https://github.com/solana-labs/solana/pull/25744
separated durable nonce and blockhash domains, which will stop double
execution going forward. However it is possible that a durable
transaction has *already* been executed once as a normal transaction and
it is now a valid durable transaction. #25744 cannot stop such
transactions to be re-executed until the nonce accounts are advanced.
This commit adds a new nonce version indicating that the nonce is moved
out of the blockhash domain, and permanently disables durable
transactions for legacy nonces which are in the blockhash domain.
AdvanceNonceAccount instruction updates nonce to blockhash. This makes it
possible that a durable transaction is executed twice both as a normal
transaction and a nonce transaction if it uses blockhash (as opposed to nonce)
for its recent_blockhash field.
The commit prevents this double execution by separating nonce and blockhash
domains; when advancing nonce account, blockhash is hashed with a fixed string.
As a result a blockhash cannot be a valid nonce value; and if transaction was
once executed as a normal transaction it cannot be re-executed as a durable
transaction again and vice-versa.
Brian Anderson
behzad nouri
Justin Starry
Michael Vines
Jack May
Jeff Washington (jwash)
Trent Nelson