示例#1
0
bool bp_script_verify(const GString *scriptSig, const GString *scriptPubKey,
		      const struct bp_tx *txTo, unsigned int nIn,
		      unsigned int flags, int nHashType)
{
	bool rc = false;
	GPtrArray *stack = g_ptr_array_new_with_free_func(
						(GDestroyNotify) buffer_free);
	GString *pubkey2 = NULL;
	GPtrArray *stackCopy = NULL;

	if (!bp_script_eval(stack, scriptSig, txTo, nIn, flags, nHashType))
		goto out;

	if (flags & SCRIPT_VERIFY_P2SH) {
		stackCopy = g_ptr_array_new_full(stack->len,
						(GDestroyNotify) buffer_free);
		stack_copy(stackCopy, stack);
	}

	if (!bp_script_eval(stack, scriptPubKey, txTo, nIn, flags, nHashType))
		goto out;
	if (stack->len == 0)
		goto out;

	if (CastToBool(stacktop(stack, -1)) == false)
		goto out;

	if ((flags & SCRIPT_VERIFY_P2SH) && is_bsp_p2sh_str(scriptPubKey)) {
		struct const_buffer sigbuf = { scriptSig->str, scriptSig->len };
		if (!is_bsp_pushonly(&sigbuf))
			goto out;
		if (stackCopy->len < 1)
			goto out;

		struct buffer *pubkey2_buf = stack_take(stackCopy, -1);
		popstack(stackCopy);

		GString *pubkey2 = g_string_sized_new(pubkey2_buf->len);
		g_string_append_len(pubkey2, pubkey2_buf->p, pubkey2_buf->len);

		buffer_free(pubkey2_buf);

		bool rc2 = bp_script_eval(stackCopy, pubkey2, txTo, nIn,
					  flags, nHashType);
		g_string_free(pubkey2, TRUE);

		if (!rc2)
			goto out;
		if (stackCopy->len == 0)
			goto out;
		if (CastToBool(stacktop(stackCopy, -1)) == false)
			goto out;
	}

	rc = true;

out:
	g_ptr_array_free(stack, TRUE);
	if (pubkey2)
		g_string_free(pubkey2, TRUE);
	if (stackCopy)
		g_ptr_array_free(stackCopy, TRUE);
	return rc;
}
示例#2
0
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;
}
示例#3
0
bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, int nHashType)
{
    CAutoBN_CTX pctx;
    CScript::const_iterator pc = script.begin();
    CScript::const_iterator pend = script.end();
    CScript::const_iterator pbegincodehash = script.begin();
    opcodetype opcode;
    valtype vchPushValue;
    vector<bool> vfExec;
    vector<valtype> altstack;
    if (script.size() > 10000)
        return false;
    int nOpCount = 0;


    try
    {
        while (pc < pend)
        {
            bool fExec = !count(vfExec.begin(), vfExec.end(), false);

            //
            // Read instruction
            //
            if (!script.GetOp(pc, opcode, vchPushValue))
                return false;
            if (vchPushValue.size() > 520)
                return false;
            if (opcode > OP_16 && ++nOpCount > 201)
                return false;

            if (opcode == OP_CAT ||
                opcode == OP_SUBSTR ||
                opcode == OP_LEFT ||
                opcode == OP_RIGHT ||
                opcode == OP_INVERT ||
                opcode == OP_AND ||
                opcode == OP_OR ||
                opcode == OP_XOR ||
                opcode == OP_2MUL ||
                opcode == OP_2DIV ||
                opcode == OP_MUL ||
                opcode == OP_DIV ||
                opcode == OP_MOD ||
                opcode == OP_LSHIFT ||
                opcode == OP_RSHIFT)
                return false;

            if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4)
                stack.push_back(vchPushValue);
            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:
                {
                    // ( -- value)
                    CBigNum bn((int)opcode - (int)(OP_1 - 1));
                    stack.push_back(bn.getvch());
                }
                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.size() < 1)
                            return false;
                        valtype& vch = stacktop(-1);
                        fValue = CastToBool(vch);
                        if (opcode == OP_NOTIF)
                            fValue = !fValue;
                        popstack(stack);
                    }
                    vfExec.push_back(fValue);
                }
                break;

                case OP_ELSE:
                {
                    if (vfExec.empty())
                        return false;
                    vfExec.back() = !vfExec.back();
                }
                break;

                case OP_ENDIF:
                {
                    if (vfExec.empty())
                        return false;
                    vfExec.pop_back();
                }
                break;

                case OP_VERIFY:
                {
                    // (true -- ) or
                    // (false -- false) and return
                    if (stack.size() < 1)
                        return false;
                    bool fValue = CastToBool(stacktop(-1));
                    if (fValue)
                        popstack(stack);
                    else
                        return false;
                }
                break;

                case OP_RETURN:
                {
                    return false;
                }
                break;


                //
                // Stack ops
                //
                case OP_TOALTSTACK:
                {
                    if (stack.size() < 1)
                        return false;
                    altstack.push_back(stacktop(-1));
                    popstack(stack);
                }
                break;

                case OP_FROMALTSTACK:
                {
                    if (altstack.size() < 1)
                        return false;
                    stack.push_back(altstacktop(-1));
                    popstack(altstack);
                }
                break;

                case OP_2DROP:
                {
                    // (x1 x2 -- )
                    if (stack.size() < 2)
                        return false;
                    popstack(stack);
                    popstack(stack);
                }
                break;

                case OP_2DUP:
                {
                    // (x1 x2 -- x1 x2 x1 x2)
                    if (stack.size() < 2)
                        return false;
                    valtype vch1 = stacktop(-2);
                    valtype vch2 = stacktop(-1);
                    stack.push_back(vch1);
                    stack.push_back(vch2);
                }
                break;

                case OP_3DUP:
                {
                    // (x1 x2 x3 -- x1 x2 x3 x1 x2 x3)
                    if (stack.size() < 3)
                        return false;
                    valtype vch1 = stacktop(-3);
                    valtype vch2 = stacktop(-2);
                    valtype vch3 = stacktop(-1);
                    stack.push_back(vch1);
                    stack.push_back(vch2);
                    stack.push_back(vch3);
                }
                break;

                case OP_2OVER:
                {
                    // (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2)
                    if (stack.size() < 4)
                        return false;
                    valtype vch1 = stacktop(-4);
                    valtype vch2 = stacktop(-3);
                    stack.push_back(vch1);
                    stack.push_back(vch2);
                }
                break;

                case OP_2ROT:
                {
                    // (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2)
                    if (stack.size() < 6)
                        return false;
                    valtype vch1 = stacktop(-6);
                    valtype vch2 = stacktop(-5);
                    stack.erase(stack.end()-6, stack.end()-4);
                    stack.push_back(vch1);
                    stack.push_back(vch2);
                }
                break;

                case OP_2SWAP:
                {
                    // (x1 x2 x3 x4 -- x3 x4 x1 x2)
                    if (stack.size() < 4)
                        return false;
                    swap(stacktop(-4), stacktop(-2));
                    swap(stacktop(-3), stacktop(-1));
                }
                break;

                case OP_IFDUP:
                {
                    // (x - 0 | x x)
                    if (stack.size() < 1)
                        return false;
                    valtype vch = stacktop(-1);
                    if (CastToBool(vch))
                        stack.push_back(vch);
                }
                break;

                case OP_DEPTH:
                {
                    // -- stacksize
                    CBigNum bn(stack.size());
                    stack.push_back(bn.getvch());
                }
                break;

                case OP_DROP:
                {
                    // (x -- )
                    if (stack.size() < 1)
                        return false;
                    popstack(stack);
                }
                break;

                case OP_DUP:
                {
                    // (x -- x x)
                    if (stack.size() < 1)
                        return false;
                    valtype vch = stacktop(-1);
                    stack.push_back(vch);
                }
                break;

                case OP_NIP:
                {
                    // (x1 x2 -- x2)
                    if (stack.size() < 2)
                        return false;
                    stack.erase(stack.end() - 2);
                }
                break;

                case OP_OVER:
                {
                    // (x1 x2 -- x1 x2 x1)
                    if (stack.size() < 2)
                        return false;
                    valtype vch = stacktop(-2);
                    stack.push_back(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.size() < 2)
                        return false;
                    int n = CastToBigNum(stacktop(-1)).getint();
                    popstack(stack);
                    if (n < 0 || n >= stack.size())
                        return false;
                    valtype vch = stacktop(-n-1);
                    if (opcode == OP_ROLL)
                        stack.erase(stack.end()-n-1);
                    stack.push_back(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.size() < 3)
                        return false;
                    swap(stacktop(-3), stacktop(-2));
                    swap(stacktop(-2), stacktop(-1));
                }
                break;

                case OP_SWAP:
                {
                    // (x1 x2 -- x2 x1)
                    if (stack.size() < 2)
                        return false;
                    swap(stacktop(-2), stacktop(-1));
                }
                break;

                case OP_TUCK:
                {
                    // (x1 x2 -- x2 x1 x2)
                    if (stack.size() < 2)
                        return false;
                    valtype vch = stacktop(-1);
                    stack.insert(stack.end()-2, vch);
                }
                break;


                //
                // Splice ops
                //
                case OP_CAT:
                {
                    // (x1 x2 -- out)
                    if (stack.size() < 2)
                        return false;
                    valtype& vch1 = stacktop(-2);
                    valtype& vch2 = stacktop(-1);
                    vch1.insert(vch1.end(), vch2.begin(), vch2.end());
                    popstack(stack);
                    if (stacktop(-1).size() > 520)
                        return false;
                }
                break;

                case OP_SUBSTR:
                {
                    // (in begin size -- out)
                    if (stack.size() < 3)
                        return false;
                    valtype& vch = stacktop(-3);
                    int nBegin = CastToBigNum(stacktop(-2)).getint();
                    int nEnd = nBegin + CastToBigNum(stacktop(-1)).getint();
                    if (nBegin < 0 || nEnd < nBegin)
                        return false;
                    if (nBegin > vch.size())
                        nBegin = vch.size();
                    if (nEnd > vch.size())
                        nEnd = vch.size();
                    vch.erase(vch.begin() + nEnd, vch.end());
                    vch.erase(vch.begin(), vch.begin() + nBegin);
                    popstack(stack);
                    popstack(stack);
                }
                break;

                case OP_LEFT:
                case OP_RIGHT:
                {
                    // (in size -- out)
                    if (stack.size() < 2)
                        return false;
                    valtype& vch = stacktop(-2);
                    int nSize = CastToBigNum(stacktop(-1)).getint();
                    if (nSize < 0)
                        return false;
                    if (nSize > vch.size())
                        nSize = vch.size();
                    if (opcode == OP_LEFT)
                        vch.erase(vch.begin() + nSize, vch.end());
                    else
                        vch.erase(vch.begin(), vch.end() - nSize);
                    popstack(stack);
                }
                break;

                case OP_SIZE:
                {
                    // (in -- in size)
                    if (stack.size() < 1)
                        return false;
                    CBigNum bn(stacktop(-1).size());
                    stack.push_back(bn.getvch());
                }
                break;


                //
                // Bitwise logic
                //
                case OP_INVERT:
                {
                    // (in - out)
                    if (stack.size() < 1)
                        return false;
                    valtype& vch = stacktop(-1);
                    for (int i = 0; i < vch.size(); i++)
                        vch[i] = ~vch[i];
                }
                break;

                case OP_AND:
                case OP_OR:
                case OP_XOR:
                {
                    // (x1 x2 - out)
                    if (stack.size() < 2)
                        return false;
                    valtype& vch1 = stacktop(-2);
                    valtype& vch2 = stacktop(-1);
                    MakeSameSize(vch1, vch2);
                    if (opcode == OP_AND)
                    {
                        for (int i = 0; i < vch1.size(); i++)
                            vch1[i] &= vch2[i];
                    }
                    else if (opcode == OP_OR)
                    {
                        for (int i = 0; i < vch1.size(); i++)
                            vch1[i] |= vch2[i];
                    }
                    else if (opcode == OP_XOR)
                    {
                        for (int i = 0; i < vch1.size(); i++)
                            vch1[i] ^= vch2[i];
                    }
                    popstack(stack);
                }
                break;

                case OP_EQUAL:
                case OP_EQUALVERIFY:
                //case OP_NOTEQUAL: // use OP_NUMNOTEQUAL
                {
                    // (x1 x2 - bool)
                    if (stack.size() < 2)
                        return false;
                    valtype& vch1 = stacktop(-2);
                    valtype& vch2 = stacktop(-1);
                    bool fEqual = (vch1 == vch2);
                    // 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_back(fEqual ? vchTrue : vchFalse);
                    if (opcode == OP_EQUALVERIFY)
                    {
                        if (fEqual)
                            popstack(stack);
                        else
                            return false;
                    }
                }
                break;


                //
                // Numeric
                //
                case OP_1ADD:
                case OP_1SUB:
                case OP_2MUL:
                case OP_2DIV:
                case OP_NEGATE:
                case OP_ABS:
                case OP_NOT:
                case OP_0NOTEQUAL:
                {
                    // (in -- out)
                    if (stack.size() < 1)
                        return false;
                    CBigNum bn = CastToBigNum(stacktop(-1));
                    switch (opcode)
                    {
                    case OP_1ADD:       bn += bnOne; break;
                    case OP_1SUB:       bn -= bnOne; break;
                    case OP_2MUL:       bn <<= 1; break;
                    case OP_2DIV:       bn >>= 1; break;
                    case OP_NEGATE:     bn = -bn; break;
                    case OP_ABS:        if (bn < bnZero) bn = -bn; break;
                    case OP_NOT:        bn = (bn == bnZero); break;
                    case OP_0NOTEQUAL:  bn = (bn != bnZero); break;
                    }
                    popstack(stack);
                    stack.push_back(bn.getvch());
                }
                break;

                case OP_ADD:
                case OP_SUB:
                case OP_MUL:
                case OP_DIV:
                case OP_MOD:
                case OP_LSHIFT:
                case OP_RSHIFT:
                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.size() < 2)
                        return false;
                    CBigNum bn1 = CastToBigNum(stacktop(-2));
                    CBigNum bn2 = CastToBigNum(stacktop(-1));
                    CBigNum bn;
                    switch (opcode)
                    {
                    case OP_ADD:
                        bn = bn1 + bn2;
                        break;

                    case OP_SUB:
                        bn = bn1 - bn2;
                        break;

                    case OP_MUL:
                        if (!BN_mul(&bn, &bn1, &bn2, pctx))
                            return false;
                        break;

                    case OP_DIV:
                        if (!BN_div(&bn, NULL, &bn1, &bn2, pctx))
                            return false;
                        break;

                    case OP_MOD:
                        if (!BN_mod(&bn, &bn1, &bn2, pctx))
                            return false;
                        break;

                    case OP_LSHIFT:
                        if (bn2 < bnZero || bn2 > CBigNum(2048))
                            return false;
                        bn = bn1 << bn2.getulong();
                        break;

                    case OP_RSHIFT:
                        if (bn2 < bnZero || bn2 > CBigNum(2048))
                            return false;
                        bn = bn1 >> bn2.getulong();
                        break;

                    case OP_BOOLAND:             bn = (bn1 != bnZero && bn2 != bnZero); break;
                    case OP_BOOLOR:              bn = (bn1 != bnZero || bn2 != bnZero); break;
                    case OP_NUMEQUAL:            bn = (bn1 == bn2); break;
                    case OP_NUMEQUALVERIFY:      bn = (bn1 == bn2); break;
                    case OP_NUMNOTEQUAL:         bn = (bn1 != bn2); break;
                    case OP_LESSTHAN:            bn = (bn1 < bn2); break;
                    case OP_GREATERTHAN:         bn = (bn1 > bn2); break;
                    case OP_LESSTHANOREQUAL:     bn = (bn1 <= bn2); break;
                    case OP_GREATERTHANOREQUAL:  bn = (bn1 >= bn2); break;
                    case OP_MIN:                 bn = (bn1 < bn2 ? bn1 : bn2); break;
                    case OP_MAX:                 bn = (bn1 > bn2 ? bn1 : bn2); break;
                    }
                    popstack(stack);
                    popstack(stack);
                    stack.push_back(bn.getvch());

                    if (opcode == OP_NUMEQUALVERIFY)
                    {
                        if (CastToBool(stacktop(-1)))
                            popstack(stack);
                        else
                            return false;
                    }
                }
                break;

                case OP_WITHIN:
                {
                    // (x min max -- out)
                    if (stack.size() < 3)
                        return false;
                    CBigNum bn1 = CastToBigNum(stacktop(-3));
                    CBigNum bn2 = CastToBigNum(stacktop(-2));
                    CBigNum bn3 = CastToBigNum(stacktop(-1));
                    bool fValue = (bn2 <= bn1 && bn1 < bn3);
                    popstack(stack);
                    popstack(stack);
                    popstack(stack);
                    stack.push_back(fValue ? vchTrue : vchFalse);
                }
                break;


                //
                // Crypto
                //
                case OP_RIPEMD160:
                case OP_SHA1:
                case OP_SHA256:
                case OP_HASH160:
                case OP_HASH256:
                {
                    // (in -- hash)
                    if (stack.size() < 1)
                        return false;
                    valtype& vch = stacktop(-1);
                    valtype vchHash((opcode == OP_RIPEMD160 || opcode == OP_SHA1 || opcode == OP_HASH160) ? 20 : 32);
                    if (opcode == OP_RIPEMD160)
                        RIPEMD160(&vch[0], vch.size(), &vchHash[0]);
                    else if (opcode == OP_SHA1)
                        SHA1(&vch[0], vch.size(), &vchHash[0]);
                    else if (opcode == OP_SHA256)
                        SHA256(&vch[0], vch.size(), &vchHash[0]);
                    else if (opcode == OP_HASH160)
                    {
                        uint160 hash160 = Hash160(vch);
                        memcpy(&vchHash[0], &hash160, sizeof(hash160));
                    }
                    else if (opcode == OP_HASH256)
                    {
                        uint256 hash = Hash(vch.begin(), vch.end());
                        memcpy(&vchHash[0], &hash, sizeof(hash));
                    }
                    popstack(stack);
                    stack.push_back(vchHash);
                }
                break;

                case OP_CODESEPARATOR:
                {
                    // Hash starts after the code separator
                    pbegincodehash = pc;
                }
                break;

                case OP_CHECKSIG:
                case OP_CHECKSIGVERIFY:
                {
                    // (sig pubkey -- bool)
                    if (stack.size() < 2)
                        return false;

                    valtype& vchSig    = stacktop(-2);
                    valtype& vchPubKey = stacktop(-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
                    CScript scriptCode(pbegincodehash, pend);

                    // Drop the signature, since there's no way for a signature to sign itself
                    scriptCode.FindAndDelete(CScript(vchSig));

                    bool fSuccess = CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType);

                    popstack(stack);
                    popstack(stack);
                    stack.push_back(fSuccess ? vchTrue : vchFalse);
                    if (opcode == OP_CHECKSIGVERIFY)
                    {
                        if (fSuccess)
                            popstack(stack);
                        else
                            return false;
                    }
                }
                break;

                case OP_CHECKMULTISIG:
                case OP_CHECKMULTISIGVERIFY:
                {
                    // ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool)

                    int i = 1;
                    if (stack.size() < i)
                        return false;

                    int nKeysCount = CastToBigNum(stacktop(-i)).getint();
                    if (nKeysCount < 0 || nKeysCount > 20)
                        return false;
                    nOpCount += nKeysCount;
                    if (nOpCount > 201)
                        return false;
                    int ikey = ++i;
                    i += nKeysCount;
                    if (stack.size() < i)
                        return false;

                    int nSigsCount = CastToBigNum(stacktop(-i)).getint();
                    if (nSigsCount < 0 || nSigsCount > nKeysCount)
                        return false;
                    int isig = ++i;
                    i += nSigsCount;
                    if (stack.size() < i)
                        return false;

                    // Subset of script starting at the most recent codeseparator
                    CScript scriptCode(pbegincodehash, pend);

                    // Drop the signatures, since there's no way for a signature to sign itself
                    for (int k = 0; k < nSigsCount; k++)
                    {
                        valtype& vchSig = stacktop(-isig-k);
                        scriptCode.FindAndDelete(CScript(vchSig));
                    }

                    bool fSuccess = true;
                    while (fSuccess && nSigsCount > 0)
                    {
                        valtype& vchSig    = stacktop(-isig);
                        valtype& vchPubKey = stacktop(-ikey);

                        // Check signature
                        if (CheckSig(vchSig, vchPubKey, scriptCode, txTo, nIn, nHashType))
                        {
                            isig++;
                            nSigsCount--;
                        }
                        ikey++;
                        nKeysCount--;

                        // If there are more signatures left than keys left,
                        // then too many signatures have failed
                        if (nSigsCount > nKeysCount)
                            fSuccess = false;
                    }

                    while (i-- > 0)
                        popstack(stack);
                    stack.push_back(fSuccess ? vchTrue : vchFalse);

                    if (opcode == OP_CHECKMULTISIGVERIFY)
                    {
                        if (fSuccess)
                            popstack(stack);
                        else
                            return false;
                    }
                }
                break;

                default:
                    return false;
            }

            // Size limits
            if (stack.size() + altstack.size() > 1000)
                return false;
        }
    }
    catch (...)
    {
        return false;
    }


    if (!vfExec.empty())
        return false;

    return true;
}