encrypt.js 3.2 KB

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  1. "use strict";
  2. Object.defineProperty(exports, "__esModule", { value: true });
  3. const crypto_1 = require("crypto");
  4. const check_iv_length_js_1 = require("../lib/check_iv_length.js");
  5. const check_cek_length_js_1 = require("./check_cek_length.js");
  6. const buffer_utils_js_1 = require("../lib/buffer_utils.js");
  7. const cbc_tag_js_1 = require("./cbc_tag.js");
  8. const webcrypto_js_1 = require("./webcrypto.js");
  9. const crypto_key_js_1 = require("../lib/crypto_key.js");
  10. const is_key_object_js_1 = require("./is_key_object.js");
  11. const invalid_key_input_js_1 = require("../lib/invalid_key_input.js");
  12. const errors_js_1 = require("../util/errors.js");
  13. const ciphers_js_1 = require("./ciphers.js");
  14. const is_key_like_js_1 = require("./is_key_like.js");
  15. function cbcEncrypt(enc, plaintext, cek, iv, aad) {
  16. const keySize = parseInt(enc.slice(1, 4), 10);
  17. if ((0, is_key_object_js_1.default)(cek)) {
  18. cek = cek.export();
  19. }
  20. const encKey = cek.subarray(keySize >> 3);
  21. const macKey = cek.subarray(0, keySize >> 3);
  22. const algorithm = `aes-${keySize}-cbc`;
  23. if (!(0, ciphers_js_1.default)(algorithm)) {
  24. throw new errors_js_1.JOSENotSupported(`alg ${enc} is not supported by your javascript runtime`);
  25. }
  26. const cipher = (0, crypto_1.createCipheriv)(algorithm, encKey, iv);
  27. const ciphertext = (0, buffer_utils_js_1.concat)(cipher.update(plaintext), cipher.final());
  28. const macSize = parseInt(enc.slice(-3), 10);
  29. const tag = (0, cbc_tag_js_1.default)(aad, iv, ciphertext, macSize, macKey, keySize);
  30. return { ciphertext, tag };
  31. }
  32. function gcmEncrypt(enc, plaintext, cek, iv, aad) {
  33. const keySize = parseInt(enc.slice(1, 4), 10);
  34. const algorithm = `aes-${keySize}-gcm`;
  35. if (!(0, ciphers_js_1.default)(algorithm)) {
  36. throw new errors_js_1.JOSENotSupported(`alg ${enc} is not supported by your javascript runtime`);
  37. }
  38. const cipher = (0, crypto_1.createCipheriv)(algorithm, cek, iv, { authTagLength: 16 });
  39. if (aad.byteLength) {
  40. cipher.setAAD(aad, { plaintextLength: plaintext.length });
  41. }
  42. const ciphertext = cipher.update(plaintext);
  43. cipher.final();
  44. const tag = cipher.getAuthTag();
  45. return { ciphertext, tag };
  46. }
  47. const encrypt = (enc, plaintext, cek, iv, aad) => {
  48. let key;
  49. if ((0, webcrypto_js_1.isCryptoKey)(cek)) {
  50. (0, crypto_key_js_1.checkEncCryptoKey)(cek, enc, 'encrypt');
  51. key = crypto_1.KeyObject.from(cek);
  52. }
  53. else if (cek instanceof Uint8Array || (0, is_key_object_js_1.default)(cek)) {
  54. key = cek;
  55. }
  56. else {
  57. throw new TypeError((0, invalid_key_input_js_1.default)(cek, ...is_key_like_js_1.types, 'Uint8Array'));
  58. }
  59. (0, check_cek_length_js_1.default)(enc, key);
  60. (0, check_iv_length_js_1.default)(enc, iv);
  61. switch (enc) {
  62. case 'A128CBC-HS256':
  63. case 'A192CBC-HS384':
  64. case 'A256CBC-HS512':
  65. return cbcEncrypt(enc, plaintext, key, iv, aad);
  66. case 'A128GCM':
  67. case 'A192GCM':
  68. case 'A256GCM':
  69. return gcmEncrypt(enc, plaintext, key, iv, aad);
  70. default:
  71. throw new errors_js_1.JOSENotSupported('Unsupported JWE Content Encryption Algorithm');
  72. }
  73. };
  74. exports.default = encrypt;