C (gcc) [M outbound.so] outbound_mod.o outbound_mod.c: In function 'mod_init': outbound_mod.c:112:25: warning: pointer targets in passing argument 1 of 'SHA1' differ in signedness [-Wpointer-sign] SHA1(flow_token_secret.s, flow_token_secret.len, ob_key.s); ~~~~~~~~~~~~~~~~~^~ In file included from outbound_mod.c:28: /usr/include/openssl/sha.h:44:16: note: expected 'const unsigned char *' but argument is of type 'char *' unsigned char *SHA1(const unsigned char *d, size_t n, unsigned char *md); ^~~~ outbound_mod.c:112:58: warning: pointer targets in passing argument 3 of 'SHA1' differ in signedness [-Wpointer-sign] SHA1(flow_token_secret.s, flow_token_secret.len, ob_key.s); ~~~~~~^~ In file included from outbound_mod.c:28: /usr/include/openssl/sha.h:44:16: note: expected 'unsigned char *' but argument is of type 'char *' unsigned char *SHA1(const unsigned char *d, size_t n, unsigned char *md); ^~~~