summaryrefslogtreecommitdiffstats
path: root/services/sync/modules/keys.sys.mjs
blob: b6a1dce19aeb58ca94f83f3589fd78d08ebe5bb0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

import { CommonUtils } from "resource://services-common/utils.sys.mjs";

import { Log } from "resource://gre/modules/Log.sys.mjs";

import { Weave } from "resource://services-sync/main.sys.mjs";

/**
 * Represents a pair of keys.
 *
 * Each key stored in a key bundle is 256 bits. One key is used for symmetric
 * encryption. The other is used for HMAC.
 *
 * A KeyBundle by itself is just an anonymous pair of keys. Other types
 * deriving from this one add semantics, such as associated collections or
 * generating a key bundle via HKDF from another key.
 */
function KeyBundle() {
  this._encrypt = null;
  this._encryptB64 = null;
  this._hmac = null;
  this._hmacB64 = null;
}
KeyBundle.prototype = {
  _encrypt: null,
  _encryptB64: null,
  _hmac: null,
  _hmacB64: null,

  equals: function equals(bundle) {
    return (
      bundle &&
      bundle.hmacKey == this.hmacKey &&
      bundle.encryptionKey == this.encryptionKey
    );
  },

  /*
   * Accessors for the two keys.
   */
  get encryptionKey() {
    return this._encrypt;
  },

  set encryptionKey(value) {
    if (!value || typeof value != "string") {
      throw new Error("Encryption key can only be set to string values.");
    }

    if (value.length < 16) {
      throw new Error("Encryption key must be at least 128 bits long.");
    }

    this._encrypt = value;
    this._encryptB64 = btoa(value);
  },

  get encryptionKeyB64() {
    return this._encryptB64;
  },

  get hmacKey() {
    return this._hmac;
  },

  set hmacKey(value) {
    if (!value || typeof value != "string") {
      throw new Error("HMAC key can only be set to string values.");
    }

    if (value.length < 16) {
      throw new Error("HMAC key must be at least 128 bits long.");
    }

    this._hmac = value;
    this._hmacB64 = btoa(value);
  },

  get hmacKeyB64() {
    return this._hmacB64;
  },

  /**
   * Populate this key pair with 2 new, randomly generated keys.
   */
  async generateRandom() {
    // Compute both at that same time
    let [generatedHMAC, generatedEncr] = await Promise.all([
      Weave.Crypto.generateRandomKey(),
      Weave.Crypto.generateRandomKey(),
    ]);
    this.keyPairB64 = [generatedEncr, generatedHMAC];
  },
};

/**
 * Represents a KeyBundle associated with a collection.
 *
 * This is just a KeyBundle with a collection attached.
 */
export function BulkKeyBundle(collection) {
  let log = Log.repository.getLogger("Sync.BulkKeyBundle");
  log.info("BulkKeyBundle being created for " + collection);
  KeyBundle.call(this);

  this._collection = collection;
}

BulkKeyBundle.fromHexKey = function (hexKey) {
  let key = CommonUtils.hexToBytes(hexKey);
  let bundle = new BulkKeyBundle();
  // [encryptionKey, hmacKey]
  bundle.keyPair = [key.slice(0, 32), key.slice(32, 64)];
  return bundle;
};

BulkKeyBundle.fromJWK = function (jwk) {
  if (!jwk || !jwk.k || jwk.kty !== "oct") {
    throw new Error("Invalid JWK provided to BulkKeyBundle.fromJWK");
  }
  return BulkKeyBundle.fromHexKey(CommonUtils.base64urlToHex(jwk.k));
};

BulkKeyBundle.prototype = {
  get collection() {
    return this._collection;
  },

  /**
   * Obtain the key pair in this key bundle.
   *
   * The returned keys are represented as raw byte strings.
   */
  get keyPair() {
    return [this.encryptionKey, this.hmacKey];
  },

  set keyPair(value) {
    if (!Array.isArray(value) || value.length != 2) {
      throw new Error("BulkKeyBundle.keyPair value must be array of 2 keys.");
    }

    this.encryptionKey = value[0];
    this.hmacKey = value[1];
  },

  get keyPairB64() {
    return [this.encryptionKeyB64, this.hmacKeyB64];
  },

  set keyPairB64(value) {
    if (!Array.isArray(value) || value.length != 2) {
      throw new Error(
        "BulkKeyBundle.keyPairB64 value must be an array of 2 keys."
      );
    }

    this.encryptionKey = CommonUtils.safeAtoB(value[0]);
    this.hmacKey = CommonUtils.safeAtoB(value[1]);
  },
};

Object.setPrototypeOf(BulkKeyBundle.prototype, KeyBundle.prototype);