Verified Commit 1035b08b authored by Kagami Sascha Rosylight's avatar Kagami Sascha Rosylight Committed by ma1
Browse files

Bug 1924154 - Disallow too small record a=RyanVM 

Original Revision: https://phabricator.services.mozilla.com/D225687

Differential Revision: https://phabricator.services.mozilla.com/D226147
parent a3372491

dom/push/PushCrypto.sys.mjs

+18 −2
Original line number Diff line number Diff line
@@ -108,6 +108,8 @@ function getEncryptionParams(encryptField) { 
// aes128gcm scheme.

function getCryptoParamsFromPayload(payload) {

  if (payload.byteLength < 21) {

    // The value 21 is from https://datatracker.ietf.org/doc/html/rfc8188#section-2.1

    // | salt (16) | rs (4) | idlen (1) | keyid (idlen) |

    throw new CryptoError("Truncated header", BAD_CRYPTO);

  }

  let rs =
@@ -115,8 +117,16 @@ function getCryptoParamsFromPayload(payload) { 
    (payload[17] << 16) |

    (payload[18] << 8) |

    payload[19];

  if (rs < 18) {

    // https://datatracker.ietf.org/doc/html/rfc8188#section-2.1

    throw new CryptoError(

      "Record sizes smaller than 18 are invalid",

      BAD_RS_PARAM

    );

  }

  let keyIdLen = payload[20];

  if (keyIdLen != 65) {

    // https://datatracker.ietf.org/doc/html/rfc8291/#section-4

    throw new CryptoError("Invalid sender public key", BAD_DH_PARAM);

  }

  if (payload.byteLength <= 21 + keyIdLen) {
@@ -171,8 +181,12 @@ export function getCryptoParamsFromHeaders(headers) { 
    throw new CryptoError("Invalid salt parameter", BAD_SALT_PARAM);

  }

  var rs = enc.rs ? parseInt(enc.rs, 10) : 4096;

  if (isNaN(rs)) {

    throw new CryptoError("rs parameter must be a number", BAD_RS_PARAM);

  if (isNaN(rs) || rs < 1 || rs > 68719476705) {

    // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-encryption-encoding-03#section-3.1

    throw new CryptoError(

      "rs parameter must be a number greater than 1 and smaller than 2^36-31",

      BAD_RS_PARAM

    );

  }

  return {

    salt,
@@ -791,6 +805,7 @@ class aes128gcmEncoder { 
  // Perform the actual encryption of the payload.

  async encrypt(key, nonce) {

    if (this.rs < 18) {

      // https://datatracker.ietf.org/doc/html/rfc8188#section-2.1

      throw new CryptoError("recordsize is too small", BAD_RS_PARAM);

    }
@@ -869,6 +884,7 @@ class aes128gcmEncoder { 
  createHeader(key) {

    // layout is "salt|32-bit-int|8-bit-int|key"

    if (key.byteLength != 65) {

      // https://datatracker.ietf.org/doc/html/rfc8291/#section-4

      throw new CryptoError("Invalid key length for header", BAD_DH_PARAM);

    }

    // the 2 ints