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Diffstat (limited to 'comphelper/source/misc/base64.cxx')
| -rw-r--r-- | comphelper/source/misc/base64.cxx | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/comphelper/source/misc/base64.cxx b/comphelper/source/misc/base64.cxx new file mode 100644 index 000000000..5e3e3ca0a --- /dev/null +++ b/comphelper/source/misc/base64.cxx @@ -0,0 +1,220 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * 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/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#include <sal/config.h> + +#include <cstddef> + +#include <comphelper/base64.hxx> + +#include <com/sun/star/uno/Sequence.hxx> + +#include <o3tl/safeint.hxx> +#include <osl/diagnose.h> + +using namespace com::sun::star; + +namespace comphelper { + +const + char aBase64EncodeTable[] = + { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', + 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', + 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' }; + +const + sal_uInt8 aBase64DecodeTable[] = + { 62,255,255,255, 63, // 43-47 +// + / + + 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255, 0,255,255, // 48-63 +// 0 1 2 3 4 5 6 7 8 9 = + + 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 64-79 +// A B C D E F G H I J K L M N O + + 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255,255, // 80-95 +// P Q R S T U V W X Y Z + + 0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 96-111 +// a b c d e f g h i j k l m n o + + 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 }; // 112-123 +// p q r s t u v w x y z + + +static void ThreeByteToFourByte(const sal_Int8* pBuffer, const sal_Int32 nStart, const sal_Int32 nFullLen, char* aCharBuffer) +{ + sal_Int32 nLen(nFullLen - nStart); + if (nLen > 3) + nLen = 3; + if (nLen == 0) + { + return; + } + + sal_Int32 nBinaer; + switch (nLen) + { + case 1: + { + nBinaer = static_cast<sal_uInt8>(pBuffer[nStart + 0]) << 16; + } + break; + case 2: + { + nBinaer = (static_cast<sal_uInt8>(pBuffer[nStart + 0]) << 16) + + (static_cast<sal_uInt8>(pBuffer[nStart + 1]) << 8); + } + break; + default: + { + nBinaer = (static_cast<sal_uInt8>(pBuffer[nStart + 0]) << 16) + + (static_cast<sal_uInt8>(pBuffer[nStart + 1]) << 8) + + static_cast<sal_uInt8>(pBuffer[nStart + 2]); + } + break; + } + + aCharBuffer[0] = aCharBuffer[1] = aCharBuffer[2] = aCharBuffer[3] = '='; + + sal_uInt8 nIndex (static_cast<sal_uInt8>((nBinaer & 0xFC0000) >> 18)); + aCharBuffer[0] = aBase64EncodeTable [nIndex]; + + nIndex = static_cast<sal_uInt8>((nBinaer & 0x3F000) >> 12); + aCharBuffer[1] = aBase64EncodeTable [nIndex]; + if (nLen > 1) + { + nIndex = static_cast<sal_uInt8>((nBinaer & 0xFC0) >> 6); + aCharBuffer[2] = aBase64EncodeTable [nIndex]; + if (nLen > 2) + { + nIndex = static_cast<sal_uInt8>((nBinaer & 0x3F)); + aCharBuffer[3] = aBase64EncodeTable [nIndex]; + } + } +} + +void Base64::encode(OStringBuffer& aStrBuffer, const uno::Sequence<sal_Int8>& aPass) +{ + sal_Int32 i(0); + sal_Int32 nBufferLength(aPass.getLength()); + const sal_Int8* pBuffer = aPass.getConstArray(); + while (i < nBufferLength) + { + char aCharBuffer[4]; + ThreeByteToFourByte(pBuffer, i, nBufferLength, aCharBuffer); + aStrBuffer.append(aCharBuffer, std::size(aCharBuffer)); + i += 3; + } +} + +void Base64::encode(OUStringBuffer& aStrBuffer, const uno::Sequence<sal_Int8>& aPass) +{ + sal_Int32 i(0); + sal_Int32 nBufferLength(aPass.getLength()); + const sal_Int8* pBuffer = aPass.getConstArray(); + while (i < nBufferLength) + { + char aCharBuffer[4]; + ThreeByteToFourByte(pBuffer, i, nBufferLength, aCharBuffer); + aStrBuffer.appendAscii(aCharBuffer, std::size(aCharBuffer)); + i += 3; + } +} + +void Base64::decode(uno::Sequence<sal_Int8>& aBuffer, std::u16string_view sBuffer) +{ + std::size_t nCharsDecoded = decodeSomeChars( aBuffer, sBuffer ); + OSL_ENSURE( nCharsDecoded == sBuffer.size(), "some bytes left in base64 decoding!" ); +} + +std::size_t Base64::decodeSomeChars(uno::Sequence<sal_Int8>& rOutBuffer, std::u16string_view rInBuffer) +{ + std::size_t nInBufferLen = rInBuffer.size(); + std::size_t nMinOutBufferLen = (nInBufferLen / 4) * 3; + if( o3tl::make_unsigned(rOutBuffer.getLength()) < nMinOutBufferLen ) + rOutBuffer.realloc( nMinOutBufferLen ); + + const sal_Unicode *pInBuffer = rInBuffer.data(); + sal_Int8 *pOutBuffer = rOutBuffer.getArray(); + sal_Int8 *pOutBufferStart = pOutBuffer; + std::size_t nCharsDecoded = 0; + + sal_uInt8 aDecodeBuffer[4]; + sal_Int32 nBytesToDecode = 0; + sal_Int32 nBytesGotFromDecoding = 3; + std::size_t nInBufferPos= 0; + while( nInBufferPos < nInBufferLen ) + { + sal_Unicode cChar = *pInBuffer; + if( cChar >= '+' && cChar <= 'z' ) + { + sal_uInt8 nByte = aBase64DecodeTable[cChar-'+']; + if( nByte != 255 ) + { + // We have found a valid character! + aDecodeBuffer[nBytesToDecode++] = nByte; + + // One '=' character at the end means 2 out bytes + // Two '=' characters at the end mean 1 out bytes + if( '=' == cChar && nBytesToDecode > 2 ) + nBytesGotFromDecoding--; + if( 4 == nBytesToDecode ) + { + // Four characters found, so we may convert now! + sal_uInt32 nOut = (aDecodeBuffer[0] << 18) + + (aDecodeBuffer[1] << 12) + + (aDecodeBuffer[2] << 6) + + aDecodeBuffer[3]; + + *pOutBuffer++ = static_cast<sal_Int8>((nOut & 0xff0000) >> 16); + if( nBytesGotFromDecoding > 1 ) + *pOutBuffer++ = static_cast<sal_Int8>((nOut & 0xff00) >> 8); + if( nBytesGotFromDecoding > 2 ) + *pOutBuffer++ = static_cast<sal_Int8>(nOut & 0xff); + nCharsDecoded = nInBufferPos + 1; + nBytesToDecode = 0; + nBytesGotFromDecoding = 3; + } + } + else + { + nCharsDecoded++; + } + } + else + { + nCharsDecoded++; + } + + nInBufferPos++; + pInBuffer++; + } + if( (pOutBuffer - pOutBufferStart) != rOutBuffer.getLength() ) + rOutBuffer.realloc( pOutBuffer - pOutBufferStart ); + + return nCharsDecoded; +} + +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |