safrole.asn

-- Syntax for Safrole protocol test vectors

SafroleModule DEFINITIONS ::= BEGIN

-- Define constants
IMPORTS validators-count, epoch-length FROM SafroleConstants;

-- Define basic types
U8 ::= INTEGER (0..255)
U32 ::= INTEGER (0..4294967295)

-- Define fixed-length arrays
ByteArray32 ::= SEQUENCE (SIZE(32)) OF U8
OpaqueHash ::= ByteArray32
Ed25519Key ::= ByteArray32
BlsKey ::= SEQUENCE (SIZE(144)) OF U8
BandersnatchKey ::= ByteArray32
EpochKeys ::= SEQUENCE (SIZE(epoch-length)) OF BandersnatchKey
TicketsBodies ::= SEQUENCE (SIZE(epoch-length)) OF TicketBody

-- Define enumerations
TicketsOrKeys ::= CHOICE {
    tickets TicketsBodies,
    keys EpochKeys 
}

-- State transition function execution error.
-- Error codes **are not specified** in the the Graypaper.
-- Feel free to ignore the actual value.
CustomErrorCode ::= ENUMERATED {
    -- Timeslot value must be strictly monotonic.
    bad-slot (0),
    -- Received a ticket while in epoch's tail.
    unexpected-ticket (1),
    -- Tickets must be sorted.
    bad-ticket-order (2),
    -- Invalid ticket ring proof.
    bad-ticket-proof (3),
    -- Invalid ticket attempt value.
    bad-ticket-attempt (4),
    -- Reserved
    reserved (5),
    -- Found a ticket duplicate.
    duplicate-ticket (6)
}

-- Define structures
TicketBody ::= SEQUENCE {
    id OpaqueHash,
    attempt U8
}

ValidatorData ::= SEQUENCE {
    bandersnatch BandersnatchKey,
    ed25519 Ed25519Key,
    bls BlsKey,
    metadata SEQUENCE (SIZE(128)) OF U8
}

ValidatorsData ::= SEQUENCE (SIZE(validators-count)) OF ValidatorData

TicketEnvelope ::= SEQUENCE {
    attempt U8,
    signature SEQUENCE (SIZE(784)) OF U8
}

EpochMark ::= SEQUENCE {
    entropy OpaqueHash,
    validators SEQUENCE (SIZE(validators-count)) OF BandersnatchKey
}

TicketsMark ::= SEQUENCE (SIZE(epoch-length)) OF TicketBody

-- Output markers.
OutputMarks ::= SEQUENCE {
    -- New epoch signal.
    epoch-mark [0] EpochMark OPTIONAL,
    -- Tickets signal.
    tickets-mark [1] TicketsMark OPTIONAL
}

-- State relevant to Safrole protocol
State ::= SEQUENCE {
    -- Most recent block's timeslot.
    tau U32,

    -- Entropy accumulator and epochal randomness.
    eta SEQUENCE (SIZE(4)) OF OpaqueHash,

    -- Validator keys and metadata which were active in the prior epoch.
    lambda ValidatorsData,

    -- Validator keys and metadata currently active.
    kappa ValidatorsData,

    -- Validator keys for the following epoch.
    gamma-k ValidatorsData,

    -- Validator keys and metadata to be drawn from next.
    iota ValidatorsData,

    -- Sealing-key contest ticket accumulator.
    gamma-a SEQUENCE (SIZE(0..epoch-length)) OF TicketBody,

    -- Sealing-key series of the current epoch.
    gamma-s TicketsOrKeys,

    -- Bandersnatch ring commitment.
    gamma-z SEQUENCE (SIZE(144)) OF U8
}

-- Input for Safrole protocol.
Input ::= SEQUENCE {
    -- Current slot.
    slot U32,
    -- Per block entropy (originated from block entropy source VRF).
    entropy OpaqueHash,
    -- Safrole extrinsic.
    extrinsic SEQUENCE (SIZE(0..16)) OF TicketEnvelope
}

-- Output from Safrole protocol
Output ::= CHOICE {
    -- Markers
    ok OutputMarks,
    -- Error code (not specified in the Graypaper)
    err CustomErrorCode
}

-- Safrole state transition function execution dump
Testcase ::= SEQUENCE {
    -- Input.
    input Input,
    -- Pre-execution state.
    pre-state State,
    -- Output.
    output Output,
    -- Post-execution state.
    post-state State
}

END