Generate UUID in Assembly

Different ways of generating UUID in assembly

  1. Random UUID Generation
  2. MAC Address-based UUID Generation
  3. Timestamp-based UUID Generation

1. Random UUID Generation

Random UUIDs can be generated using various methods and libraries in assembly language. Here is an example code snippet using MASM: 

      ; Include necessary libraries and define variables
      .data
      randomUuid db 16 dup(0)

      .code
      generate_random_uuid proc
        ; Generate random bytes
        invoke CryptGenRandom, NULL, 16, offset randomUuid

        ; Use random bytes to create a UUID
        lea esi, randomUuid
        mov edi, offset uuid
        mov ecx, 16
        rep movsb

        ; Optional: Set the version and variant bits

        ret
      generate_random_uuid endp

2. MAC Address-based UUID Generation

Another way to generate a UUID in assembly is by using the MAC address. This method ensures uniqueness by relying on the unique identifier of the network interface card (NIC). 

      .data
      macAddress db "00-11-22-33-44-55", 0

      .code
      generate_mac_uuid proc
        ; Convert the MAC address to bytes
        invoke sscanf, addr macAddress, "%2x-%2x-%2x-%2x-%2x-%2x", \
          offset macBytes[0], offset macBytes[1], offset macBytes[2], \
          offset macBytes[3], offset macBytes[4], offset macBytes[5]

        ; Create a UUID using the MAC address
        xor eax, eax
        mov edi, offset uuid
        mov ecx, 6
        rep stosb

        ret
      generate_mac_uuid endp

3. Timestamp-based UUID Generation

Timestamp-based UUIDs use the current system time and a random or sequential value to generate a unique identifier. Here's an example of generating a timestamp-based UUID in assembly: 

      .code
      generate_timestamp_uuid proc
        ; Get the current timestamp (in milliseconds)
        invoke GetSystemTimeAsFileTime, addr timestamp
        mov eax, dword ptr [timestamp]
        mov edx, dword ptr [timestamp + 4]
        shr edx, 20
        shr eax, 12
        or eax, edx

        ; Use the timestamp to create a UUID
        mov edi, offset uuid
        mov ecx, 16
        rep stosb

        ret
      generate_timestamp_uuid endp

Conclusion

In this article, we explored different methods for generating UUIDs in assembly language. We discussed random UUID generation, MAC address-based UUID generation, and timestamp-based UUID generation. Each method has its advantages and can be used based on specific requirements. By using these techniques, you can easily generate unique identifiers in your assembly programs.