Security-55163.44.tar.gz

[apple/security.git] / libsecurity_filedb / lib / MetaAttribute.cpp

diff --git a/libsecurity_filedb/lib/MetaAttribute.cpp b/libsecurity_filedb/lib/MetaAttribute.cpp
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+++ b/libsecurity_filedb/lib/MetaAttribute.cpp
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+/*
+ * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
+ * 
+ * The contents of this file constitute Original Code as defined in and are
+ * subject to the Apple Public Source License Version 1.2 (the 'License').
+ * You may not use this file except in compliance with the License. Please obtain
+ * a copy of the License at http://www.apple.com/publicsource and read it before
+ * using this file.
+ * 
+ * This 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.
+ */
+
+
+//
+// MetaAttribute.cpp
+//
+
+#include "MetaAttribute.h"
+#include "MetaRecord.h"
+
+MetaAttribute::~MetaAttribute()
+{
+}
+
+// Construct an instance of an appropriate subclass of MetaAttribute
+// based on the given format.
+
+MetaAttribute *
+MetaAttribute::create(Format format, uint32 attributeIndex,
+       uint32 attributeId)
+{
+       switch (format)
+       {
+               case CSSM_DB_ATTRIBUTE_FORMAT_STRING:
+                       return new TypedMetaAttribute<StringValue>(format, attributeIndex, attributeId);
+
+               case CSSM_DB_ATTRIBUTE_FORMAT_SINT32:
+                       return new TypedMetaAttribute<SInt32Value>(format, attributeIndex, attributeId);
+                       
+               case CSSM_DB_ATTRIBUTE_FORMAT_UINT32:
+                       return new TypedMetaAttribute<UInt32Value>(format, attributeIndex, attributeId);
+
+               case CSSM_DB_ATTRIBUTE_FORMAT_BIG_NUM:
+                       return new TypedMetaAttribute<BigNumValue>(format, attributeIndex, attributeId);
+                       
+               case CSSM_DB_ATTRIBUTE_FORMAT_REAL:
+                       return new TypedMetaAttribute<DoubleValue>(format, attributeIndex, attributeId);
+
+               case CSSM_DB_ATTRIBUTE_FORMAT_TIME_DATE:
+                       return new TypedMetaAttribute<TimeDateValue>(format, attributeIndex, attributeId);
+
+               case CSSM_DB_ATTRIBUTE_FORMAT_BLOB:
+                       return new TypedMetaAttribute<BlobValue>(format, attributeIndex, attributeId);
+                       
+               case CSSM_DB_ATTRIBUTE_FORMAT_MULTI_UINT32:
+                       return new TypedMetaAttribute<MultiUInt32Value>(format, attributeIndex, attributeId);
+                                                                                                               
+           case CSSM_DB_ATTRIBUTE_FORMAT_COMPLEX:
+               default:
+                       CssmError::throwMe(CSSMERR_DL_UNSUPPORTED_FIELD_FORMAT);
+       }
+}
+
+void
+MetaAttribute::packNumberOfValues(WriteSection &ws, uint32 numValues, uint32 &valueOffset) const
+{
+       uint32 offset = MetaRecord::OffsetAttributeOffsets + mAttributeIndex * AtomSize;
+       
+       if (numValues == 0) {
+               // a zero offset means the attribute has no values
+               ws.put(offset, 0);
+       }
+       else if (numValues == 1) {
+               // setting the low bit of the offset means that there is exactly one value
+                ws.put(offset, valueOffset | 1);
+       }
+       else {
+               // write the offset, then write the number of values at that position
+               ws.put(offset, valueOffset);
+               valueOffset = ws.put(valueOffset, numValues);
+       }
+}
+
+void
+MetaAttribute::unpackNumberOfValues(const ReadSection &rs, uint32 &numValues,
+       uint32 &valueOffset) const
+{
+       uint32 offset = MetaRecord::OffsetAttributeOffsets + mAttributeIndex * AtomSize;
+       valueOffset = rs[offset];
+       
+       if (valueOffset == 0)
+               // a zero offset means no values
+               numValues = 0;
+       else if (valueOffset & 1) {
+               // setting the LSB means exactly one value
+               valueOffset ^= 1;
+               numValues = 1;
+       }
+       else {
+               // otherwise, the number of values is at the offset, and the values follow
+               numValues = rs[valueOffset];
+               valueOffset += AtomSize;
+       }
+}
+
+void
+MetaAttribute::packAttribute(WriteSection &ws, uint32 &valueOffset, uint32 numValues,
+       const CSSM_DATA *values) const
+{
+       packNumberOfValues(ws, numValues, valueOffset);
+       for (uint32 i = 0; i < numValues; i++)
+               packValue(ws, valueOffset, values[i]);
+}
+
+void
+MetaAttribute::unpackAttribute(const ReadSection &rs, Allocator &allocator,
+       uint32 &numValues, CSSM_DATA *&values) const
+{
+       uint32 valueOffset;
+       unpackNumberOfValues(rs, numValues, valueOffset);
+       
+       // Rough check for number of values; will be more like 10 or 20
+       if (numValues > 1024)
+               CssmError::throwMe(CSSMERR_DL_DATABASE_CORRUPT);
+
+       values = reinterpret_cast<CSSM_DATA *>(allocator.malloc(numValues * sizeof(CSSM_DATA)));
+       
+       for (uint32 i = 0; i < numValues; i++)
+               unpackValue(rs, valueOffset, values[i], allocator);
+}
+
+uint32
+MetaAttribute::getNumberOfValues(const ReadSection &rs) const
+{
+       uint32 numValues, valueOffset;
+       unpackNumberOfValues(rs, numValues, valueOffset);
+       return numValues;
+}
+
+void
+MetaAttribute::copyValueBytes(uint32 valueIndex, const ReadSection &rs, WriteSection &ws,
+       uint32 &writeOffset) const
+{
+       uint32 numValues, valueOffset;
+       unpackNumberOfValues(rs, numValues, valueOffset);
+
+       // skip bytes before the desired value
+       for (uint32 i = 0; i < valueIndex; i++)
+               skipValue(rs, valueOffset);
+               
+       // copy the value bytes into the write section
+       copyValue(rs, valueOffset, ws, writeOffset);
+}