transaction_context - [mainnet]

use 0x1::error;
use 0x1::features;
use 0x1::option;
use 0x1::string;

Constants

The transaction context extension feature is not enabled.

const ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED: u64 = 2;

Transaction context is only available in the user transaction prologue, execution, or epilogue phases.

const ETRANSACTION_CONTEXT_NOT_AVAILABLE: u64 = 1;

Structs

`AUID`

A wrapper denoting aptos unique identifer (AUID) for storing an address

struct AUID has drop, store

Fields

unique_address: address

`EntryFunctionPayload`

Represents the entry function payload.

struct EntryFunctionPayload has copy, drop

Fields

account_address: address
module_name: string::String
function_name: string::String
ty_args_names: vector<string::String>
args: vector<vector<u8>>

`MultisigPayload`

Represents the multisig payload.

struct MultisigPayload has copy, drop

Fields

multisig_address: address
entry_function_payload: option::Option<transaction_context::EntryFunctionPayload>

Functions

`get_txn_hash`

Returns the transaction hash of the current transaction.

fun get_txn_hash(): vector<u8>

Implementation

native fun get_txn_hash(): vector<u8>;

`get_transaction_hash`

Returns the transaction hash of the current transaction. Internally calls the private function get_txn_hash. This function is created for to feature gate the get_txn_hash function.

public fun get_transaction_hash(): vector<u8>

Implementation

public fun get_transaction_hash(): vector<u8> {
    get_txn_hash()
}

`generate_unique_address`

Returns a universally unique identifier (of type address) generated by hashing the transaction hash of this transaction and a sequence number specific to this transaction. This function can be called any number of times inside a single transaction. Each such call increments the sequence number and generates a new unique address. Uses Scheme in types/src/transaction/authenticator.rs for domain separation from other ways of generating unique addresses.

fun generate_unique_address(): address

Implementation

native fun generate_unique_address(): address;

`generate_auid_address`

Returns a aptos unique identifier. Internally calls the private function generate_unique_address. This function is created for to feature gate the generate_unique_address function.

public fun generate_auid_address(): address

Implementation

public fun generate_auid_address(): address {
    generate_unique_address()
}

`get_script_hash`

Returns the script hash of the current entry function.

public fun get_script_hash(): vector<u8>

Implementation

public native fun get_script_hash(): vector<u8>;

`generate_auid`

This method runs generate_unique_address native function and returns the generated unique address wrapped in the AUID class.

public fun generate_auid(): transaction_context::AUID

Implementation

public fun generate_auid(): AUID {
    return AUID {
        unique_address: generate_unique_address()
    }
}

`auid_address`

Returns the unique address wrapped in the given AUID struct.

public fun auid_address(auid: &transaction_context::AUID): address

Implementation

public fun auid_address(auid: &AUID): address {
    auid.unique_address
}

`sender`

Returns the sender’s address for the current transaction. This function aborts if called outside of the transaction prologue, execution, or epilogue phases.

public fun sender(): address

Implementation

public fun sender(): address {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    sender_internal()
}

`sender_internal`

fun sender_internal(): address

Implementation

native fun sender_internal(): address;

`secondary_signers`

Returns the list of the secondary signers for the current transaction. If the current transaction has no secondary signers, this function returns an empty vector. This function aborts if called outside of the transaction prologue, execution, or epilogue phases.

public fun secondary_signers(): vector<address>

Implementation

public fun secondary_signers(): vector<address> {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    secondary_signers_internal()
}

`secondary_signers_internal`

fun secondary_signers_internal(): vector<address>

Implementation

native fun secondary_signers_internal(): vector<address>;

`gas_payer`

Returns the gas payer address for the current transaction. It is either the sender’s address if no separate gas fee payer is specified for the current transaction, or the address of the separate gas fee payer if one is specified. This function aborts if called outside of the transaction prologue, execution, or epilogue phases.

public fun gas_payer(): address

Implementation

public fun gas_payer(): address {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    gas_payer_internal()
}

`gas_payer_internal`

fun gas_payer_internal(): address

Implementation

native fun gas_payer_internal(): address;

`max_gas_amount`

Returns the max gas amount in units which is specified for the current transaction. This function aborts if called outside of the transaction prologue, execution, or epilogue phases.

public fun max_gas_amount(): u64

Implementation

public fun max_gas_amount(): u64 {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    max_gas_amount_internal()
}

`max_gas_amount_internal`

fun max_gas_amount_internal(): u64

Implementation

native fun max_gas_amount_internal(): u64;

`gas_unit_price`

Returns the gas unit price in Octas which is specified for the current transaction. This function aborts if called outside of the transaction prologue, execution, or epilogue phases.

public fun gas_unit_price(): u64

Implementation

public fun gas_unit_price(): u64 {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    gas_unit_price_internal()
}

`gas_unit_price_internal`

fun gas_unit_price_internal(): u64

Implementation

native fun gas_unit_price_internal(): u64;

`chain_id`

Returns the chain ID specified for the current transaction. This function aborts if called outside of the transaction prologue, execution, or epilogue phases.

public fun chain_id(): u8

Implementation

public fun chain_id(): u8 {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    chain_id_internal()
}

`chain_id_internal`

fun chain_id_internal(): u8

Implementation

native fun chain_id_internal(): u8;

`entry_function_payload`

Returns the entry function payload if the current transaction has such a payload. Otherwise, return None. This function aborts if called outside of the transaction prologue, execution, or epilogue phases.

public fun entry_function_payload(): option::Option<transaction_context::EntryFunctionPayload>

Implementation

public fun entry_function_payload(): Option<EntryFunctionPayload> {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    entry_function_payload_internal()
}

`entry_function_payload_internal`

fun entry_function_payload_internal(): option::Option<transaction_context::EntryFunctionPayload>

Implementation

native fun entry_function_payload_internal(): Option<EntryFunctionPayload>;

`account_address`

Returns the account address of the entry function payload.

public fun account_address(payload: &transaction_context::EntryFunctionPayload): address

Implementation

public fun account_address(payload: &EntryFunctionPayload): address {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    payload.account_address
}

`module_name`

Returns the module name of the entry function payload.

public fun module_name(payload: &transaction_context::EntryFunctionPayload): string::String

Implementation

public fun module_name(payload: &EntryFunctionPayload): String {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    payload.module_name
}

`function_name`

Returns the function name of the entry function payload.

public fun function_name(payload: &transaction_context::EntryFunctionPayload): string::String

Implementation

public fun function_name(payload: &EntryFunctionPayload): String {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    payload.function_name
}

`type_arg_names`

Returns the type arguments names of the entry function payload.

public fun type_arg_names(payload: &transaction_context::EntryFunctionPayload): vector<string::String>

Implementation

public fun type_arg_names(payload: &EntryFunctionPayload): vector<String> {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    payload.ty_args_names
}

`args`

Returns the arguments of the entry function payload.

public fun args(payload: &transaction_context::EntryFunctionPayload): vector<vector<u8>>

Implementation

public fun args(payload: &EntryFunctionPayload): vector<vector<u8>> {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    payload.args
}

`multisig_payload`

Returns the multisig payload if the current transaction has such a payload. Otherwise, return None. This function aborts if called outside of the transaction prologue, execution, or epilogue phases.

public fun multisig_payload(): option::Option<transaction_context::MultisigPayload>

Implementation

public fun multisig_payload(): Option<MultisigPayload> {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    multisig_payload_internal()
}

`multisig_payload_internal`

fun multisig_payload_internal(): option::Option<transaction_context::MultisigPayload>

Implementation

native fun multisig_payload_internal(): Option<MultisigPayload>;

`multisig_address`

Returns the multisig account address of the multisig payload.

public fun multisig_address(payload: &transaction_context::MultisigPayload): address

Implementation

public fun multisig_address(payload: &MultisigPayload): address {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    payload.multisig_address
}

`inner_entry_function_payload`

Returns the inner entry function payload of the multisig payload.

public fun inner_entry_function_payload(payload: &transaction_context::MultisigPayload): option::Option<transaction_context::EntryFunctionPayload>

Implementation

public fun inner_entry_function_payload(payload: &MultisigPayload): Option<EntryFunctionPayload> {
    assert!(features::transaction_context_extension_enabled(), error::invalid_state(ETRANSACTION_CONTEXT_EXTENSION_NOT_ENABLED));
    payload.entry_function_payload
}

Specification

`get_txn_hash`

fun get_txn_hash(): vector<u8>

pragma opaque;
aborts_if [abstract] false;
ensures result == spec_get_txn_hash();

fun spec_get_txn_hash(): vector<u8>;

`get_transaction_hash`

public fun get_transaction_hash(): vector<u8>

pragma opaque;
aborts_if [abstract] false;
ensures result == spec_get_txn_hash();
// This enforces high-level requirement 1:
ensures [abstract] len(result) == 32;

`generate_unique_address`

fun generate_unique_address(): address

pragma opaque;
aborts_if [abstract] false;
ensures [abstract] result == spec_generate_unique_address();

fun spec_generate_unique_address(): address;

`generate_auid_address`

public fun generate_auid_address(): address

pragma opaque;
aborts_if [abstract] false;
// This enforces high-level requirement 3:
ensures [abstract] result == spec_generate_unique_address();

`get_script_hash`

public fun get_script_hash(): vector<u8>

High-level Requirements

No.	Requirement	Criticality	Implementation	Enforcement
1	Fetching the transaction hash should return a vector with 32 bytes.	Medium	The get_transaction_hash function calls the native function get_txn_hash, which fetches the NativeTransactionContext struct and returns the txn_hash field.	Audited that the native function returns the txn hash, whose size is 32 bytes. This has been modeled as the abstract postcondition that the returned vector is of length 32. Formally verified via get_txn_hash.
2	Fetching the unique address should never abort.	Low	The function auid_address returns the unique address from a supplied AUID resource.	Formally verified via auid_address.
3	Generating the unique address should return a vector with 32 bytes.	Medium	The generate_auid_address function checks calls the native function generate_unique_address which fetches the NativeTransactionContext struct, increments the auid_counter by one, and then creates a new authentication key from a preimage, which is then returned.	Audited that the native function returns an address, and the length of an address is 32 bytes. This has been modeled as the abstract postcondition that the returned vector is of length 32. Formally verified via generate_auid_address.
4	Fetching the script hash of the current entry function should never fail and should return a vector with 32 bytes if the transaction payload is a script, otherwise an empty vector.	Low	The native function get_script_hash returns the NativeTransactionContext.script_hash field.	Audited that the native function holds the required property. This has been modeled as the abstract spec. Formally verified via get_script_hash.

Module-level Specification

pragma opaque;
// This enforces high-level requirement 4:
aborts_if [abstract] false;
ensures [abstract] result == spec_get_script_hash();
ensures [abstract] len(result) == 32;

fun spec_get_script_hash(): vector<u8>;

`auid_address`

public fun auid_address(auid: &transaction_context::AUID): address

// This enforces high-level requirement 2:
aborts_if false;

`sender_internal`

fun sender_internal(): address

pragma opaque;

`secondary_signers_internal`

fun secondary_signers_internal(): vector<address>

pragma opaque;

`gas_payer_internal`

fun gas_payer_internal(): address

pragma opaque;

`max_gas_amount_internal`

fun max_gas_amount_internal(): u64

pragma opaque;

`gas_unit_price_internal`

fun gas_unit_price_internal(): u64

pragma opaque;

`chain_id_internal`

fun chain_id_internal(): u8

pragma opaque;

`entry_function_payload_internal`

fun entry_function_payload_internal(): option::Option<transaction_context::EntryFunctionPayload>

pragma opaque;

`multisig_payload_internal`

fun multisig_payload_internal(): option::Option<transaction_context::MultisigPayload>

pragma opaque;