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CryptoBuffer.cpp (4485B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #include "CryptoBuffer.h"
      8 
      9 #include "mozilla/Base64.h"
     10 #include "mozilla/dom/BufferSourceBinding.h"
     11 #include "mozilla/dom/UnionTypes.h"
     12 #include "secitem.h"
     13 
     14 namespace mozilla::dom {
     15 
     16 uint8_t* CryptoBuffer::Assign(const CryptoBuffer& aData) {
     17  // Same as in nsTArray_Impl::operator=, but return the value
     18  // returned from ReplaceElementsAt to enable OOM detection
     19  return ReplaceElementsAt(0, Length(), aData.Elements(), aData.Length(),
     20                           fallible);
     21 }
     22 
     23 uint8_t* CryptoBuffer::Assign(const uint8_t* aData, uint32_t aLength) {
     24  return ReplaceElementsAt(0, Length(), aData, aLength, fallible);
     25 }
     26 
     27 uint8_t* CryptoBuffer::Assign(const nsACString& aString) {
     28  return Assign(reinterpret_cast<uint8_t const*>(aString.BeginReading()),
     29                aString.Length());
     30 }
     31 
     32 uint8_t* CryptoBuffer::Assign(const SECItem* aItem) {
     33  MOZ_ASSERT(aItem);
     34  return Assign(aItem->data, aItem->len);
     35 }
     36 
     37 uint8_t* CryptoBuffer::Assign(const nsTArray<uint8_t>& aData) {
     38  return ReplaceElementsAt(0, Length(), aData.Elements(), aData.Length(),
     39                           fallible);
     40 }
     41 
     42 uint8_t* CryptoBuffer::Assign(const ArrayBuffer& aData) {
     43  Clear();
     44  return aData.AppendDataTo(*this) ? Elements() : nullptr;
     45 }
     46 
     47 uint8_t* CryptoBuffer::Assign(const ArrayBufferView& aData) {
     48  Clear();
     49  return aData.AppendDataTo(*this) ? Elements() : nullptr;
     50 }
     51 
     52 uint8_t* CryptoBuffer::Assign(const BufferSource& aData) {
     53  Clear();
     54 
     55  return AppendTypedArrayDataTo(aData, *this) ? Elements() : nullptr;
     56 }
     57 
     58 uint8_t* CryptoBuffer::Assign(const OwningBufferSource& aData) {
     59  Clear();
     60 
     61  return AppendTypedArrayDataTo(aData, *this) ? Elements() : nullptr;
     62 }
     63 
     64 uint8_t* CryptoBuffer::Assign(const Uint8Array& aArray) {
     65  Clear();
     66  return aArray.AppendDataTo(*this) ? Elements() : nullptr;
     67 }
     68 
     69 uint8_t* CryptoBuffer::AppendSECItem(const SECItem* aItem) {
     70  MOZ_ASSERT(aItem);
     71  return AppendElements(aItem->data, aItem->len, fallible);
     72 }
     73 
     74 uint8_t* CryptoBuffer::AppendSECItem(const SECItem& aItem) {
     75  return AppendElements(aItem.data, aItem.len, fallible);
     76 }
     77 
     78 // Helpers to encode/decode JWK's special flavor of Base64
     79 // * No whitespace
     80 // * No padding
     81 // * URL-safe character set
     82 nsresult CryptoBuffer::FromJwkBase64(const nsString& aBase64) {
     83  NS_ConvertUTF16toUTF8 temp(aBase64);
     84  temp.StripWhitespace();
     85 
     86  // JWK prohibits padding per RFC 7515, section 2.
     87  nsresult rv =
     88      Base64URLDecode(temp, Base64URLDecodePaddingPolicy::Reject, *this);
     89  NS_ENSURE_SUCCESS(rv, rv);
     90 
     91  return NS_OK;
     92 }
     93 
     94 nsresult CryptoBuffer::ToJwkBase64(nsString& aBase64) const {
     95  // Shortcut for the empty octet string
     96  if (Length() == 0) {
     97    aBase64.Truncate();
     98    return NS_OK;
     99  }
    100 
    101  nsAutoCString base64;
    102  nsresult rv = Base64URLEncode(Length(), Elements(),
    103                                Base64URLEncodePaddingPolicy::Omit, base64);
    104  NS_ENSURE_SUCCESS(rv, rv);
    105 
    106  CopyASCIItoUTF16(base64, aBase64);
    107  return NS_OK;
    108 }
    109 
    110 bool CryptoBuffer::ToSECItem(PLArenaPool* aArena, SECItem* aItem) const {
    111  aItem->type = siBuffer;
    112  aItem->data = nullptr;
    113 
    114  if (!::SECITEM_AllocItem(aArena, aItem, Length())) {
    115    return false;
    116  }
    117  // If this CryptoBuffer is of 0 length, aItem->data will be null. Passing
    118  // null to memcpy is not valid, even if the length is 0, so return early.
    119  if (!aItem->data) {
    120    MOZ_ASSERT(Length() == 0);
    121    return true;
    122  }
    123  memcpy(aItem->data, Elements(), Length());
    124  return true;
    125 }
    126 
    127 JSObject* CryptoBuffer::ToUint8Array(JSContext* aCx,
    128                                     ErrorResult& aError) const {
    129  return Uint8Array::Create(aCx, *this, aError);
    130 }
    131 
    132 JSObject* CryptoBuffer::ToArrayBuffer(JSContext* aCx,
    133                                      ErrorResult& aError) const {
    134  return ArrayBuffer::Create(aCx, *this, aError);
    135 }
    136 
    137 // "BigInt" comes from the WebCrypto spec
    138 // ("unsigned long" isn't very "big", of course)
    139 // Likewise, the spec calls for big-endian ints
    140 bool CryptoBuffer::GetBigIntValue(unsigned long& aRetVal) {
    141  if (Length() > sizeof(aRetVal)) {
    142    return false;
    143  }
    144 
    145  aRetVal = 0;
    146  for (size_t i = 0; i < Length(); ++i) {
    147    aRetVal = (aRetVal << 8) + ElementAt(i);
    148  }
    149  return true;
    150 }
    151 
    152 }  // namespace mozilla::dom