C++ Section::getBlockCount方法代码示例

//! The boot tag for \a section is taken into account, thus making the
//! result offset point to the first block of the actual section data.
//!
//! \note The offset will only be valid if all encryption keys and all
//! sections have already been added to the image.
uint32_t EncoreBootImage::getSectionOffset(Section * section)
{
	// start with boot image headers 
	uint32_t offset = numberOfCipherBlocks(sizeof(boot_image_header_t));	// header
	offset += numberOfCipherBlocks(sizeof(section_header_t)) * sectionCount();	// section table
	offset += 2 * keyCount();	// key dictiontary
	
	// add up sections before this one
	section_iterator_t it = beginSection();
	for (; it != endSection() && *it != section; ++it)
	{
		Section * thisSection = *it;
		
		// insert padding for section alignment
		offset += getPadBlockCountForSection(thisSection, offset);
		
		// add one for boot tag associated with this section
		offset++;
		
		// now add the section's contents
		offset += thisSection->getBlockCount();
	}
	
	// and add padding for this section
	offset += getPadBlockCountForSection(section, offset);
	
	// skip over this section's boot tag
	offset++;
	
	return offset;
}

//.........这里部分代码省略.........
	if (isEncrypted())
	{
		key_iterator_t it = beginKeys();
		for (i=0; it != endKeys(); ++it, ++i)
		{
			// write CBC-MAC result for this key, then update SHA-1
			RijndaelCBCMAC & mac = (macs.get())[i];
			const RijndaelCBCMAC::block_t & macResult = mac.getMAC();
			stream.write(reinterpret_cast<const char *>(&macResult), sizeof(RijndaelCBCMAC::block_t));
			hash.Update(reinterpret_cast<const uint8_t *>(&macResult), sizeof(RijndaelCBCMAC::block_t));
			fileBlocksWritten++;
			
			// encrypt DEK with this key, write it out, and update image digest
			Rijndael cipher;
			cipher.init(Rijndael::CBC, Rijndael::Encrypt, *it, Rijndael::Key16Bytes, imageHeader.m_iv);
			AESKey<128>::key_t wrappedSessionKey;
			cipher.blockEncrypt(m_sessionKey, sizeof(AESKey<128>::key_t) * 8, wrappedSessionKey);
			stream.write(reinterpret_cast<char *>(&wrappedSessionKey), sizeof(wrappedSessionKey));
			hash.Update(reinterpret_cast<uint8_t *>(&wrappedSessionKey), sizeof(wrappedSessionKey));
			fileBlocksWritten++;
		}
	}
	
	// write sections and boot tags
	{
		section_iterator_t it = beginSection();
		for (; it != endSection(); ++it)
		{
			section_iterator_t itCopy = it;
			bool isLastSection = (++itCopy == endSection());
			
			Section * section = *it;
			cipher_block_t block;
			unsigned blockCount = section->getBlockCount();
			unsigned blocksWritten = 0;
			
			Rijndael cipher;
			cipher.init(Rijndael::CBC, Rijndael::Encrypt, m_sessionKey, Rijndael::Key16Bytes, imageHeader.m_iv);
			
			// Compute the number of padding blocks needed to align the section. This first
			// call to getPadBlockCountForOffset() passes an offset that excludes
			// the boot tag for this section.
			unsigned paddingBlocks = getPadBlockCountForSection(section, fileBlocksWritten);
			
			// Insert nop commands as padding to align the start of the section, if
			// the section has special alignment requirements.
			NopCommand nop;
			while (paddingBlocks--)
			{
				blockCount = nop.getBlockCount();
				blocksWritten = 0;
				while (blocksWritten < blockCount)
				{
					nop.getBlocks(blocksWritten, 1, &block);
					
					if (isEncrypted())
					{
						// re-init after encrypt to update IV
						cipher.blockEncrypt(block, sizeof(cipher_block_t) * 8, block);
						cipher.init(Rijndael::CBC, Rijndael::Encrypt, m_sessionKey, Rijndael::Key16Bytes, block);
					}
					
					stream.write(reinterpret_cast<char *>(&block), sizeof(cipher_block_t));
					hash.Update(reinterpret_cast<uint8_t *>(&block), sizeof(cipher_block_t));
					
					blocksWritten++;

//! The identifier, length, and flags fields are taken from \a section.
//!
//! \todo How does length get set correctly if the length is supposed to include
//!		this command?
EncoreBootImage::TagCommand::TagCommand(const Section & section)
{
	m_sectionIdentifier = section.getIdentifier();
	m_sectionLength = section.getBlockCount();
	m_sectionFlags = section.getFlags();
}