dom/crypto/CryptoBuffer.cpp

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