Copied TCP impl from other project, basic Block implementation, randomx pow, signing via secp256k1

include/block/transaction.h

@@ -0,0 +1,48 @@
+#ifndef TRANSACTION_H
+#define TRANSACTION_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <crypto/crypto.h>
+
+// Special sender/recipient address marker for coinbase logic: 32 bytes of 0xFF.
+static inline bool Address_IsCoinbase(const uint8_t address[32]) {
+    if (!address) {
+        return false;
+    }
+
+    for (size_t i = 0; i < 32; ++i) {
+        if (address[i] != 0xFF) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+// 178 bytes total for v1
+typedef struct {
+    uint8_t version;
+    uint8_t senderAddress[32];
+    uint8_t recipientAddress[32];
+    uint64_t amount;
+    uint64_t fee; // Rewarded to the miner; can be zero, but the miner may choose to ignore transactions with very low fees
+    uint8_t compressedPublicKey[33];
+    // Timestamp is dictated by the block
+} transaction_t;
+
+typedef struct {
+    uint8_t txHash[32];
+    uint8_t signature[64]; // Signature of the hash
+} transaction_sig_t;
+
+typedef struct {
+    transaction_t transaction;
+    transaction_sig_t signature;
+} signed_transaction_t;
+
+void Transaction_CalculateHash(const signed_transaction_t* tx, uint8_t* outHash);
+void Transaction_Sign(signed_transaction_t* tx, const uint8_t* privateKey);
+bool Transaction_Verify(const signed_transaction_t* tx);
+
+#endif