DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (b6057e17f856)

VCS Links

Line Code
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

#include "Base64.h"

#include "nsIInputStream.h"
#include "nsString.h"

#include "plbase64.h"

namespace {

// BEGIN base64 encode code copied and modified from NSPR
const unsigned char* base =
  (unsigned char*)"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                  "abcdefghijklmnopqrstuvwxyz"
                  "0123456789+/";

template <typename T>
static void
Encode3to4(const unsigned char* aSrc, T* aDest)
{
  uint32_t b32 = (uint32_t)0;
  int i, j = 18;

  for (i = 0; i < 3; ++i) {
    b32 <<= 8;
    b32 |= (uint32_t)aSrc[i];
  }

  for (i = 0; i < 4; ++i) {
    aDest[i] = base[(uint32_t)((b32 >> j) & 0x3F)];
    j -= 6;
  }
}

template <typename T>
static void
Encode2to4(const unsigned char* aSrc, T* aDest)
{
  aDest[0] = base[(uint32_t)((aSrc[0] >> 2) & 0x3F)];
  aDest[1] = base[(uint32_t)(((aSrc[0] & 0x03) << 4) | ((aSrc[1] >> 4) & 0x0F))];
  aDest[2] = base[(uint32_t)((aSrc[1] & 0x0F) << 2)];
  aDest[3] = (unsigned char)'=';
}

template <typename T>
static void
Encode1to4(const unsigned char* aSrc, T* aDest)
{
  aDest[0] = base[(uint32_t)((aSrc[0] >> 2) & 0x3F)];
  aDest[1] = base[(uint32_t)((aSrc[0] & 0x03) << 4)];
  aDest[2] = (unsigned char)'=';
  aDest[3] = (unsigned char)'=';
}

template <typename T>
static void
Encode(const unsigned char* aSrc, uint32_t aSrcLen, T* aDest)
{
  while (aSrcLen >= 3) {
    Encode3to4(aSrc, aDest);
    aSrc += 3;
    aDest += 4;
    aSrcLen -= 3;
  }

  switch (aSrcLen) {
    case 2:
      Encode2to4(aSrc, aDest);
      break;
    case 1:
      Encode1to4(aSrc, aDest);
      break;
    case 0:
      break;
    default:
      NS_NOTREACHED("coding error");
  }
}

// END base64 encode code copied and modified from NSPR.

template <typename T>
struct EncodeInputStream_State
{
  unsigned char c[3];
  uint8_t charsOnStack;
  typename T::char_type* buffer;
};

template <typename T>
NS_METHOD
EncodeInputStream_Encoder(nsIInputStream* aStream,
                          void* aClosure,
                          const char* aFromSegment,
                          uint32_t aToOffset,
                          uint32_t aCount,
                          uint32_t* aWriteCount)
{
  NS_ASSERTION(aCount > 0, "Er, what?");

  EncodeInputStream_State<T>* state =
    static_cast<EncodeInputStream_State<T>*>(aClosure);

  // If we have any data left from last time, encode it now.
  uint32_t countRemaining = aCount;
  const unsigned char* src = (const unsigned char*)aFromSegment;
  if (state->charsOnStack) {
    unsigned char firstSet[4];
    if (state->charsOnStack == 1) {
      firstSet[0] = state->c[0];
      firstSet[1] = src[0];
      firstSet[2] = (countRemaining > 1) ? src[1] : '\0';
      firstSet[3] = '\0';
    } else /* state->charsOnStack == 2 */ {
      firstSet[0] = state->c[0];
      firstSet[1] = state->c[1];
      firstSet[2] = src[0];
      firstSet[3] = '\0';
    }
    Encode(firstSet, 3, state->buffer);
    state->buffer += 4;
    countRemaining -= (3 - state->charsOnStack);
    src += (3 - state->charsOnStack);
    state->charsOnStack = 0;
  }

  // Encode the bulk of the
  uint32_t encodeLength = countRemaining - countRemaining % 3;
  NS_ABORT_IF_FALSE(encodeLength % 3 == 0,
                    "Should have an exact number of triplets!");
  Encode(src, encodeLength, state->buffer);
  state->buffer += (encodeLength / 3) * 4;
  src += encodeLength;
  countRemaining -= encodeLength;

  // We must consume all data, so if there's some data left stash it
  *aWriteCount = aCount;

  if (countRemaining) {
    // We should never have a full triplet left at this point.
    NS_ABORT_IF_FALSE(countRemaining < 3, "We should have encoded more!");
    state->c[0] = src[0];
    state->c[1] = (countRemaining == 2) ? src[1] : '\0';
    state->charsOnStack = countRemaining;
  }

  return NS_OK;
}

template <typename T>
nsresult
EncodeInputStream(nsIInputStream* aInputStream,
                  T& aDest,
                  uint32_t aCount,
                  uint32_t aOffset)
{
  nsresult rv;
  uint64_t count64 = aCount;

  if (!aCount) {
    rv = aInputStream->Available(&count64);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
    // if count64 is over 4GB, it will be failed at the below condition,
    // then will return NS_ERROR_OUT_OF_MEMORY
    aCount = (uint32_t)count64;
  }

  uint64_t countlong =
    (count64 + 2) / 3 * 4; // +2 due to integer math.
  if (countlong + aOffset > UINT32_MAX) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  uint32_t count = uint32_t(countlong);

  aDest.SetLength(count + aOffset);
  if (aDest.Length() != count + aOffset) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  EncodeInputStream_State<T> state;
  state.charsOnStack = 0;
  state.c[2] = '\0';
  state.buffer = aOffset + aDest.BeginWriting();

  while (1) {
    uint32_t read = 0;

    rv = aInputStream->ReadSegments(&EncodeInputStream_Encoder<T>,
                                    (void*)&state,
                                    aCount,
                                    &read);
    if (NS_FAILED(rv)) {
      if (rv == NS_BASE_STREAM_WOULD_BLOCK) {
        NS_RUNTIMEABORT("Not implemented for async streams!");
      }
      if (rv == NS_ERROR_NOT_IMPLEMENTED) {
        NS_RUNTIMEABORT("Requires a stream that implements ReadSegments!");
      }
      return rv;
    }

    if (!read) {
      break;
    }
  }

  // Finish encoding if anything is left
  if (state.charsOnStack) {
    Encode(state.c, state.charsOnStack, state.buffer);
  }

  if (aDest.Length()) {
    // May belong to an nsCString with an unallocated buffer, so only null
    // terminate if there is a need to.
    *aDest.EndWriting() = '\0';
  }

  return NS_OK;
}

} // namespace (anonymous)

namespace mozilla {

nsresult
Base64EncodeInputStream(nsIInputStream* aInputStream,
                        nsACString& aDest,
                        uint32_t aCount,
                        uint32_t aOffset)
{
  return EncodeInputStream<nsACString>(aInputStream, aDest, aCount, aOffset);
}

nsresult
Base64EncodeInputStream(nsIInputStream* aInputStream,
                        nsAString& aDest,
                        uint32_t aCount,
                        uint32_t aOffset)
{
  return EncodeInputStream<nsAString>(aInputStream, aDest, aCount, aOffset);
}

nsresult
Base64Encode(const nsACString& aBinaryData, nsACString& aString)
{
  // Check for overflow.
  if (aBinaryData.Length() > (UINT32_MAX / 4) * 3) {
    return NS_ERROR_FAILURE;
  }

  // Don't ask PR_Base64Encode to encode empty strings
  if (aBinaryData.IsEmpty()) {
    aString.Truncate();
    return NS_OK;
  }

  uint32_t stringLen = ((aBinaryData.Length() + 2) / 3) * 4;

  char* buffer;

  // Add one byte for null termination.
  if (aString.SetCapacity(stringLen + 1, fallible_t()) &&
      (buffer = aString.BeginWriting()) &&
      PL_Base64Encode(aBinaryData.BeginReading(), aBinaryData.Length(), buffer)) {
    // PL_Base64Encode doesn't null terminate the buffer for us when we pass
    // the buffer in. Do that manually.
    buffer[stringLen] = '\0';

    aString.SetLength(stringLen);
    return NS_OK;
  }

  aString.Truncate();
  return NS_ERROR_INVALID_ARG;
}

nsresult
Base64Encode(const nsAString& aString, nsAString& aBinaryData)
{
  NS_LossyConvertUTF16toASCII string(aString);
  nsAutoCString binaryData;

  nsresult rv = Base64Encode(string, binaryData);
  if (NS_SUCCEEDED(rv)) {
    CopyASCIItoUTF16(binaryData, aBinaryData);
  } else {
    aBinaryData.Truncate();
  }

  return rv;
}

nsresult
Base64Decode(const nsACString& aString, nsACString& aBinaryData)
{
  // Check for overflow.
  if (aString.Length() > UINT32_MAX / 3) {
    return NS_ERROR_FAILURE;
  }

  // Don't ask PR_Base64Decode to decode the empty string
  if (aString.IsEmpty()) {
    aBinaryData.Truncate();
    return NS_OK;
  }

  uint32_t binaryDataLen = ((aString.Length() * 3) / 4);

  char* buffer;

  // Add one byte for null termination.
  if (aBinaryData.SetCapacity(binaryDataLen + 1, fallible_t()) &&
      (buffer = aBinaryData.BeginWriting()) &&
      PL_Base64Decode(aString.BeginReading(), aString.Length(), buffer)) {
    // PL_Base64Decode doesn't null terminate the buffer for us when we pass
    // the buffer in. Do that manually, taking into account the number of '='
    // characters we were passed.
    if (!aString.IsEmpty() && aString[aString.Length() - 1] == '=') {
      if (aString.Length() > 1 && aString[aString.Length() - 2] == '=') {
        binaryDataLen -= 2;
      } else {
        binaryDataLen -= 1;
      }
    }
    buffer[binaryDataLen] = '\0';

    aBinaryData.SetLength(binaryDataLen);
    return NS_OK;
  }

  aBinaryData.Truncate();
  return NS_ERROR_INVALID_ARG;
}

nsresult
Base64Decode(const nsAString& aBinaryData, nsAString& aString)
{
  NS_LossyConvertUTF16toASCII binaryData(aBinaryData);
  nsAutoCString string;

  nsresult rv = Base64Decode(binaryData, string);
  if (NS_SUCCEEDED(rv)) {
    CopyASCIItoUTF16(string, aString);
  } else {
    aString.Truncate();
  }

  return rv;
}

} // namespace mozilla