[SR-Users] Kamailio 5.5 STIR SHAKEN private key buffer size error

Hi, I am trying STIR/SHAKEN using libstirshaken in Kamailio 5.5. I used a self signed certificate as this is just a test in the local docker environment. However, when I try to add identity with private key (stirshaken_add_identity_with_key), I get "[error_code: 447] Buffer for key from file /tmp/cert/private.pem too short (2000 <= 3247)" I have tried using 2048 and 4096 size root@5907e44bd056:/tmp/cert# openssl rsa -in private.pem -text -noout | grep "Private-Key" RSA Private-Key: (4096 bit, 2 primes) Could you tell me what is wrong with the certificate? Kamailio version: root@5907e44bd056:/usr/local/kamailio/etc/kamailio# kamailio -v version: kamailio 5.5.4 (x86_64/linux) 469465 Error: 0(404) ERROR: {1 30587 INVITE NzIhM1-2YABveZZ1mPvs3m3tw8K7meSq} stirshaken [stirshaken_mod.c:761]: ki_stirshaken_add_identity_with_key(): Failed to load private key 0(404) DEBUG: {1 30587 INVITE NzIhM1-2YABveZZ1mPvs3m3tw8K7meSq} stirshaken [stirshaken_mod.c:117]: stirshaken_print_error_details(): failure details: 0(404) DEBUG: {1 30587 INVITE NzIhM1-2YABveZZ1mPvs3m3tw8K7meSq} stirshaken [stirshaken_mod.c:118]: stirshaken_print_error_details(): failure reason is: src/stir_shaken_ssl.c:2112: [error_code: 447] Buffer for key from file /tmp/cert/private.pem too short (2000 <= 3247) 0(404) DEBUG: {1 30587 INVITE NzIhM1-2YABveZZ1mPvs3m3tw8K7meSq} stirshaken [stirshaken_mod.c:119]: stirshaken_print_error_details(): failure error code is: 447 0(404) ERROR: {1 30587 INVITE NzIhM1-2YABveZZ1mPvs3m3tw8K7meSq} <script>: Failed Regards *Maharaja Azhagiah*