98 lines
3.7 KiB
JavaScript
98 lines
3.7 KiB
JavaScript
|
"use strict";
|
||
|
Object.defineProperty(exports, "__esModule", { value: true });
|
||
|
const crypto_1 = require("crypto");
|
||
|
const check_iv_length_js_1 = require("../lib/check_iv_length.js");
|
||
|
const check_cek_length_js_1 = require("./check_cek_length.js");
|
||
|
const buffer_utils_js_1 = require("../lib/buffer_utils.js");
|
||
|
const errors_js_1 = require("../util/errors.js");
|
||
|
const timing_safe_equal_js_1 = require("./timing_safe_equal.js");
|
||
|
const cbc_tag_js_1 = require("./cbc_tag.js");
|
||
|
const webcrypto_js_1 = require("./webcrypto.js");
|
||
|
const crypto_key_js_1 = require("../lib/crypto_key.js");
|
||
|
const is_key_object_js_1 = require("./is_key_object.js");
|
||
|
const invalid_key_input_js_1 = require("../lib/invalid_key_input.js");
|
||
|
const ciphers_js_1 = require("./ciphers.js");
|
||
|
const is_key_like_js_1 = require("./is_key_like.js");
|
||
|
function cbcDecrypt(enc, cek, ciphertext, iv, tag, aad) {
|
||
|
const keySize = parseInt(enc.slice(1, 4), 10);
|
||
|
if ((0, is_key_object_js_1.default)(cek)) {
|
||
|
cek = cek.export();
|
||
|
}
|
||
|
const encKey = cek.subarray(keySize >> 3);
|
||
|
const macKey = cek.subarray(0, keySize >> 3);
|
||
|
const macSize = parseInt(enc.slice(-3), 10);
|
||
|
const algorithm = `aes-${keySize}-cbc`;
|
||
|
if (!(0, ciphers_js_1.default)(algorithm)) {
|
||
|
throw new errors_js_1.JOSENotSupported(`alg ${enc} is not supported by your javascript runtime`);
|
||
|
}
|
||
|
const expectedTag = (0, cbc_tag_js_1.default)(aad, iv, ciphertext, macSize, macKey, keySize);
|
||
|
let macCheckPassed;
|
||
|
try {
|
||
|
macCheckPassed = (0, timing_safe_equal_js_1.default)(tag, expectedTag);
|
||
|
}
|
||
|
catch {
|
||
|
}
|
||
|
if (!macCheckPassed) {
|
||
|
throw new errors_js_1.JWEDecryptionFailed();
|
||
|
}
|
||
|
let plaintext;
|
||
|
try {
|
||
|
const decipher = (0, crypto_1.createDecipheriv)(algorithm, encKey, iv);
|
||
|
plaintext = (0, buffer_utils_js_1.concat)(decipher.update(ciphertext), decipher.final());
|
||
|
}
|
||
|
catch {
|
||
|
}
|
||
|
if (!plaintext) {
|
||
|
throw new errors_js_1.JWEDecryptionFailed();
|
||
|
}
|
||
|
return plaintext;
|
||
|
}
|
||
|
function gcmDecrypt(enc, cek, ciphertext, iv, tag, aad) {
|
||
|
const keySize = parseInt(enc.slice(1, 4), 10);
|
||
|
const algorithm = `aes-${keySize}-gcm`;
|
||
|
if (!(0, ciphers_js_1.default)(algorithm)) {
|
||
|
throw new errors_js_1.JOSENotSupported(`alg ${enc} is not supported by your javascript runtime`);
|
||
|
}
|
||
|
try {
|
||
|
const decipher = (0, crypto_1.createDecipheriv)(algorithm, cek, iv, { authTagLength: 16 });
|
||
|
decipher.setAuthTag(tag);
|
||
|
if (aad.byteLength) {
|
||
|
decipher.setAAD(aad, { plaintextLength: ciphertext.length });
|
||
|
}
|
||
|
const plaintext = decipher.update(ciphertext);
|
||
|
decipher.final();
|
||
|
return plaintext;
|
||
|
}
|
||
|
catch {
|
||
|
throw new errors_js_1.JWEDecryptionFailed();
|
||
|
}
|
||
|
}
|
||
|
const decrypt = (enc, cek, ciphertext, iv, tag, aad) => {
|
||
|
let key;
|
||
|
if ((0, webcrypto_js_1.isCryptoKey)(cek)) {
|
||
|
(0, crypto_key_js_1.checkEncCryptoKey)(cek, enc, 'decrypt');
|
||
|
key = crypto_1.KeyObject.from(cek);
|
||
|
}
|
||
|
else if (cek instanceof Uint8Array || (0, is_key_object_js_1.default)(cek)) {
|
||
|
key = cek;
|
||
|
}
|
||
|
else {
|
||
|
throw new TypeError((0, invalid_key_input_js_1.default)(cek, ...is_key_like_js_1.types, 'Uint8Array'));
|
||
|
}
|
||
|
(0, check_cek_length_js_1.default)(enc, key);
|
||
|
(0, check_iv_length_js_1.default)(enc, iv);
|
||
|
switch (enc) {
|
||
|
case 'A128CBC-HS256':
|
||
|
case 'A192CBC-HS384':
|
||
|
case 'A256CBC-HS512':
|
||
|
return cbcDecrypt(enc, key, ciphertext, iv, tag, aad);
|
||
|
case 'A128GCM':
|
||
|
case 'A192GCM':
|
||
|
case 'A256GCM':
|
||
|
return gcmDecrypt(enc, key, ciphertext, iv, tag, aad);
|
||
|
default:
|
||
|
throw new errors_js_1.JOSENotSupported('Unsupported JWE Content Encryption Algorithm');
|
||
|
}
|
||
|
};
|
||
|
exports.default = decrypt;
|