From modules/tls/tls_init.c
``` /* attempt to guess if the library was compiled with kerberos or * compression support from the cflags */ lib_cflags=SSLeay_version(SSLEAY_CFLAGS); lib_kerberos=0; lib_zlib=0; if ((lib_cflags==0) || strstr(lib_cflags, "not available")){ lib_kerberos=-1; lib_zlib=-1; }else{ if (strstr(lib_cflags, "-DZLIB")) lib_zlib=1; if (strstr(lib_cflags, "-DKRB5_")) lib_kerberos=1; } LOG(L_INFO, "tls: _init_tls_h: compiled with openssl version " ""%s" (0x%08lx), kerberos support: %s, compression: %s\n", OPENSSL_VERSION_TEXT, (long)OPENSSL_VERSION_NUMBER, kerberos_support?"on":"off", comp_support?"on":"off"); LOG(L_INFO, "tls: init_tls_h: installed openssl library version " ""%s" (0x%08lx), kerberos support: %s, " " zlib compression: %s" "\n %s\n", SSLeay_version(SSLEAY_VERSION), ssl_version, (lib_kerberos==1)?"on":(lib_kerberos==0)?"off":"unknown", (lib_zlib==1)?"on":(lib_zlib==0)?"off":"unknown", SSLeay_version(SSLEAY_CFLAGS)); if (lib_kerberos!=kerberos_support){ if (lib_kerberos!=-1){ LOG(L_CRIT, "ERROR: tls: init_tls_h: openssl compile options" " mismatch: library has kerberos support" " %s and Kamailio tls %s (unstable configuration)\n" " (tls_force_run in kamailio.cfg will override this" " check)\n", lib_kerberos?"enabled":"disabled", kerberos_support?"enabled":"disabled" ); if (cfg_get(tls, tls_cfg, force_run)) LOG(L_WARN, "tls: init_tls_h: tls_force_run turned on, " "ignoring kerberos support mismatch\n"); else return -1; /* exit, is safer */ }else{ LOG(L_WARN, "WARNING: tls: init_tls_h: openssl compile options" " missing -- cannot detect if kerberos support is" " enabled. Possible unstable configuration\n"); } } ```