Transaction validation - phase 1 (MS5.6)

[sandtreader]

Description

Validate transaction witness signatures and other 'phase 1' items

Intersect Milestone

MS5.6

Acceptance Criteria

• Able to phase 1 validate all existing Transactions (TXs)

Expected Deliverables

• Transaction Phase 1 validation module
• Test cases and reports

Design Notes

(from ChatGPT)

• Well-formed CBOR / basic syntax
  • Transaction decodes correctly from CBOR.
  • All expected fields are present and correctly typed.
• Size limits
  • Transaction size ≤ maxTxSize protocol parameter.
  • Number of inputs, outputs, certificates, witnesses ≤ limits.
• Key validity
  • All input key hashes and witness signatures are valid Ed25519 signatures over the Tx body.
  • VKey witnesses match the inputs they are supposed to authorize.
• Scripts (native or Plutus) referenced are present.
• Fee and value preservation (basic)
  • Declared fee ≥ minFee (protocol parameter).
  • No negative values in outputs.
  • Token bundle policy IDs / asset names well-formed.
• Timelock validity
  • Transaction validity interval (TTL, start slot, expiry) is syntactically correct.
  • If native scripts with timelock conditions are present, their conditions are checked.
• Auxiliary data structure
  • Metadata, if present, is CBOR-valid and within size limits.

This list should be validated against the spec and Haskell code.

This should output a ValidationResult message on 'cardano.validation.tx-phase-1'.