H5: Use pubkey hash for storage paths (V3+) and zero sensitive bytes#915
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DavidGershony wants to merge 2 commits into
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H5: Use pubkey hash for storage paths (V3+) and zero sensitive bytes#915DavidGershony wants to merge 2 commits into
DavidGershony wants to merge 2 commits into
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DeriveLeadInvestorSecretHash: - V3+: hash only the derived public key (no private material needed) - V1/V2: zero the ExtKey byte array in a finally block after hashing DeriveNostrStoragePassword: - Zero the private key byte array in a finally block after hashing - Remove redundant .Replace/ToLower (Encoders.Hex already returns lowercase) These changes ensure sensitive key material doesn't linger in memory after use, reducing the window for memory-scraping attacks.
dangershony
reviewed
Jul 7, 2026
| if (projectVersion >= 3) | ||
| { | ||
| // V3+: Hash only the public key (deterministic, doesn't expose private key bytes) | ||
| var pubKeyBytes = extPubKey.PubKey.ToBytes(); |
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this is deriving the secret hash, if we derive using the pubkey and the pubkey is leaked then anyone can derive the hash no?
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Summary
Avoid exposing private key bytes in derivation paths and ensure all sensitive byte arrays are zeroed after use.
Changes
DeriveLeadInvestorSecretHash
finallyblockDeriveNostrStoragePassword
finallyblock after hashing.Replace("-", "").ToLower()(Encoders.Hex.EncodeDataalready returns lowercase hex without dashes)Rationale
Private key bytes left unzeroed in managed memory can be read by memory-scraping malware or appear in crash dumps. By zeroing them immediately after use and (for V3+) avoiding private key bytes entirely, we reduce the attack surface.
Testing
All 154 shared tests pass. V1/V2 derivation produces the same hash output as before (backward compatible).