protobuf/objectivec/GPBWireFormat.m
Thomas Van Lenten c18aa7795a Validate the tag numbers when parsing. ()
There was a twist code path (that some times showed up due to what happened to
be in memory in failure cases), that would cast a bogus wire type into the
enum, and then fall through switch statements.

Resolve this by validating all wire types when parsing tags and throwing the
error at that point so it can't enter the system.

As added safety, stick in a few asserts for apis that get passed tags to ensure
they also are only seeing valid data.

Bonus: Tweak the parsing loop to skip some work when we get the end marker
(zero tag) instead of still looping through all the fields.
2016-06-29 09:51:13 -04:00

86 lines
3.6 KiB
Objective-C

// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
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// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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#import "GPBWireFormat.h"
#import "GPBUtilities_PackagePrivate.h"
enum {
GPBWireFormatTagTypeBits = 3,
GPBWireFormatTagTypeMask = 7 /* = (1 << GPBWireFormatTagTypeBits) - 1 */,
};
uint32_t GPBWireFormatMakeTag(uint32_t fieldNumber, GPBWireFormat wireType) {
return (fieldNumber << GPBWireFormatTagTypeBits) | wireType;
}
GPBWireFormat GPBWireFormatGetTagWireType(uint32_t tag) {
return (GPBWireFormat)(tag & GPBWireFormatTagTypeMask);
}
uint32_t GPBWireFormatGetTagFieldNumber(uint32_t tag) {
return GPBLogicalRightShift32(tag, GPBWireFormatTagTypeBits);
}
BOOL GPBWireFormatIsValidTag(uint32_t tag) {
uint32_t formatBits = (tag & GPBWireFormatTagTypeMask);
// The valid GPBWireFormat* values are 0-5, anything else is not a valid tag.
BOOL result = (formatBits <= 5);
return result;
}
GPBWireFormat GPBWireFormatForType(GPBDataType type, BOOL isPacked) {
if (isPacked) {
return GPBWireFormatLengthDelimited;
}
static const GPBWireFormat format[GPBDataType_Count] = {
GPBWireFormatVarint, // GPBDataTypeBool
GPBWireFormatFixed32, // GPBDataTypeFixed32
GPBWireFormatFixed32, // GPBDataTypeSFixed32
GPBWireFormatFixed32, // GPBDataTypeFloat
GPBWireFormatFixed64, // GPBDataTypeFixed64
GPBWireFormatFixed64, // GPBDataTypeSFixed64
GPBWireFormatFixed64, // GPBDataTypeDouble
GPBWireFormatVarint, // GPBDataTypeInt32
GPBWireFormatVarint, // GPBDataTypeInt64
GPBWireFormatVarint, // GPBDataTypeSInt32
GPBWireFormatVarint, // GPBDataTypeSInt64
GPBWireFormatVarint, // GPBDataTypeUInt32
GPBWireFormatVarint, // GPBDataTypeUInt64
GPBWireFormatLengthDelimited, // GPBDataTypeBytes
GPBWireFormatLengthDelimited, // GPBDataTypeString
GPBWireFormatLengthDelimited, // GPBDataTypeMessage
GPBWireFormatStartGroup, // GPBDataTypeGroup
GPBWireFormatVarint // GPBDataTypeEnum
};
return format[type];
}