-/*
- * Copyright (c) 2006,2011-2014 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@
- */
-
-//
-// blob - generic extensible binary blob frame
-//
-// To define a new type of binary blob:
-// class MyBlob : public Blob<MyBlob, magic number> { ... }
-// Pick a unique magic number (32-bit). Blobs are understood to be a MyBlob
-// header possibly followed by more data as a contiguous memory area. Length
-// is overall (including the header), so a fixed-size blob would have length
-// sizeof(MyBlob). Both length and magic are stored in NBO.
-//
-// You are highly encouraged to follow these rules:
-// Store all integers in NBO, including offsets.
-// Use internal offsets to "point to" dynamically-sized elements past the
-// header (using the at<Type>(offset) method for access).
-// Don't use pointers in your blob.
-// If you follow those rules, your blobs will be fully relocatable, byte-order
-// independent, and generally spreading happiness around your code.
-//
-#ifndef _H_BLOB
-#define _H_BLOB
-
-#include <security_utilities/endian.h>
-#include <security_utilities/memutils.h>
-#include <security_utilities/errors.h>
-
-namespace Security {
-
-
-//
-// All blobs in memory have this form.
-// You can have polymorphic memory blobs (C style) using different magics numbers.
-//
-class BlobCore {
-public:
- typedef uint32_t Offset;
- typedef uint32_t Magic;
-
- Magic magic() const { return mMagic; }
- size_t length() const { return mLength; }
-
- void initialize(Magic magic, size_t length = 0)
- { mMagic = magic; mLength = (uint32_t)length; }
-
- bool validateBlob(Magic magic, size_t minSize = 0, size_t maxSize = 0) const;
-
- template <class T, class Offset>
- T *at(Offset offset)
- { return LowLevelMemoryUtilities::increment<T>(this, offset); }
-
- template <class T, class Offset>
- const T *at(Offset offset) const
- { return LowLevelMemoryUtilities::increment<const T>(this, offset); }
-
- template <class Offset1, class Offset2>
- bool contains(Offset1 offset, Offset2 size) const
- { return offset >= 0 && size_t(offset) >= sizeof(BlobCore) && (size_t(offset) + size) <= this->length(); }
-
- template <class Base, class Offset>
- bool contains(Base *ptr, Offset size) const
- { return contains(LowLevelMemoryUtilities::difference(ptr, this), size); }
-
- char *stringAt(Offset offset);
- const char *stringAt(Offset offset) const;
-
- void *data() { return this; }
- const void *data() const { return this; }
- void length(size_t size) { mLength = (uint32_t)size; }
-
- BlobCore *clone() const
- {
- if (BlobCore *copy = (BlobCore *)malloc(this->length())) {
- memcpy(copy, this, this->length());
- return copy;
- }
- UnixError::throwMe(ENOMEM);
- }
-
- template <class BlobType>
- bool is() const { return magic() == BlobType::typeMagic; }
-
- static BlobCore *readBlob(std::FILE *file) { return readBlob(file, 0, 0, 0); }
- static BlobCore *readBlob(int fd) { return readBlob(fd, 0, 0, 0); }
-
-protected:
- static BlobCore *readBlob(std::FILE *file, uint32_t magic, size_t minSize, size_t maxSize); // streaming
- static BlobCore *readBlob(int fd, uint32_t magic, size_t minSize, size_t maxSize); // streaming
- static BlobCore *readBlob(int fd, size_t offset, uint32_t magic, size_t minSize, size_t maxSize); // pread(2)@offset
-
-protected:
- Endian<uint32_t> mMagic;
- Endian<uint32_t> mLength;
-};
-
-
-// basic validation helper
-inline bool BlobCore::validateBlob(Magic magic, size_t minSize /* = 0 */, size_t maxSize /* = 0 */) const
-{
- uint32_t length = this->mLength;
- if (magic && magic != this->mMagic) {
- errno = EINVAL;
- return false;
- }
- if (minSize ? (length < minSize) : (length < sizeof(BlobCore))) {
- errno = EINVAL;
- return false;
- }
- if (maxSize && length > maxSize) {
- errno = ENOMEM;
- return false;
- }
- return true;
-}
-
-
-//
-// Typed Blobs (BlobCores that know their real type and magic)
-//
-template <class BlobType, uint32_t _magic>
-class Blob: public BlobCore {
-public:
- void initialize(size_t size = 0) { BlobCore::initialize(_magic, size); }
-
- static const Magic typeMagic = _magic;
-
- bool validateBlob() const
- { return BlobCore::validateBlob(_magic, sizeof(BlobType)); }
-
- bool validateBlob(size_t extLength) const
- { return extLength >= sizeof(BlobType) && validateBlob() && mLength == extLength; }
-
- static BlobType *specific(BlobCore *blob, bool unalloc = false)
- {
- if (BlobType *p = static_cast<BlobType *>(blob)) {
- if (p->validateBlob())
- return p;
- if (unalloc)
- ::free(p);
- }
- return NULL;
- }
-
- static const BlobType *specific(const BlobCore *blob)
- {
- const BlobType *p = static_cast<const BlobType *>(blob);
- if (p && p->validateBlob())
- return p;
- return NULL;
- }
-
- BlobType *clone() const
- { assert(validateBlob()); return specific(this->BlobCore::clone()); }
-
- static BlobType *readBlob(int fd)
- { return specific(BlobCore::readBlob(fd, _magic, sizeof(BlobType), 0), true); }
-
- static BlobType *readBlob(int fd, size_t offset, size_t maxSize = 0)
- { return specific(BlobCore::readBlob(fd, offset, _magic, sizeof(BlobType), maxSize), true); }
-
- static BlobType *readBlob(std::FILE *file)
- { return specific(BlobCore::readBlob(file, _magic, sizeof(BlobType), 0), true); }
-};
-
-
-//
-// A generic blob wrapped around arbitrary (flat) binary data.
-// This can be used to "regularize" plain binary data, so it can be handled
-// as a genuine Blob (e.g. for insertion into a SuperBlob).
-//
-class BlobWrapper : public Blob<BlobWrapper, 0xfade0b01> {
-public:
- static BlobWrapper *alloc(size_t length, Magic magic = BlobWrapper::typeMagic);
- static BlobWrapper *alloc(const void *data, size_t length, Magic magic = BlobWrapper::typeMagic);
-
- unsigned char dataArea[0];
-
- // override data/length to point to the payload (only)
- void *data() { return dataArea; }
- const void *data() const { return dataArea; }
- size_t length() const { return BlobCore::length() - sizeof(BlobCore); }
-};
-
-
-} // Security
-
-#endif //_H_BLOB
projects / apple / security.git / blobdiff