74 lines
1.8 KiB
Go
74 lines
1.8 KiB
Go
package nonce
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import (
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"github.com/tendermint/basecoin"
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"github.com/tendermint/basecoin/stack"
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"github.com/tendermint/basecoin/state"
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)
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//nolint
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const (
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NameNonce = "nonce"
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)
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// ReplayCheck uses the sequence to check for replay attacks
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type ReplayCheck struct {
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stack.PassOption
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}
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// Name of the module - fulfills Middleware interface
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func (ReplayCheck) Name() string {
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return NameNonce
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}
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var _ stack.Middleware = ReplayCheck{}
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// CheckTx verifies tx is not being replayed - fulfills Middlware interface
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func (r ReplayCheck) CheckTx(ctx basecoin.Context, store state.SimpleDB,
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tx basecoin.Tx, next basecoin.Checker) (res basecoin.Result, err error) {
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stx, err := r.checkIncrementNonceTx(ctx, store, tx)
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if err != nil {
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return res, err
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}
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return next.CheckTx(ctx, store, stx)
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}
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// DeliverTx verifies tx is not being replayed - fulfills Middlware interface
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// NOTE It is okay to modify the sequence before running the wrapped TX because if the
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// wrapped Tx fails, the state changes are not applied
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func (r ReplayCheck) DeliverTx(ctx basecoin.Context, store state.SimpleDB,
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tx basecoin.Tx, next basecoin.Deliver) (res basecoin.Result, err error) {
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stx, err := r.checkIncrementNonceTx(ctx, store, tx)
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if err != nil {
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return res, err
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}
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return next.DeliverTx(ctx, store, stx)
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}
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// checkNonceTx varifies the nonce sequence, an increment sequence number
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func (r ReplayCheck) checkIncrementNonceTx(ctx basecoin.Context, store state.SimpleDB,
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tx basecoin.Tx) (basecoin.Tx, error) {
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// make sure it is a the nonce Tx (Tx from this package)
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nonceTx, ok := tx.Unwrap().(Tx)
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if !ok {
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return tx, ErrNoNonce()
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}
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err := nonceTx.ValidateBasic()
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if err != nil {
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return tx, err
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}
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// check the nonce sequence number
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err = nonceTx.CheckIncrementSeq(ctx, store)
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if err != nil {
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return tx, err
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}
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return nonceTx.Tx, nil
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}
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