+int auth_get_data(const char *username, void *data, size_t data_len) {
+ char filename[FILENAME_MAX];
+ int fd;
+ int len = 0;
+
+ if (!valid_name(username))
+ return 0;
+
+ snprintf(filename, FILENAME_MAX, "%s/%s/auth", blergconf.data_path, username);
+ fd = open(filename, O_RDONLY);
+ if (fd == -1)
+ return 0;
+ flock(fd, LOCK_SH);
+ len = read(fd, data, data_len);
+ flock(fd, LOCK_UN);
+ close(fd);
+
+ if (len < 0) {
+ perror("auth_get_data");
+ return 0;
+ } else if (len < data_len) {
+ fprintf(stderr, "Short read getting auth data\n");
+ return 0;
+ }
+
+ return 1;
+}
+
+int auth_check_scrypt(struct auth_v2 *auth, const char *username, const char *password) {
+ unsigned char givenpw[SCRYPT_OUTPUT_SIZE];
+ int r;
+
+ r = crypto_scrypt(password, strlen(password), auth->salt, SCRYPT_SALT_SIZE, SCRYPT_N, SCRYPT_r, SCRYPT_p, givenpw, SCRYPT_OUTPUT_SIZE);
+ if (r != 0) {
+ fprintf(stderr, "Failure in scrypt for %s\n", username);
+ return 0;
+ }
+
+ if (memcmp(givenpw, auth->password, SCRYPT_OUTPUT_SIZE) == 0)
+ return 1;
+ else
+ return 0;
+}
+
+int auth_check_password_v1(const char *username, const char *password) {
+ struct auth_v2 auth;
+ int r;
+
+ if (auth_get_password(username, (char *)auth.password) == 0)
+ return 0;
+
+ if (auth_get_salt(username, auth.salt) == 0)
+ return 0;
+
+ return auth_check_scrypt(&auth, username, password);
+}
+
+int auth_check_password_v2(const char *username, const char *password) {
+ struct auth_v2 auth;
+ int r;
+
+ if (auth_get_data(username, (void *) &auth, sizeof(struct auth_v2)) == 0)
+ return 0;
+
+ return auth_check_scrypt(&auth, username, password);
+}
+
+int auth_check_password(const char *username, const char *password) {
+ int version = auth_get_password_version(username);
+
+ switch(version) {
+ case 0:
+ if (auth_check_password_v0(username, password)) {
+ /* Refresh to the newest version */
+ auth_set_password(username, password);
+ return 1;
+ } else {
+ return 0;
+ }
+ break;
+ case 1:
+ if (auth_check_password_v1(username, password)) {
+ /* Refresh to the newest version */
+ auth_set_password(username, password);
+ return 1;
+ } else {
+ return 0;
+ }
+ break;
+ case 2:
+ return auth_check_password_v2(username, password);
+ }
+ fprintf(stderr, "auth_check_password fell through. Bad password version?\n");
+ return 0;
+}
+