-/*
- * Copyright (c) 2000-2004,2011-2012,2014 Apple Inc. All Rights Reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-
-
-//
-// memstreams - primitive memory block streaming support
-//
-#ifndef _H_MEMSTREAMS
-#define _H_MEMSTREAMS
-
-#include <stdint.h>
-#include <security_utilities/memutils.h>
-#include <security_utilities/endian.h>
-#include <security_utilities/errors.h>
-
-
-namespace Security
-{
-
-//
-// Encapsulate these very sharp tools in a separate namespace
-//
-namespace LowLevelMemoryUtilities
-{
-
-
-//
-// A simple utility for incremental creation of a contiguous memory block.
-//
-// Note that Writer and Writer::Counter go together. They use the same alignment
-// and padding rules, so Writer::Counter will correctly calculate total buffer
-// size for Writer, *presuming* that they are called in the same order.
-//
-// This layer allocates no memory; that's up to the caller (you).
-//
-// WARNING: There is no check for overflow. If you write too much, you will die.
-// Writer::Counter can tell you how much you need.
-//
-class Writer {
-private:
- void *advance(size_t size)
- {
- void *here = alignUp(writePos);
- writePos = increment(here, size);
- return here;
- }
-
-public:
- Writer() { }
- Writer(void *base) : writePos(base) { }
- void operator = (void *base) { writePos = base; }
-
- template <class T>
- T *operator () (const T &obj)
- { T *here = (T *)advance(sizeof(T)); *here = obj; return here; }
-
- void *operator () (const void *addr, size_t size)
- { void *here = advance(size); return memcpy(here, addr, size); }
-
- char *operator () (const char *s)
- { return (char *)(*this)(s, strlen(s) + 1); }
-
- void countedData(const void *data, size_t length)
- {
- if (length > uint32_t(~0))
- UnixError::throwMe(ERANGE);
- Endian<uint32_t> temp = (uint32_t)length; (*this)(temp); (*this)(data, length);
- }
-
- template <class Data>
- void countedData(const Data &data)
- { countedData(data.data(), data.length()); }
-
- class Counter;
-
-private:
- void *writePos; // next byte address
-};
-
-class Writer::Counter {
-private:
- void align() { totalSoFar = alignUp(totalSoFar); }
-
-public:
- Counter() : totalSoFar(0) { }
- operator size_t () { return totalSoFar; }
-
- template <class T> size_t operator () (const T &) { align(); return totalSoFar += sizeof(T); }
- size_t insert(size_t size) { align(); return totalSoFar += size; }
- size_t operator () (const char *s) { align(); return totalSoFar += strlen(s) + 1; }
-
- void countedData(const void *, size_t length)
- { insert(sizeof(length)); insert(length); }
-
- template <class Data>
- void countedData(const Data &data)
- { countedData(data.data(), data.length()); }
-
-private:
- size_t totalSoFar; // total size counted so far
-};
-
-
-//
-// The Reader counter-part for a Writer.
-// Again, Reader and Writer share alignment and representation rules, so what was
-// Written shall be Read again, just fine.
-//
-class Reader {
-private:
- const void *advance(size_t size = 0)
- {
- const void *here = alignUp(readPos);
- readPos = increment(here, size);
- return here;
- }
-
-public:
- Reader() { }
- Reader(const void *base) : readPos(base) { }
- void operator = (const void *base) { readPos = base; }
-
- template <class T>
- void operator () (T &obj) { obj = *reinterpret_cast<const T *>(advance(sizeof(T))); }
- void operator () (void *addr, size_t size) { memcpy(addr, advance(size), size); }
- void operator () (const char * &s)
- { s = reinterpret_cast<const char *>(advance()); advance(strlen(s) + 1); }
- template <class T>
- const T *get(size_t size)
- { return reinterpret_cast<const T *>(advance(size)); }
-
- void countedData(const void * &data, size_t &length)
- { Endian<uint32_t> temp; (*this)(temp); length = temp; data = advance(length); }
-
-private:
- // Explicitly forbid some invocations that are likely to be wrong.
- void operator () (char * &s); // can't get writable string in-place
-
-private:
- const void *readPos; // next byte address
-};
-
-
-} // end namespace LowLevelMemoryUtilities
-
-} // end namespace Security
-
-#endif //_H_MEMUTILS
projects / apple / security.git / blobdiff