Fragment TLS 1.3 NewSessionTicket to max fragment length

[embhorn]

Description

Split the ticket into several records when it is larger than the negotiated max fragment length.

Fixes #11079

Testing

Added a regression test.

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[Copilot]

Copilot review overview

🟡 Changes recommended

The regression test can pass without exercising fragmentation when the generated ticket fits in one record.

Review effort: Balanced
Findings: 1

Open (1)

• Ensure regression test always requires fragmented session tickets · New

What changed in this PR

Adds TLS 1.3 NewSessionTicket fragmentation to respect negotiated record limits.

Changes:

• Fragments oversized tickets across adjacent TLS records.
• Updates ticket-size rationale for resumed ClientHello messages.
• Adds a fragmentation and resumption test.

File	Description
src/​tls13.c	Implements ticket fragmentation.
src/​internal.c	Updates the peer-certificate exclusion rationale.
tests/​api/​test_tls13.c	Adds the regression test.
tests/​api/​test_tls13.h	Registers the new test.

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[github-actions]

MemBrowse Memory Report

gcc-arm-cortex-m4-openssl-compat

• FLASH: .text +256 B (+0.0%, 789,276 B / 1,048,576 B, total: 75% used)

gcc-arm-cortex-m4-pq

• FLASH: .text +256 B (+0.1%, 307,184 B / 1,048,576 B, total: 29% used)

gcc-arm-cortex-m4-rsa-only

• FLASH: .text +192 B (+0.1%, 337,328 B / 1,048,576 B, total: 32% used)

gcc-arm-cortex-m4-tls13

• FLASH: .text +192 B (+0.1%, 246,110 B / 262,144 B, total: 94% used)

gcc-arm-cortex-m7-pq

• FLASH: .text +192 B (+0.1%, 308,080 B / 1,048,576 B, total: 29% used)

gcc-arm-cortex-m7-tls13

• FLASH: .text +256 B (+0.1%, 246,174 B / 262,144 B, total: 94% used)
  No memory changes detected for:
• gcc-arm-cortex-m0plus
• gcc-arm-cortex-m3
• gcc-arm-cortex-m4
• gcc-arm-cortex-m4-baremetal
• gcc-arm-cortex-m4-crypto-only
• gcc-arm-cortex-m4-dtls13
• gcc-arm-cortex-m4-min-ecc
• gcc-arm-cortex-m4-pkcs7
• gcc-arm-cortex-m4-sp-math
• gcc-arm-cortex-m4-tls12
• gcc-arm-cortex-m7
• linuxkm-pie
• linuxkm-standard
• stm32-sim-stm32h753