mode-cfb.js 4.1 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677
  1. // Cipher Feedback
  2. var __classPrivateFieldSet = (this && this.__classPrivateFieldSet) || function (receiver, state, value, kind, f) {
  3. if (kind === "m") throw new TypeError("Private method is not writable");
  4. if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
  5. if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
  6. return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
  7. };
  8. var __classPrivateFieldGet = (this && this.__classPrivateFieldGet) || function (receiver, state, kind, f) {
  9. if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
  10. if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
  11. return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
  12. };
  13. var _CFB_instances, _CFB_iv, _CFB_shiftRegister, _CFB_shift;
  14. import { ModeOfOperation } from "./mode.js";
  15. export class CFB extends ModeOfOperation {
  16. constructor(key, iv, segmentSize = 8) {
  17. super("CFB", key, CFB);
  18. _CFB_instances.add(this);
  19. _CFB_iv.set(this, void 0);
  20. _CFB_shiftRegister.set(this, void 0);
  21. // This library currently only handles byte-aligned segmentSize
  22. if (!Number.isInteger(segmentSize) || (segmentSize % 8)) {
  23. throw new TypeError("invalid segmentSize");
  24. }
  25. Object.defineProperties(this, {
  26. segmentSize: { enumerable: true, value: segmentSize }
  27. });
  28. if (iv) {
  29. if (iv.length % 16) {
  30. throw new TypeError("invalid iv size (must be 16 bytes)");
  31. }
  32. __classPrivateFieldSet(this, _CFB_iv, new Uint8Array(iv), "f");
  33. }
  34. else {
  35. __classPrivateFieldSet(this, _CFB_iv, new Uint8Array(16), "f");
  36. }
  37. __classPrivateFieldSet(this, _CFB_shiftRegister, this.iv, "f");
  38. }
  39. get iv() { return new Uint8Array(__classPrivateFieldGet(this, _CFB_iv, "f")); }
  40. encrypt(plaintext) {
  41. if (8 * plaintext.length % this.segmentSize) {
  42. throw new TypeError("invalid plaintext size (must be multiple of segmentSize bytes)");
  43. }
  44. const segmentSize = this.segmentSize / 8;
  45. const ciphertext = new Uint8Array(plaintext);
  46. for (let i = 0; i < ciphertext.length; i += segmentSize) {
  47. const xorSegment = this.aes.encrypt(__classPrivateFieldGet(this, _CFB_shiftRegister, "f"));
  48. for (let j = 0; j < segmentSize; j++) {
  49. ciphertext[i + j] ^= xorSegment[j];
  50. }
  51. __classPrivateFieldGet(this, _CFB_instances, "m", _CFB_shift).call(this, ciphertext.subarray(i));
  52. }
  53. return ciphertext;
  54. }
  55. decrypt(ciphertext) {
  56. if (8 * ciphertext.length % this.segmentSize) {
  57. throw new TypeError("invalid ciphertext size (must be multiple of segmentSize bytes)");
  58. }
  59. const segmentSize = this.segmentSize / 8;
  60. const plaintext = new Uint8Array(ciphertext);
  61. for (let i = 0; i < plaintext.length; i += segmentSize) {
  62. const xorSegment = this.aes.encrypt(__classPrivateFieldGet(this, _CFB_shiftRegister, "f"));
  63. for (let j = 0; j < segmentSize; j++) {
  64. plaintext[i + j] ^= xorSegment[j];
  65. }
  66. __classPrivateFieldGet(this, _CFB_instances, "m", _CFB_shift).call(this, ciphertext.subarray(i));
  67. }
  68. return plaintext;
  69. }
  70. }
  71. _CFB_iv = new WeakMap(), _CFB_shiftRegister = new WeakMap(), _CFB_instances = new WeakSet(), _CFB_shift = function _CFB_shift(data) {
  72. const segmentSize = this.segmentSize / 8;
  73. // Shift the register
  74. __classPrivateFieldGet(this, _CFB_shiftRegister, "f").set(__classPrivateFieldGet(this, _CFB_shiftRegister, "f").subarray(segmentSize));
  75. __classPrivateFieldGet(this, _CFB_shiftRegister, "f").set(data.subarray(0, segmentSize), 16 - segmentSize);
  76. };
  77. //# sourceMappingURL=mode-cfb.js.map