static uint8_t s2n_default_verify_host()

in tls/s2n_connection.c [215:245]

• 20 lines of code
• 10 McCabe index (conditional complexity)

static uint8_t s2n_default_verify_host(const char *host_name, size_t len, void *data)
{
    /* if present, match server_name of the connection using rules
     * outlined in RFC6125 6.4. */

    struct s2n_connection *conn = data;

    if (conn->server_name[0] == '\0') {
        return 0;
    }

    /* complete match */
    if (strlen(conn->server_name) == len && strncasecmp(conn->server_name, host_name, len) == 0) {
        return 1;
    }

    /* match 1 level of wildcard */
    if (len > 2 && host_name[0] == '*' && host_name[1] == '.') {
        const char *suffix = strchr(conn->server_name, '.');

        if (suffix == NULL) {
            return 0;
        }

        if (strlen(suffix) == len - 1 && strncasecmp(suffix, host_name + 1, len - 1) == 0) {
            return 1;
        }
    }

    return 0;
}