+/*************************************************
+* Drop privs for checking TLS config *
+*************************************************/
+
+/* We want to validate TLS options during readconf, but do not want to be
+root when we call into the TLS library, in case of library linkage errors
+which cause segfaults; before this check, those were always done as the Exim
+runtime user and it makes sense to continue with that.
+
+Assumes: tls_require_ciphers has been set, if it will be
+ exim_user has been set, if it will be
+ exim_group has been set, if it will be
+
+Returns: bool for "okay"; false will cause caller to immediately exit.
+*/
+
+#ifdef SUPPORT_TLS
+static BOOL
+tls_dropprivs_validate_require_cipher(void)
+{
+const uschar *errmsg;
+pid_t pid;
+int rc, status;
+void (*oldsignal)(int);
+
+oldsignal = signal(SIGCHLD, SIG_DFL);
+
+fflush(NULL);
+if ((pid = fork()) < 0)
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "fork failed for TLS check");
+
+if (pid == 0)
+ {
+ /* in some modes, will have dropped privilege already */
+ if (!geteuid())
+ exim_setugid(exim_uid, exim_gid, FALSE,
+ US"calling tls_validate_require_cipher");
+
+ errmsg = tls_validate_require_cipher();
+ if (errmsg)
+ {
+ log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
+ "tls_require_ciphers invalid: %s", errmsg);
+ }
+ fflush(NULL);
+ _exit(0);
+ }
+
+do {
+ rc = waitpid(pid, &status, 0);
+} while (rc < 0 && errno == EINTR);
+
+DEBUG(D_tls)
+ debug_printf("tls_validate_require_cipher child %d ended: status=0x%x\n",
+ (int)pid, status);
+
+signal(SIGCHLD, oldsignal);
+
+return status == 0;
+}
+#endif /* SUPPORT_TLS */
+
+
+
+
git://git.exim.org / exim.git / blobdiff