michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "Base64.h"
michael@0: 
michael@0: #include "nsIInputStream.h"
michael@0: #include "nsString.h"
michael@0: 
michael@0: #include "plbase64.h"
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: // BEGIN base64 encode code copied and modified from NSPR
michael@0: const unsigned char *base = (unsigned char *)"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
michael@0: 
michael@0: template <typename T>
michael@0: static void
michael@0: Encode3to4(const unsigned char *src, T *dest)
michael@0: {
michael@0:     uint32_t b32 = (uint32_t)0;
michael@0:     int i, j = 18;
michael@0: 
michael@0:     for( i = 0; i < 3; i++ )
michael@0:     {
michael@0:         b32 <<= 8;
michael@0:         b32 |= (uint32_t)src[i];
michael@0:     }
michael@0: 
michael@0:     for( i = 0; i < 4; i++ )
michael@0:     {
michael@0:         dest[i] = base[ (uint32_t)((b32>>j) & 0x3F) ];
michael@0:         j -= 6;
michael@0:     }
michael@0: }
michael@0: 
michael@0: template <typename T>
michael@0: static void
michael@0: Encode2to4(const unsigned char *src, T *dest)
michael@0: {
michael@0:     dest[0] = base[ (uint32_t)((src[0]>>2) & 0x3F) ];
michael@0:     dest[1] = base[ (uint32_t)(((src[0] & 0x03) << 4) | ((src[1] >> 4) & 0x0F)) ];
michael@0:     dest[2] = base[ (uint32_t)((src[1] & 0x0F) << 2) ];
michael@0:     dest[3] = (unsigned char)'=';
michael@0: }
michael@0: 
michael@0: template <typename T>
michael@0: static void
michael@0: Encode1to4(const unsigned char *src, T *dest)
michael@0: {
michael@0:     dest[0] = base[ (uint32_t)((src[0]>>2) & 0x3F) ];
michael@0:     dest[1] = base[ (uint32_t)((src[0] & 0x03) << 4) ];
michael@0:     dest[2] = (unsigned char)'=';
michael@0:     dest[3] = (unsigned char)'=';
michael@0: }
michael@0: 
michael@0: template <typename T>
michael@0: static void
michael@0: Encode(const unsigned char *src, uint32_t srclen, T *dest)
michael@0: {
michael@0:     while( srclen >= 3 )
michael@0:     {
michael@0:         Encode3to4(src, dest);
michael@0:         src += 3;
michael@0:         dest += 4;
michael@0:         srclen -= 3;
michael@0:     }
michael@0: 
michael@0:     switch( srclen )
michael@0:     {
michael@0:         case 2:
michael@0:             Encode2to4(src, dest);
michael@0:             break;
michael@0:         case 1:
michael@0:             Encode1to4(src, dest);
michael@0:             break;
michael@0:         case 0:
michael@0:             break;
michael@0:         default:
michael@0:             NS_NOTREACHED("coding error");
michael@0:     }
michael@0: }
michael@0: 
michael@0: // END base64 encode code copied and modified from NSPR.
michael@0: 
michael@0: template <typename T>
michael@0: struct EncodeInputStream_State {
michael@0:   unsigned char c[3];
michael@0:   uint8_t charsOnStack;
michael@0:   typename T::char_type* buffer;
michael@0: };
michael@0: 
michael@0: template <typename T>
michael@0: NS_METHOD
michael@0: EncodeInputStream_Encoder(nsIInputStream *aStream,
michael@0:                           void *aClosure,
michael@0:                           const char *aFromSegment,
michael@0:                           uint32_t aToOffset,
michael@0:                           uint32_t aCount,
michael@0:                           uint32_t *aWriteCount)
michael@0: {
michael@0:   NS_ASSERTION(aCount > 0, "Er, what?");
michael@0: 
michael@0:   EncodeInputStream_State<T>* state =
michael@0:     static_cast<EncodeInputStream_State<T>*>(aClosure);
michael@0: 
michael@0:   // If we have any data left from last time, encode it now.
michael@0:   uint32_t countRemaining = aCount;
michael@0:   const unsigned char *src = (const unsigned char*)aFromSegment;
michael@0:   if (state->charsOnStack) {
michael@0:     unsigned char firstSet[4];
michael@0:     if (state->charsOnStack == 1) {
michael@0:       firstSet[0] = state->c[0];
michael@0:       firstSet[1] = src[0];
michael@0:       firstSet[2] = (countRemaining > 1) ? src[1] : '\0';
michael@0:       firstSet[3] = '\0';
michael@0:     } else /* state->charsOnStack == 2 */ {
michael@0:       firstSet[0] = state->c[0];
michael@0:       firstSet[1] = state->c[1];
michael@0:       firstSet[2] = src[0];
michael@0:       firstSet[3] = '\0';
michael@0:     }
michael@0:     Encode(firstSet, 3, state->buffer);
michael@0:     state->buffer += 4;
michael@0:     countRemaining -= (3 - state->charsOnStack);
michael@0:     src += (3 - state->charsOnStack);
michael@0:     state->charsOnStack = 0;
michael@0:   }
michael@0: 
michael@0:   // Encode the bulk of the 
michael@0:   uint32_t encodeLength = countRemaining - countRemaining % 3;
michael@0:   NS_ABORT_IF_FALSE(encodeLength % 3 == 0,
michael@0:                     "Should have an exact number of triplets!");
michael@0:   Encode(src, encodeLength, state->buffer);
michael@0:   state->buffer += (encodeLength / 3) * 4;
michael@0:   src += encodeLength;
michael@0:   countRemaining -= encodeLength;
michael@0: 
michael@0:   // We must consume all data, so if there's some data left stash it
michael@0:   *aWriteCount = aCount;
michael@0: 
michael@0:   if (countRemaining) {
michael@0:     // We should never have a full triplet left at this point.
michael@0:     NS_ABORT_IF_FALSE(countRemaining < 3, "We should have encoded more!");
michael@0:     state->c[0] = src[0];
michael@0:     state->c[1] = (countRemaining == 2) ? src[1] : '\0';
michael@0:     state->charsOnStack = countRemaining;
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: template <typename T>
michael@0: nsresult
michael@0: EncodeInputStream(nsIInputStream *aInputStream, 
michael@0:                   T &aDest,
michael@0:                   uint32_t aCount,
michael@0:                   uint32_t aOffset)
michael@0: {
michael@0:   nsresult rv;
michael@0:   uint64_t count64 = aCount;
michael@0: 
michael@0:   if (!aCount) {
michael@0:     rv = aInputStream->Available(&count64);
michael@0:     if (NS_WARN_IF(NS_FAILED(rv)))
michael@0:       return rv;
michael@0:     // if count64 is over 4GB, it will be failed at the below condition,
michael@0:     // then will return NS_ERROR_OUT_OF_MEMORY
michael@0:     aCount = (uint32_t)count64;
michael@0:   }
michael@0: 
michael@0:   uint64_t countlong =
michael@0:     (count64 + 2) / 3 * 4; // +2 due to integer math.
michael@0:   if (countlong + aOffset > UINT32_MAX)
michael@0:     return NS_ERROR_OUT_OF_MEMORY;
michael@0: 
michael@0:   uint32_t count = uint32_t(countlong);
michael@0: 
michael@0:   aDest.SetLength(count + aOffset);
michael@0:   if (aDest.Length() != count + aOffset)
michael@0:     return NS_ERROR_OUT_OF_MEMORY;
michael@0: 
michael@0:   EncodeInputStream_State<T> state;
michael@0:   state.charsOnStack = 0;
michael@0:   state.c[2] = '\0';
michael@0:   state.buffer = aOffset + aDest.BeginWriting();
michael@0: 
michael@0:   while (1) {
michael@0:     uint32_t read = 0;
michael@0: 
michael@0:     rv = aInputStream->ReadSegments(&EncodeInputStream_Encoder<T>,
michael@0:                                     (void*)&state,
michael@0:                                     aCount,
michael@0:                                     &read);
michael@0:     if (NS_FAILED(rv)) {
michael@0:       if (rv == NS_BASE_STREAM_WOULD_BLOCK)
michael@0:         NS_RUNTIMEABORT("Not implemented for async streams!");
michael@0:       if (rv == NS_ERROR_NOT_IMPLEMENTED)
michael@0:         NS_RUNTIMEABORT("Requires a stream that implements ReadSegments!");
michael@0:       return rv;
michael@0:     }
michael@0: 
michael@0:     if (!read)
michael@0:       break;
michael@0:   }
michael@0: 
michael@0:   // Finish encoding if anything is left
michael@0:   if (state.charsOnStack)
michael@0:     Encode(state.c, state.charsOnStack, state.buffer);
michael@0: 
michael@0:   if (aDest.Length())
michael@0:     // May belong to an nsCString with an unallocated buffer, so only null
michael@0:     // terminate if there is a need to.
michael@0:     *aDest.EndWriting() = '\0';
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: } // namespace (anonymous)
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: nsresult
michael@0: Base64EncodeInputStream(nsIInputStream *aInputStream, 
michael@0:                         nsACString &aDest,
michael@0:                         uint32_t aCount,
michael@0:                         uint32_t aOffset)
michael@0: {
michael@0:   return EncodeInputStream<nsACString>(aInputStream, aDest, aCount, aOffset);
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: Base64EncodeInputStream(nsIInputStream *aInputStream, 
michael@0:                         nsAString &aDest,
michael@0:                         uint32_t aCount,
michael@0:                         uint32_t aOffset)
michael@0: {
michael@0:   return EncodeInputStream<nsAString>(aInputStream, aDest, aCount, aOffset);
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: Base64Encode(const nsACString &aBinaryData, nsACString &aString)
michael@0: {
michael@0:   // Check for overflow.
michael@0:   if (aBinaryData.Length() > (UINT32_MAX / 4) * 3) {
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   // Don't ask PR_Base64Encode to encode empty strings
michael@0:   if (aBinaryData.IsEmpty()) {
michael@0:     aString.Truncate();
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   uint32_t stringLen = ((aBinaryData.Length() + 2) / 3) * 4;
michael@0: 
michael@0:   char *buffer;
michael@0: 
michael@0:   // Add one byte for null termination.
michael@0:   if (aString.SetCapacity(stringLen + 1, fallible_t()) &&
michael@0:     (buffer = aString.BeginWriting()) &&
michael@0:     PL_Base64Encode(aBinaryData.BeginReading(), aBinaryData.Length(), buffer)) {
michael@0:     // PL_Base64Encode doesn't null terminate the buffer for us when we pass
michael@0:     // the buffer in. Do that manually.
michael@0:     buffer[stringLen] = '\0';
michael@0: 
michael@0:     aString.SetLength(stringLen);
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   aString.Truncate();
michael@0:   return NS_ERROR_INVALID_ARG;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: Base64Encode(const nsAString &aString, nsAString &aBinaryData)
michael@0: {
michael@0:   NS_LossyConvertUTF16toASCII string(aString);
michael@0:   nsAutoCString binaryData;
michael@0: 
michael@0:   nsresult rv = Base64Encode(string, binaryData);
michael@0:   if (NS_SUCCEEDED(rv)) {
michael@0:     CopyASCIItoUTF16(binaryData, aBinaryData);
michael@0:   } else {
michael@0:     aBinaryData.Truncate();
michael@0:   }
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: Base64Decode(const nsACString &aString, nsACString &aBinaryData)
michael@0: {
michael@0:   // Check for overflow.
michael@0:   if (aString.Length() > UINT32_MAX / 3) {
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   // Don't ask PR_Base64Decode to decode the empty string
michael@0:   if (aString.IsEmpty()) {
michael@0:     aBinaryData.Truncate();
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   uint32_t binaryDataLen = ((aString.Length() * 3) / 4);
michael@0: 
michael@0:   char *buffer;
michael@0: 
michael@0:   // Add one byte for null termination.
michael@0:   if (aBinaryData.SetCapacity(binaryDataLen + 1, fallible_t()) &&
michael@0:     (buffer = aBinaryData.BeginWriting()) &&
michael@0:     PL_Base64Decode(aString.BeginReading(), aString.Length(), buffer)) {
michael@0:     // PL_Base64Decode doesn't null terminate the buffer for us when we pass
michael@0:     // the buffer in. Do that manually, taking into account the number of '='
michael@0:     // characters we were passed.
michael@0:     if (!aString.IsEmpty() && aString[aString.Length() - 1] == '=') {
michael@0:       if (aString.Length() > 1 && aString[aString.Length() - 2] == '=') {
michael@0:         binaryDataLen -= 2;
michael@0:       } else {
michael@0:         binaryDataLen -= 1;
michael@0:       }
michael@0:     }
michael@0:     buffer[binaryDataLen] = '\0';
michael@0: 
michael@0:     aBinaryData.SetLength(binaryDataLen);
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   aBinaryData.Truncate();
michael@0:   return NS_ERROR_INVALID_ARG;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: Base64Decode(const nsAString &aBinaryData, nsAString &aString)
michael@0: {
michael@0:   NS_LossyConvertUTF16toASCII binaryData(aBinaryData);
michael@0:   nsAutoCString string;
michael@0: 
michael@0:   nsresult rv = Base64Decode(binaryData, string);
michael@0:   if (NS_SUCCEEDED(rv)) {
michael@0:     CopyASCIItoUTF16(string, aString);
michael@0:   } else {
michael@0:     aString.Truncate();
michael@0:   }
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: } // namespace mozilla