To make it more clear let's compile a program with another executable inside of it. Name array, find the name and its index, for ex- 1 st function is CsrAllocateCaptureBuffer 2. It is very important to specify the function attribute correctly. The two fields OffsetToData and Size indicate the location and size of the actual resource data. Each member of the array is equvalent to the each directory entry in the root directory.
If the bit is set and the NumberOfRelocations field in the section header is 0xffff, the actual relocation count is stored in the 32-bit VirtualAddress field of the first relocation. Its specification is derived somewhat from the Unix Coff common object file format. It is used for storage by the routine that is supplied to manage delay-loading. For program images, this is the starting address. The pointers are 32 bits each and are relative to the image base.
Import Address Table The structure and content of the import address table are identical to those of the import lookup table, until the file is bound. For example, consider how separate debug files are managed for an executable. This section is needed for specific information about. Because addresses can point across section borders, relocations should be done after each section is loaded into memory. Offset Size Field Description 24 4 BaseOfData The address that is relative to the image base of the beginning-of-data section when it is loaded into memory.
These strings are stored together after the last Resource Directory entry and before the first Resource Data entry. This is a declarative field for the linker that indicates that the compiler has already emitted this value. Valid only for object files. Following is a summary of these fields. Standard Fields As you see in the above picture, we have two fields that are again categorized into some headers. Machine In the first line, we print the machine field as a hex value.
If this is less than VirtualSize, the remainder of the section is zero-filled. It must be greater than or equal to FileAlignment. This specifies what type of app this is, if it is an app. There are also two dwUselessparameters in the structure that serve as padding to keep the structure aligned properly within the section. The raw data of this debug entry may be empty, or may contain a calculated hash value preceded by a four-byte value that represents the hash value length. A value of non-zero is a common symbol with a size that is specified by the value. Each line-number record is of the following format.
It is referenced through the szName field. We will target a basic structure like Intel, as shown below: 0x14d Intel i860 We will see above characteristics in the tool later. This is an offset to the location of the section body in the file. Note that in my source-code I didn't imported all these functions, but the compiler did. We'll cover this in more detail in future detail. To determine whether the name itself or an offset is given, test the first 4 bytes for equality to zero. Note that relocations on instructions use the bundle's offset and slot number for the relocation offset.
To make things easier, I created a enum called MachineType and set it to the following values the values are in winnt. This header is optional in the sense that some files specifically, object files do not have it. There is some ways to get this resources in the run-time, advanced ways and basic ways. The Value field specifies the n th bit in the bit field. Once we determine which section contains the directory, the section header for that section is then used to find the exact file offset location of the data directory.
The value should be a power of 2 between 512 and 64 K, inclusive. Please update this article to reflect recent events or newly available information. This is valid only for object files. Section Table Section Headers Each row of the section table is, in effect, a section header. It is distinct from Microsoft Visual C++ debug information.
The Value field specifies the offset of the symbol within the section. This symbol gives the address that is to be used for the relocation. A file hash is similar to a checksum in that it also detects file corruption. The external symbol, sym2, must always be linked; typically, it is defined in the module that contains the weak reference to sym1. A debug directory entry has the following format: Offset Size Field Description 0 4 Characteristics Reserved, must be zero. In the next image we will see that now it got the value in the index 0 of the field array AddressOfNameOrdinals and with this value it was able to sought the function address in the array field AddressOfFunctions.
This information appears after the header: Offset Size Field Description 0 4 Number of Members An unsigned long that contains the number of archive members. The magic field is at the beginning of the optional header. What about if one of them was missing? The file size is 32768 bytes. If the specified symbol has section storage class, then the symbol's address is the address with the first section of the same name. The pattern2 is not in the binary and should not be found, the other two patterns should. All the articles I saw on the web was in unmanaged code, I thought it would be fun to explore this from a managed perspective.