smb3-seal: byte-swap SessionId for the wire in smb3_encrypt_pdu() - #478
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sahlberg merged 1 commit intoAug 28, 2026
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The SMB2_TRANSFORM_HEADER's OriginalMessageSize and EncryptionAlgorithm fields are explicitly converted with htole32/ htole16 before being written, but SessionId was copied via a raw memcpy of the host-order value. A no-op bug on little-endian hosts, where host order already equals wire order; on big-endian (PPC) it produces a byte-reversed SessionId in every encrypted PDU, which a server has no reason to accept -- confirmed on a PPC Tiger iBook via packet capture, where smb2_set_seal(ctx, 1) got rejected identically by both macOS's and Windows 11's standard SMB3 sharing right after the first TRANSFORM_HEADER-wrapped PDU. Fixes sahlberg#477.
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sahlberg confirmed the bug on Issue #477 and asked for a PR with a different style (a direct pointer-cast assignment instead of a scoped local variable + memcpy). Re-verified on real hardware with the new form against both macOS's and Windows 11's SMB3 sharing. Sent as sahlberg/libsmb2#478, and updated the PPCPorts patch (#236) to match.
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Awesome, thanks. Merged! I will set up a Linux PPC environment under qemu. I should be able to reproduce the issue there and then I can try to wire it into my test environmet. Thanks! |
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Fixes #477.
Per your feedback there -- switched from the scoped-variable version to a direct pointer-cast assignment:
Re-tested on the same PPC hardware (Tiger iBook G4) with this exact form:
smb2_set_seal(ctx, 1)connects successfully against both macOS's and Windows 11's standard SMB3 sharing.