Struct Commitment

pub struct Commitment {
    pub id: U256,
    pub digest: FixedBytes<32>,
    pub configID: FixedBytes<32>,
}

A Solidity struct representing a commitment used for validation within Steel proofs.

This struct is used to commit to a specific claim, such as the hash of an execution block or a beacon chain state root. It includes an identifier combining the claim type (version) and a specific instance identifier (e.g., block number), the claim digest itself, and a configuration ID to ensure the commitment is valid for the intended network configuration. This structure is designed to be ABI-compatible with Solidity for on-chain verification.

struct Commitment { uint256 id; bytes32 digest; bytes32 configID; }

Fields

id: U256

Packed commitment identifier and version.

This field encodes two distinct pieces of information into a single 256-bit unsigned integer:

1. Version (Top 16 bits): Bits [255..240] store a u16 representing the type or version of the claim being made. See CommitmentVersion for defined values like Block or Beacon.
2. Identifier (Bottom 64 bits): Bits [63..0] store a u64 value that uniquely identifies the specific instance of the claim. For example, for a Block commitment, this would be the block number. For a Beacon commitment, it would be the slot number.

Use Commitment::decode_id to unpack this field into its constituent parts in Rust code. The packing scheme ensures efficient storage and retrieval while maintaining compatibility with Solidity’s uint256.

digest: FixedBytes<32>

The cryptographic digest representing the core claim data.

This is the actual data being attested to. The exact meaning depends on the version specified in the id field.

configID: FixedBytes<32>

A cryptographic digest identifying the network and prover configuration.

This ID acts as a fingerprint of the context in which the commitment was generated, including details like the Ethereum chain ID, active hard forks (part of the chain spec), and potentially prover-specific settings. Verification must ensure this configID matches the verifier’s current environment configuration to prevent cross-chain or misconfigured proof validation.

Implementations

impl Commitment

pub const ABI_ENCODED_SIZE: usize = 96usize

The size in bytes of the ABI-encoded commitment (3 fields * 32 bytes/field = 96 bytes).

pub const fn new( version: u16, id: u64, digest: B256, config_id: B256, ) -> Commitment

Creates a new Commitment by packing the version and identifier into the id field.

pub fn decode_id(&self) -> (U256, u16)

Decodes the packed Commitment.id field into the identifier part and the version.

This function extracts the version from the top 16 bits and returns the remaining part of the id field (which contains the instance identifier in its lower 64 bits) along with the u16 version.

pub fn abi_encode(&self) -> Vec<u8>

ABI-encodes the commitment into a byte vector according to Solidity ABI specifications.

Trait Implementations

impl Clone for Commitment

fn clone(&self) -> Commitment

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Commitment

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Commitment

fn default() -> Commitment

Returns the “default value” for a type.

impl EventTopic for Commitment

fn topic_preimage_length(rust: &Self::RustType) -> usize

The number of bytes this type occupies in another topic’s preimage, usually a multiple of 32.

fn encode_topic_preimage(rust: &Self::RustType, out: &mut Vec<u8>)

Encodes this type as preimage bytes which are then hashed in complex types’ [encode_topic][EventTopic::encode_topic].

fn encode_topic(rust: &Self::RustType) -> WordToken

Indexed event parameter encoding.

impl Hash for Commitment

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Commitment

fn eq(&self, other: &Commitment) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl SolStruct for Commitment

const NAME: &'static str = "Commitment"

The struct name.

fn eip712_root_type() -> Cow<'static, str>

Return the root EIP-712 type. This type is used to construct the encodeType string.

fn eip712_components() -> Vec<Cow<'static, str>>

Returns component EIP-712 types. These types are used to construct the encodeType string. These are the types of the struct’s fields, and should not include the root type.

fn eip712_encode_type() -> Cow<'static, str>

The EIP-712-encoded type string.

fn eip712_encode_data(&self) -> Vec<u8>

Encodes this domain using EIP-712 encodeData.

fn eip712_type_hash(&self) -> FixedBytes<32>

Calculates the EIP-712 typeHash for this struct.

fn eip712_hash_struct(&self) -> FixedBytes<32>

Calculates the EIP-712 hashStruct for this value.

fn eip712_signing_hash(&self, domain: &Eip712Domain) -> FixedBytes<32>

Calculate the EIP-712 signing hash for this struct. Note that this does not sign the hash, only calculates it.

impl SolType for Commitment

const SOL_NAME: &'static str = <Self as alloy_sol_types::SolStruct>::NAME

The name of this type in Solidity.

const ENCODED_SIZE: Option<usize> = <UnderlyingSolTuple as alloy_sol_types::SolType>::ENCODED_SIZE

The statically-known ABI-encoded size of the type.

const PACKED_ENCODED_SIZE: Option<usize> = <UnderlyingSolTuple as alloy_sol_types::SolType>::PACKED_ENCODED_SIZE

The statically-known Non-standard Packed Mode ABI-encoded size of the type.

type RustType = Commitment

The corresponding Rust type.

type Token<'a> = <(Uint<256>, FixedBytes<32>, FixedBytes<32>) as SolType>::Token<'a>

The corresponding ABI token type.

fn valid_token(token: &Self::Token<'_>) -> bool

Returns true if the given token can be detokenized with this type.

fn detokenize(token: Self::Token<'_>) -> Self::RustType

Detokenize this type’s value from the given token.

const DYNAMIC: bool = _

Whether the ABI-encoded size is dynamic.

fn sol_type_name() -> Cow<'static, str>

👎Deprecated since 0.6.3: use SOL_NAME instead

Returns the name of this type in Solidity.

fn abi_encoded_size<E>(rust: &E) -> usize

where E: SolTypeValue<Self> + ?Sized,

Calculate the ABI-encoded size of the data, counting both head and tail words. For a single-word type this will always be 32.

fn type_check(token: &Self::Token<'_>) -> Result<(), Error>

Returns an error if the given token cannot be detokenized with this type.

fn tokenize<E>(rust: &E) -> Self::Token<'_>

where E: SolTypeValue<Self> + ?Sized,

Tokenizes the given value into this type’s token.

fn eip712_data_word<E>(rust: &E) -> FixedBytes<32>

where E: SolTypeValue<Self> + ?Sized,

Encode this data according to EIP-712 encodeData rules, and hash it if necessary.

fn abi_packed_encoded_size<E>(rust: &E) -> usize

where E: SolTypeValue<Self> + ?Sized,

Returns the length of this value when ABI-encoded in Non-standard Packed Mode.

fn abi_encode_packed_to<E>(rust: &E, out: &mut Vec<u8>)

where E: SolTypeValue<Self> + ?Sized,

Non-standard Packed Mode ABI encoding.

fn abi_encode_packed<E>(rust: &E) -> Vec<u8>

where E: SolTypeValue<Self> + ?Sized,

Non-standard Packed Mode ABI encoding.

fn abi_encode<E>(rust: &E) -> Vec<u8>

where E: SolTypeValue<Self> + ?Sized,

Tokenizes and ABI-encodes the given value by wrapping it in a single-element sequence.

fn abi_encode_params<E>(rust: &E) -> Vec<u8>

where E: SolTypeValue<Self> + ?Sized, Self::Token<'a>: for<'a> TokenSeq<'a>,

Tokenizes and ABI-encodes the given value as function parameters.

fn abi_encode_sequence<E>(rust: &E) -> Vec<u8>

where E: SolTypeValue<Self> + ?Sized, Self::Token<'a>: for<'a> TokenSeq<'a>,

Tokenizes and ABI-encodes the given value as a sequence.

fn abi_decode(data: &[u8]) -> Result<Self::RustType, Error>

Decodes this type’s value from an ABI blob by interpreting it as a single-element sequence.

fn abi_decode_validate(data: &[u8]) -> Result<Self::RustType, Error>

Decodes this type’s value from an ABI blob by interpreting it as single-element sequence, with validation.

fn abi_decode_params<'de>(data: &'de [u8]) -> Result<Self::RustType, Error>

where Self::Token<'de>: TokenSeq<'de>,

Decodes this type’s value from an ABI blob by interpreting it as function parameters.

fn abi_decode_params_validate<'de>( data: &'de [u8], ) -> Result<Self::RustType, Error>

where Self::Token<'de>: TokenSeq<'de>,

Decodes this type’s value from an ABI blob by interpreting it as function parameters, with validation.

fn abi_decode_sequence<'de>(data: &'de [u8]) -> Result<Self::RustType, Error>

where Self::Token<'de>: TokenSeq<'de>,

Decodes this type’s value from an ABI blob by interpreting it as a sequence.

fn abi_decode_sequence_validate<'de>( data: &'de [u8], ) -> Result<Self::RustType, Error>

where Self::Token<'de>: TokenSeq<'de>,

Decodes this type’s value from an ABI blob by interpreting it as sequence, with validation.

impl SolTypeValue<Commitment> for Commitment

fn stv_to_tokens(&self) -> <Self as SolType>::Token<'_>

fn stv_abi_encoded_size(&self) -> usize

fn stv_eip712_data_word(&self) -> Word

fn stv_abi_encode_packed_to(&self, out: &mut Vec<u8>)

fn stv_abi_packed_encoded_size(&self) -> usize

impl SolValue for Commitment

type SolType = Commitment

The Solidity type that this type corresponds to.

fn sol_name(&self) -> &'static str

The name of the associated Solidity type.

fn sol_type_name(&self) -> Cow<'static, str>

👎Deprecated since 0.6.3: use sol_name instead

The name of the associated Solidity type.

fn tokenize(&self) -> <Self::SolType as SolType>::Token<'_>

Tokenizes the given value into this type’s token.

fn detokenize(token: <Self::SolType as SolType>::Token<'_>) -> Self

where Self: From<<Self::SolType as SolType>::RustType>,

Detokenize a value from the given token.

fn abi_encoded_size(&self) -> usize

Calculate the ABI-encoded size of the data.

fn eip712_data_word(&self) -> FixedBytes<32>

Encode this data according to EIP-712 encodeData rules, and hash it if necessary.

fn abi_encode_packed_to(&self, out: &mut Vec<u8>)

Non-standard Packed Mode ABI encoding.

fn abi_encode_packed(&self) -> Vec<u8>

Non-standard Packed Mode ABI encoding.

fn abi_encode(&self) -> Vec<u8>

ABI-encodes the value.

fn abi_encode_sequence(&self) -> Vec<u8>

where <Self::SolType as SolType>::Token<'a>: for<'a> TokenSeq<'a>,

Encodes an ABI sequence.

fn abi_encode_params(&self) -> Vec<u8>

where <Self::SolType as SolType>::Token<'a>: for<'a> TokenSeq<'a>,

Encodes an ABI sequence suitable for function parameters.

fn abi_decode(data: &[u8]) -> Result<Self, Error>

where Self: From<<Self::SolType as SolType>::RustType>,

ABI-decode this type from the given data.

fn abi_decode_validate(data: &[u8]) -> Result<Self, Error>

where Self: From<<Self::SolType as SolType>::RustType>,

ABI-decode this type from the given data, with validation.

fn abi_decode_params<'de>(data: &'de [u8]) -> Result<Self, Error>

where Self: From<<Self::SolType as SolType>::RustType>, <Self::SolType as SolType>::Token<'de>: TokenSeq<'de>,

ABI-decode this type from the given data.

fn abi_decode_params_validate<'de>(data: &'de [u8]) -> Result<Self, Error>

where Self: From<<Self::SolType as SolType>::RustType>, <Self::SolType as SolType>::Token<'de>: TokenSeq<'de>,

ABI-decode this type from the given data, with validation.

fn abi_decode_sequence<'de>(data: &'de [u8]) -> Result<Self, Error>

where Self: From<<Self::SolType as SolType>::RustType>, <Self::SolType as SolType>::Token<'de>: TokenSeq<'de>,

ABI-decode this type from the given data.

fn abi_decode_sequence_validate<'de>(data: &'de [u8]) -> Result<Self, Error>

where Self: From<<Self::SolType as SolType>::RustType>, <Self::SolType as SolType>::Token<'de>: TokenSeq<'de>,

ABI-decode this type from the given data, with validation.

impl Eq for Commitment

impl StructuralPartialEq for Commitment