->v, z0);
element_t M;
element_init_G1(M, pairing);
element_from_hash(M, hash, hashlen);
unsigned int hash_input_length = element_length_in_bytes(T1) +
element_length_in_bytes(T2) +
element_length_in_bytes(T3) +
element_length_in_bytes(R1) +
element_length_in_bytes(R2) +
element_length_in_bytes(R3) +
element_length_in_bytes(R4) +
element_length_in_bytes(R5) +
element_length_in_bytes(M);
unsigned char *hash_input = malloc(hash_input_length);
hash_input += element_to_bytes(hash_input, T1);
hash_input += element_to_bytes(hash_input, T2);
hash_input += element_to_bytes(hash_input, T3);
hash_input += element_to_bytes(hash_input, R1);
hash_input += element_to_bytes(hash_input, R2);
hash_input += element_to_bytes(hash_input, R3);
hash_input += element_to_bytes(hash_input, R4);
hash_input += element_to_bytes(hash_input, R5);
hash_input += element_to_bytes(hash_input, M); // Could avoid converting to bytes and from bytes
hash_input -= hash_input_length;
hash_ctx_t context;
unsigned char digest[hash_length];
hash_init(context);
hash_update(context, hash_input, hash_input_length);
hash_final(digest, context);
free(hash_input);
element_from_hash(c, digest, sizeof(digest));
element_clear(M);
//now the r's represent the values of the s's
//no need to allocate yet more variables
element_mul(z0, c, alpha);
element_add(ralpha, ralpha, z0);
element_mul(z0, c, beta);
element_add(rbeta, rbeta, z0);
element_mul(z1, c, gsk->x);
element_add(rx, rx, z1);
element_mul(z0, z1, alpha);
element_add(rdelta1, rdelta1, z0);
element_mul(z0, z1, beta);
element_add(rdelta2, rdelta2, z0);
writeptr += element_to_bytes(writeptr, T1);
writeptr += element_to_bytes(writeptr, T2);
writeptr += element_to_bytes(writeptr, T3);
writeptr += element_to_bytes(writeptr, c);
writeptr += element_to_bytes(writeptr, ralpha);
writeptr += element_to_bytes(writeptr, rbeta);
writeptr += element_to_bytes(writeptr, rx);
writeptr += element_to_bytes(writeptr, rdelta1);
writeptr += element_to_bytes(writeptr, rdelta2);
#ifdef DEBUG
element_printf("T1: %B\n", T1);
element_printf("T2: %B\n", T2);
element_printf("T3: %B\n", T3);
element_printf("R1: %B\n", R1);
element_printf("R2: %B\n", R2);
element_printf("R3: %B\n", R3);
element_printf("R4: %B\n", R4);
element_printf("R5: %B\n", R5);
element_printf("c: %B\n", c);
#endif
element_clear(T1);
element_clear(T2);
element_clear(T3);
element_clear(R1);
element_clear(R2);
element_clear(R3);
element_clear(R4);
element_clear(R5);
element_clear(alpha);
element_clear(beta);
element_clear(c);
element_clear(ralpha);
element_clear(rbeta);
element_clear(rx);
element_clear(rdelta1);
element_clear(rdelta2);
//clear temp variables
element_clear(z0);
element_clear(z1);
element_clear(e10);
element_clear(et0);
}
int bbs_verify(unsigned char *sig, int hashlen, void *hash, bbs_group_public_key_t gpk)
{
bbs_sys_param_ptr param = gpk->param;
pairing_ptr pairing = param->pairing;
field_ptr Fp = pairing->Zr;
element_t T1, T2, T3;
element_t R1, R2, R3, R4, R5;
element_t c, salpha, sbeta, sx, sdelta1, sdelta2;
element_t e10, e20, e21, et0, z0, z1;
unsigned char *readptr = sig;
element_init_G1(T1, pairing);
element_init_G1(T2, pairing);
element_init_G1(T3, pairing);
element_init_G1(R1, pairing);
element_init_G1(R2, pairing);
element_init_GT(R3, pairing);
element_init_G1(R4, pairing);
element_init_G1(R5, pairing);
element_init(c, Fp);
element_init(salpha, Fp);
element_init(sbeta, Fp);
element_init(sx, Fp);
element_init(sdelta1, Fp);
element_init(sdelta2, Fp);
element_init_G1(e10, pairing);
element_init_G2(e20, pairing);
element_init_G2(e21, pairing);
element_init_GT(et0, pairing);
element_init(z0, Fp);
element_init(z1, Fp);
readptr += element_from_bytes(T1, readptr);
readptr += element_from_bytes(T2, readptr);
readptr += element_from_bytes(T3, readptr);
readptr += element_from_bytes(c, readptr);
readptr += element_from_bytes(salpha, readptr);
readptr += element_from_bytes(sbeta, readptr);
readptr += element_from_bytes(sx, readptr);
readptr += element_from_bytes(sdelta1, readptr);
readptr += element_from_bytes(sdelta2, readptr);
element_neg(z0, c);
//element_pow_zn(R1, gpk->u, salpha);
//element_pow_zn(e10, T1, z0);
//element_mul(R1, R1, e10);
element_pow2_zn(R1, gpk->u, salpha, T1, z0);
//element_pow_zn(R2, gpk->v, sbeta);
//element_pow_zn(e10, T2, z0);
//element_mul(R2, R2, e10);
element_pow2_zn(R2, gpk->v, sbeta, T2, z0);
element_neg(z0, sdelta1);
//element_pow_zn(R4, gpk->u, z0);
//element_pow_zn(e10, T1, sx);
//element_mul(R4, R4, e10);
element_pow2_zn(R4, gpk->u, z0, T1, sx);
element_neg(z0, sdelta2);
//element_pow_zn(R5, gpk->v, z0);
//element_pow_zn(e10, T2, sx);
//element_mul(R5, R5, e10);
element_pow2_zn(R5, gpk->v, z0, T2, sx);
/*
* compute R3 more efficiently. use precomputed e(g1,g2)^{-1},
* e(h,g2), and e(h,w). this leaves e(T3,g2)^sx and e(T3,w)^c;
* compute these with one pairing as e(T3, g2^sx w^c).
*/
//element_pow_zn(e20, gpk->g2, sx);
//element_pow_zn(e21, gpk->w, c);
//element_mul(e20, e20, e21);
element_pow2_zn(e20, gpk->g2, sx, gpk->w, c);
pairing_apply(R3, T3, e20, pairing);
//element_pow_zn(et0, gpk->pr_g1_g2_inv, c);
//element_mul(R3, R3, et0);
element_add(z0, salpha, sbeta);
element_neg(z0, z0);
//element_pow_zn(et0, gpk->pr_h_w, z0);
//element_mul(R3, R3, et0);
element_add(z1, sdelta1, sdelta2);
element_neg(z1, z1);
//element_pow_zn(et0, gpk->pr_h_g2, z1);
element_pow3_zn(et0, gpk->pr_g1_g2_inv, c, gpk->pr_h_w, z0, gpk->pr_h_g2, z1);
element_mul(R3, R3, et0);
#ifdef DEBUG
element_printf("T1: %B\n", T1);
element_printf("T2: %B\n", T2);
element_printf("T3: %B\n", T3);
element_printf("R1: %B\n", R1);
element_printf("R2: %B\n", R2);
element_printf("R3: %B\n", R3);
element_printf("R4: %B\n", R4);
element_printf("R5: %B\n", R5);
#endif
int result = 0;
element_t M;
element_init_G1(M, pairing);
element_from_hash(M, hash, hashlen);
unsigned int hash_input_length = element_length_in_bytes(T1) +
element_length_in_bytes(T2) +
element_length_in_bytes(T3) +
element_length_in_bytes(R1) +
element_length_in_bytes(R2) +
element_length_in_bytes(R3) +
element_length_in_bytes(R4) +
element_length_in_bytes(R5) +
element_length_in_bytes(M);
unsigned char *hash_input = malloc(hash_input_length);
hash_input += element_to_bytes(hash_input, T1);
hash_input += element_to_bytes(hash_input, T2);
hash_input += element_to_bytes(hash_input, T3);
hash_input += element_to_bytes(hash_input, R1);
hash_input += element_to_bytes(hash_input, R2);
hash_input += element_to_bytes(hash_input, R3);
hash_input += element_to_bytes(hash_input, R4);
hash_input += element_to_bytes(hash_input, R5);
hash_input += element_to_bytes(hash_input, M); // Could avoid converting to bytes and from bytes
hash_input -= hash_input_length;
hash_ctx_t context;
unsigned char digest[hash_length];
hash_init(context);
hash_update(context, hash_input, hash_input_length);
hash_final(digest, context);
free(hash_input);
element_t c1;
element_init(c1, Fp);
element_from_hash(c1, digest, sizeof(digest));
if (!element_cmp(c, c1)) {
result = 1;
}
element_clear(M);
element_clear(c1);
element_clear(T1);
element_clear(T2);
element_clear(T3);
element_clear(R1);
element_clear(R2);
element_clear(R3);
element_clear(R4);
element_clear(R5);
element_clear(c);
element_clear(salpha);
element_clear(sbeta);
element_clear(sx);
element_clear(sdelta1);
element_clear(sdelta2);
element_clear(e10);
element_clear(e20);
element_clear(e21);
element_clear(et0);
element_clear(z0);
element_clear(z1);
return result;
}