Capstone Parser: Boundaries and Diagnostics

Reconstruct cursor positions and diagnose unsafe partial results or displays.

Get every question correct to pass this checkpoint. You can review feedback, revise your answers, and submit again.

1. The worked binary-bitmap wire message is 48 bytes. Parse receives how many hex characters?

Select one answer.

96 48 24 64

2. Switch only an 8-byte binary bitmap to 16 hex-ASCII bytes. A field formerly starting at wire offset 14 now starts at:

Select one answer.

28 16 14 22

3. The actual FieldSpec has no LengthEncoding member. What prefix encoding does this exercise use?

Select one answer.

The same encoding as the value Automatically BCD for numeric fields ASCII decimal digits for every variable-length prefix Inferred from the first prefix byte

4. A five-digit BCD LLVAR payload is 01 23 45. What are decoded value and consumed bytes including prefix?

Select one answer.

012345; 3 bytes 12345; 5 bytes 01234; 5 bytes 12345; 7 bytes

5. The prefix bytes are -1. What should happen?

Select one answer.

Reject before using a length or slicing Accept negative one as a signed integer Treat the minus as a zero Consume the remainder as data

6. After DE2, the profile lacks DE3 while DE4 is also present. What is the result?

Select one answer.

Skip DE3 without moving the cursor, then parse DE4 Infer DE3 width from DE4 values Return nil error with missing fields defaulted Completed DE2 plus non-nil error; DE4 absent

7. A complete message is followed by one extra byte. How does this Parse API handle it?

Select one answer.

Return a consumed-byte count Silently ignore it Reject trailing data Treat it as a second message automatically

8. Text masks DE2, but JSON preserves its RawHex. Which claim is correct?

Select one answer.

JSON is exempt from the display policy The PAN remains recoverable from the JSON hex Hex is encryption so the PAN is protected Only plaintext is sensitive

9. DE4 contains 000000001234 but no currency exponent is supplied. Display should:

Select one answer.

Retain digits labeled as minor units Always show 12.34 Always show 1.234 Infer scale from leading zeros

10. Does a successful parse prove the transaction MAC is valid?

Select one answer.

Yes; hex decoding checks the MAC Yes; a bitmap binds the fields cryptographically Only if the MTI is 0100 No; parsing and authentication are separate checks

Auto-advance on pass

Join Discord