import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

xpcom/io/Base64.cpp

@@ -0,0 +1,645 @@
+/* -*- 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 "mozilla/UniquePtrExtensions.h"
+#include "nsIInputStream.h"
+#include "nsString.h"
+#include "nsTArray.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>
+nsresult
+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;
+  MOZ_ASSERT(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.
+    MOZ_ASSERT(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);
+
+  if (!aDest.SetLength(count + aOffset, mozilla::fallible)) {
+    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;
+}
+
+static const char kBase64URLAlphabet[] =
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
+
+// Maps an encoded character to a value in the Base64 URL alphabet, per
+// RFC 4648, Table 2. Invalid input characters map to UINT8_MAX.
+static const uint8_t kBase64URLDecodeTable[] = {
+  255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255,
+  62 /* - */,
+  255, 255,
+  52, 53, 54, 55, 56, 57, 58, 59, 60, 61, /* 0 - 9 */
+  255, 255, 255, 255, 255, 255, 255,
+  0, 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, /* A - Z */
+  255, 255, 255, 255,
+  63 /* _ */,
+  255,
+  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, /* a - z */
+  255, 255, 255, 255,
+};
+
+bool
+Base64URLCharToValue(char aChar, uint8_t* aValue) {
+  uint8_t index = static_cast<uint8_t>(aChar);
+  *aValue = kBase64URLDecodeTable[index & 0x7f];
+  return (*aValue != 255) && !(index & ~0x7f);
+}
+
+} // namespace
+
+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 char* aBinary, uint32_t aBinaryLen, char** aBase64)
+{
+  // Check for overflow.
+  if (aBinaryLen > (UINT32_MAX / 4) * 3) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Don't ask PR_Base64Encode to encode empty strings.
+  if (aBinaryLen == 0) {
+    *aBase64 = (char*)moz_xmalloc(1);
+    (*aBase64)[0] = '\0';
+    return NS_OK;
+  }
+
+  *aBase64 = nullptr;
+  uint32_t base64Len = ((aBinaryLen + 2) / 3) * 4;
+
+  // Add one byte for null termination.
+  UniqueFreePtr<char[]> base64((char*)malloc(base64Len + 1));
+  if (!base64) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  if (!PL_Base64Encode(aBinary, aBinaryLen, base64.get())) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // PL_Base64Encode doesn't null terminate the buffer for us when we pass
+  // the buffer in. Do that manually.
+  base64[base64Len] = '\0';
+
+  *aBase64 = base64.release();
+  return NS_OK;
+}
+
+nsresult
+Base64Encode(const nsACString& aBinary, nsACString& aBase64)
+{
+  // Check for overflow.
+  if (aBinary.Length() > (UINT32_MAX / 4) * 3) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Don't ask PR_Base64Encode to encode empty strings.
+  if (aBinary.IsEmpty()) {
+    aBase64.Truncate();
+    return NS_OK;
+  }
+
+  uint32_t base64Len = ((aBinary.Length() + 2) / 3) * 4;
+
+  // Add one byte for null termination.
+  if (!aBase64.SetCapacity(base64Len + 1, fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  char* base64 = aBase64.BeginWriting();
+  if (!PL_Base64Encode(aBinary.BeginReading(), aBinary.Length(), base64)) {
+    aBase64.Truncate();
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // PL_Base64Encode doesn't null terminate the buffer for us when we pass
+  // the buffer in. Do that manually.
+  base64[base64Len] = '\0';
+
+  aBase64.SetLength(base64Len);
+  return NS_OK;
+}
+
+nsresult
+Base64Encode(const nsAString& aBinary, nsAString& aBase64)
+{
+  NS_LossyConvertUTF16toASCII binary(aBinary);
+  nsAutoCString base64;
+
+  nsresult rv = Base64Encode(binary, base64);
+  if (NS_SUCCEEDED(rv)) {
+    CopyASCIItoUTF16(base64, aBase64);
+  } else {
+    aBase64.Truncate();
+  }
+
+  return rv;
+}
+
+static nsresult
+Base64DecodeHelper(const char* aBase64, uint32_t aBase64Len, char* aBinary,
+                   uint32_t* aBinaryLen)
+{
+  MOZ_ASSERT(aBinary);
+  if (!PL_Base64Decode(aBase64, aBase64Len, aBinary)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // 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 (aBase64Len != 0 && aBase64[aBase64Len - 1] == '=') {
+    if (aBase64Len > 1 && aBase64[aBase64Len - 2] == '=') {
+      *aBinaryLen -= 2;
+    } else {
+      *aBinaryLen -= 1;
+    }
+  }
+  aBinary[*aBinaryLen] = '\0';
+  return NS_OK;
+}
+
+nsresult
+Base64Decode(const char* aBase64, uint32_t aBase64Len, char** aBinary,
+             uint32_t* aBinaryLen)
+{
+  // Check for overflow.
+  if (aBase64Len > UINT32_MAX / 3) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Don't ask PR_Base64Decode to decode the empty string.
+  if (aBase64Len == 0) {
+    *aBinary = (char*)moz_xmalloc(1);
+    (*aBinary)[0] = '\0';
+    *aBinaryLen = 0;
+    return NS_OK;
+  }
+
+  *aBinary = nullptr;
+  *aBinaryLen = (aBase64Len * 3) / 4;
+
+  // Add one byte for null termination.
+  UniqueFreePtr<char[]> binary((char*)malloc(*aBinaryLen + 1));
+  if (!binary) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  nsresult rv =
+    Base64DecodeHelper(aBase64, aBase64Len, binary.get(), aBinaryLen);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  *aBinary = binary.release();
+  return NS_OK;
+}
+
+nsresult
+Base64Decode(const nsACString& aBase64, nsACString& aBinary)
+{
+  // Check for overflow.
+  if (aBase64.Length() > UINT32_MAX / 3) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Don't ask PR_Base64Decode to decode the empty string
+  if (aBase64.IsEmpty()) {
+    aBinary.Truncate();
+    return NS_OK;
+  }
+
+  uint32_t binaryLen = ((aBase64.Length() * 3) / 4);
+
+  // Add one byte for null termination.
+  if (!aBinary.SetCapacity(binaryLen + 1, fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  char* binary = aBinary.BeginWriting();
+  nsresult rv = Base64DecodeHelper(aBase64.BeginReading(), aBase64.Length(),
+                                   binary, &binaryLen);
+  if (NS_FAILED(rv)) {
+    aBinary.Truncate();
+    return rv;
+  }
+
+  aBinary.SetLength(binaryLen);
+  return NS_OK;
+}
+
+nsresult
+Base64Decode(const nsAString& aBase64, nsAString& aBinary)
+{
+  NS_LossyConvertUTF16toASCII base64(aBase64);
+  nsAutoCString binary;
+
+  nsresult rv = Base64Decode(base64, binary);
+  if (NS_SUCCEEDED(rv)) {
+    CopyASCIItoUTF16(binary, aBinary);
+  } else {
+    aBinary.Truncate();
+  }
+
+  return rv;
+}
+
+nsresult
+Base64URLDecode(const nsACString& aBase64,
+                Base64URLDecodePaddingPolicy aPaddingPolicy,
+                FallibleTArray<uint8_t>& aBinary)
+{
+  // Don't decode empty strings.
+  if (aBase64.IsEmpty()) {
+    aBinary.Clear();
+    return NS_OK;
+  }
+
+  // Check for overflow.
+  uint32_t base64Len = aBase64.Length();
+  if (base64Len > UINT32_MAX / 3) {
+    return NS_ERROR_FAILURE;
+  }
+  const char* base64 = aBase64.BeginReading();
+
+  // The decoded length may be 1-2 bytes over, depending on the final quantum.
+  uint32_t binaryLen = (base64Len * 3) / 4;
+
+  // Determine whether to check for and ignore trailing padding.
+  bool maybePadded = false;
+  switch (aPaddingPolicy) {
+    case Base64URLDecodePaddingPolicy::Require:
+      if (base64Len % 4) {
+        // Padded input length must be a multiple of 4.
+        return NS_ERROR_INVALID_ARG;
+      }
+      maybePadded = true;
+      break;
+
+    case Base64URLDecodePaddingPolicy::Ignore:
+      // Check for padding only if the length is a multiple of 4.
+      maybePadded = !(base64Len % 4);
+      break;
+
+    // If we're expecting unpadded input, no need for additional checks.
+    // `=` isn't in the decode table, so padded strings will fail to decode.
+    default:
+      MOZ_FALLTHROUGH_ASSERT("Invalid decode padding policy");
+    case Base64URLDecodePaddingPolicy::Reject:
+      break;
+  }
+  if (maybePadded && base64[base64Len - 1] == '=') {
+    if (base64[base64Len - 2] == '=') {
+      base64Len -= 2;
+    } else {
+      base64Len -= 1;
+    }
+  }
+
+  if (NS_WARN_IF(!aBinary.SetCapacity(binaryLen, mozilla::fallible))) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  aBinary.SetLengthAndRetainStorage(binaryLen);
+  uint8_t* binary = aBinary.Elements();
+
+  for (; base64Len >= 4; base64Len -= 4) {
+    uint8_t w, x, y, z;
+    if (!Base64URLCharToValue(*base64++, &w) ||
+        !Base64URLCharToValue(*base64++, &x) ||
+        !Base64URLCharToValue(*base64++, &y) ||
+        !Base64URLCharToValue(*base64++, &z)) {
+      return NS_ERROR_INVALID_ARG;
+    }
+    *binary++ = w << 2 | x >> 4;
+    *binary++ = x << 4 | y >> 2;
+    *binary++ = y << 6 | z;
+  }
+
+  if (base64Len == 3) {
+    uint8_t w, x, y;
+    if (!Base64URLCharToValue(*base64++, &w) ||
+        !Base64URLCharToValue(*base64++, &x) ||
+        !Base64URLCharToValue(*base64++, &y)) {
+      return NS_ERROR_INVALID_ARG;
+    }
+    *binary++ = w << 2 | x >> 4;
+    *binary++ = x << 4 | y >> 2;
+  } else if (base64Len == 2) {
+    uint8_t w, x;
+    if (!Base64URLCharToValue(*base64++, &w) ||
+        !Base64URLCharToValue(*base64++, &x)) {
+      return NS_ERROR_INVALID_ARG;
+    }
+    *binary++ = w << 2 | x >> 4;
+  } else if (base64Len) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // Set the length to the actual number of decoded bytes.
+  aBinary.TruncateLength(binary - aBinary.Elements());
+  return NS_OK;
+}
+
+nsresult
+Base64URLEncode(uint32_t aBinaryLen, const uint8_t* aBinary,
+                Base64URLEncodePaddingPolicy aPaddingPolicy,
+                nsACString& aBase64)
+{
+  // Don't encode empty strings.
+  if (aBinaryLen == 0) {
+    aBase64.Truncate();
+    return NS_OK;
+  }
+
+  // Check for overflow.
+  if (aBinaryLen > (UINT32_MAX / 4) * 3) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Allocate a buffer large enough to hold the encoded string with padding.
+  // Add one byte for null termination.
+  uint32_t base64Len = ((aBinaryLen + 2) / 3) * 4;
+  if (NS_WARN_IF(!aBase64.SetCapacity(base64Len + 1, fallible))) {
+    aBase64.Truncate();
+    return NS_ERROR_FAILURE;
+  }
+
+  char* base64 = aBase64.BeginWriting();
+
+  uint32_t index = 0;
+  for (; index + 3 <= aBinaryLen; index += 3) {
+    *base64++ = kBase64URLAlphabet[aBinary[index] >> 2];
+    *base64++ = kBase64URLAlphabet[((aBinary[index] & 0x3) << 4) |
+                                   (aBinary[index + 1] >> 4)];
+    *base64++ = kBase64URLAlphabet[((aBinary[index + 1] & 0xf) << 2) |
+                                   (aBinary[index + 2] >> 6)];
+    *base64++ = kBase64URLAlphabet[aBinary[index + 2] & 0x3f];
+  }
+
+  uint32_t remaining = aBinaryLen - index;
+  if (remaining == 1) {
+    *base64++ = kBase64URLAlphabet[aBinary[index] >> 2];
+    *base64++ = kBase64URLAlphabet[((aBinary[index] & 0x3) << 4)];
+  } else if (remaining == 2) {
+    *base64++ = kBase64URLAlphabet[aBinary[index] >> 2];
+    *base64++ = kBase64URLAlphabet[((aBinary[index] & 0x3) << 4) |
+                                   (aBinary[index + 1] >> 4)];
+    *base64++ = kBase64URLAlphabet[((aBinary[index + 1] & 0xf) << 2)];
+  }
+
+  uint32_t length = base64 - aBase64.BeginWriting();
+  if (aPaddingPolicy == Base64URLEncodePaddingPolicy::Include) {
+    if (length % 4 == 2) {
+      *base64++ = '=';
+      *base64++ = '=';
+      length += 2;
+    } else if (length % 4 == 3) {
+      *base64++ = '=';
+      length += 1;
+    }
+  } else {
+    MOZ_ASSERT(aPaddingPolicy == Base64URLEncodePaddingPolicy::Omit,
+               "Invalid encode padding policy");
+  }
+
+  // Null terminate and truncate to the actual number of characters.
+  *base64 = '\0';
+  aBase64.SetLength(length);
+
+  return NS_OK;
+}
+
+} // namespace mozilla