pkg/tinydtls: DTLS handshake does not work #19595
Description
Description
The DTLS handshake does not work anymore since 2023.01.
I'm currently running examples/gcoap_dtls and see that the client sends "Client Hello" but gets no response from the server. After some seconds the node generates an Alert, probably as a result of a failed handshake.
DTLS seems to be working fine on 2022.10.
Steps to reproduce the issue
Try examples/gcoap_dtls with the default settings and perform a GET request using DTLS (port 5684).
Expected results
> coap get fe80::804e:b4ff:fe15:3164 5684 /.well-known/core
coap get fe80::804e:b4ff:fe15:3164 5684 /.well-known/core
gcoap_cli: sending msg ID 26500, 23 bytes
> gcoap: response Success, code 2.05, 46 bytes
</cli/stats>;ct=0;rt="count";obs,</riot/board>
Actual results
> coap get [fe80::804e:b4ff:fe15:3164]:5684 /.well-known/core
coap get [fe80::804e:b4ff:fe15:3164]:5684 /.well-known/core
gcoap_cli: sending msg ID 12284, 23 bytes
Versions
Operating System Environment
----------------------------
Operating System: "Arch Linux"
Kernel: Linux 6.2.9-arch1-1 x86_64 unknown
System shell: GNU bash, version 5.1.16(1)-release (x86_64-pc-linux-gnu)
make's shell: GNU bash, version 5.1.16(1)-release (x86_64-pc-linux-gnu)
Installed compiler toolchains
-----------------------------
native gcc: gcc (GCC) 12.2.1 20230201
arm-none-eabi-gcc: arm-none-eabi-gcc (GNU Tools for Arm Embedded Processors 7-2017-q4-major) 7.2.1 20170904 (release) [ARM/embedded-7-branch revision 255204]
avr-gcc: avr-gcc (GCC) 12.2.0
msp430-elf-gcc: missing
riscv-none-elf-gcc: missing
riscv64-unknown-elf-gcc: missing
riscv-none-embed-gcc: missing
xtensa-esp32-elf-gcc: missing
xtensa-esp8266-elf-gcc: missing
clang: clang version 15.0.7
Installed compiler libs
-----------------------
arm-none-eabi-newlib: "2.5.0"
msp430-elf-newlib: missing
riscv-none-elf-newlib: missing
riscv64-unknown-elf-newlib: missing
riscv-none-embed-newlib: missing
xtensa-esp32-elf-newlib: missing
xtensa-esp8266-elf-newlib: missing
avr-libc: "2.1.0" ("20220128")
Installed development tools
---------------------------
ccache: ccache version 4.8
cmake: cmake version 3.26.2
cppcheck: missing
doxygen: 1.9.6
git: git version 2.40.0
make: GNU Make 4.4.1
openocd: Open On-Chip Debugger 0.11.0
python: Python 3.10.10
python2: Python 2.7.18
python3: Python 3.10.10
flake8: 6.0.0 (mccabe: 0.7.0, pycodestyle: 2.10.0, pyflakes: 3.0.1) CPython 3.10.10 on
coccinelle: missing