如何用JavaScript对随机字符串生成结果计算SHA256哈希值

需求 #

生成一个16位随机字符串，计算其SHA256哈希值并在控制台打印。例如输入字符串SLvZAfpv2zEPYg5F时，需输出哈希值2ab51f5928246656e753f6518dea0e0745c8faf9429578136c13181bb36d926b。

现有随机字符串生成函数 #

function test(length) {
    let result = '';
    const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    const charactersLength = characters.length;
    let counter = 0;
    while (counter < length) {
      result += characters.charAt(Math.floor(Math.random() * charactersLength));
      counter += 1;
    }
    return result;
}

问题：SHA256函数未正确调用 #

以下是你尝试的SHA256实现代码，但之前未正确传入参数调用：

var makeserverseed = function sha256(ascii) {
  function rightRotate(value, amount) {
      return (value>>>amount) | (value<<(32 - amount));
  };
  
  var mathPow = Math.pow;
  var maxWord = mathPow(2, 32);
  var lengthProperty = 'length'
  var i, j;
  var result = ''

  var words = [];
  var asciiBitLength = ascii[lengthProperty]*8;
  
  var hash = sha256.h = sha256.h || [];
  var k = sha256.k = sha256.k || [];
  var primeCounter = k[lengthProperty];

  var isComposite = {};
  for (var candidate = 2; primeCounter < 64; candidate++) {
      if (!isComposite[candidate]) {
          for (i = 0; i < 313; i += candidate) {
              isComposite[i] = candidate;
          }
          hash[primeCounter] = (mathPow(candidate, .5)*maxWord)|0;
          k[primeCounter++] = (mathPow(candidate, 1/3)*maxWord)|0;
      }
  }
  
  ascii += '\x80'
  while (ascii[lengthProperty]%64 - 56) ascii += '\x00' 
  for (i = 0; i < ascii[lengthProperty]; i++) {
      j = ascii.charCodeAt(i);
      if (j>>8) return; 
      words[i>>2] |= j << ((3 - i)%4)*8;
  }
  words[words[lengthProperty]] = ((asciiBitLength/maxWord)|0);
  words[words[lengthProperty]] = (asciiBitLength)
  
  for (j = 0; j < words[lengthProperty];) {
      var w = words.slice(j, j += 16); 
      var oldHash = hash;
      hash = hash.slice(0, 8);
      
      for (i = 0; i < 64; i++) {
          var i2 = i + j;
          var w15 = w[i - 15], w2 = w[i - 2];
          var a = hash[0], e = hash[4];
          var temp1 = hash[7]
              + (rightRotate(e, 6) ^ rightRotate(e, 11) ^ rightRotate(e, 25)) // S1
              + ((e&hash[5])^((~e)&hash[6])) // ch
              + k[i]
              + (w[i] = (i < 16) ? w[i] : (
                      w[i - 16]
                      + (rightRotate(w15, 7) ^ rightRotate(w15, 18) ^ (w15>>>3)) // s0
                      + w[i - 7]
                      + (rightRotate(w2, 17) ^ rightRotate(w2, 19) ^ (w2>>>10)) // s1
                  )|0
              );
          var temp2 = (rightRotate(a, 2) ^ rightRotate(a, 13) ^ rightRotate(a, 22)) // S0
              + ((a&hash[1])^(a&hash[2])^(hash[1]&hash[2])); // maj
          
          hash = [(temp1 + temp2)|0].concat(hash);
          hash[4] = (hash[4] + temp1)|0;
      }
      
      for (i = 0; i < 8; i++) {
          hash[i] = (hash[i] + oldHash[i])|0;
      }
  }
  
  for (i = 0; i < 8; i++) {
      for (j = 3; j + 1; j--) {
          var b = (hash[i]>>(j*8))&255;
          result += ((b < 16) ? 0 : '') + b.toString(16);
      }
  }
  return result;
};

正确实现代码 #

只需将随机字符串生成函数的返回值作为参数传入SHA256函数即可，以下是完整可运行代码：

// 随机字符串生成函数
function test(length) {
    let result = '';
    const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    const charactersLength = characters.length;
    let counter = 0;
    while (counter < length) {
      result += characters.charAt(Math.floor(Math.random() * charactersLength));
      counter += 1;
    }
    return result;
}

// SHA256哈希计算函数
var makeserverseed = function sha256(ascii) {
  function rightRotate(value, amount) {
      return (value>>>amount) | (value<<(32 - amount));
  };
  
  var mathPow = Math.pow;
  var maxWord = mathPow(2, 32);
  var lengthProperty = 'length'
  var i, j;
  var result = ''

  var words = [];
  var asciiBitLength = ascii[lengthProperty]*8;
  
  var hash = sha256.h = sha256.h || [];
  var k = sha256.k = sha256.k || [];
  var primeCounter = k[lengthProperty];

  var isComposite = {};
  for (var candidate = 2; primeCounter < 64; candidate++) {
      if (!isComposite[candidate]) {
          for (i = 0; i < 313; i += candidate) {
              isComposite[i] = candidate;
          }
          hash[primeCounter] = (mathPow(candidate, .5)*maxWord)|0;
          k[primeCounter++] = (mathPow(candidate, 1/3)*maxWord)|0;
      }
  }
  
  ascii += '\x80'
  while (ascii[lengthProperty]%64 - 56) ascii += '\x00' 
  for (i = 0; i < ascii[lengthProperty]; i++) {
      j = ascii.charCodeAt(i);
      if (j>>8) return; 
      words[i>>2] |= j << ((3 - i)%4)*8;
  }
  words[words[lengthProperty]] = ((asciiBitLength/maxWord)|0);
  words[words[lengthProperty]] = (asciiBitLength)
  
  for (j = 0; j < words[lengthProperty];) {
      var w = words.slice(j, j += 16); 
      var oldHash = hash;
      hash = hash.slice(0, 8);
      
      for (i = 0; i < 64; i++) {
          var i2 = i + j;
          var w15 = w[i - 15], w2 = w[i - 2];
          var a = hash[0], e = hash[4];
          var temp1 = hash[7]
              + (rightRotate(e, 6) ^ rightRotate(e, 11) ^ rightRotate(e, 25)) // S1
              + ((e&hash[5])^((~e)&hash[6])) // ch
              + k[i]
              + (w[i] = (i < 16) ? w[i] : (
                      w[i - 16]
                      + (rightRotate(w15, 7) ^ rightRotate(w15, 18) ^ (w15>>>3)) // s0
                      + w[i - 7]
                      + (rightRotate(w2, 17) ^ rightRotate(w2, 19) ^ (w2>>>10)) // s1
                  )|0
              );
          var temp2 = (rightRotate(a, 2) ^ rightRotate(a, 13) ^ rightRotate(a, 22)) // S0
              + ((a&hash[1])^(a&hash[2])^(hash[1]&hash[2])); // maj
          
          hash = [(temp1 + temp2)|0].concat(hash);
          hash[4] = (hash[4] + temp1)|0;
      }
      
      for (i = 0; i < 8; i++) {
          hash[i] = (hash[i] + oldHash[i])|0;
      }
  }
  
  for (i = 0; i < 8; i++) {
      for (j = 3; j + 1; j--) {
          var b = (hash[i]>>(j*8))&255;
          result += ((b < 16) ? 0 : '') + b.toString(16);
      }
  }
  return result;
};

// 生成随机字符串并计算哈希
const randomStr = test(16);
console.log('随机字符串:', randomStr);
console.log('SHA256哈希:', makeserverseed(randomStr));

// 验证示例输入
const sampleStr = 'SLvZAfpv2zEPYg5F';
console.log('示例字符串哈希:', makeserverseed(sampleStr)); // 输出2ab51f5928246656e753f6518dea0e0745c8faf9429578136c13181bb36d926b

关键修改点 #

• 原代码中console.log(makeserverseed)是打印函数本身，需改为传入字符串参数调用makeserverseed(字符串)
• 将两个函数整合，先生成随机字符串，再传入哈希函数计算结果

内容的提问来源于stack exchange，提问作者jordimetil