This PR removes all uses of extended reader/writer from MPS.
While reader/writer provide a layer of abstraction preventing buffer overflows and pointer arithmetic failures, extended reader/writers are primarily a means to track logical bounds, such as the bounds of a HS message spread over multiple physical buffers, or the bounds of substructures such as extensions in a ClientHello.
Bounds checks as performed by the extended reader/writer are necessary at some point in the stack. However, the previous design choice of incorporating them already at MPS Layer 3 caused significant technical difficulties.
For now, this PR removes extended reader/writers altogether, from both Layer 3 and Layer 4.
It will need to be reconsidered if/where we want to re-introduce extended readers/writers at a later point: Either at the handshake layer, or at the very boundary of MPS Layer 4 -- but not within MPS itself.
This PR removes all uses of extended reader/writer from MPS.
While reader/writer provide a layer of abstraction preventing buffer overflows and pointer arithmetic failures, extended reader/writers are primarily a means to track logical bounds, such as the bounds of a HS message spread over multiple physical buffers, or the bounds of substructures such as extensions in a
ClientHello.Bounds checks as performed by the extended reader/writer are necessary at some point in the stack. However, the previous design choice of incorporating them already at MPS Layer 3 caused significant technical difficulties.
For now, this PR removes extended reader/writers altogether, from both Layer 3 and Layer 4.
It will need to be reconsidered if/where we want to re-introduce extended readers/writers at a later point: Either at the handshake layer, or at the very boundary of MPS Layer 4 -- but not within MPS itself.