C2: Add WordsMemory/PassphraseMemory and use cached ExtKey in PsbtOperations#911
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DavidGershony wants to merge 1 commit into
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C2: Add WordsMemory/PassphraseMemory and use cached ExtKey in PsbtOperations#911DavidGershony wants to merge 1 commit into
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…rations Add ReadOnlyMemory<char> properties (WordsMemory, PassphraseMemory) to WalletWords for zero-allocation read access to mnemonic data. The backing char arrays are already zeroed on Dispose(). Add security documentation to the Words getter warning that each access creates an unzeroed string copy on the managed heap. Fix PsbtOperations.SignTransaction to use GetOrDeriveExtKey() instead of accessing .Words directly, reducing unnecessary string allocations of the mnemonic.
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Summary
Reduce mnemonic exposure by adding zero-allocation
ReadOnlyMemory<char>accessors and fixingPsbtOperationsto use the cached ExtKey instead of re-reading.Words.Changes
WordsMemoryandPassphraseMemoryproperties that expose the backingchar[]without creating new string copies. Add security documentation to theWordsgetter._hdOperations.GetExtendedKey(walletWords.Words, walletWords.Passphrase)withwalletWords.GetOrDeriveExtKey(_hdOperations)to use the cached key and avoid extra mnemonic string allocations.Rationale
Every call to
.Wordscreates a newstringon the managed heap that cannot be deterministically zeroed. By preferringGetOrDeriveExtKey()(which derives once and caches), we minimize the number of mnemonic string copies that linger in memory.Testing
All 154 shared tests pass.