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[DTLS 1.3] Prep the Transcript_Hash_state + introduce strong record types - #6006
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reneme merged 5 commits intoOct 6, 2026
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🟡 Changes recommended
Successful handshakes can dereference a reset transcript optional, and additional transcript and type-invariant regressions remain unresolved.
Review effort: Balanced
Findings: 2
Open (5)
What changed in this PR
Prepares TLS 1.3 internals for future DTLS 1.3 support through typed transcript components, optional transcript lifetime, and typed record variants.
Changes:
- Splits handshake headers from message bodies during transcript hashing.
- Introduces typed TLS record variants and record-number types.
- Makes channel transcript state optional after handshake completion.
| File | Description |
|---|---|
src/tests/test_tls_transcript_hash_13.cpp |
Updates transcript-hash tests. |
src/tests/test_tls_record_layer_13.cpp |
Tests typed record variants. |
src/tests/test_tls_handshake_layer_13.cpp |
Supplies TLS flavor to transcript state. |
src/tests/test_tls_cipher_state.cpp |
Validates decrypted record variants. |
src/lib/tls/tls13/tls_types_13.h |
Adds handshake and record strong types. |
src/lib/tls/tls13/tls_transcript_hash_13.h |
Revises transcript-hash API and buffering. |
src/lib/tls/tls13/tls_transcript_hash_13.cpp |
Implements split transcript processing. |
src/lib/tls/tls13/tls_server_impl_13.cpp |
Adapts server transcript ownership. |
src/lib/tls/tls13/tls_record_layer_13.h |
Exposes variant-based record results. |
src/lib/tls/tls13/tls_record_layer_13.cpp |
Returns annotated record alternatives. |
src/lib/tls/tls13/tls_record_13.h |
Defines typed record alternatives. |
src/lib/tls/tls13/tls_record_13.cpp |
Maps content types to record variants. |
src/lib/tls/tls13/tls_messages_13.h |
Adds TLS flavor to ClientHello construction. |
src/lib/tls/tls13/tls_handshake_layer_13.cpp |
Splits headers before transcript updates. |
src/lib/tls/tls13/tls_client_impl_13.cpp |
Adapts client transcript ownership. |
src/lib/tls/tls13/tls_cipher_state.h |
Returns typed decrypted records. |
src/lib/tls/tls13/tls_cipher_state.cpp |
Annotates decrypted record content. |
src/lib/tls/tls13/tls_channel_impl_13.h |
Makes transcript state optional. |
src/lib/tls/tls13/tls_channel_impl_13.cpp |
Handles variant records and transcript state. |
src/lib/tls/tls13/msg_client_hello_13.cpp |
Propagates TLS flavor for PSK binders. |
src/lib/tls/tls_magic.h |
Adds handshake constants and MessageHash. |
src/lib/tls/tls_magic.cpp |
Stringifies MessageHash. |
src/lib/tls/tls_handshake_transitions.cpp |
Adds transition-mask support. |
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This is a 'virtual handshake message type' used to calculate a transcript hash based on a previous ClientHello in the HelloRetryRequest case. Co-Authored-By: Amos Treiber <amos.treiber@rohde-schwarz.com>
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This introduces a bunch of subclasses to the generic Record_Content struct, one for each supported record type (AppData, Handshake, CCS, Alert). In a later patch this will be used for type safe dispatching of those types. Co-Authored-By: Amos Treiber <amos.treiber@rohde-schwarz.com>
This allows resetting the transcript hash state after the handshake completed. Co-Authored-By: René Meusel <rene.meusel@rohde-schwarz.com>
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Transcript_Hash_State::update() now takes the 4-byte handshake protocol header and the serialized handshake message as separate, strongly typed parameters. This is a preparatory refactoring for DTLS 1.3, where the handshake protocol header carries additional fields (message_seq, fragment_offset, fragment_length) that must not be naively hashed. Also introduces strong types for marshalled handshake messages, message flights and fragments as well as DTLS record numbers in tls_types_13.h and passes the TLS_Flavor down to the transcript hash state. Co-Authored-By: René Meusel <rene.meusel@rohde-schwarz.com>
Co-Authored-By: René Meusel <rene.meusel@rohde-schwarz.com>
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This prepares the
Transcript_Hash_Statefor DTLS 1.3 (#5000) and adds strong record types (as subclasses of theRecord_Contentstruct). The strong types are currently just unpacked at the usage location, but that'll change with the coming patches.Details;
Handshake_Type::MessageHash— introduces the virtual handshake message type (RFC 9846 4.3.11.2) used for the transcript hash in the HelloRetryRequest case.Record_Contentstrong types — adds subclasses of the genericRecord_Contentfor each record type (AppData, Handshake, CCS, Alert) to enable type-safe dispatching in a later patch.std::optional<Transcript_Hash_State>— the transcript hash state inChannel_Impl_13can now be reset after the handshake completesTranscript_Hash_State—::update()now explicitly takes the 4-byte handshake protocol header and the serialized message as separate strongly typed parameters, since DTLS 1.3 headers carry extra fields that must not be hashed.No functional changes; each commit builds and passes the tests.