oak_techniques: [OAK-T5.003]
spec_id: oak-detection-T5.003
version: 0.1.0
maturity: stable
maintainer: "@iZonex"
license: Apache-2.0

scope: |
  Detect post-launch supply expansion against existing holders — either
  via retained mint authority (ERC-20 / SPL mint role; SPL Token-2022
  permanent-delegate materialisation) exercised against deployer-
  cluster recipients, or via smart-contract-platform balance-tracking
  bugs (reentrancy-into-mint, dual-counted balances) that produce
  unauthorised supply expansion. Excludes: T1.005 (transfer-fee
  extraction — different primitive); T5.001 / T5.002 (LP-side
  removal); T1.002 (PD-extension presence per se — T5.003 fires when
  the extension is exercised to materialise tokens).

data_sources: [contract_bytecode, contract_source, mint_event_log,
               total_supply_oracle, funder_graph, lending_pool_state]

detection_logic:
  description: |
    Three orthogonal paths plus a balance-tracking cross-check.
    PATH A (post-launch mint to deployer cluster): Mint / Transfer-from-
    zero events post-launch where the recipient is in the deployer
    funder cluster. PATH B (totalSupply vs published-tokenomics
    reconciliation): on-chain totalSupply trajectory diverges from
    the published emission schedule by > schedule_divergence. PATH C
    (Solana SPL permanent-delegate exercise): non-renounced mint
    authority + Token-2022 PD extension materialises tokens at
    deployer-controlled accounts. CROSS-CHECK (balance-tracking):
    sum of Transfer-from-zero events does not match Δ totalSupply —
    indicates a non-standard supply-mutation path (reentrancy-into-
    mint, dual-counted-balance bug).
  pseudocode: |
    # PATH A — post-launch mint to deployer-cluster recipients
    cluster ← funder_graph_cluster(deployer(C), hops = trace_hops)
    for each event E ∈ contract_events(C)
        where E.kind == Mint or (E.kind == Transfer and E.from == 0x0):
      if E.block < C.deployment_block + grace_blocks: continue
      if E.recipient ∈ cluster:
        share ← E.amount / max(circulating_supply(C, E.block), 1)
        if share > mint_share_threshold:
          emit(PATH_A, contract=C, event=E, recipient=E.recipient,
               share, severity=critical)

    # PATH B — totalSupply vs tokenomics schedule
    for each rolling block b on contract C:
      observed ← totalSupply(C, b)
      scheduled ← tokenomics_schedule(C).at(b)
      if scheduled == None: continue       # no published schedule
      divergence ← (observed − scheduled) / max(scheduled, 1)
      if divergence > schedule_divergence:
        emit(PATH_B, contract=C, block=b, observed, scheduled,
             divergence, severity=critical)

    # PATH C — Solana SPL permanent-delegate exercise
    for each Token-2022 mint M with EXT_PERM_DELEGATE configured:
      delegate ← M.permanent_delegate_authority
      if delegate == 0 or delegate ∈ vetted_delegate_allowlist: continue
      for ix ∈ tx_history(M, after = M.creation_slot):
        if ix.kind ∈ {MintTo, MintToChecked} and ix.authority == delegate:
          target ← ix.account.owner
          if target ∈ deployer_cluster(M, hops = trace_hops):
            emit(PATH_C, mint=M, delegate, target, amount=ix.amount,
                 severity=critical)

    # CROSS-CHECK — balance-tracking integrity
    for each block b on contract C:
      mints_in_block ← Σ E.amount for E in events(C, b)
                          if (E.kind == Transfer and E.from == 0x0)
      delta_supply ← totalSupply(C, b) − totalSupply(C, b−1)
      if delta_supply > mints_in_block + accounting_floor:
        emit(CROSS_CHECK, contract=C, block=b,
             unaccounted_delta=delta_supply − mints_in_block,
             severity=critical)

parameters:
  trace_hops:               { type: integer, default: 3 }
  grace_blocks:             { type: integer, default: 100 }    # ignore launch initialisation
  mint_share_threshold:     { type: number,  default: 0.05 }   # > 5% of circulating
  schedule_divergence:      { type: number,  default: 0.10 }   # > 10% above schedule
  vetted_delegate_allowlist: { type: list,   default: [] }
  accounting_floor:         { type: number,  default: 1 }

output_alert: [oak_technique, detection_path, severity, chain,
               contract_address, mint, recipient, share,
               divergence, unaccounted_delta, evidence]

test_fixtures:
  positive:
    - 2020-12-cover-protocol-blacksmith-mint    # canonical balance-tracking bug → infinite-mint
  negative:
    - "ERC-20 with renounced mint authority and totalSupply tracking schedule exactly"
    - "Solana SPL mint without Token-2022 permanent-delegate extension"
    - "Vested-team-allocation mint to a documented vesting contract"

false_positive_modes:
  - rebase / yield-bearing tokens that legitimately mutate supply per a documented model — annotate via tokenomics_schedule
  - liquid-staking protocols whose mint events fund staked-asset wrapping (recipients are users, not deployer cluster)
  - airdrop-claim contracts that mint to recipients on demand (PATH A's mint_share_threshold + cluster filter handles)
  - PATH B false positives where the published schedule is informal / approximate (require non-trivial divergence and tokenomics_schedule presence)

mitigations: [OAK-M02, OAK-M03, OAK-M05, OAK-M17, OAK-M25]

reference_implementations:
  - { target: slither-plugin,    chain: evm,    url: "" }
  - { target: forta-bot,         chain: evm,    url: "" }
  - { target: goplus,            chain: cross-chain, url: "" }
  - { target: rugcheck,          chain: solana, url: "" }
  - { target: helius-indexer,    chain: solana, url: "" }
  - { target: mg-detectors-rs,   chain: cross-chain, url: "" }