bool bsp_getop(struct bscript_op *op, struct bscript_parser *bp)
{
if (bp->buf->len == 0)
return false; /* EOF */
unsigned char opcode;
if (!deser_bytes(&opcode, bp->buf, 1))
goto err_out;
op->op = opcode;
uint32_t data_len;
if (opcode < OP_PUSHDATA1)
data_len = opcode;
else if (opcode == OP_PUSHDATA1) {
uint8_t v8;
if (!deser_bytes(&v8, bp->buf, 1))
goto err_out;
data_len = v8;
}
else if (opcode == OP_PUSHDATA2) {
uint16_t v16;
if (!deser_u16(&v16, bp->buf))
goto err_out;
data_len = v16;
}
else if (opcode == OP_PUSHDATA4) {
uint32_t v32;
if (!deser_u32(&v32, bp->buf))
goto err_out;
data_len = v32;
} else {
assert(!is_bsp_pushdata(opcode));
op->data.p = NULL;
op->data.len = 0;
return true;
}
op->data.p = bp->buf->p;
op->data.len = data_len;
if (!deser_skip(bp->buf, data_len))
goto err_out;
return true;
err_out:
bp->error = true;
return false;
}
static void test_txout(const struct bitc_txout *txout)
{
struct const_buffer buf = { txout->scriptPubKey->str,
txout->scriptPubKey->len };
struct bscript_parser bsp;
struct bscript_op op;
clist *ops = NULL;
/*
* parse script
*/
bsp_start(&bsp, &buf);
while (bsp_getop(&op, &bsp)) {
struct bscript_op *op_p;
op_p = memdup(&op, sizeof(op));
ops = clist_append(ops, op_p);
}
assert(!bsp.error);
/*
* build script
*/
clist *tmp = ops;
cstring *s = cstr_new_sz(256);
while (tmp) {
struct bscript_op *op_p;
op_p = tmp->data;
tmp = tmp->next;
if (is_bsp_pushdata(op_p->op)) {
bsp_push_data(s, op_p->data.p, op_p->data.len);
} else {
bsp_push_op(s, op_p->op);
}
}
clist_free_ext(ops, free);
/* byte-compare original and newly created scripts */
assert(cstr_equal(s, txout->scriptPubKey));
cstr_free(s, true);
}
bool is_bsp_pushonly(struct const_buffer *buf)
{
struct bscript_parser bp;
struct bscript_op op;
bsp_start(&bp, buf);
while (bsp_getop(&op, &bp))
if (!is_bsp_pushdata(op.op))
return false;
if (bp.error)
return false;
return true;
}
static bool bp_script_eval(GPtrArray *stack, const GString *script,
const struct bp_tx *txTo, unsigned int nIn,
unsigned int flags, int nHashType)
{
struct const_buffer pc = { script->str, script->len };
struct const_buffer pend = { script->str + script->len, 0 };
struct const_buffer pbegincodehash = { script->str, script->len };
struct bscript_op op;
bool rc = false;
GByteArray *vfExec = g_byte_array_new();
GPtrArray *altstack = g_ptr_array_new_with_free_func(
(GDestroyNotify) buffer_free);
BIGNUM bn;
BN_init(&bn);
if (script->len > 10000)
goto out;
bool fStrictEncodings = flags & SCRIPT_VERIFY_STRICTENC;
unsigned int nOpCount = 0;
struct bscript_parser bp;
bsp_start(&bp, &pc);
while (pc.p < pend.p) {
bool fExec = !count_false(vfExec);
if (!bsp_getop(&op, &bp))
goto out;
enum opcodetype opcode = op.op;
if (op.data.len > 520)
goto out;
if (opcode > OP_16 && ++nOpCount > 201)
goto out;
if (disabled_op[opcode])
goto out;
if (fExec && is_bsp_pushdata(opcode))
stack_push(stack, (struct buffer *) &op.data);
else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))
switch (opcode) {
//
// Push value
//
case OP_1NEGATE:
case OP_1:
case OP_2:
case OP_3:
case OP_4:
case OP_5:
case OP_6:
case OP_7:
case OP_8:
case OP_9:
case OP_10:
case OP_11:
case OP_12:
case OP_13:
case OP_14:
case OP_15:
case OP_16:
bn_set_int(&bn, (int)opcode - (int)(OP_1 - 1));
stack_push_str(stack, bn_getvch(&bn));
break;
//
// Control
//
case OP_NOP:
case OP_NOP1: case OP_NOP2: case OP_NOP3: case OP_NOP4: case
OP_NOP5:
case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case
OP_NOP10:
break;
case OP_IF:
case OP_NOTIF: {
// <expression> if [statements] [else [statements]] endif
bool fValue = false;
if (fExec) {
if (stack->len < 1)
goto out;
struct buffer *vch = stacktop(stack, -1);
fValue = CastToBool(vch);
if (opcode == OP_NOTIF)
fValue = !fValue;
popstack(stack);
}
guint8 vc = (guint8) fValue;
g_byte_array_append(vfExec, &vc, 1);
break;
}
case OP_ELSE: {
if (vfExec->len == 0)
goto out;
guint8 *v = &vfExec->data[vfExec->len - 1];
*v = !(*v);
break;
}
case OP_ENDIF:
if (vfExec->len == 0)
goto out;
g_byte_array_remove_index(vfExec, vfExec->len - 1);
break;
case OP_VERIFY: {
if (stack->len < 1)
goto out;
bool fValue = CastToBool(stacktop(stack, -1));
if (fValue)
popstack(stack);
else
goto out;
break;
}
case OP_RETURN:
goto out;
//
// Stack ops
//
case OP_TOALTSTACK:
if (stack->len < 1)
goto out;
stack_push(altstack, stacktop(stack, -1));
popstack(stack);
break;
case OP_FROMALTSTACK:
if (altstack->len < 1)
goto out;
stack_push(stack, stacktop(altstack, -1));
popstack(altstack);
break;
case OP_2DROP:
// (x1 x2 -- )
if (stack->len < 2)
goto out;
popstack(stack);
popstack(stack);
break;
case OP_2DUP: {
// (x1 x2 -- x1 x2 x1 x2)
if (stack->len < 2)
goto out;
struct buffer *vch1 = stacktop(stack, -2);
struct buffer *vch2 = stacktop(stack, -1);
stack_push(stack, vch1);
stack_push(stack, vch2);
break;
}
case OP_3DUP: {
// (x1 x2 x3 -- x1 x2 x3 x1 x2 x3)
if (stack->len < 3)
goto out;
struct buffer *vch1 = stacktop(stack, -3);
struct buffer *vch2 = stacktop(stack, -2);
struct buffer *vch3 = stacktop(stack, -1);
stack_push(stack, vch1);
stack_push(stack, vch2);
stack_push(stack, vch3);
break;
}
case OP_2OVER: {
// (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2)
if (stack->len < 4)
goto out;
struct buffer *vch1 = stacktop(stack, -4);
struct buffer *vch2 = stacktop(stack, -3);
stack_push(stack, vch1);
stack_push(stack, vch2);
break;
}
case OP_2ROT: {
// (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2)
if (stack->len < 6)
goto out;
struct buffer *vch1 = stack_take(stack, -6);
struct buffer *vch2 = stack_take(stack, -5);
g_ptr_array_remove_range(stack, stack->len - 6, 2);
stack_push(stack, vch1);
stack_push(stack, vch2);
break;
}
case OP_2SWAP:
// (x1 x2 x3 x4 -- x3 x4 x1 x2)
if (stack->len < 4)
goto out;
stack_swap(stack, -4, -2);
stack_swap(stack, -3, -1);
break;
case OP_IFDUP: {
// (x - 0 | x x)
if (stack->len < 1)
goto out;
struct buffer *vch = stacktop(stack, -1);
if (CastToBool(vch))
stack_push(stack, vch);
break;
}
case OP_DEPTH:
// -- stacksize
BN_set_word(&bn, stack->len);
stack_push_str(stack, bn_getvch(&bn));
break;
case OP_DROP:
// (x -- )
if (stack->len < 1)
goto out;
popstack(stack);
break;
case OP_DUP: {
// (x -- x x)
if (stack->len < 1)
goto out;
struct buffer *vch = stacktop(stack, -1);
stack_push(stack, vch);
break;
}
case OP_NIP:
// (x1 x2 -- x2)
if (stack->len < 2)
goto out;
g_ptr_array_remove_index(stack, stack->len - 2);
break;
case OP_OVER: {
// (x1 x2 -- x1 x2 x1)
if (stack->len < 2)
goto out;
struct buffer *vch = stacktop(stack, -2);
stack_push(stack, vch);
break;
}
case OP_PICK:
case OP_ROLL: {
// (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn)
// (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)
if (stack->len < 2)
goto out;
int n = stackint(stack, -1);
popstack(stack);
if (n < 0 || n >= (int)stack->len)
goto out;
struct buffer *vch = stacktop(stack, -n-1);
if (opcode == OP_ROLL) {
vch = buffer_copy(vch->p, vch->len);
g_ptr_array_remove_index(stack,
stack->len - n - 1);
stack_push_nocopy(stack, vch);
} else
stack_push(stack, vch);
break;
}
case OP_ROT: {
// (x1 x2 x3 -- x2 x3 x1)
// x2 x1 x3 after first swap
// x2 x3 x1 after second swap
if (stack->len < 3)
goto out;
stack_swap(stack, -3, -2);
stack_swap(stack, -2, -1);
break;
}
case OP_SWAP: {
// (x1 x2 -- x2 x1)
if (stack->len < 2)
goto out;
stack_swap(stack, -2, -1);
break;
}
case OP_TUCK: {
// (x1 x2 -- x2 x1 x2)
if (stack->len < 2)
goto out;
struct buffer *vch = stacktop(stack, -1);
stack_insert(stack, vch, -2);
break;
}
case OP_SIZE: {
// (in -- in size)
if (stack->len < 1)
goto out;
struct buffer *vch = stacktop(stack, -1);
BN_set_word(&bn, vch->len);
stack_push_str(stack, bn_getvch(&bn));
break;
}
case OP_EQUAL:
case OP_EQUALVERIFY: {
// (x1 x2 - bool)
if (stack->len < 2)
goto out;
struct buffer *vch1 = stacktop(stack, -2);
struct buffer *vch2 = stacktop(stack, -1);
bool fEqual = ((vch1->len == vch2->len) &&
memcmp(vch1->p, vch2->p, vch1->len) == 0);
// OP_NOTEQUAL is disabled because it would be too easy to say
// something like n != 1 and have some wiseguy pass in 1 with extra
// zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001)
//if (opcode == OP_NOTEQUAL)
// fEqual = !fEqual;
popstack(stack);
popstack(stack);
stack_push_char(stack, fEqual ? 1 : 0);
if (opcode == OP_EQUALVERIFY) {
if (fEqual)
popstack(stack);
else
goto out;
}
break;
}
//
// Numeric
//
case OP_1ADD:
case OP_1SUB:
case OP_NEGATE:
case OP_ABS:
case OP_NOT:
case OP_0NOTEQUAL: {
// (in -- out)
if (stack->len < 1)
goto out;
if (!CastToBigNum(&bn, stacktop(stack, -1)))
goto out;
switch (opcode)
{
case OP_1ADD:
BN_add_word(&bn, 1);
break;
case OP_1SUB:
BN_sub_word(&bn, 1);
break;
case OP_NEGATE:
BN_set_negative(&bn, !BN_is_negative(&bn));
break;
case OP_ABS:
if (BN_is_negative(&bn))
BN_set_negative(&bn, 0);
break;
case OP_NOT:
BN_set_word(&bn, BN_is_zero(&bn) ? 1 : 0);
break;
case OP_0NOTEQUAL:
BN_set_word(&bn, BN_is_zero(&bn) ? 0 : 1);
break;
default:
// impossible
goto out;
}
popstack(stack);
stack_push_str(stack, bn_getvch(&bn));
break;
}
case OP_ADD:
case OP_SUB:
case OP_BOOLAND:
case OP_BOOLOR:
case OP_NUMEQUAL:
case OP_NUMEQUALVERIFY:
case OP_NUMNOTEQUAL:
case OP_LESSTHAN:
case OP_GREATERTHAN:
case OP_LESSTHANOREQUAL:
case OP_GREATERTHANOREQUAL:
case OP_MIN:
case OP_MAX: {
// (x1 x2 -- out)
if (stack->len < 2)
goto out;
BIGNUM bn1, bn2;
BN_init(&bn1);
BN_init(&bn2);
if (!CastToBigNum(&bn1, stacktop(stack, -2)) ||
!CastToBigNum(&bn2, stacktop(stack, -1))) {
BN_clear_free(&bn1);
BN_clear_free(&bn2);
goto out;
}
switch (opcode)
{
case OP_ADD:
BN_add(&bn, &bn1, &bn2);
break;
case OP_SUB:
BN_sub(&bn, &bn1, &bn2);
break;
case OP_BOOLAND:
BN_set_word(&bn,
(!BN_is_zero(&bn1) && !BN_is_zero(&bn2)) ?
1 : 0);
break;
case OP_BOOLOR:
BN_set_word(&bn,
(!BN_is_zero(&bn1) || !BN_is_zero(&bn2)) ?
1 : 0);
break;
case OP_NUMEQUAL:
case OP_NUMEQUALVERIFY:
BN_set_word(&bn,
(BN_cmp(&bn1, &bn2) == 0) ? 1 : 0);
break;
case OP_NUMNOTEQUAL:
BN_set_word(&bn,
(BN_cmp(&bn1, &bn2) != 0) ? 1 : 0);
break;
case OP_LESSTHAN:
BN_set_word(&bn,
(BN_cmp(&bn1, &bn2) < 0) ? 1 : 0);
break;
case OP_GREATERTHAN:
BN_set_word(&bn,
(BN_cmp(&bn1, &bn2) > 0) ? 1 : 0);
break;
case OP_LESSTHANOREQUAL:
BN_set_word(&bn,
(BN_cmp(&bn1, &bn2) <= 0) ? 1 : 0);
break;
case OP_GREATERTHANOREQUAL:
BN_set_word(&bn,
(BN_cmp(&bn1, &bn2) >= 0) ? 1 : 0);
break;
case OP_MIN:
if (BN_cmp(&bn1, &bn2) < 0)
BN_copy(&bn, &bn1);
else
BN_copy(&bn, &bn2);
break;
case OP_MAX:
if (BN_cmp(&bn1, &bn2) > 0)
BN_copy(&bn, &bn1);
else
BN_copy(&bn, &bn2);
break;
default:
// impossible
break;
}
popstack(stack);
popstack(stack);
stack_push_str(stack, bn_getvch(&bn));
BN_clear_free(&bn1);
BN_clear_free(&bn2);
if (opcode == OP_NUMEQUALVERIFY)
{
if (CastToBool(stacktop(stack, -1)))
popstack(stack);
else
goto out;
}
break;
}
case OP_WITHIN: {
// (x min max -- out)
if (stack->len < 3)
goto out;
BIGNUM bn1, bn2, bn3;
BN_init(&bn1);
BN_init(&bn2);
BN_init(&bn3);
bool rc1 = CastToBigNum(&bn1, stacktop(stack, -3));
bool rc2 = CastToBigNum(&bn2, stacktop(stack, -2));
bool rc3 = CastToBigNum(&bn3, stacktop(stack, -1));
bool fValue = (BN_cmp(&bn2, &bn1) <= 0 &&
BN_cmp(&bn1, &bn3) < 0);
popstack(stack);
popstack(stack);
popstack(stack);
stack_push_char(stack, fValue ? 1 : 0);
BN_clear_free(&bn1);
BN_clear_free(&bn2);
BN_clear_free(&bn3);
if (!rc1 || !rc2 || !rc3)
goto out;
break;
}
//
// Crypto
//
case OP_RIPEMD160:
case OP_SHA1:
case OP_SHA256:
case OP_HASH160:
case OP_HASH256: {
// (in -- hash)
if (stack->len < 1)
goto out;
struct buffer *vch = stacktop(stack, -1);
unsigned int hashlen;
unsigned char md[32];
switch (opcode) {
case OP_RIPEMD160:
hashlen = 20;
RIPEMD160(vch->p, vch->len, md);
break;
case OP_SHA1:
hashlen = 20;
SHA1(vch->p, vch->len, md);
break;
case OP_SHA256:
hashlen = 32;
SHA256(vch->p, vch->len, md);
break;
case OP_HASH160:
hashlen = 20;
bu_Hash160(md, vch->p, vch->len);
break;
case OP_HASH256:
hashlen = 32;
bu_Hash(md, vch->p, vch->len);
break;
default:
// impossible
goto out;
}
popstack(stack);
struct buffer buf = { md, hashlen };
stack_push(stack, &buf);
break;
}
case OP_CODESEPARATOR:
// Hash starts after the code separator
memcpy(&pbegincodehash, &pc, sizeof(pc));
break;
case OP_CHECKSIG:
case OP_CHECKSIGVERIFY: {
// (sig pubkey -- bool)
if (stack->len < 2)
goto out;
struct buffer *vchSig = stacktop(stack, -2);
struct buffer *vchPubKey = stacktop(stack, -1);
////// debug print
//PrintHex(vchSig.begin(), vchSig.end(), "sig: %s\n");
//PrintHex(vchPubKey.begin(), vchPubKey.end(), "pubkey: %s\n");
// Subset of script starting at the most recent codeseparator
GString *scriptCode = g_string_sized_new(pbegincodehash.len);
g_string_append_len(scriptCode,
pbegincodehash.p,
pbegincodehash.len);
// Drop the signature, since there's no way for
// a signature to sign itself
string_find_del(scriptCode, vchSig);
bool fSuccess =
(!fStrictEncodings ||
(IsCanonicalSignature(vchSig) &&
IsCanonicalPubKey(vchPubKey)));
if (fSuccess)
fSuccess = bp_checksig(vchSig, vchPubKey,
scriptCode,
txTo, nIn, nHashType);
g_string_free(scriptCode, TRUE);
popstack(stack);
popstack(stack);
stack_push_char(stack, fSuccess ? 1 : 0);
if (opcode == OP_CHECKSIGVERIFY)
{
if (fSuccess)
popstack(stack);
else
goto out;
}
break;
}
case OP_CHECKMULTISIG:
case OP_CHECKMULTISIGVERIFY: {
// ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool)
int i = 1;
if ((int)stack->len < i)
goto out;
int nKeysCount = stackint(stack, -i);
if (nKeysCount < 0 || nKeysCount > 20)
goto out;
nOpCount += nKeysCount;
if (nOpCount > 201)
goto out;
int ikey = ++i;
i += nKeysCount;
if ((int)stack->len < i)
goto out;
int nSigsCount = stackint(stack, -i);
if (nSigsCount < 0 || nSigsCount > nKeysCount)
goto out;
int isig = ++i;
i += nSigsCount;
if ((int)stack->len < i)
goto out;
// Subset of script starting at the most recent codeseparator
GString *scriptCode = g_string_sized_new(pbegincodehash.len);
g_string_append_len(scriptCode,
pbegincodehash.p,
pbegincodehash.len);
// Drop the signatures, since there's no way for
// a signature to sign itself
int k;
for (k = 0; k < nSigsCount; k++)
{
struct buffer *vchSig =stacktop(stack, -isig-k);
string_find_del(scriptCode, vchSig);
}
bool fSuccess = true;
while (fSuccess && nSigsCount > 0)
{
struct buffer *vchSig = stacktop(stack, -isig);
struct buffer *vchPubKey = stacktop(stack, -ikey);
// Check signature
bool fOk =
(!fStrictEncodings ||
(IsCanonicalSignature(vchSig) &&
IsCanonicalPubKey(vchPubKey)));
if (fOk)
fOk = bp_checksig(vchSig, vchPubKey,
scriptCode, txTo, nIn,
nHashType);
if (fOk) {
isig++;
nSigsCount--;
}
ikey++;
nKeysCount--;
// If there are more signatures left than keys left,
// then too many signatures have failed
if (nSigsCount > nKeysCount)
fSuccess = false;
}
g_string_free(scriptCode, TRUE);
while (i-- > 0)
popstack(stack);
stack_push_char(stack, fSuccess ? 1 : 0);
if (opcode == OP_CHECKMULTISIGVERIFY)
{
if (fSuccess)
popstack(stack);
else
goto out;
}
break;
}
default:
goto out;
}
if (stack->len + altstack->len > 1000)
goto out;
}
rc = (vfExec->len == 0 && bp.error == false);
out:
BN_clear_free(&bn);
g_ptr_array_free(altstack, TRUE);
g_byte_array_unref(vfExec);
return rc;
}