The M2 verdict run on J3R452 04555A4A0B2190 tripped SW=0x6FC4 on
AUTH0 (AliroCrypto.expandScratch makeTransientByteArray failure).
Summed CLEAR_ON_DESELECT allocations exceeded the ~3,120 B pool:
- PersonalizationApplet/CoseVerifier scratch: 768 B
- AliroApplet: 838 B (sessionState + scratch + derivedKeys + saltVolatile + kdh)
- StepUpApplet + StepUpSession: ~893 B (responseBuffer + scratchPlaintext + ...)
- AliroGcm + AliroCrypto (lazy, at first AUTH0): 720 B
Total ~3,220 B vs ~3,120 B cap.
CoseVerifier's 768 B was M2A.2's conservative sizing for up to 512 B COSE
payload. Aliro's IssuerAuth payload is ~188 B today. Tighten:
- MAX_PAYLOAD 512 -> 256 (still 36% headroom over actual)
- scratch 768 -> 384 (Sig_structure ~310 B + DER sig 72 B = ~382 B)
Saved 384 B, brings total to ~2,836 B. CAP rebuilt (100,990 B),
reinstalled + repersonalized + bench-test re-run -- GREEN.
Verdict log: docs/verdicts/2026-06-12-m2-pcsc-verdict.log
RESULT: OK -- applet round-trip on real hardware
0x5E signaling_bitmap: 0x0005
APDU latencies: select 23 ms, auth0 667 ms, auth1 3,258 ms
STEP-UP M2: OK -- EXCHANGE + ENVELOPE Access Document round-trip
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