Lua:md5memory

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function md5memory(address, size) : string

Calculates and returns the MD5 checksum of a block of memory starting at the specified address. The result is returned as a lowercase hexadecimal string (32 hex characters). This is useful for integrity checks of memory regions, detecting runtime modifications, or comparing memory snapshots.

Function Parameters

Parameter	Type	Description
address	CEAddressString or Integer	Start address of the memory block to hash.
size	number	Number of bytes to read from address and include in the hash.

Returns

A string containing the MD5 hash of the memory block in lowercase hexadecimal (e.g. 9e107d9d372bb6826bd81d3542a419d6).

Description

The function reads size raw bytes starting at address, computes the MD5 digest over those bytes, and returns the digest formatted as a 32-character lowercase hexadecimal string. If the memory region cannot be read (invalid address, insufficient permissions, or target process not available), the function may raise an error.

Usage Examples

-- Simple usage with numeric address
local hash = md5memory(0x401000, 1024)
print("MD5: " .. hash)  -- e.g. MD5: 9e107d9d372bb6826bd81d3542a419d6

-- Using a module+offset string
local hash2 = md5memory("kernel32.dll+0x1234", 256)
print("Region MD5: " .. hash2)

-- Output:
-- MD5: a754c02f5e872ca0008b37755928a914 
-- Region MD5: 215a614d8b4156943fe865bb7d5e2c8c 

Notes

• The function hashes the raw bytes read from memory; CPU endianness or text encoding does not affect the MD5 result.
• Reading large regions can be slow and may consume significant memory depending on implementation; consider hashing in chunks if available.
• MD5 is not collision-resistant; do not rely on MD5 where collision resistance is required.
• When comparing MD5 strings, normalize case (lowercase) or use a case-insensitive comparison.
• Permission or process-targeting issues can prevent reading memory; ensure the correct process/context is selected before calling the function.