+
+void hexify(char *dst, char *src, int len) {
+ static char hex[] = "0123456789abcdef";
+ int i;
+
+ for (i = 0; i < len; i++) {
+ dst[i * 2] = hex[(src[i] & 0xF0) >> 4];
+ dst[i * 2 + 1] = hex[src[i] & 0xF];
+ }
+}
+
+char *create_random_token() {
+ unsigned char buf[TOKEN_SIZE];
+ char *token;
+ int rand_fd;
+
+ rand_fd = open("/dev/urandom", O_RDONLY);
+ if (rand_fd == -1) {
+ perror("Could not open /dev/urandom\n");
+ return 0;
+ }
+ read(rand_fd, buf, TOKEN_SIZE);
+ close(rand_fd);
+
+ token = malloc(TOKEN_SIZE * 2 + 1);
+ hexify(token, buf, TOKEN_SIZE);
+ token[TOKEN_SIZE * 2] = 0;
+
+ return token;
+}
+
+char * auth_login(const char *username, const char *password) {
+ char filename[512];
+ int token_fd;
+
+ if (!auth_check_password(username, password))
+ return NULL;
+
+ char *token = create_random_token();
+
+ sprintf(filename, "%s/%s/tokens", DATA_PATH, username);
+ if (access(filename, F_OK) != 0) {
+ if (mkdir(filename, 0700) == -1) {
+ perror("Could not create auth token dir");
+ return NULL;
+ }
+ }
+
+ sprintf(filename, "%s/%s/tokens/%s", DATA_PATH, username, token);
+ token_fd = open(filename, O_WRONLY | O_CREAT, 0600);
+ if (token_fd == -1) {
+ perror("Could not open token");
+ return NULL;
+ }
+ close(token_fd);
+
+ return token;
+}
+
+int auth_logout(const char *username, const char *token) {
+ char filename[512];
+
+ if (!valid_name(username))
+ return 0;
+
+ sprintf(filename, "%s/%s/tokens", DATA_PATH, username);
+ if (access(filename, F_OK) != 0) {
+ return 0;
+ }
+
+ sprintf(filename, "%s/%s/tokens/%s", DATA_PATH, username, token);
+ if (unlink(filename) == -1)
+ return 0;
+
+ return 1;
+}
+
+int auth_check_token(const char *username, const char *given_token) {
+ char filename[512];
+
+ sprintf(filename, "%s/%s/tokens/%s", DATA_PATH, username, given_token);
+
+ return (access(filename, F_OK) == 0);
+}