Files
vystem/Blastproof/initfsgen/merkle.c
2026-03-31 22:15:00 +02:00

62 lines
1.9 KiB
C

#include <stdint.h>
#include <string.h>
#include "utils.h"
#include "utilsx1.h"
#include "wots.h"
#include "wotsx1.h"
#include "merkle.h"
#include "address.h"
#include "params.h"
/*
* This generates a Merkle signature (WOTS signature followed by the Merkle
* authentication path). This is in this file because most of the complexity
* is involved with the WOTS signature; the Merkle authentication path logic
* is mostly hidden in treehashx4
*/
void merkle_sign(uint8_t *sig, unsigned char *root,
const spx_ctx *ctx,
uint32_t wots_addr[8], uint32_t tree_addr[8],
uint32_t idx_leaf)
{
unsigned char *auth_path = sig + SPX_WOTS_BYTES;
struct leaf_info_x1 info = { 0 };
unsigned steps[ SPX_WOTS_LEN ];
info.wots_sig = sig;
chain_lengths(steps, root);
info.wots_steps = steps;
set_type(&tree_addr[0], SPX_ADDR_TYPE_HASHTREE);
set_type(&info.pk_addr[0], SPX_ADDR_TYPE_WOTSPK);
copy_subtree_addr(&info.leaf_addr[0], wots_addr);
copy_subtree_addr(&info.pk_addr[0], wots_addr);
info.wots_sign_leaf = idx_leaf;
treehashx1(root, auth_path, ctx,
idx_leaf, 0,
SPX_TREE_HEIGHT,
wots_gen_leafx1,
tree_addr, &info);
}
/* Compute root node of the top-most subtree. */
void merkle_gen_root(unsigned char *root, const spx_ctx *ctx)
{
/* We do not need the auth path in key generation, but it simplifies the
code to have just one treehash routine that computes both root and path
in one function. */
unsigned char auth_path[SPX_TREE_HEIGHT * SPX_N + SPX_WOTS_BYTES];
uint32_t top_tree_addr[8] = {0};
uint32_t wots_addr[8] = {0};
set_layer_addr(top_tree_addr, SPX_D - 1);
set_layer_addr(wots_addr, SPX_D - 1);
merkle_sign(auth_path, root, ctx,
wots_addr, top_tree_addr,
(uint32_t)~0 /* ~0 means "don't bother generating an auth path */ );
}