kris/xmss-KAT-generator
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Check if a NEXT-tree exists before updating it

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This commit is contained in:
Joost Rijneveld 2015-10-05 21:57:10 +02:00
parent 4c19fe61e4
commit 2af61cea82
1 changed files with 31 additions and 22 deletions
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53
xmss_fast.c
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@ -844,6 +844,7 @@ int xmssmt_sign(unsigned char *sk, bds_state *states, unsigned char *wots_sigs,
unsigned int n = params->n;
unsigned int m = params->m;
unsigned int tree_h = params->xmss_par.h;
unsigned int h = params->h;
unsigned int k = params->xmss_par.k;
unsigned int idx_len = params->index_len;
unsigned long long idx_tree;
@ -951,34 +952,39 @@ int xmssmt_sign(unsigned char *sk, bds_state *states, unsigned char *wots_sigs,
SET_LAYER_ADDRESS(ots_addr, 0);
SET_TREE_ADDRESS(ots_addr, (idx_tree + 1));
// mandatory update for NEXT_0 (does not count towards h-k)
bds_state_update(&states[params->d], sk_seed, &(params->xmss_par), pub_seed, ots_addr);
updates = tree_h - k;
for (i = 0; i < params->d; i++) {
if (((idx + 1) & ((1 << ((i+1)*tree_h)) - 1)) == 0) {
memcpy(&tmp, states+params->d + i, sizeof(bds_state));
memcpy(states+params->d + i, states + i, sizeof(bds_state));
memcpy(states + i, &tmp, sizeof(bds_state));
// if a NEXT-tree exists within the hypertree
if ((1 + idx_tree) * (1 << tree_h) + idx_leaf < (1 << h)) {
// mandatory update for NEXT_0 (does not count towards h-k)
bds_state_update(&states[params->d], sk_seed, &(params->xmss_par), pub_seed, ots_addr);
SET_TREE_ADDRESS(ots_addr, ((idx + 1) >> ((i+2) * tree_h)));
SET_OTS_ADDRESS(ots_addr, (((idx >> ((i+1) * tree_h)) + 1) & ((1 << tree_h)-1)));
SET_LAYER_ADDRESS(ots_addr, (i+1));
// check if we're at the end of a tree
for (i = 0; i < params->d; i++) {
if (((idx + 1) & ((1 << ((i+1)*tree_h)) - 1)) == 0) {
memcpy(&tmp, states+params->d + i, sizeof(bds_state));
memcpy(states+params->d + i, states + i, sizeof(bds_state));
memcpy(states + i, &tmp, sizeof(bds_state));
get_seed(ots_seed, sk+params->index_len, ots_addr);
wots_sign(wots_sigs + i*params->xmss_par.wots_par.keysize, states[i].stack, ots_seed, &(params->xmss_par.wots_par), pub_seed, ots_addr);
SET_TREE_ADDRESS(ots_addr, ((idx + 1) >> ((i+2) * tree_h)));
SET_OTS_ADDRESS(ots_addr, (((idx >> ((i+1) * tree_h)) + 1) & ((1 << tree_h)-1)));
SET_LAYER_ADDRESS(ots_addr, (i+1));
states[params->d + i].stackoffset = 0;
states[params->d + i].next_leaf = 0;
get_seed(ots_seed, sk+params->index_len, ots_addr);
wots_sign(wots_sigs + i*params->xmss_par.wots_par.keysize, states[i].stack, ots_seed, &(params->xmss_par.wots_par), pub_seed, ots_addr);
updates--; // WOTS-signing counts as one update
states[params->d + i].stackoffset = 0;
states[params->d + i].next_leaf = 0;
// this bds_round is needed to initialise the state, but should not perform updates
// note that one should still pass the (reduced) current idx, as bds_round sets up for idx+1
bds_round(&states[i+1], ((idx >> ((i+1)*tree_h))) & ((1 << tree_h)-1), sk_seed, &(params->xmss_par), 0, pub_seed, ots_addr);
for (j = 0; j < tree_h-k; j++) {
states[i].treehash[j].completed = 1;
updates--; // WOTS-signing counts as one update
// this bds_round is needed to initialise the state, but should not perform updates
// note that one should still pass the (reduced) current idx, as bds_round sets up for idx+1
bds_round(&states[i+1], ((idx >> ((i+1)*tree_h))) & ((1 << tree_h)-1), sk_seed, &(params->xmss_par), 0, pub_seed, ots_addr);
for (j = 0; j < tree_h-k; j++) {
states[i].treehash[j].completed = 1;
}
}
}
}
@ -1005,8 +1011,11 @@ int xmssmt_sign(unsigned char *sk, bds_state *states, unsigned char *wots_sigs,
updates--;
}
SET_TREE_ADDRESS(ots_addr, (idx_tree + 1));
while (updates > 0 && !bds_state_update(&states[params->d + i], sk_seed, &(params->xmss_par), pub_seed, ots_addr)) {
updates--;
// if a NEXT-tree exists for this level;
if ((1 + idx_tree) * (1 << tree_h) + idx_leaf < (1 << (h - tree_h * i))) {
while (updates > 0 && !bds_state_update(&states[params->d + i], sk_seed, &(params->xmss_par), pub_seed, ots_addr)) {
updates--;
}
}
}