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#include "config.h"
#include <assert.h>
#include <bitcoin/block.h>
#include <bitcoin/chainparams.h>
#include <bitcoin/tx.h>
#include <ccan/mem/mem.h>
#include <ccan/str/hex/hex.h>
#include <common/type_to_string.h>
#include <wire/wire.h>
/* Sets *cursor to NULL and returns NULL when a pull fails. */
static const u8 *pull(const u8 **cursor, size_t *max, void *copy, size_t n)
{
const u8 *p = *cursor;
if (*max < n) {
*cursor = NULL;
*max = 0;
/* Just make sure we don't leak uninitialized mem! */
if (copy)
memset(copy, 0, n);
return NULL;
}
*cursor += n;
*max -= n;
assert(p);
if (copy)
memcpy(copy, p, n);
return memcheck(p, n);
}
static u32 pull_le32(const u8 **cursor, size_t *max)
{
le32 ret;
if (!pull(cursor, max, &ret, sizeof(ret)))
return 0;
return le32_to_cpu(ret);
}
static u64 pull_varint(const u8 **cursor, size_t *max)
{
u64 ret;
size_t len;
len = varint_get(*cursor, *max, &ret);
if (len == 0) {
*cursor = NULL;
*max = 0;
return 0;
}
pull(cursor, max, NULL, len);
return ret;
}
static void sha256_varint(struct sha256_ctx *ctx, u64 val)
{
u8 vt[VARINT_MAX_LEN];
size_t vtlen;
vtlen = varint_put(vt, val);
sha256_update(ctx, vt, vtlen);
}
static void bitcoin_block_pull_dynafed_params(const u8 **cursor, size_t *len, struct sha256_ctx *shactx)
{
u8 type;
u64 l1, l2;
pull(cursor, len, &type, 1);
sha256_update(shactx, &type, 1);
switch ((enum dynafed_params_type)type) {
case DYNAFED_PARAMS_NULL:
break;
case DYNAFED_PARAMS_COMPACT:
/* "scriptPubKey" used for block signing */
l1 = pull_varint(cursor, len);
sha256_varint(shactx, l1);
sha256_update(shactx, *cursor, l1);
pull(cursor, len, NULL, l1);
/* signblock_witness_limit */
sha256_update(shactx, *cursor, 4);
pull(cursor, len, NULL, 4);
/* Skip elided_root */
sha256_update(shactx, *cursor, 32);
pull(cursor, len, NULL, 32);
break;
case DYNAFED_PARAMS_FULL:
/* "scriptPubKey" used for block signing */
l1 = pull_varint(cursor, len);
sha256_varint(shactx, l1);
sha256_update(shactx, *cursor, l1);
pull(cursor, len, NULL, l1);
/* signblock_witness_limit */
sha256_update(shactx, *cursor, 4);
pull(cursor, len, NULL, 4);
/* fedpeg_program */
l1 = pull_varint(cursor, len);
sha256_varint(shactx, l1);
sha256_update(shactx, *cursor, l1);
pull(cursor, len, NULL, l1);
/* fedpegscript */
l1 = pull_varint(cursor, len);
sha256_varint(shactx, l1);
sha256_update(shactx, *cursor, l1);
pull(cursor, len, NULL, l1);
/* extension space */
l2 = pull_varint(cursor, len);
sha256_varint(shactx, l2);
for (size_t i = 0; i < l2; i++) {
l1 = pull_varint(cursor, len);
sha256_varint(shactx, l1);
sha256_update(shactx, *cursor, l1);
pull(cursor, len, NULL, l1);
}
break;
}
}
static void bitcoin_block_pull_dynafed_details(const u8 **cursor, size_t *len, struct sha256_ctx *shactx)
{
bitcoin_block_pull_dynafed_params(cursor, len, shactx);
bitcoin_block_pull_dynafed_params(cursor, len, shactx);
/* Consume the signblock_witness */
u64 numwitnesses = pull_varint(cursor, len);
for (size_t i=0; i<numwitnesses; i++) {
u64 witsize = pull_varint(cursor, len);
pull(cursor, len, NULL, witsize);
}
}
/* Encoding is <blockhdr> <varint-num-txs> <tx>... */
struct bitcoin_block *
bitcoin_block_from_hex(const tal_t *ctx, const struct chainparams *chainparams,
const char *hex, size_t hexlen)
{
struct bitcoin_block *b;
u8 *linear_tx;
const u8 *p;
size_t len, i, num, templen;
struct sha256_ctx shactx;
bool is_dynafed;
u32 height;
if (hexlen && hex[hexlen-1] == '\n')
hexlen--;
/* Set up the block for success. */
b = tal(ctx, struct bitcoin_block);
/* De-hex the array. */
len = hex_data_size(hexlen);
p = linear_tx = tal_arr(ctx, u8, len);
if (!hex_decode(hex, hexlen, linear_tx, len))
return tal_free(b);
sha256_init(&shactx);
b->hdr.version = pull_le32(&p, &len);
sha256_le32(&shactx, b->hdr.version);
pull(&p, &len, &b->hdr.prev_hash, sizeof(b->hdr.prev_hash));
sha256_update(&shactx, &b->hdr.prev_hash, sizeof(b->hdr.prev_hash));
pull(&p, &len, &b->hdr.merkle_hash, sizeof(b->hdr.merkle_hash));
sha256_update(&shactx, &b->hdr.merkle_hash, sizeof(b->hdr.merkle_hash));
b->hdr.timestamp = pull_le32(&p, &len);
sha256_le32(&shactx, b->hdr.timestamp);
if (is_elements(chainparams)) {
/* A dynafed block is signalled by setting the MSB of the version. */
is_dynafed = (b->hdr.version >> 31 == 1);
/* elements_header.height */
height = pull_le32(&p, &len);
sha256_le32(&shactx, height);
if (is_dynafed) {
bitcoin_block_pull_dynafed_details(&p, &len, &shactx);
} else {
/* elemens_header.challenge */
templen = pull_varint(&p, &len);
sha256_varint(&shactx, templen);
sha256_update(&shactx, p, templen);
pull(&p, &len, NULL, templen);
/* elements_header.solution. Not hashed since it'd be
* a circular dependency. */
templen = pull_varint(&p, &len);
pull(&p, &len, NULL, templen);
}
} else {
b->hdr.target = pull_le32(&p, &len);
sha256_le32(&shactx, b->hdr.target);
b->hdr.nonce = pull_le32(&p, &len);
sha256_le32(&shactx, b->hdr.nonce);
}
sha256_double_done(&shactx, &b->hdr.hash.shad);
num = pull_varint(&p, &len);
b->tx = tal_arr(b, struct bitcoin_tx *, num);
b->txids = tal_arr(b, struct bitcoin_txid, num);
for (i = 0; i < num; i++) {
b->tx[i] = pull_bitcoin_tx(b->tx, &p, &len);
b->tx[i]->chainparams = chainparams;
bitcoin_txid(b->tx[i], &b->txids[i]);
}
/* We should end up not overrunning, nor have extra */
if (!p || len)
return tal_free(b);
tal_free(linear_tx);
return b;
}
void bitcoin_block_blkid(const struct bitcoin_block *b,
struct bitcoin_blkid *out)
{
*out = b->hdr.hash;
}
/* We do the same hex-reversing crud as txids. */
bool bitcoin_blkid_from_hex(const char *hexstr, size_t hexstr_len,
struct bitcoin_blkid *blockid)
{
struct bitcoin_txid fake_txid;
if (!bitcoin_txid_from_hex(hexstr, hexstr_len, &fake_txid))
return false;
blockid->shad = fake_txid.shad;
return true;
}
bool bitcoin_blkid_to_hex(const struct bitcoin_blkid *blockid,
char *hexstr, size_t hexstr_len)
{
struct bitcoin_txid fake_txid;
fake_txid.shad = blockid->shad;
return bitcoin_txid_to_hex(&fake_txid, hexstr, hexstr_len);
}
static char *fmt_bitcoin_blkid(const tal_t *ctx,
const struct bitcoin_blkid *blkid)
{
char *hexstr = tal_arr(ctx, char, hex_str_size(sizeof(*blkid)));
bitcoin_blkid_to_hex(blkid, hexstr, hex_str_size(sizeof(*blkid)));
return hexstr;
}
REGISTER_TYPE_TO_STRING(bitcoin_blkid, fmt_bitcoin_blkid);
void fromwire_bitcoin_blkid(const u8 **cursor, size_t *max,
struct bitcoin_blkid *blkid)
{
fromwire_sha256_double(cursor, max, &blkid->shad);
}
void towire_bitcoin_blkid(u8 **pptr, const struct bitcoin_blkid *blkid)
{
towire_sha256_double(pptr, &blkid->shad);
}
void towire_chainparams(u8 **cursor, const struct chainparams *chainparams)
{
towire_bitcoin_blkid(cursor, &chainparams->genesis_blockhash);
}
void fromwire_chainparams(const u8 **cursor, size_t *max,
const struct chainparams **chainparams)
{
struct bitcoin_blkid genesis;
fromwire_bitcoin_blkid(cursor, max, &genesis);
*chainparams = chainparams_by_chainhash(&genesis);
}