bool bp_script_verify(const cstring *scriptSig, const cstring *scriptPubKey,
const struct bp_tx *txTo, unsigned int nIn,
unsigned int flags, int nHashType)
{
bool rc = false;
parr *stack = parr_new(0, buffer_freep);
parr *stackCopy = NULL;
struct const_buffer sigbuf = { scriptSig->str, scriptSig->len };
if ((flags & SCRIPT_VERIFY_SIGPUSHONLY) != 0 && !is_bsp_pushonly(&sigbuf))
goto out;
if (!bp_script_eval(stack, scriptSig, txTo, nIn, flags, nHashType))
goto out;
if (flags & SCRIPT_VERIFY_P2SH) {
stackCopy = parr_new(stack->len, buffer_freep);
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)) {
// scriptSig must be literals-only or validation fails
if (!is_bsp_pushonly(&sigbuf))
goto out;
// stack cannot be empty here, because if it was the
// P2SH HASH <> EQUAL scriptPubKey would be evaluated with
// an empty stack and the script_eval above would return false.
if (stackCopy->len < 1)
goto out;
struct buffer *pubKeySerialized = stack_take(stackCopy, -1);
popstack(stackCopy);
cstring *pubkey2 = cstr_new_buf(pubKeySerialized->p, pubKeySerialized->len);
buffer_freep(pubKeySerialized);
bool rc2 = bp_script_eval(stackCopy, pubkey2, txTo, nIn,
flags, nHashType);
cstr_free(pubkey2, true);
if (!rc2)
goto out;
if (stackCopy->len == 0)
goto out;
if (CastToBool(stacktop(stackCopy, -1)) == false)
goto out;
}
// The CLEANSTACK check is only performed after potential P2SH evaluation,
// as the non-P2SH evaluation of a P2SH script will obviously not result in
// a clean stack (the P2SH inputs remain).
if ((flags & SCRIPT_VERIFY_CLEANSTACK) != 0) {
// Disallow CLEANSTACK without P2SH, as otherwise a switch CLEANSTACK->P2SH+CLEANSTACK
// would be possible, which is not a softfork (and P2SH should be one).
assert((flags & SCRIPT_VERIFY_P2SH) != 0);
if (stackCopy->len != 1)
goto out;
}
rc = true;
out:
parr_free(stack, true);
if (stackCopy)
parr_free(stackCopy, true);
return rc;
}
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;
}