C 语言实现简易区块链

Posted 2021-12-23 广州吴彦祖

C 语言实现简易区块链

总结：C 语言真不是我这种菜鸡所能驾驭的…

• 无奈哈希函数太麻烦，就采用 base64 替代下哈希函数吧，其他符合区块链理论

  #include <stdio.h>
  #include <string.h>
  #include <time.h>
  #include <stdlib.h>
  
  // base64 编码
  static const char *ALPHA_BASE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  void Base64(const char *buf, const long size, char *base64Char) 
      int a = 0;
      int i = 0;
      while (i < size) 
          char b0 = buf[i++];
          char b1 = (i < size) ? buf[i++] : 0;
          char b2 = (i < size) ? buf[i++] : 0;
  
          int int63 = 0x3F;
          int int255 = 0xFF;
          base64Char[a++] = ALPHA_BASE[(b0 >> 2) & int63];
          base64Char[a++] = ALPHA_BASE[((b0 << 4) | ((b1 & int255) >> 4)) & int63];
          base64Char[a++] = ALPHA_BASE[((b1 << 2) | ((b2 & int255) >> 6)) & int63];
          base64Char[a++] = ALPHA_BASE[b2 & int63];
      
      switch (size % 3) 
          case 1:
              base64Char[--a] = '=';
          case 2:
              base64Char[--a] = '=';
      
  
  // 获取当前时间戳
  void timeStamp(char *timeStamp) 
      time_t t = time(NULL);
      int _timeStamp_ = time(&t);
      while (_timeStamp_ != 0) 
          timeStamp[strlen(timeStamp)] = (_timeStamp_ % 10) + '0';
          _timeStamp_ /= 10;
      
  
  
  typedef struct block 
      char prevHash[256];
      char hash[256];
      char timeStamp[20];
      char data[1024];
   Block;
  
  void setBlockHash(Block *block) 
      char str[2048];
      strcat(str, block->prevHash);
      strcat(str, block->hash);
      timeStamp(block->timeStamp);
      strcat(str, block->data);
      Base64(str, strlen(str), block->hash);
  
  
  char* getBlockHash(Block block) 
      char *res = block.hash;
      return res;
  
  
  // 创建区块
  Block createBlock(char prevHash[1024], char data[1024]) 
      Block block;
      strcpy(block.prevHash, prevHash);
      strcpy(block.data, data);
      timeStamp((&block)->timeStamp);
  
      char _hash_[2048];
      strcpy(_hash_, prevHash);
      strcat(_hash_, block.timeStamp);
      strcat(_hash_, data);
      Base64(_hash_, strlen(_hash_), block.hash);
      return block;
  
  
  typedef struct blockChain 
      Block block;
   BlockChain;
  BlockChain blockChain[1024];
  int blockChainPosition = 0;
  // 创世区块
  void Init_BlockChain() 
      char headHash[16];
      char headMsg[] = "Genesis Block";
      Base64(headMsg, strlen(headMsg), headHash);
      blockChain[blockChainPosition++].block = createBlock(headHash, "Genesis Block");
  
  
  void addBlock(char *data) 
      blockChain[blockChainPosition].block = createBlock(blockChain[blockChainPosition - 1].block.prevHash, data);
      char _block_[2048];
      strcat(_block_, blockChain[blockChainPosition].block.prevHash);
      strcat(_block_, blockChain[blockChainPosition].block.hash);
      strcat(_block_, blockChain[blockChainPosition].block.timeStamp);
      Base64(_block_, strlen(_block_), blockChain[blockChainPosition].block.prevHash);
      blockChainPosition++;
  
  
  int main() 
      Init_BlockChain();
  
      addBlock("this is block A");
      addBlock("this is block B");
  
      for (int i = 1; i < blockChainPosition; i++) 
          printf("PrevHash: %s\\n", blockChain[i].block.prevHash);
          printf("PrevHash: %s\\n", blockChain[i].block.hash);
          printf("PrevHash: %s\\n", blockChain[i].block.data);
          printf("\\n");
      
      return 0;
  
  

• 运行结果

  PrevHash: UjJWdVpYTnBjeUJDYkc5amF3PT1VakpXZFZwWVRuQmplVUpEWWtjNWFtRjNQVDAyTWpNNU9URTRNell4ZEdocGN5QnBjeUJpYkc5amF5QkI2MjM5OTE4MzYx
  PrevHash: UjJWdVpYTnBjeUJDYkc5amF3PT02MjM5OTE4MzYxdGhpcyBpcyBibG9jayBB
  PrevHash: this is block A
  
  PrevHash: UjJWdVpYTnBjeUJDYkc5amF3PT1VakpXZFZwWVRuQmplVUpEWWtjNWFtRjNQVDAyTWpNNU9URTRNell4ZEdocGN5QnBjeUJpYkc5amF5QkI2MjM5OTE4MzYxVWpKV2RWcFlUbkJqZVVKRFlrYzVhbUYzUFQxVmFrcFhaRlp3V1ZSdVFtcGxWVXBFV1d0ak5XRnRSak5RVkRBeVRXcE5OVTlVUlRSTmVsbDRaRWRvY0dONVFuQmplVUpwWWtjNWFtRjVRa0kyTWpNNU9URTRNell4VldwS1YyUldjRmxVYmtKcVpWVktSRmxyWXpWaGJVWXpVRlF4Vm1GcmNGaGFSbHAzVjFaU2RWRnRjR3hXVlhCRlYxZDBhazVYUm5SU2FrNVJWa1JCZVZSWGNFNU9WVGxWVWxSU1RtVnNiRFJhUldSdlkwZE9OVkZ1UW1wbFZVcHdXV3RqTldGdFJqVlJhMGt5VFdwTk5VOVVSVFJOZWxsNE5qSXpPVGt4T0RNMk1UWXlNems1TVRnek5qRjBhR2x6SUdseklHSnNiMk5ySUVKMGFHbHpJR2x6SUdKc2IyTnJJRUk9NjIzOTkxODM2MTYyMzk5MTgzNjF0aGlzIGlzIGJsb2NrIEI=pH|
  
  PrevHash: RjVRa0kyTWpNNU9URTRNell4VldwS1YyUldjRmxVYmtKcVpWVktSRmxyWXpWaGJVWXpVRlF4Vm1GcmNGaGFSbHAzVjFaU2RWRnRjR3hXVlhCRlYxZDBhazVYUm5SU2FrNVJWa1JCZVZSWGNFNU9WVGxWVWxSU1RtVnNiRFJhUldSdlkwZE9OVkZ1UW1wbFZVcHdXV3RqTldGdFJqVlJhMGt5VFdwTk5VOVVSVFJOZWxsNE5qSXpPVGt4T0RNMk1UWXlNems1TVRnek5qRjBhR2x6SUdseklHSnNiMk5ySUVKMGFHbHpJR2x6SUdKc2IyTnJJRUk9NjIzOTkxODM2MTYyMzk5MTgzNjF0aGlzIGlzIGJsb2NrIEI=pH|
  
  PrevHash: R2x6SUdseklHSnNiMk5ySUVKMGFHbHpJR2x6SUdKc2IyTnJJRUk9NjIzOTkxODM2MTYyMzk5MTgzNjF0aGlzIGlzIGJsb2NrIEI=pH|