dom/crypto/CryptoBuffer.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   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 {
  13 namespace dom {
  14
  15 uint8_t*
  16 CryptoBuffer::Assign(const CryptoBuffer& aData)
  17 {
  18   // Same as in nsTArray_Impl::operator=, but return the value
  19   // returned from ReplaceElementsAt to enable OOM detection
  20   return ReplaceElementsAt(0, Length(), aData.Elements(), aData.Length());
  21 }
  22
  23 uint8_t*
  24 CryptoBuffer::Assign(const uint8_t* aData, uint32_t aLength)
  25 {
  26   return ReplaceElementsAt(0, Length(), aData, aLength);
  27 }
  28
  29 uint8_t*
  30 CryptoBuffer::Assign(const SECItem* aItem)
  31 {
  32   MOZ_ASSERT(aItem);
  33   return Assign(aItem->data, aItem->len);
  34 }
  35
  36 uint8_t*
  37 CryptoBuffer::Assign(const ArrayBuffer& aData)
  38 {
  39   aData.ComputeLengthAndData();
  40   return Assign(aData.Data(), aData.Length());
  41 }
  42
  43 uint8_t*
  44 CryptoBuffer::Assign(const ArrayBufferView& aData)
  45 {
  46   aData.ComputeLengthAndData();
  47   return Assign(aData.Data(), aData.Length());
  48 }
  49
  50 uint8_t*
  51 CryptoBuffer::Assign(const ArrayBufferViewOrArrayBuffer& aData)
  52 {
  53   if (aData.IsArrayBufferView()) {
  54     return Assign(aData.GetAsArrayBufferView());
  55   } else if (aData.IsArrayBuffer()) {
  56     return Assign(aData.GetAsArrayBuffer());
  57   }
  58
  59   // If your union is uninitialized, something's wrong
  60   MOZ_ASSERT(false);
  61   SetLength(0);
  62   return nullptr;
  63 }
  64
  65 uint8_t*
  66 CryptoBuffer::Assign(const OwningArrayBufferViewOrArrayBuffer& aData)
  67 {
  68   if (aData.IsArrayBufferView()) {
  69     return Assign(aData.GetAsArrayBufferView());
  70   } else if (aData.IsArrayBuffer()) {
  71     return Assign(aData.GetAsArrayBuffer());
  72   }
  73
  74   // If your union is uninitialized, something's wrong
  75   MOZ_ASSERT(false);
  76   SetLength(0);
  77   return nullptr;
  78 }
  79
  80 // Helpers to encode/decode JWK's special flavor of Base64
  81 // * No whitespace
  82 // * No padding
  83 // * URL-safe character set
  84 nsresult
  85 CryptoBuffer::FromJwkBase64(const nsString& aBase64)
  86 {
  87   NS_ConvertUTF16toUTF8 temp(aBase64);
  88   temp.StripWhitespace();
  89
  90   // Re-add padding
  91   if (temp.Length() % 4 == 3) {
  92     temp.AppendLiteral("=");
  93   } else if (temp.Length() % 4 == 2) {
  94     temp.AppendLiteral("==");
  95   } if (temp.Length() % 4 == 1) {
  96     return NS_ERROR_FAILURE; // bad Base64
  97   }
  98
  99   // Translate from URL-safe character set to normal
 100   temp.ReplaceChar('-', '+');
 101   temp.ReplaceChar('_', '/');
 102
 103   // Perform the actual base64 decode
 104   nsCString binaryData;
 105   nsresult rv = Base64Decode(temp, binaryData);
 106   NS_ENSURE_SUCCESS(rv, rv);
 107
 108   if (!Assign((const uint8_t*) binaryData.BeginReading(),
 109               binaryData.Length())) {
 110     return NS_ERROR_FAILURE;
 111   }
 112
 113   return NS_OK;
 114 }
 115
 116 nsresult
 117 CryptoBuffer::ToJwkBase64(nsString& aBase64)
 118 {
 119   // Shortcut for the empty octet string
 120   if (Length() == 0) {
 121     aBase64.Truncate();
 122     return NS_OK;
 123   }
 124
 125   // Perform the actual base64 encode
 126   nsCString base64;
 127   nsDependentCSubstring binaryData((const char*) Elements(),
 128                                    (const char*) (Elements() + Length()));
 129   nsresult rv = Base64Encode(binaryData, base64);
 130   NS_ENSURE_SUCCESS(rv, rv);
 131
 132   // Strip padding
 133   base64.Trim("=");
 134
 135   // Translate to the URL-safe charset
 136   base64.ReplaceChar('+', '-');
 137   base64.ReplaceChar('/', '_');
 138   if (base64.FindCharInSet("+/", 0) != kNotFound) {
 139     return NS_ERROR_FAILURE;
 140   }
 141
 142   CopyASCIItoUTF16(base64, aBase64);
 143   return NS_OK;
 144 }
 145
 146 SECItem*
 147 CryptoBuffer::ToSECItem() const
 148 {
 149   uint8_t* data = (uint8_t*) moz_malloc(Length());
 150   if (!data) {
 151     return nullptr;
 152   }
 153
 154   SECItem* item = ::SECITEM_AllocItem(nullptr, nullptr, 0);
 155   item->type = siBuffer;
 156   item->data = data;
 157   item->len = Length();
 158
 159   memcpy(item->data, Elements(), Length());
 160
 161   return item;
 162 }
 163
 164 JSObject*
 165 CryptoBuffer::ToUint8Array(JSContext* aCx) const
 166 {
 167   return Uint8Array::Create(aCx, Length(), Elements());
 168 }
 169
 170
 171 // "BigInt" comes from the WebCrypto spec
 172 // ("unsigned long" isn't very "big", of course)
 173 // Likewise, the spec calls for big-endian ints
 174 bool
 175 CryptoBuffer::GetBigIntValue(unsigned long& aRetVal)
 176 {
 177   if (Length() > sizeof(aRetVal)) {
 178     return false;
 179   }
 180
 181   aRetVal = 0;
 182   for (size_t i=0; i < Length(); ++i) {
 183     aRetVal = (aRetVal << 8) + ElementAt(i);
 184   }
 185   return true;
 186 }
 187
 188 } // namespace dom
 189 } // namespace mozilla