CID update to RFC 9146

The DTLS 1.2 CID specification has been published as RFC 9146. This PR updates the implementation to match the RFC content.

Signed-off-by: Hannes Tschofenig <hannes.tschofenig@arm.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 7f259f5..e89108e 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2449,6 +2449,25 @@
     tests/compat.sh
 }
 
+component_test_variable_ssl_in_out_buffer_len_CID_legacy () {
+    msg "build: MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID (legacy) enabled (ASan build)"
+    scripts/config.py set MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
+    scripts/config.py set MBEDTLS_SSL_DTLS_CONNECTION_ID
+    scripts/config.py set MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT 1
+
+    CC=gcc cmake -D CMAKE_BUILD_TYPE:String=Asan .
+    make
+
+    msg "test: MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID"
+    make test
+
+    msg "test: ssl-opt.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID enabled"
+    tests/ssl-opt.sh
+
+    msg "test: compat.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID enabled"
+    tests/compat.sh
+}
+
 component_test_ssl_alloc_buffer_and_mfl () {
     msg "build: default config with memory buffer allocator and MFL extension"
     scripts/config.py set MBEDTLS_MEMORY_BUFFER_ALLOC_C