Should be correct for building RSA

src/crypto/axtls/os_port.h

 	return -1;
 }
 
-#define CONFIG_SSL_CERT_VERIFICATION 1
 #define CONFIG_SSL_MAX_CERTS 1
 #define CONFIG_X509_MAX_CA_CERTS 1
 #define CONFIG_SSL_EXPIRY_TIME 24
 #define CONFIG_SSL_ENABLE_CLIENT 1
+#define CONFIG_BIGINT_CLASSICAL 1
 
 #endif