Unsigned.

database/salt_store.cpp

@@ -13,7 +13,7 @@ SaltStore::SaltStore(uint64_t key_lifetime, size_t salt_size, std::string secret
 
 std::string SaltStore::getSalt() {
 	expireKeys();
-	char bfr[salt_size];
+	unsigned char bfr[salt_size];
 	FILE * rand_in = fopen("/dev/urandom", "r");
 	if(!rand_in) {
 		fprintf(stderr, "Could not open /dev/urandom!\n");
@@ -32,7 +32,7 @@ std::string SaltStore::getSalt() {
   }
 	bfr[salt_size-1] = 0;
 
-	std::string salt(bfr);
+	std::string salt((char*)bfr);
 
 	valid_keys.push_back(std::pair<uint64_t, SHA1Hash>((uint64_t)time(NULL), SHA1Hash(salt + secret)));
 	return salt;