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adaptation of transaction checks to allow transactions with more than…
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… 1in and 1out
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@polespinasa
polespinasa committed Apr 30, 2024
1 parent a7460a6 commit 223940d
Showing 1 changed file with 71 additions and 60 deletions.
131 changes: 71 additions & 60 deletions server/grouphug-server/src/utils/transactions.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -61,49 +61,50 @@ pub fn get_previous_utxo_value(utxo: OutPoint) -> f32 {
}

pub fn previous_utxo_spent(tx: &Transaction) -> bool {
// Validates that the utxo pointed to by the transaction input has not been spent.
// Validates that the UTXOs pointed to by the transaction inputs have not been spent.

// Connect to Electrum node
let client = Client::new(&crate::CONFIG.electrum.endpoint).unwrap();

let blockchain = ElectrumBlockchain::from(client);

// Get the previous transaction from the input
let outpoint = tx.input[0].previous_output;
let tx_result = blockchain.get_tx(&outpoint.txid);

match tx_result {
Ok(Some(tx)) => {

// validate if the output has been spent
let utxo_script_pubkey = &tx.output[outpoint.vout as usize].script_pubkey;
let utxo_list = blockchain.script_list_unspent(&utxo_script_pubkey);

match utxo_list {
Ok(returned_utxo_list) => {
if returned_utxo_list.len() > 0 {
return true;
}
else {
eprintln!("Transaction already spent");
for i in 0..tx.input.len() {
// Get the previous transaction from the input
let outpoint = tx.input[i].previous_output;
let tx_result = blockchain.get_tx(&outpoint.txid);

match tx_result {
Ok(Some(tx)) => {

// validate if the output has been spent
let utxo_script_pubkey = &tx.output[outpoint.vout as usize].script_pubkey;
let utxo_list = blockchain.script_list_unspent(&utxo_script_pubkey);

match utxo_list {
Ok(returned_utxo_list) => {
if returned_utxo_list.len() == 0 {
eprintln!("Transaction already spent");
return false;
}
},
Err(_e) => {
eprintln!("Error querying for the UTXO");
return false;
}
},
Err(_e) => {
eprintln!("Error querying for the UTXO");
return false;
}
},
Ok(None) => {
eprint!("Petition succeed but no tx was returned");
return false;
},
Err(_e) => {
eprintln!("Could not retrieve previous transaction");
return false;
}
},
Ok(None) => {
eprint!("Petition succeed but no tx was returned");
return false;
},
Err(_e) => {
eprintln!("Could not retrieve previous transaction");
return false;
}
}

return true;
}

pub fn check_absolute_locktime(tx: &Transaction) -> bool {
Expand All @@ -115,7 +116,13 @@ pub fn check_absolute_locktime(tx: &Transaction) -> bool {

pub fn check_dust_limit(tx: &Transaction) -> bool {
// Return true or false if the tx value is >= than the DUST_LIMIT.
return tx.output[0].value >= crate::CONFIG.dust.limit;
for output in &tx.output {
if output.value < crate::CONFIG.dust.limit {
return false;
}

}
return true;
}

pub fn check_tx_version(tx: &Transaction) -> bool {
Expand All @@ -129,28 +136,28 @@ pub fn get_num_inputs_and_outputs(tx: &Transaction) -> (usize, usize) {
}

pub fn check_sighash_single_anyone_can_pay(tx: &Transaction) -> bool {
// Ensure that the signature is using SIGHASH_SINGLE|ANYONECANPAY
// Script must be simple P2WPKH (witness: <signature> <pubkey>)

if tx.input[0].witness.len() != 2 {
return false;
}

let input_query = tx.input[0].witness.to_vec()[0].clone();
// Ensure that all signatures are using SIGHASH_SINGLE|ANYONECANPAY
// All scripts must be simple P2WPKH (witness: <signature> <pubkey>)

match input_query.last() {
Some(input) => {
// 131 decimal representation of 0x83 designated to SIGHASH_SINGLE | ANYONECANPAY
if *input != 131 as u8{
for i in 0..tx.input.len() {
if tx.input[i].witness.len() != 2 {
return false;
}
let input_query = tx.input[i].witness.to_vec()[0].clone();

match input_query.last() {
Some(input) => {
// 131 decimal representation of 0x83 designated to SIGHASH_SINGLE | ANYONECANPAY
if *input != 131 as u8{
return false;
}
},
None => {
// There's no witness
return false;
}
},
None => {
// There's no witness
return false;
}
}

return true;
}

Expand Down Expand Up @@ -184,10 +191,10 @@ pub fn validate_tx_query_one_to_one_single_anyone_can_pay(tx_hex: &str ) -> (boo
return (false, msg, real_fee_rate);
}

// Check that there is only one input
// Check that the number of inputs and outputs is the same
let num_inputs_and_outputs: (usize, usize) = get_num_inputs_and_outputs(&tx);
if num_inputs_and_outputs != (1,1) {
let msg = format!("Number of inputs and outputs must be 1. Inputs = {} | Outputs = {}", num_inputs_and_outputs.0, num_inputs_and_outputs.1);
if num_inputs_and_outputs.0 != num_inputs_and_outputs.1 {
let msg = format!("Number of inputs and outputs must be equal. Inputs = {} | Outputs = {}", num_inputs_and_outputs.0, num_inputs_and_outputs.1);
return (false, msg, real_fee_rate);
}

Expand All @@ -213,15 +220,19 @@ pub fn validate_tx_query_one_to_one_single_anyone_can_pay(tx_hex: &str ) -> (boo
}


// Check that previous utxo value is not 0
// Aka is not an op_return
let previous_utxo_value: f32 = get_previous_utxo_value(tx.input[0].previous_output);
if previous_utxo_value == 0.0 {
let msg = String::from("There's an error loading the previous utxo value");
return (false,msg, real_fee_rate);
} else{
real_fee_rate = (previous_utxo_value - tx.output[0].value as f32)/tx.vsize() as f32;
// Check that the previous utxos values are not 0
// Aka there is no OP_RETURN
let mut total_fee: f32 = 0.0;
for i in 0..tx.input.len() {
let previous_utxo_value: f32 = get_previous_utxo_value(tx.input[i].previous_output);
if previous_utxo_value == 0.0 {
let msg = String::from("There's an error loading the previous utxo value");
return (false,msg, real_fee_rate);
} else{
total_fee += previous_utxo_value - tx.output[i].value as f32;
}
}
real_fee_rate = total_fee/tx.vsize() as f32;

// Check that the fee rate is not under 1sat/vb
if real_fee_rate <= 1.01 {
Expand Down

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