Added Simple blockchain class

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

Block.cpp

@@ -7,7 +7,7 @@
 
 size_t Block::max_height = 0;
 
-std::string Block::calculateHash() {
+void Block::calculateHash() {
     memset(hash, 0, SHA256_DIGEST_LENGTH);
     SHA256_CTX sha;
     SHA256_Init(&sha);
@@ -15,9 +15,9 @@ std::string Block::calculateHash() {
     unsigned char md[SHA256_DIGEST_LENGTH];
     SHA256_Final(md, &sha);
     std::stringstream ss;
-    for (int i = 0; i < SHA256_DIGEST_LENGTH; i++)
-        ss << std::hex << (int) md[i];
-    return ss.str();
+    for (unsigned char i : md)
+        ss << std::hex << (int) i;
+    strcpy(hash,ss.str().c_str());
 }
 
 Block::Block(Transaction tr[], size_t count, const char *prev_hash) {
@@ -28,18 +28,32 @@ Block::Block(Transaction tr[], size_t count, const char *prev_hash) {
     }
 
     if (strcmp(prev_hash, "") == 0)
-        memset(this->prev_hash, 0, SHA256_DIGEST_LENGTH);
+        memset(this->prev_hash, 0, SHA256_CBLOCK+1);
     else
         strcpy(this->prev_hash, prev_hash);
     height = ++max_height;
-    strcpy(hash, calculateHash().c_str());
+    calculateHash();
 }
 
 Transaction &Transaction::operator=(Transaction &tr) {
     if(this != &tr){
         strcpy(sender,tr.getSender());
         strcpy(reciver,tr.getReciever());
+        strcpy(hash,tr.getHash());
         amount = tr.getAmount();
     }
     return *this;
-}
+}
+
+void Transaction::calculateHash() {
+    memset(hash, 0, SHA256_DIGEST_LENGTH);
+    SHA256_CTX sha;
+    SHA256_Init(&sha);
+    SHA256_Update(&sha, this, sizeof(Transaction));
+    unsigned char md[SHA256_DIGEST_LENGTH];
+    SHA256_Final(md, &sha);
+    std::stringstream ss;
+    for (unsigned char i : md)
+        ss << std::hex << (int) i;
+    strcpy(hash,ss.str().c_str());
+}

Block.h

@@ -11,34 +11,43 @@
 #include <iostream>
 #include <vector>
 #include <openssl/sha.h>
+#include <openssl/ripemd.h>
+
 #include "config.h"
 
 class Transaction{
-    char sender[KEY_LENGTH];
-    char reciver[KEY_LENGTH];
+    char sender[RIPEMD160_DIGEST_LENGTH];
+    char reciver[RIPEMD160_DIGEST_LENGTH];
+    char hash[SHA256_CBLOCK+1];
     int amount;
 public:
     Transaction(){
         amount = 0;
-        memset(sender,0,KEY_LENGTH);
-        memset(reciver,0,KEY_LENGTH);
+        memset(sender,0,RIPEMD160_DIGEST_LENGTH);
+        memset(reciver,0,RIPEMD160_DIGEST_LENGTH);
+        memset(hash,0,SHA256_CBLOCK+1);
     }
 
     Transaction(const char* sender,const char* to,int amount):amount(amount){
-        memset(this->reciver,0,KEY_LENGTH);
-        memset(this->sender,0,KEY_LENGTH);
-        strncpy(this->sender,sender,KEY_LENGTH);
-        strncpy(this->reciver,to,KEY_LENGTH);
+        memset(this->reciver,0,RIPEMD160_DIGEST_LENGTH);
+        memset(this->sender,0,RIPEMD160_DIGEST_LENGTH);
+        strncpy(this->sender,sender,RIPEMD160_DIGEST_LENGTH);
+        strncpy(this->reciver,to,RIPEMD160_DIGEST_LENGTH);
+        calculateHash();
     }
     char* getSender() const { return (char*)sender;  }
     char* getReciever() const { return (char*)reciver;   }
+    char* getHash() const { return (char*)hash;  }
     int getAmount() const { return amount;  }
     Transaction& operator=(Transaction& tr);
+
+private:
+    void calculateHash();
 };
 
 class Block {
-    char hash[SHA256_DIGEST_LENGTH];
-    char prev_hash[SHA256_DIGEST_LENGTH];
+    char hash[SHA256_CBLOCK+1];
+    char prev_hash[SHA256_CBLOCK+1];
     Transaction transactions[MAX_BLOCK_TRANSACTION];
     size_t height;
     static size_t max_height;
@@ -49,7 +58,7 @@ public:
     char* getPerviousHash() const { return (char*)prev_hash;}
     Block(Transaction tr[],size_t count, const char *prev_hash = "");
 private:
-    std::string calculateHash();
+    void calculateHash();
 };
 
 

Blockchain.cpp

@@ -0,0 +1,36 @@
+//
+// Keszitette: Toldi Balázs Ádám
+// Datum: 2020. 03. 15.
+//
+
+#include "Blockchain.h"
+
+int Blockchain::difficulty = 2;
+int Blockchain::blockReward = 50;
+
+
+int Blockchain::getBlockReward() {
+    return blockReward;
+}
+
+int Blockchain::getDifficulty() {
+    return difficulty;
+}
+
+const std::vector<Block> &Blockchain::getBlockList() const {
+    return blockList;
+}
+
+bool Blockchain::verifyBlocks() const{
+    std::string prev_hash = blockList.rbegin()->getPerviousHash();
+    for (auto it = blockList.rbegin()+1;it < blockList.rend();++it) {
+        if(it->getHash() != prev_hash)
+            return false;
+    }
+    return true;
+}
+
+bool Blockchain::addBlock(Block &b) {
+    blockList.push_back(b);
+    return verifyBlocks();
+}

Blockchain.h

@@ -0,0 +1,26 @@
+//
+// Keszitette: Toldi Balázs Ádám
+// Datum: 2020. 03. 15.
+//
+
+#ifndef BLOCKCHAIN_BLOCKCHAIN_H
+#define BLOCKCHAIN_BLOCKCHAIN_H
+
+#include <vector>
+#include <string>
+#include "Block.h"
+
+class Blockchain {
+    static int difficulty;
+    static int blockReward;
+    std::vector<Block> blockList;
+public:
+    const std::vector<Block> &getBlockList() const;
+    static int getDifficulty();
+    static int getBlockReward();
+    bool verifyBlocks() const;
+    bool addBlock(Block& b);
+};
+
+
+#endif //BLOCKCHAIN_BLOCKCHAIN_H

CMakeLists.txt

@@ -3,7 +3,7 @@ project(blockchain)
 
 set(CMAKE_CXX_STANDARD 14)
 find_package(OpenSSL REQUIRED)
-add_executable(blockchain main.cpp Block.cpp Block.h config.h)
+add_executable(blockchain main.cpp Block.cpp Block.h config.h Blockchain.cpp Blockchain.h)
 add_executable(test test/main.cpp Block.cpp Block.h)
 include_directories(${OPENSSL_INCLUDE_DIR})
 target_link_libraries(test ${OPENSSL_LIBRARIES})

config.h

@@ -7,6 +7,5 @@
 #define BLOCKCHAIN_CONFIG_H
 
 #define MAX_BLOCK_TRANSACTION 60
-#define KEY_LENGTH 33
 
 #endif //BLOCKCHAIN_CONFIG_H

main.cpp

@@ -1,14 +1,16 @@
 #include <iostream>
 #include "Block.h"
+#include "Blockchain.h"
 
 int main() {
     std::cout << "Hello, World!" << std::endl;
     Transaction tr("","Balazs",100);
-    Transaction tr2("","Balazs",100);
-    Transaction tr3("","Balazs",100);
-    Transaction trs[] = {tr,tr2,tr3};
-    Block b(trs,3);
+    Transaction trs[] = {tr};
+    Block b(trs,1);
+    std::cout << b.getHash() << std::endl;
     Block b2(nullptr,0,b.getHash());
-    std::cout << b2.getHash() << std::endl;
+    std::cout << b.getHash() << std::endl;
+    std::cout << b2.getPerviousHash() << std::endl;
+    Blockchain bc;
     return 0;
 }