Describe the bug

For Digest Authentication of an PJSUA(2) account during registration process, if the password is > 16 characters, then registration will fail without any error message.

Steps to reproduce

Use an authentication key (K) in https://docs.pjsip.org/en/latest/api/generated/pjsip/group/group__PJSUA2__SIP__Types.html#_CPPv4N2pj12AuthCredInfo4akaKE with a length > 16 characters and try to register using Digest Authentication:

auto auth = pj::AuthCredInfo("Digest", realm, username, PJSIP_CRED_DATA_EXT_AKA , 0);
auth.akaK = password;
config.sipConfig.authCreds.push_back(std::move(auth));  // config is of type pj::AccountConfig. config is used when creating an account.

PJSIP version

2.14.1, 2.15

Context

Latest version of the standard supports the following lengths of authentication parameters:

The length of the authentication key (K) has changed over time.

Log, call stack, etc

Registration fails silently, when a SIP 401 is received after the initial unprotected SIP REGISTER had been sent.