Merge pull request #1150 from jasonandjay/main

feat: optimize BTC Readme

BTC/Basic/tools/bech32m.js

@@ -0,0 +1,121 @@
+const CHARSET = 'qpzry9x8gf2tvdw0s3jn54khce6mua7l';
+
+// 将字符转换为数值
+function charToValue(char) {
+  const index = CHARSET.indexOf(char);
+  if (index === -1) {
+    throw new Error('Invalid character');
+  }
+  return index;
+}
+
+// 将数值转换为字符
+function valueToChar(value) {
+  return CHARSET[value];
+}
+
+// 多项式模数计算 Bech32 校验和
+function polymod(values) {
+  let checksum = 1;
+  for (let value of values) {
+    const top = checksum >> 25;
+    checksum = ((checksum & 0x1ffffff) << 5) ^ value;
+    for (let i = 0; i < 5; i++) {
+      if ((top >> i) & 1) {
+        checksum ^= (0x3b6a57b2 >> (5 * i)) & 0x1ffffff;
+      }
+    }
+  }
+  return checksum;
+}
+
+// 扩展人类可读部分（HRP, Human-Readable Part）以帮助计算校验和
+function hrpExpand(hrp) {
+  const ret = [];
+  // 先将每个字符转换为其ASCII码除以32的余数
+  for (let i = 0; i < hrp.length; i++) {
+    ret.push(hrp.charCodeAt(i) >> 5);
+  }
+  // 添加分隔符
+  ret.push(0);
+  // 再将每个字符转换为其ASCII码的低5位
+  for (let i = 0; i < hrp.length; i++) {
+    ret.push(hrp.charCodeAt(i) & 31);
+  }
+  return ret;
+}
+
+// 计算校验和的最终值（Bech32m）
+function createChecksum(hrp, data) {
+  const values = hrpExpand(hrp).concat(data).concat([0, 0, 0, 0, 0, 0]);
+  const polymodValue = polymod(values) ^ 0x2bc830a3; // Bech32m 标识多项式
+  let result = [];
+  for (let i = 0; i < 6; ++i) {
+    result.push((polymodValue >> (5 * (5 - i))) & 31);
+  }
+  return result;
+}
+
+// 验证校验和
+function verifyChecksum(hrp, data) {
+  const expandedHrp = hrpExpand(hrp);
+  const values = expandedHrp.concat(data);
+  return polymod(values) === 0x2bc830a3; // 对于 Bech32, 有效校验和会返回1, 对于 Bech32m 需要验证不同的常量
+}
+
+function convertBits(data, fromBits, toBits, pad = true) {
+  let acc = 0;
+  let bits = 0;
+  const ret = [];
+  const maxv = (1 << toBits) - 1;
+  for (let i = 0; i < data.length; ++i) {
+    let value = data[i];
+    if (value < 0 || value >> fromBits !== 0) {
+      return null;
+    }
+    acc = (acc << fromBits) | value;
+    bits += fromBits;
+    while (bits >= toBits) {
+      bits -= toBits;
+      ret.push((acc >> bits) & maxv);
+    }
+  }
+  if (pad) {
+    if (bits > 0) {
+      ret.push((acc << (toBits - bits)) & maxv);
+    }
+  } else if (bits >= fromBits || (acc << (toBits - bits)) & maxv) {
+    return null;
+  }
+  return ret;
+}
+
+function encodeBech32m(hrp, data) {
+  const combined = data.concat(createChecksum(hrp, data));
+  let result = hrp + '1';
+  for (let datum of combined) {
+    result += valueToChar(datum);
+  }
+  return result;
+}
+
+function decodeBech32m(bech32mStr) {
+  const pos = bech32mStr.lastIndexOf('1');
+  const hrp = bech32mStr.slice(0, pos);
+  const data = [];
+  for (let i = pos + 1; i < bech32mStr.length; ++i) {
+    data.push(charToValue(bech32mStr[i]));
+  }
+  if (!verifyChecksum(hrp, data)) {
+    throw new Error('Invalid checksum');
+  }
+  return { hrp, data: data.slice(0, data.length - 6) };
+}
+
+const hrp = 'bc';
+const data = [15, 2, 20, 3, 5, 18]; // 随机示例数据
+const encoded = encodeBech32m(hrp, data);
+console.log('Encoded:', encoded);
+
+const decoded = decodeBech32m(encoded);
+console.log('Decoded:', decoded);