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m3u8-hls

m3u8

このスクリプトは単体で利用できません。右のようなメタデータを含むスクリプトから、ライブラリとして読み込まれます: // @require https://update.greasyfork.org/scripts/468820/1208011/m3u8-hls.js

このスクリプトの質問や評価の投稿はこちら通報はこちらへお寄せください。
//引用 https://github.com/video-dev/hls.js

function removePadding(buffer) {
  const outputBytes = buffer.byteLength;
  const paddingBytes = outputBytes && (new DataView(buffer)).getUint8(outputBytes - 1);
  if (paddingBytes) {
    return buffer.slice(0, outputBytes - paddingBytes);
  } else {
    return buffer;
  }
}

function AESDecryptor() {
  return {
    constructor() {
      this.rcon = [0x0, 0x1, 0x2, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36];
      this.subMix = [new Uint32Array(256), new Uint32Array(256), new Uint32Array(256), new Uint32Array(256)];
      this.invSubMix = [new Uint32Array(256), new Uint32Array(256), new Uint32Array(256), new Uint32Array(256)];
      this.sBox = new Uint32Array(256);
      this.invSBox = new Uint32Array(256);

      // Changes during runtime
      this.key = new Uint32Array(0);

      this.initTable();
    },

    // Using view.getUint32() also swaps the byte order.
    uint8ArrayToUint32Array_(arrayBuffer) {
      let view = new DataView(arrayBuffer);
      let newArray = new Uint32Array(4);
      for (let i = 0; i < 4; i++) {
        newArray[i] = view.getUint32(i * 4);
      }

      return newArray;
    },

    initTable() {
      let sBox = this.sBox;
      let invSBox = this.invSBox;
      let subMix = this.subMix;
      let subMix0 = subMix[0];
      let subMix1 = subMix[1];
      let subMix2 = subMix[2];
      let subMix3 = subMix[3];
      let invSubMix = this.invSubMix;
      let invSubMix0 = invSubMix[0];
      let invSubMix1 = invSubMix[1];
      let invSubMix2 = invSubMix[2];
      let invSubMix3 = invSubMix[3];

      let d = new Uint32Array(256);
      let x = 0;
      let xi = 0;
      let i = 0;
      for (i = 0; i < 256; i++) {
        if (i < 128) {
          d[i] = i << 1;
        } else {
          d[i] = (i << 1) ^ 0x11b;
        }
      }

      for (i = 0; i < 256; i++) {
        let sx = xi ^ (xi << 1) ^ (xi << 2) ^ (xi << 3) ^ (xi << 4);
        sx = (sx >>> 8) ^ (sx & 0xff) ^ 0x63;
        sBox[x] = sx;
        invSBox[sx] = x;

        // Compute multiplication
        let x2 = d[x];
        let x4 = d[x2];
        let x8 = d[x4];

        // Compute sub/invSub bytes, mix columns tables
        let t = (d[sx] * 0x101) ^ (sx * 0x1010100);
        subMix0[x] = (t << 24) | (t >>> 8);
        subMix1[x] = (t << 16) | (t >>> 16);
        subMix2[x] = (t << 8) | (t >>> 24);
        subMix3[x] = t;

        // Compute inv sub bytes, inv mix columns tables
        t = (x8 * 0x1010101) ^ (x4 * 0x10001) ^ (x2 * 0x101) ^ (x * 0x1010100);
        invSubMix0[sx] = (t << 24) | (t >>> 8);
        invSubMix1[sx] = (t << 16) | (t >>> 16);
        invSubMix2[sx] = (t << 8) | (t >>> 24);
        invSubMix3[sx] = t;

        // Compute next counter
        if (!x) {
          x = xi = 1;
        } else {
          x = x2 ^ d[d[d[x8 ^ x2]]];
          xi ^= d[d[xi]];
        }
      }
    },

    expandKey(keyBuffer) {
      // convert keyBuffer to Uint32Array
      let key = this.uint8ArrayToUint32Array_(keyBuffer);
      let sameKey = true;
      let offset = 0;

      while (offset < key.length && sameKey) {
        sameKey = (key[offset] === this.key[offset]);
        offset++;
      }

      if (sameKey) {
        return;
      }

      this.key = key;
      let keySize = this.keySize = key.length;

      if (keySize !== 4 && keySize !== 6 && keySize !== 8) {
        throw new Error('Invalid aes key size=' + keySize);
      }

      let ksRows = this.ksRows = (keySize + 6 + 1) * 4;
      let ksRow;
      let invKsRow;

      let keySchedule = this.keySchedule = new Uint32Array(ksRows);
      let invKeySchedule = this.invKeySchedule = new Uint32Array(ksRows);
      let sbox = this.sBox;
      let rcon = this.rcon;

      let invSubMix = this.invSubMix;
      let invSubMix0 = invSubMix[0];
      let invSubMix1 = invSubMix[1];
      let invSubMix2 = invSubMix[2];
      let invSubMix3 = invSubMix[3];

      let prev;
      let t;

      for (ksRow = 0; ksRow < ksRows; ksRow++) {
        if (ksRow < keySize) {
          prev = keySchedule[ksRow] = key[ksRow];
          continue;
        }
        t = prev;

        if (ksRow % keySize === 0) {
          // Rot word
          t = (t << 8) | (t >>> 24);

          // Sub word
          t = (sbox[t >>> 24] << 24) | (sbox[(t >>> 16) & 0xff] << 16) | (sbox[(t >>> 8) & 0xff] << 8) | sbox[t & 0xff];

          // Mix Rcon
          t ^= rcon[(ksRow / keySize) | 0] << 24;
        } else if (keySize > 6 && ksRow % keySize === 4) {
          // Sub word
          t = (sbox[t >>> 24] << 24) | (sbox[(t >>> 16) & 0xff] << 16) | (sbox[(t >>> 8) & 0xff] << 8) | sbox[t & 0xff];
        }

        keySchedule[ksRow] = prev = (keySchedule[ksRow - keySize] ^ t) >>> 0;
      }

      for (invKsRow = 0; invKsRow < ksRows; invKsRow++) {
        ksRow = ksRows - invKsRow;
        if (invKsRow & 3) {
          t = keySchedule[ksRow];
        } else {
          t = keySchedule[ksRow - 4];
        }

        if (invKsRow < 4 || ksRow <= 4) {
          invKeySchedule[invKsRow] = t;
        } else {
          invKeySchedule[invKsRow] = invSubMix0[sbox[t >>> 24]] ^ invSubMix1[sbox[(t >>> 16) & 0xff]] ^ invSubMix2[sbox[(t >>> 8) & 0xff]] ^ invSubMix3[sbox[t & 0xff]];
        }

        invKeySchedule[invKsRow] = invKeySchedule[invKsRow] >>> 0;
      }
    },

    // Adding this as a method greatly improves performance.
    networkToHostOrderSwap(word) {
      return (word << 24) | ((word & 0xff00) << 8) | ((word & 0xff0000) >> 8) | (word >>> 24);
    },

    decrypt(inputArrayBuffer, offset, aesIV, removePKCS7Padding) {
      let nRounds = this.keySize + 6;
      let invKeySchedule = this.invKeySchedule;
      let invSBOX = this.invSBox;

      let invSubMix = this.invSubMix;
      let invSubMix0 = invSubMix[0];
      let invSubMix1 = invSubMix[1];
      let invSubMix2 = invSubMix[2];
      let invSubMix3 = invSubMix[3];

      let initVector = this.uint8ArrayToUint32Array_(aesIV);
      let initVector0 = initVector[0];
      let initVector1 = initVector[1];
      let initVector2 = initVector[2];
      let initVector3 = initVector[3];

      let inputInt32 = new Int32Array(inputArrayBuffer);
      let outputInt32 = new Int32Array(inputInt32.length);

      let t0, t1, t2, t3;
      let s0, s1, s2, s3;
      let inputWords0, inputWords1, inputWords2, inputWords3;

      let ksRow, i;
      let swapWord = this.networkToHostOrderSwap;

      while (offset < inputInt32.length) {
        inputWords0 = swapWord(inputInt32[offset]);
        inputWords1 = swapWord(inputInt32[offset + 1]);
        inputWords2 = swapWord(inputInt32[offset + 2]);
        inputWords3 = swapWord(inputInt32[offset + 3]);

        s0 = inputWords0 ^ invKeySchedule[0];
        s1 = inputWords3 ^ invKeySchedule[1];
        s2 = inputWords2 ^ invKeySchedule[2];
        s3 = inputWords1 ^ invKeySchedule[3];

        ksRow = 4;

        // Iterate through the rounds of decryption
        for (i = 1; i < nRounds; i++) {
          t0 = invSubMix0[s0 >>> 24] ^ invSubMix1[(s1 >> 16) & 0xff] ^ invSubMix2[(s2 >> 8) & 0xff] ^ invSubMix3[s3 & 0xff] ^ invKeySchedule[ksRow];
          t1 = invSubMix0[s1 >>> 24] ^ invSubMix1[(s2 >> 16) & 0xff] ^ invSubMix2[(s3 >> 8) & 0xff] ^ invSubMix3[s0 & 0xff] ^ invKeySchedule[ksRow + 1];
          t2 = invSubMix0[s2 >>> 24] ^ invSubMix1[(s3 >> 16) & 0xff] ^ invSubMix2[(s0 >> 8) & 0xff] ^ invSubMix3[s1 & 0xff] ^ invKeySchedule[ksRow + 2];
          t3 = invSubMix0[s3 >>> 24] ^ invSubMix1[(s0 >> 16) & 0xff] ^ invSubMix2[(s1 >> 8) & 0xff] ^ invSubMix3[s2 & 0xff] ^ invKeySchedule[ksRow + 3];
          // Update state
          s0 = t0;
          s1 = t1;
          s2 = t2;
          s3 = t3;

          ksRow = ksRow + 4;
        }

        // Shift rows, sub bytes, add round key
        t0 = ((invSBOX[s0 >>> 24] << 24) ^ (invSBOX[(s1 >> 16) & 0xff] << 16) ^ (invSBOX[(s2 >> 8) & 0xff] << 8) ^ invSBOX[s3 & 0xff]) ^ invKeySchedule[ksRow];
        t1 = ((invSBOX[s1 >>> 24] << 24) ^ (invSBOX[(s2 >> 16) & 0xff] << 16) ^ (invSBOX[(s3 >> 8) & 0xff] << 8) ^ invSBOX[s0 & 0xff]) ^ invKeySchedule[ksRow + 1];
        t2 = ((invSBOX[s2 >>> 24] << 24) ^ (invSBOX[(s3 >> 16) & 0xff] << 16) ^ (invSBOX[(s0 >> 8) & 0xff] << 8) ^ invSBOX[s1 & 0xff]) ^ invKeySchedule[ksRow + 2];
        t3 = ((invSBOX[s3 >>> 24] << 24) ^ (invSBOX[(s0 >> 16) & 0xff] << 16) ^ (invSBOX[(s1 >> 8) & 0xff] << 8) ^ invSBOX[s2 & 0xff]) ^ invKeySchedule[ksRow + 3];
        ksRow = ksRow + 3;

        // Write
        outputInt32[offset] = swapWord(t0 ^ initVector0);
        outputInt32[offset + 1] = swapWord(t3 ^ initVector1);
        outputInt32[offset + 2] = swapWord(t2 ^ initVector2);
        outputInt32[offset + 3] = swapWord(t1 ^ initVector3);

        // reset initVector to last 4 unsigned int
        initVector0 = inputWords0;
        initVector1 = inputWords1;
        initVector2 = inputWords2;
        initVector3 = inputWords3;

        offset = offset + 4;
      }

      return removePKCS7Padding ? removePadding(outputInt32.buffer) : outputInt32.buffer;
    },

    destroy() {
      this.key = undefined;
      this.keySize = undefined;
      this.ksRows = undefined;

      this.sBox = undefined;
      this.invSBox = undefined;
      this.subMix = undefined;
      this.invSubMix = undefined;
      this.keySchedule = undefined;
      this.invKeySchedule = undefined;

      this.rcon = undefined;
    },
  }
}