1 files changed, 129 insertions, 0 deletions
diff --git a/src/script/bitcoinconsensus.cpp b/src/script/bitcoinconsensus.cpp
new file mode 100644
index 000000000..01cfeb23f
--- /dev/null
+++ b/src/script/bitcoinconsensus.cpp
@@ -0,0 +1,129 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <script/bitcoinconsensus.h>
+
+#include <primitives/transaction.h>
+#include <pubkey.h>
+#include <script/interpreter.h>
+#include <version.h>
+
+namespace {
+
+/** A class that deserializes a single CTransaction one time. */
+class TxInputStream
+{
+public:
+    TxInputStream(int nTypeIn, int nVersionIn, const unsigned char *txTo, size_t txToLen) :
+    m_type(nTypeIn),
+    m_version(nVersionIn),
+    m_data(txTo),
+    m_remaining(txToLen)
+    {}
+
+    void read(char* pch, size_t nSize)
+    {
+        if (nSize > m_remaining)
+            throw std::ios_base::failure(std::string(__func__) + ": end of data");
+
+        if (pch == nullptr)
+            throw std::ios_base::failure(std::string(__func__) + ": bad destination buffer");
+
+        if (m_data == nullptr)
+            throw std::ios_base::failure(std::string(__func__) + ": bad source buffer");
+
+        memcpy(pch, m_data, nSize);
+        m_remaining -= nSize;
+        m_data += nSize;
+    }
+
+    template<typename T>
+    TxInputStream& operator>>(T&& obj)
+    {
+        ::Unserialize(*this, obj);
+        return *this;
+    }
+
+    int GetVersion() const { return m_version; }
+    int GetType() const { return m_type; }
+private:
+    const int m_type;
+    const int m_version;
+    const unsigned char* m_data;
+    size_t m_remaining;
+};
+
+inline int set_error(bitcoinconsensus_error* ret, bitcoinconsensus_error serror)
+{
+    if (ret)
+        *ret = serror;
+    return 0;
+}
+
+struct ECCryptoClosure
+{
+    ECCVerifyHandle handle;
+};
+
+ECCryptoClosure instance_of_eccryptoclosure;
+} // namespace
+
+/** Check that all specified flags are part of the libconsensus interface. */
+static bool verify_flags(unsigned int flags)
+{
+    return (flags & ~(bitcoinconsensus_SCRIPT_FLAGS_VERIFY_ALL)) == 0;
+}
+
+static int verify_script(const unsigned char *scriptPubKey, unsigned int scriptPubKeyLen, CAmount amount,
+                                    const unsigned char *txTo        , unsigned int txToLen,
+                                    unsigned int nIn, unsigned int flags, bitcoinconsensus_error* err)
+{
+    if (!verify_flags(flags)) {
+        return set_error(err, bitcoinconsensus_ERR_INVALID_FLAGS);
+    }
+    try {
+        TxInputStream stream(SER_NETWORK, PROTOCOL_VERSION, txTo, txToLen);
+        CTransaction tx(deserialize, stream);
+        if (nIn >= tx.vin.size())
+            return set_error(err, bitcoinconsensus_ERR_TX_INDEX);
+        if (GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION) != txToLen)
+            return set_error(err, bitcoinconsensus_ERR_TX_SIZE_MISMATCH);
+
+        // Regardless of the verification result, the tx did not error.
+        set_error(err, bitcoinconsensus_ERR_OK);
+
+        PrecomputedTransactionData txdata(tx);
+        return VerifyScript(tx.vin[nIn].scriptSig, CScript(scriptPubKey, scriptPubKey + scriptPubKeyLen), &tx.vin[nIn].scriptWitness, flags, TransactionSignatureChecker(&tx, nIn, amount, txdata), nullptr);
+    } catch (const std::exception&) {
+        return set_error(err, bitcoinconsensus_ERR_TX_DESERIALIZE); // Error deserializing
+    }
+}
+
+int bitcoinconsensus_verify_script_with_amount(const unsigned char *scriptPubKey, unsigned int scriptPubKeyLen, int64_t amount,
+                                    const unsigned char *txTo        , unsigned int txToLen,
+                                    unsigned int nIn, unsigned int flags, bitcoinconsensus_error* err)
+{
+    CAmount am(amount);
+    return ::verify_script(scriptPubKey, scriptPubKeyLen, am, txTo, txToLen, nIn, flags, err);
+}
+
+
+int bitcoinconsensus_verify_script(const unsigned char *scriptPubKey, unsigned int scriptPubKeyLen,
+                                   const unsigned char *txTo        , unsigned int txToLen,
+                                   unsigned int nIn, unsigned int flags, bitcoinconsensus_error* err)
+{
+    if (flags & bitcoinconsensus_SCRIPT_FLAGS_VERIFY_WITNESS) {
+        return set_error(err, bitcoinconsensus_ERR_AMOUNT_REQUIRED);
+    }
+
+    CAmount am(0);
+    return ::verify_script(scriptPubKey, scriptPubKeyLen, am, txTo, txToLen, nIn, flags, err);
+}
+
+unsigned int bitcoinconsensus_version()
+{
+    // Just use the API version for now
+    return BITCOINCONSENSUS_API_VER;
+}