eth_valkyoth_protocol/transaction/
access_list.rs

1use eth_valkyoth_codec::{DecodeError, DecodeLimits, RlpItem, RlpList, RlpScalar};
2use eth_valkyoth_primitives::{Address, B256, ChainId, Gas, Nonce, Wei};
3
4use super::{TransactionEnvelope, decode_transaction_envelope};
5use crate::transaction::fields::{
6    ADDRESS_BYTES, decode_chain_id as decode_shared_chain_id, decode_to as decode_shared_to,
7    decode_u64_field as decode_shared_u64_field, decode_u256_field as decode_shared_u256_field,
8    next_list as next_shared_list, next_scalar as next_shared_scalar,
9};
10
11mod error;
12
13pub use error::{AccessListTransactionDecodeError, AccessListTransactionDecodeErrorCategory};
14
15/// EIP-2930 transaction type byte.
16pub const ACCESS_LIST_TRANSACTION_TYPE: u8 = 0x01;
17/// Number of fields in an EIP-2930 access-list transaction payload.
18pub const ACCESS_LIST_TRANSACTION_FIELD_COUNT: usize = 11;
19
20const ACCESS_LIST_ENTRY_FIELD_COUNT: usize = 2;
21const B256_BYTES: usize = 32;
22
23/// Borrowed EIP-2930 transaction decoded only into field domains.
24///
25/// This type is intentionally unvalidated: no sender recovery, signature
26/// validity, gas accounting, account-state check, duplicate access-list policy,
27/// or fork validity is performed.
28#[derive(Clone, Copy, Debug, Eq, PartialEq)]
29pub struct UnvalidatedAccessListTransaction<'a> {
30    /// Chain ID encoded in the signed transaction domain.
31    pub chain_id: ChainId,
32    /// Account nonce.
33    pub nonce: Nonce,
34    /// Gas price in wei.
35    pub gas_price: Wei,
36    /// Gas limit.
37    pub gas_limit: Gas,
38    /// Call or contract-creation target.
39    pub to: AccessListTransactionTo,
40    /// Transferred value in wei.
41    pub value: Wei,
42    /// Borrowed transaction input data.
43    pub input: &'a [u8],
44    /// Borrowed access list.
45    pub access_list: AccessList<'a>,
46    /// Signature y parity.
47    pub y_parity: SignatureYParity,
48    /// Raw canonical U256 signature `r` value.
49    ///
50    /// This is not checked for secp256k1 scalar validity.
51    pub r: [u8; 32],
52    /// Raw canonical U256 signature `s` value.
53    ///
54    /// This is not checked against the EIP-2 low-s bound or secp256k1 scalar
55    /// validity.
56    pub s: [u8; 32],
57}
58
59/// EIP-2930 transaction call/create target.
60#[derive(Clone, Copy, Debug, Eq, PartialEq)]
61pub enum AccessListTransactionTo {
62    /// Contract creation transaction with an empty `to` field.
63    Create,
64    /// Message call to an address.
65    Call(Address),
66}
67
68/// EIP-2930 signature y parity.
69#[derive(Clone, Copy, Debug, Eq, PartialEq)]
70pub enum SignatureYParity {
71    /// Even y coordinate.
72    Even,
73    /// Odd y coordinate.
74    Odd,
75}
76
77/// Invalid EIP-2930/EIP-1559 signature y-parity bit.
78#[derive(Clone, Copy, Debug, Eq, PartialEq)]
79pub struct InvalidSignatureYParity {
80    value: u64,
81}
82
83impl InvalidSignatureYParity {
84    /// Returns the rejected y-parity integer.
85    #[must_use]
86    pub const fn value(self) -> u64 {
87        self.value
88    }
89}
90
91impl SignatureYParity {
92    /// Creates y parity from its wire integer.
93    pub const fn try_new(value: u64) -> Result<Self, InvalidSignatureYParity> {
94        match value {
95            0 => Ok(Self::Even),
96            1 => Ok(Self::Odd),
97            _ => Err(InvalidSignatureYParity { value }),
98        }
99    }
100
101    /// Returns the raw y-parity bit.
102    #[must_use]
103    pub const fn get(self) -> u8 {
104        match self {
105            Self::Even => 0,
106            Self::Odd => 1,
107        }
108    }
109}
110
111/// Borrowed EIP-2930 access list.
112#[derive(Clone, Copy, Debug, Eq, PartialEq)]
113pub struct AccessList<'a> {
114    list: RlpList<'a>,
115    storage_key_count: usize,
116}
117
118impl<'a> AccessList<'a> {
119    /// Returns the number of address entries.
120    #[must_use]
121    pub const fn address_count(self) -> usize {
122        self.list.item_count()
123    }
124
125    /// Returns the total number of storage keys across all entries.
126    #[must_use]
127    pub const fn storage_key_count(self) -> usize {
128        self.storage_key_count
129    }
130
131    /// Returns an iterator over access-list entries.
132    ///
133    /// The transaction decoder validates every access-list entry before
134    /// returning this borrowed model. Iterating re-parses the same bounded RLP
135    /// bytes so callers can use zero-copy access without storing decoded
136    /// entries.
137    #[must_use]
138    pub const fn entries(self) -> AccessListEntries<'a> {
139        AccessListEntries {
140            items: self.list.items(),
141        }
142    }
143}
144
145/// Borrowed EIP-2930 access-list entry.
146#[derive(Clone, Copy, Debug, Eq, PartialEq)]
147pub struct AccessListEntry<'a> {
148    /// Accessed address.
149    pub address: Address,
150    /// Storage keys for this address.
151    pub storage_keys: AccessListStorageKeys<'a>,
152}
153
154/// Borrowed storage-key list for one access-list address.
155#[derive(Clone, Copy, Debug, Eq, PartialEq)]
156pub struct AccessListStorageKeys<'a> {
157    list: RlpList<'a>,
158}
159
160impl<'a> AccessListStorageKeys<'a> {
161    /// Returns the number of storage keys in this entry.
162    #[must_use]
163    pub const fn len(self) -> usize {
164        self.list.item_count()
165    }
166
167    /// Returns true when this entry has no storage keys.
168    #[must_use]
169    pub const fn is_empty(self) -> bool {
170        self.list.is_empty()
171    }
172
173    /// Returns an iterator over storage keys.
174    ///
175    /// The parent access-list decoder validates every storage key before
176    /// returning this borrowed model. Iterating re-parses the same bounded RLP
177    /// bytes so callers can use zero-copy access without storing decoded keys.
178    #[must_use]
179    pub const fn keys(self) -> AccessListStorageKeyItems<'a> {
180        AccessListStorageKeyItems {
181            items: self.list.items(),
182        }
183    }
184}
185
186/// Iterator over borrowed access-list entries.
187#[derive(Clone, Debug)]
188pub struct AccessListEntries<'a> {
189    items: eth_valkyoth_codec::RlpListItems<'a>,
190}
191
192impl<'a> Iterator for AccessListEntries<'a> {
193    type Item = Result<AccessListEntry<'a>, AccessListTransactionDecodeError>;
194
195    fn next(&mut self) -> Option<Self::Item> {
196        self.items
197            .next()
198            .map(|item| decode_access_list_entry_item(item).map_err(map_access_list_decode_error))
199    }
200}
201
202impl core::iter::FusedIterator for AccessListEntries<'_> {}
203
204/// Iterator over borrowed storage keys.
205#[derive(Clone, Debug)]
206pub struct AccessListStorageKeyItems<'a> {
207    items: eth_valkyoth_codec::RlpListItems<'a>,
208}
209
210impl Iterator for AccessListStorageKeyItems<'_> {
211    type Item = Result<B256, AccessListTransactionDecodeError>;
212
213    fn next(&mut self) -> Option<Self::Item> {
214        self.items
215            .next()
216            .map(|item| decode_storage_key_item(item).map_err(map_access_list_decode_error))
217    }
218}
219
220impl core::iter::FusedIterator for AccessListStorageKeyItems<'_> {}
221
222/// EIP-2930 transaction field identifier.
223#[non_exhaustive]
224#[derive(Clone, Copy, Debug, Eq, PartialEq)]
225pub enum AccessListTransactionField {
226    /// Whole typed-transaction payload.
227    Payload,
228    /// `chainId`.
229    ChainId,
230    /// `nonce`.
231    Nonce,
232    /// `gasPrice`.
233    GasPrice,
234    /// `gasLimit`.
235    GasLimit,
236    /// `to`.
237    To,
238    /// `value`.
239    Value,
240    /// `data`.
241    Data,
242    /// `accessList`.
243    AccessList,
244    /// `signatureYParity`.
245    SignatureYParity,
246    /// `signatureR`.
247    SignatureR,
248    /// `signatureS`.
249    SignatureS,
250}
251
252/// Decodes an EIP-2930 access-list transaction into unvalidated field domains.
253pub fn decode_access_list_transaction<'a>(
254    input: &'a [u8],
255    limits: DecodeLimits,
256) -> Result<UnvalidatedAccessListTransaction<'a>, AccessListTransactionDecodeError> {
257    match decode_transaction_envelope(input, limits)
258        .map_err(AccessListTransactionDecodeError::Envelope)?
259    {
260        TransactionEnvelope::Typed(typed)
261            if typed.transaction_type.get() == ACCESS_LIST_TRANSACTION_TYPE =>
262        {
263            decode_access_list_payload(typed.payload, limits)
264        }
265        TransactionEnvelope::Typed(typed) => {
266            Err(AccessListTransactionDecodeError::WrongTransactionType {
267                type_byte: typed.transaction_type.get(),
268            })
269        }
270        TransactionEnvelope::Legacy(_) => {
271            Err(AccessListTransactionDecodeError::WrongTransactionType { type_byte: 0 })
272        }
273    }
274}
275
276fn decode_access_list_payload<'a>(
277    payload: &'a [u8],
278    limits: DecodeLimits,
279) -> Result<UnvalidatedAccessListTransaction<'a>, AccessListTransactionDecodeError> {
280    let list = eth_valkyoth_codec::decode_rlp_list(payload, limits)
281        .map_err(|source| field_error(AccessListTransactionField::Payload, source))?;
282    if list.item_count() != ACCESS_LIST_TRANSACTION_FIELD_COUNT {
283        return Err(AccessListTransactionDecodeError::WrongFieldCount {
284            expected: ACCESS_LIST_TRANSACTION_FIELD_COUNT,
285            found: list.item_count(),
286        });
287    }
288
289    let mut fields = list.items();
290    let chain_id = decode_shared_chain_id(
291        &mut fields,
292        AccessListTransactionField::ChainId,
293        field_error,
294    )?;
295    let nonce = Nonce::new(decode_shared_u64_field(
296        &mut fields,
297        AccessListTransactionField::Nonce,
298        field_error,
299    )?);
300    let gas_price = Wei::from_be_bytes(decode_shared_u256_field(
301        &mut fields,
302        AccessListTransactionField::GasPrice,
303        field_error,
304    )?);
305    let gas_limit = Gas::new(decode_shared_u64_field(
306        &mut fields,
307        AccessListTransactionField::GasLimit,
308        field_error,
309    )?);
310    let to = decode_shared_to(
311        next_shared_scalar(&mut fields, AccessListTransactionField::To, field_error)?,
312        |found| AccessListTransactionDecodeError::InvalidToLength { found },
313    )?;
314    let value = Wei::from_be_bytes(decode_shared_u256_field(
315        &mut fields,
316        AccessListTransactionField::Value,
317        field_error,
318    )?);
319    let input =
320        next_shared_scalar(&mut fields, AccessListTransactionField::Data, field_error)?.payload();
321    limits
322        .check_single_allocation_limit(input.len())
323        .map_err(|source| field_error(AccessListTransactionField::Data, source))?;
324    let access_list = decode_access_list(next_shared_list(
325        &mut fields,
326        AccessListTransactionField::AccessList,
327        field_error,
328    )?)
329    .map_err(map_access_list_decode_error)?;
330    let y_parity = SignatureYParity::try_new(decode_shared_u64_field(
331        &mut fields,
332        AccessListTransactionField::SignatureYParity,
333        field_error,
334    )?)
335    .map_err(|error| AccessListTransactionDecodeError::InvalidYParity {
336        value: error.value(),
337    })?;
338    let r = decode_shared_u256_field(
339        &mut fields,
340        AccessListTransactionField::SignatureR,
341        field_error,
342    )?;
343    let s = decode_shared_u256_field(
344        &mut fields,
345        AccessListTransactionField::SignatureS,
346        field_error,
347    )?;
348
349    Ok(UnvalidatedAccessListTransaction {
350        chain_id,
351        nonce,
352        gas_price,
353        gas_limit,
354        to,
355        value,
356        input,
357        access_list,
358        y_parity,
359        r,
360        s,
361    })
362}
363
364pub(crate) fn decode_access_list(
365    list: RlpList<'_>,
366) -> Result<AccessList<'_>, AccessListDecodeError> {
367    // Eager validation proves the borrowed model is well-formed. Later
368    // iteration intentionally re-parses these bounded bytes instead of storing
369    // decoded entries in an allocation-backed structure.
370    let mut storage_key_count = 0usize;
371    for item in list.items() {
372        let entry = decode_access_list_entry_item(item)?;
373        storage_key_count =
374            eth_valkyoth_codec::checked_len_add(storage_key_count, entry.storage_keys.len())
375                .map_err(AccessListDecodeError::FieldDecode)?;
376    }
377    Ok(AccessList {
378        list,
379        storage_key_count,
380    })
381}
382
383fn decode_access_list_entry_item(
384    item: Result<RlpItem<'_>, DecodeError>,
385) -> Result<AccessListEntry<'_>, AccessListDecodeError> {
386    let item = item.map_err(AccessListDecodeError::FieldDecode)?;
387    let RlpItem::List(list) = item else {
388        return Err(AccessListDecodeError::FieldDecode(
389            DecodeError::UnexpectedScalar,
390        ));
391    };
392    if list.item_count() != ACCESS_LIST_ENTRY_FIELD_COUNT {
393        return Err(AccessListDecodeError::InvalidAccessListEntryFieldCount {
394            found: list.item_count(),
395        });
396    }
397
398    let mut fields = list.items();
399    let address = decode_access_list_address(next_shared_scalar(
400        &mut fields,
401        AccessListTransactionField::AccessList,
402        |_, source| AccessListDecodeError::FieldDecode(source),
403    )?)?;
404    let storage_keys = AccessListStorageKeys {
405        list: next_shared_list(
406            &mut fields,
407            AccessListTransactionField::AccessList,
408            |_, source| AccessListDecodeError::FieldDecode(source),
409        )?,
410    };
411
412    for key in storage_keys.list.items() {
413        let _ = decode_storage_key_item(key)?;
414    }
415    Ok(AccessListEntry {
416        address,
417        storage_keys,
418    })
419}
420
421fn decode_storage_key_item(
422    item: Result<RlpItem<'_>, DecodeError>,
423) -> Result<B256, AccessListDecodeError> {
424    let item = item.map_err(AccessListDecodeError::FieldDecode)?;
425    let RlpItem::Scalar(scalar) = item else {
426        return Err(AccessListDecodeError::FieldDecode(
427            DecodeError::UnexpectedList,
428        ));
429    };
430    let found = scalar.payload().len();
431    let bytes: [u8; B256_BYTES] = scalar
432        .payload()
433        .try_into()
434        .map_err(|_| AccessListDecodeError::InvalidStorageKeyLength { found })?;
435    Ok(B256::from_bytes(bytes))
436}
437
438fn decode_access_list_address(scalar: RlpScalar<'_>) -> Result<Address, AccessListDecodeError> {
439    let found = scalar.payload().len();
440    let bytes: [u8; ADDRESS_BYTES] = scalar
441        .payload()
442        .try_into()
443        .map_err(|_| AccessListDecodeError::InvalidAccessListAddressLength { found })?;
444    Ok(Address::from_bytes(bytes))
445}
446
447const fn field_error(
448    field: AccessListTransactionField,
449    source: DecodeError,
450) -> AccessListTransactionDecodeError {
451    AccessListTransactionDecodeError::FieldDecode { field, source }
452}
453
454/// Internal access-list structure decode failure.
455#[derive(Clone, Copy, Debug, Eq, PartialEq)]
456pub(crate) enum AccessListDecodeError {
457    FieldDecode(DecodeError),
458    InvalidAccessListEntryFieldCount { found: usize },
459    InvalidAccessListAddressLength { found: usize },
460    InvalidStorageKeyLength { found: usize },
461}
462
463pub(crate) const fn map_access_list_decode_error(
464    error: AccessListDecodeError,
465) -> AccessListTransactionDecodeError {
466    match error {
467        AccessListDecodeError::FieldDecode(source) => {
468            field_error(AccessListTransactionField::AccessList, source)
469        }
470        AccessListDecodeError::InvalidAccessListEntryFieldCount { found } => {
471            AccessListTransactionDecodeError::InvalidAccessListEntryFieldCount { found }
472        }
473        AccessListDecodeError::InvalidAccessListAddressLength { found } => {
474            AccessListTransactionDecodeError::InvalidAccessListAddressLength { found }
475        }
476        AccessListDecodeError::InvalidStorageKeyLength { found } => {
477            AccessListTransactionDecodeError::InvalidStorageKeyLength { found }
478        }
479    }
480}
eth_valkyoth_protocol/transaction/access_list.rs

eth_valkyoth_protocol/transaction/
access_list.rs
