diff options
Diffstat (limited to 'moon-abe/libbswabe-0.9/core.c')
| -rw-r--r-- | moon-abe/libbswabe-0.9/core.c | 912 |
1 files changed, 912 insertions, 0 deletions
diff --git a/moon-abe/libbswabe-0.9/core.c b/moon-abe/libbswabe-0.9/core.c new file mode 100644 index 00000000..825882a7 --- /dev/null +++ b/moon-abe/libbswabe-0.9/core.c @@ -0,0 +1,912 @@ +#include <stdlib.h> +#include <string.h> +#ifndef BSWABE_DEBUG +#define NDEBUG +#endif +#include <assert.h> + +#include <openssl/sha.h> +#include <glib.h> +#include <pbc.h> + +#include "bswabe.h" +#include "private.h" + +#define TYPE_A_PARAMS \ +"type a\n" \ +"q 87807107996633125224377819847540498158068831994142082" \ +"1102865339926647563088022295707862517942266222142315585" \ +"8769582317459277713367317481324925129998224791\n" \ +"h 12016012264891146079388821366740534204802954401251311" \ +"822919615131047207289359704531102844802183906537786776\n" \ +"r 730750818665451621361119245571504901405976559617\n" \ +"exp2 159\n" \ +"exp1 107\n" \ +"sign1 1\n" \ +"sign0 1\n" + +char last_error[256]; + +char* +bswabe_error() +{ + return last_error; +} + +void +raise_error(char* fmt, ...) +{ + va_list args; + +#ifdef BSWABE_DEBUG + va_start(args, fmt); + vfprintf(stderr, fmt, args); + va_end(args); + exit(1); +#else + va_start(args, fmt); + vsnprintf(last_error, 256, fmt, args); + va_end(args); +#endif +} + +void +element_from_string( element_t h, char* s ) +{ + unsigned char* r; + + r = malloc(SHA_DIGEST_LENGTH); + SHA1((unsigned char*) s, strlen(s), r); + element_from_hash(h, r, SHA_DIGEST_LENGTH); + + free(r); +} + +void +bswabe_setup( bswabe_pub_t** pub, bswabe_msk_t** msk ) +{ + element_t alpha; + + /* initialize */ + + *pub = malloc(sizeof(bswabe_pub_t)); + *msk = malloc(sizeof(bswabe_msk_t)); + + (*pub)->pairing_desc = strdup(TYPE_A_PARAMS); + pairing_init_set_buf((*pub)->p, (*pub)->pairing_desc, strlen((*pub)->pairing_desc)); + + element_init_G1((*pub)->g, (*pub)->p); + element_init_G1((*pub)->h, (*pub)->p); + element_init_G2((*pub)->gp, (*pub)->p); + element_init_GT((*pub)->g_hat_alpha, (*pub)->p); + element_init_Zr(alpha, (*pub)->p); + element_init_Zr((*msk)->beta, (*pub)->p); + element_init_G2((*msk)->g_alpha, (*pub)->p); + + /* compute */ + + element_random(alpha); + element_random((*msk)->beta); + element_random((*pub)->g); + element_random((*pub)->gp); + + element_pow_zn((*msk)->g_alpha, (*pub)->gp, alpha); /* g_alpha = gp^a */ + element_pow_zn((*pub)->h, (*pub)->g, (*msk)->beta); /* h = g^b */ + pairing_apply((*pub)->g_hat_alpha, (*pub)->g, (*msk)->g_alpha, (*pub)->p); /* g_hat_aplha = e(g,g_aplha) = e(g,gp)^a */ +} + +bswabe_prv_t* bswabe_keygen( bswabe_pub_t* pub, + bswabe_msk_t* msk, + char** attributes ) +{ + bswabe_prv_t* prv; + element_t g_r; + element_t r; + element_t beta_inv; + + /* initialize */ + + prv = malloc(sizeof(bswabe_prv_t)); + + element_init_G2(prv->d, pub->p); + element_init_G2(g_r, pub->p); + element_init_Zr(r, pub->p); + element_init_Zr(beta_inv, pub->p); + + prv->comps = g_array_new(0, 1, sizeof(bswabe_prv_comp_t)); + + /* compute */ + + element_random(r); + element_pow_zn(g_r, pub->gp, r); /* g_r = gp^r */ + + element_mul(prv->d, msk->g_alpha, g_r); /* gp^r*gp^a = gp^(r+a) */ + element_invert(beta_inv, msk->beta); /* (1/b) */ + element_pow_zn(prv->d, prv->d, beta_inv); /* d = gp^((r+a) * 1/b) */ + + while( *attributes ) + { + bswabe_prv_comp_t c; + element_t h_rp; + element_t rp; + + c.attr = *(attributes++); + + element_init_G2(c.d, pub->p); + element_init_G1(c.dp, pub->p); + element_init_G2(h_rp, pub->p); + element_init_Zr(rp, pub->p); + + element_from_string(h_rp, c.attr); /* h_rp = H(attr) */ + element_random(rp); + + element_pow_zn(h_rp, h_rp, rp); /* h_rp = H(attr)^rp */ + + element_mul(c.d, g_r, h_rp); /* d = h_rp * gp^r = H(attr)^rp * gp^r */ + element_pow_zn(c.dp, pub->g, rp); /* dp = g^rp */ + element_clear(h_rp); + element_clear(rp); + + g_array_append_val(prv->comps, c); + } + + return prv; +} + +/* Generates a node of the policy tree with threshold k */ +bswabe_policy_t* +base_node( int k, char* s ) +{ + bswabe_policy_t* p; + + p = (bswabe_policy_t*) malloc(sizeof(bswabe_policy_t)); + p->k = k; + p->attr = s ? strdup(s) : 0; /* s if not empty, null otherwise */ + p->children = g_ptr_array_new(); + p->q = 0; + + return p; +} + +/* + TODO convert this to use a GScanner and handle quotes and / or + escapes to allow attributes with whitespace or = signs in them +*/ + +bswabe_policy_t* +parse_policy_postfix( char* s ) +{ + char** toks; + char** cur_toks; + char* tok; + GPtrArray* stack; /* pointers to bswabe_policy_t's */ + bswabe_policy_t* root; + + toks = g_strsplit(s, " ", 0); + cur_toks = toks; + stack = g_ptr_array_new(); + + while( *cur_toks ) + { + int i, k, n; + + tok = *(cur_toks++); + + if( !*tok ) + continue; + + if( sscanf(tok, "%dof%d", &k, &n) != 2 ) + /* push leaf token */ + g_ptr_array_add(stack, base_node(1, tok)); + else + { + bswabe_policy_t* node; + + /* parse "kofn" operator */ + + if( k < 1 ) + { + raise_error("error parsing \"%s\": trivially satisfied operator \"%s\"\n", s, tok); + return 0; + } + else if( k > n ) + { + raise_error("error parsing \"%s\": unsatisfiable operator \"%s\"\n", s, tok); + return 0; + } + else if( n == 1 ) + { + raise_error("error parsing \"%s\": identity operator \"%s\"\n", s, tok); + return 0; + } + else if( n > stack->len ) + { + raise_error("error parsing \"%s\": stack underflow at \"%s\"\n", s, tok); + return 0; + } + + /* pop n things and fill in children */ + node = base_node(k, 0); + g_ptr_array_set_size(node->children, n); + for( i = n - 1; i >= 0; i-- ) + node->children->pdata[i] = g_ptr_array_remove_index(stack, stack->len - 1); + + /* push result */ + g_ptr_array_add(stack, node); + } + } + + if( stack->len > 1 ) + { + raise_error("error parsing \"%s\": extra tokens left on stack\n", s); + return 0; + } + else if( stack->len < 1 ) + { + raise_error("error parsing \"%s\": empty policy\n", s); + return 0; + } + + root = g_ptr_array_index(stack, 0); + + g_strfreev(toks); + g_ptr_array_free(stack, 0); + + return root; +} + +/* Generates a degree *deg* polynomial with 0 coef equal to zero_val */ +bswabe_polynomial_t* +rand_poly( int deg, element_t zero_val ) +{ + int i; + bswabe_polynomial_t* q; + + q = (bswabe_polynomial_t*) malloc(sizeof(bswabe_polynomial_t)); + q->deg = deg; + q->coef = (element_t*) malloc(sizeof(element_t) * (deg + 1)); + + for( i = 0; i < q->deg + 1; i++ ) + element_init_same_as(q->coef[i], zero_val); + + element_set(q->coef[0], zero_val); + + for( i = 1; i < q->deg + 1; i++ ) + element_random(q->coef[i]); + + return q; +} + +void +eval_poly( element_t r, bswabe_polynomial_t* q, element_t x ) +{ + int i; + element_t s, t; + + element_init_same_as(s, r); + element_init_same_as(t, r); + + element_set0(r); + element_set1(t); + + for( i = 0; i < q->deg + 1; i++ ) + { + /* r += q->coef[i] * t */ + element_mul(s, q->coef[i], t); + element_add(r, r, s); + + /* t *= x */ + element_mul(t, t, x); + } + + element_clear(s); + element_clear(t); +} + +/* Recursive algorithm to fill the policy. Works on each node starting from the root: + - Fills the polynomial q of each node + - c & cp for leaves (i.e. children->len == 0) + - Recursively fills the children +*/ + +void +fill_policy( bswabe_policy_t* p, bswabe_pub_t* pub, element_t e ) +{ + int i; + element_t r; + element_t t; + element_t h; + + element_init_Zr(r, pub->p); + element_init_Zr(t, pub->p); + element_init_G2(h, pub->p); + + p->q = rand_poly(p->k - 1, e); + + if( p->children->len == 0 ) + { + element_init_G1(p->c, pub->p); + element_init_G2(p->cp, pub->p); + + element_from_string(h, p->attr); + element_pow_zn(p->c, pub->g, p->q->coef[0]); /* c = g^q(0) */ + element_pow_zn(p->cp, h, p->q->coef[0]); /* cp = H(attr)^q(0) */ + } + else + for( i = 0; i < p->children->len; i++ ) + { + element_set_si(r, i + 1); + eval_poly(t, p->q, r); + fill_policy(g_ptr_array_index(p->children, i), pub, t); + } + + element_clear(r); + element_clear(t); + element_clear(h); +} + +bswabe_cph_t* +bswabe_enc( bswabe_pub_t* pub, element_t m, char* policy ) +{ + bswabe_cph_t* cph; + element_t s; + + /* initialize */ + + cph = malloc(sizeof(bswabe_cph_t)); + + element_init_Zr(s, pub->p); + element_init_GT(m, pub->p); + element_init_GT(cph->cs, pub->p); + element_init_G1(cph->c, pub->p); + cph->policy = policy; + cph->p = parse_policy_postfix(policy); /* Assign the policy */ + /* compute */ + + element_random(m); + element_random(s); + element_pow_zn(cph->cs, pub->g_hat_alpha, s); /* g_hat_aplha = e(g,g_aplha) = e(g,gp)^a */ + /* cs = e(g,gp)^(as) */ + element_mul(cph->cs, cph->cs, m); /* cs = me(g,gp)^(as) */ + + element_pow_zn(cph->c, pub->h, s); /* c = h^s */ + + fill_policy(cph->p, pub, s); /* The zero_val of the root polynomial is s (qr(0) = s) */ + return cph; +} + +/* Recursively verify if the ciphertext policy is satisfied by the private key */ + +void +check_sat( bswabe_policy_t* p, bswabe_prv_t* prv ) +{ + int i, l; + + p->satisfiable = 0; + if( p->children->len == 0 ) /* If leave */ + { + for( i = 0; i < prv->comps->len; i++ ) + if( !strcmp(g_array_index(prv->comps, bswabe_prv_comp_t, i).attr, + p->attr) ) + { + p->satisfiable = 1; + p->attri = i; + break; + } + } + else + { + for( i = 0; i < p->children->len; i++ ) /* Recursively applies to the children */ + check_sat(g_ptr_array_index(p->children, i), prv); + + l = 0; + for( i = 0; i < p->children->len; i++ ) /* Checks how many children nodes are satisfied */ + if( ((bswabe_policy_t*) g_ptr_array_index(p->children, i))->satisfiable ) + l++; + + if( l >= p->k ) /* k is the threshold value */ + p->satisfiable = 1; + } +} + +/* Picks a set of k children that satisfy the policy */ +void +pick_sat_naive( bswabe_policy_t* p, bswabe_prv_t* prv ) +{ + int i, k, l; + + assert(p->satisfiable == 1); + + if( p->children->len == 0 ) + return; + + p->satl = g_array_new(0, 0, sizeof(int)); + + l = 0; + for( i = 0; i < p->children->len && l < p->k; i++ ) + if( ((bswabe_policy_t*) g_ptr_array_index(p->children, i))->satisfiable ) + { + pick_sat_naive(g_ptr_array_index(p->children, i), prv); + l++; + k = i + 1; + g_array_append_val(p->satl, k); + } +} + +/* TODO there should be a better way of doing this */ +bswabe_policy_t* cur_comp_pol; +int +cmp_int( const void* a, const void* b ) +{ + int k, l; + + k = ((bswabe_policy_t*) g_ptr_array_index(cur_comp_pol->children, *((int*)a)))->min_leaves; + l = ((bswabe_policy_t*) g_ptr_array_index(cur_comp_pol->children, *((int*)b)))->min_leaves; + + return + k < l ? -1 : + k == l ? 0 : 1; +} + +void +pick_sat_min_leaves( bswabe_policy_t* p, bswabe_prv_t* prv ) +{ + int i, k, l; + int* c; + + assert(p->satisfiable == 1); + + if( p->children->len == 0 ) + p->min_leaves = 1; + else + { + for( i = 0; i < p->children->len; i++ ) + if( ((bswabe_policy_t*) g_ptr_array_index(p->children, i))->satisfiable ) + pick_sat_min_leaves(g_ptr_array_index(p->children, i), prv); + + c = alloca(sizeof(int) * p->children->len); + for( i = 0; i < p->children->len; i++ ) + c[i] = i; + + cur_comp_pol = p; + qsort(c, p->children->len, sizeof(int), cmp_int); + + p->satl = g_array_new(0, 0, sizeof(int)); + p->min_leaves = 0; + l = 0; + + for( i = 0; i < p->children->len && l < p->k; i++ ) + if( ((bswabe_policy_t*) g_ptr_array_index(p->children, c[i]))->satisfiable ) + { + l++; + p->min_leaves += ((bswabe_policy_t*) g_ptr_array_index(p->children, c[i]))->min_leaves; + k = c[i] + 1; + g_array_append_val(p->satl, k); + } + assert(l == p->k); + } +} + +void +lagrange_coef( element_t r, GArray* s, int i ) +{ + int j, k; + element_t t; + + element_init_same_as(t, r); + + element_set1(r); + for( k = 0; k < s->len; k++ ) + { + j = g_array_index(s, int, k); + if( j == i ) + continue; + element_set_si(t, - j); + element_mul(r, r, t); /* num_muls++; */ + element_set_si(t, i - j); + element_invert(t, t); + element_mul(r, r, t); /* num_muls++; */ + } + + element_clear(t); +} + +void +dec_leaf_naive( element_t r, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + bswabe_prv_comp_t* c; + element_t s; + + c = &(g_array_index(prv->comps, bswabe_prv_comp_t, p->attri)); + + element_init_GT(s, pub->p); + + pairing_apply(r, p->c, c->d, pub->p); /* num_pairings++; */ + pairing_apply(s, p->cp, c->dp, pub->p); /* num_pairings++; */ + element_invert(s, s); + element_mul(r, r, s); /* num_muls++; */ + + element_clear(s); +} + +void dec_node_naive( element_t r, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ); + +void +dec_internal_naive( element_t r, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + int i; + element_t s; + element_t t; + + element_init_GT(s, pub->p); + element_init_Zr(t, pub->p); + + element_set1(r); + for( i = 0; i < p->satl->len; i++ ) + { + dec_node_naive + (s, g_ptr_array_index + (p->children, g_array_index(p->satl, int, i) - 1), prv, pub); + lagrange_coef(t, p->satl, g_array_index(p->satl, int, i)); + element_pow_zn(s, s, t); /* num_exps++; */ + element_mul(r, r, s); /* num_muls++; */ + } + + element_clear(s); + element_clear(t); +} + +void +dec_node_naive( element_t r, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + assert(p->satisfiable); + if( p->children->len == 0 ) + dec_leaf_naive(r, p, prv, pub); + else + dec_internal_naive(r, p, prv, pub); +} + +void +dec_naive( element_t r, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + dec_node_naive(r, p, prv, pub); +} + +void +dec_leaf_merge( element_t exp, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + bswabe_prv_comp_t* c; + element_t s; + + c = &(g_array_index(prv->comps, bswabe_prv_comp_t, p->attri)); + + if( !c->used ) + { + c->used = 1; + element_init_G1(c->z, pub->p); + element_init_G1(c->zp, pub->p); + element_set1(c->z); + element_set1(c->zp); + } + + element_init_G1(s, pub->p); + + element_pow_zn(s, p->c, exp); /* num_exps++; */ + element_mul(c->z, c->z, s); /* num_muls++; */ + + element_pow_zn(s, p->cp, exp); /* num_exps++; */ + element_mul(c->zp, c->zp, s); /* num_muls++; */ + + element_clear(s); +} + +void dec_node_merge( element_t exp, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ); + +void +dec_internal_merge( element_t exp, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + int i; + element_t t; + element_t expnew; + + element_init_Zr(t, pub->p); + element_init_Zr(expnew, pub->p); + + for( i = 0; i < p->satl->len; i++ ) + { + lagrange_coef(t, p->satl, g_array_index(p->satl, int, i)); + element_mul(expnew, exp, t); /* num_muls++; */ + dec_node_merge(expnew, g_ptr_array_index + (p->children, g_array_index(p->satl, int, i) - 1), prv, pub); + } + + element_clear(t); + element_clear(expnew); +} + +void +dec_node_merge( element_t exp, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + assert(p->satisfiable); + if( p->children->len == 0 ) + dec_leaf_merge(exp, p, prv, pub); + else + dec_internal_merge(exp, p, prv, pub); +} + +void +dec_merge( element_t r, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + int i; + element_t one; + element_t s; + + /* first mark all attributes as unused */ + for( i = 0; i < prv->comps->len; i++ ) + g_array_index(prv->comps, bswabe_prv_comp_t, i).used = 0; + + /* now fill in the z's and zp's */ + element_init_Zr(one, pub->p); + element_set1(one); + dec_node_merge(one, p, prv, pub); + element_clear(one); + + /* now do all the pairings and multiply everything together */ + element_set1(r); + element_init_GT(s, pub->p); + for( i = 0; i < prv->comps->len; i++ ) + if( g_array_index(prv->comps, bswabe_prv_comp_t, i).used ) + { + bswabe_prv_comp_t* c = &(g_array_index(prv->comps, bswabe_prv_comp_t, i)); + + pairing_apply(s, c->z, c->d, pub->p); /* num_pairings++; */ + element_mul(r, r, s); /* num_muls++; */ + + pairing_apply(s, c->zp, c->dp, pub->p); /* num_pairings++; */ + element_invert(s, s); + element_mul(r, r, s); /* num_muls++; */ + } + element_clear(s); +} + +void +dec_leaf_flatten( element_t r, element_t exp, + bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + bswabe_prv_comp_t* c; + element_t s; + element_t t; + + c = &(g_array_index(prv->comps, bswabe_prv_comp_t, p->attri)); + + element_init_GT(s, pub->p); + element_init_GT(t, pub->p); + + pairing_apply(s, p->c, c->d, pub->p); /* num_pairings++; */ + pairing_apply(t, p->cp, c->dp, pub->p); /* num_pairings++; */ + element_invert(t, t); + element_mul(s, s, t); /* num_muls++; */ + element_pow_zn(s, s, exp); /* num_exps++; */ + + element_mul(r, r, s); /* num_muls++; */ + + element_clear(s); + element_clear(t); +} + +void dec_node_flatten( element_t r, element_t exp, + bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ); + +void +dec_internal_flatten( element_t r, element_t exp, + bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + int i; + element_t t; + element_t expnew; + + element_init_Zr(t, pub->p); + element_init_Zr(expnew, pub->p); + + for( i = 0; i < p->satl->len; i++ ) + { + lagrange_coef(t, p->satl, g_array_index(p->satl, int, i)); + element_mul(expnew, exp, t); /* num_muls++; */ + dec_node_flatten(r, expnew, g_ptr_array_index + (p->children, g_array_index(p->satl, int, i) - 1), prv, pub); + } + + element_clear(t); + element_clear(expnew); +} + +void +dec_node_flatten( element_t r, element_t exp, + bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + assert(p->satisfiable); + if( p->children->len == 0 ) + dec_leaf_flatten(r, exp, p, prv, pub); + else + dec_internal_flatten(r, exp, p, prv, pub); +} + +void +dec_flatten( element_t r, bswabe_policy_t* p, bswabe_prv_t* prv, bswabe_pub_t* pub ) +{ + element_t one; + + element_init_Zr(one, pub->p); + + element_set1(one); + element_set1(r); + + dec_node_flatten(r, one, p, prv, pub); + + element_clear(one); +} + +int +bswabe_dec( bswabe_pub_t* pub, bswabe_prv_t* prv, bswabe_cph_t* cph, element_t m ) +{ + element_t t; + + element_init_GT(m, pub->p); + element_init_GT(t, pub->p); + + check_sat(cph->p, prv); + if( !cph->p->satisfiable ) + { + raise_error("cannot decrypt, attributes in key do not satisfy policy\n"); + return 0; + } + +/* if( no_opt_sat ) */ +/* pick_sat_naive(cph->p, prv); */ +/* else */ + pick_sat_min_leaves(cph->p, prv); + +/* if( dec_strategy == DEC_NAIVE ) */ +/* dec_naive(t, cph->p, prv, pub); */ +/* else if( dec_strategy == DEC_FLATTEN ) */ + dec_flatten(t, cph->p, prv, pub); +/* else */ +/* dec_merge(t, cph->p, prv, pub); */ + + element_mul(m, cph->cs, t); /* num_muls++; */ + + pairing_apply(t, cph->c, prv->d, pub->p); /* num_pairings++; */ + element_invert(t, t); + element_mul(m, m, t); /* num_muls++; */ + + return 1; +} + +// Returns the policy of a ciphertext +char* bswabe_policyList( bswabe_cph_t* cph) + { + return cph->policy; + } + +char** bswabe_attrList( bswabe_prv_t* prv) + { + int i; + char** attrList; + attrList = malloc(sizeof(char*)*(prv->comps->len+1)); + + for( i = 0; i < prv->comps->len; i++ ) + attrList[i]= g_array_index(prv->comps, bswabe_prv_comp_t, i).attr; + + attrList[prv->comps->len] = 0; + return attrList; + } + +/* Generate an encrypted keyword using the public key and a clear keyword */ +peks_sew_t peks_enc( bswabe_pub_t* pub, char* w ) +{ + peks_sew_t sew; + element_t hr; /* h^r */ + element_t hw; /* H_1(W) */ + element_t r; + + /* initialize */ + + element_init_Zr(r, pub->p); + element_init_G1(hr, pub->p); + element_init_G1(hw, pub->p); + element_init_GT(sew.B, pub->p); + element_init_G1(sew.A, pub->p); + + /* compute */ + + element_random(r); + element_pow_zn(hr, pub->h, r); /* h^r */ + element_pow_zn(sew.A, pub->g, r); /* A = g^r */ + element_from_string(hw, w); /* H_1(W) */ + + pairing_apply(sew.B, hw, hr, pub->p); /* B = e( H_1(W), h^r ) */ + +// element_clear(r); +// element_clear(hr); +// element_clear(hw); + return sew; +} + +/* Generates an encrypted index using the public key and a clear index. + Each keyword of the clear index should be on a different line */ +peks_ind_t* peks_enc_ind( bswabe_pub_t* pub, char* ind_file ) +{ + peks_ind_t* ind; + + FILE* f; + + /* initialize */ + + ind = malloc(sizeof(peks_ind_t)); + + ind->comps = g_array_new(0, 1, sizeof(peks_sew_t)); + + f = fopen(ind_file, "r"); + + char line[256]; + + /* compute */ + while (fgets(line, sizeof(line), f)) + { + peks_sew_t sew; + sew = peks_enc(pub, line); + g_array_append_val(ind->comps, sew); + } + + return ind; +} + +/* Generates a trapdoor using private key and a word */ +peks_trap_t* peks_trap( bswabe_pub_t* pub, bswabe_msk_t* msk, char* w ) +{ + peks_trap_t* trap; + element_t hw; /* H_1(W) */ + + /* initialize */ + + trap = malloc(sizeof(peks_trap_t)); + element_init_G1(hw, pub->p); + element_init_G1(trap->T, pub->p); + + /* compute */ + + element_from_string(hw, w); /* H_1(W) */ + element_pow_zn(trap->T, hw, msk->beta); + + return trap; +} + +/* Tests if the encrypted word match with the trapdoor */ +int peks_test( bswabe_pub_t* pub, peks_sew_t sew, peks_trap_t* trap ) +{ + element_t test; + + /* initialize */ + + element_init_GT(test, pub->p); + + /* compute */ + + pairing_apply(test, trap->T, sew.A, pub->p); /* test = e( T_W, A ) */ + + return element_cmp(test, sew.B); +} + +/* Tests if the encrypted index match with the trapdoor */ +int peks_test_ind( bswabe_pub_t* pub, peks_ind_t* ind, peks_trap_t* trap ) +{ + int i; + /* compute */ + for( i = 0; i < ind->comps->len; i++ ) + { + if( !peks_test(pub, g_array_index(ind->comps, peks_sew_t, i), trap)) + return 0; + } + + return 1; +} |