Timed out RSA key ops, may leave uncalled for responses in the imsg return

path.  These have to be dropped or every subsequent call will cause decrypt
errors. Use a sequence number cookie to keep the systems in sync.
Diff from niklas@ with some minor adjustments by myself.

diff --git a/usr.sbin/relayd/ca.c b/usr.sbin/relayd/ca.c
index 91bf346..6679842 100644 (file)
--- a/usr.sbin/relayd/ca.c
+++ b/usr.sbin/relayd/ca.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ca.c,v 1.35 2019/05/31 15:15:37 reyk Exp $    */
+/*     $OpenBSD: ca.c,v 1.36 2021/03/23 16:34:31 claudio Exp $ */
 
 /*
  * Copyright (c) 2014 Reyk Floeter <reyk@openbsd.org>
@@ -334,6 +334,7 @@ rsae_send_imsg(int flen, const u_char *from, u_char *to, RSA *rsa,
        struct imsg      imsg;
        int              n, done = 0, cnt = 0;
        u_char          *toptr;
+       static u_int     seq = 0;
 
        if ((hash = RSA_get_ex_data(rsa, 0)) == NULL)
                return (0);
@@ -350,6 +351,7 @@ rsae_send_imsg(int flen, const u_char *from, u_char *to, RSA *rsa,
        cko.cko_flen = flen;
        cko.cko_tlen = RSA_size(rsa);
        cko.cko_padding = padding;
+       cko.cko_cookie = seq++;
 
        iov[cnt].iov_base = &cko;
        iov[cnt++].iov_len = sizeof(cko);
@@ -372,8 +374,10 @@ rsae_send_imsg(int flen, const u_char *from, u_char *to, RSA *rsa,
                case -1:
                        fatal("%s: poll", __func__);
                case 0:
-                       log_warnx("%s: priv%s poll timeout", __func__,
-                           cmd == IMSG_CA_PRIVENC ? "enc" : "dec");
+                       log_warnx("%s: priv%s poll timeout, keyop #%x",
+                           __func__,
+                           cmd == IMSG_CA_PRIVENC ? "enc" : "dec",
+                           cko.cko_cookie);
                        return (-1);
                default:
                        break;
@@ -388,12 +392,25 @@ rsae_send_imsg(int flen, const u_char *from, u_char *to, RSA *rsa,
                                fatalx("imsg_get error");
                        if (n == 0)
                                break;
-                       if (imsg.hdr.type != cmd)
-                               fatalx("invalid response");
 
                        IMSG_SIZE_CHECK(&imsg, (&cko));
                        memcpy(&cko, imsg.data, sizeof(cko));
 
+                       /*
+                        * Due to earlier timed out requests, there may be
+                        * responses that need to be skipped.
+                        */
+                       if (cko.cko_cookie != seq - 1) {
+                               log_warnx(
+                                   "%s: priv%s obsolete keyop #%x", __func__,
+                                   cmd == IMSG_CA_PRIVENC ? "enc" : "dec",
+                                   cko.cko_cookie);
+                               continue;
+                       }
+
+                       if (imsg.hdr.type != cmd)
+                               fatalx("invalid response");
+
                        ret = cko.cko_tlen;
                        if (ret > 0) {
                                if (IMSG_DATA_SIZE(&imsg) !=

diff --git a/usr.sbin/relayd/relayd.h b/usr.sbin/relayd/relayd.h
index 735c650..27a2d37 100644 (file)
--- a/usr.sbin/relayd/relayd.h
+++ b/usr.sbin/relayd/relayd.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: relayd.h,v 1.265 2021/01/27 20:33:05 eric Exp $       */
+/*     $OpenBSD: relayd.h,v 1.266 2021/03/23 16:34:31 claudio Exp $    */
 
 /*
  * Copyright (c) 2006 - 2016 Reyk Floeter <reyk@openbsd.org>
@@ -269,6 +269,7 @@ struct ctl_keyop {
        int                      cko_flen;
        int                      cko_tlen;
        int                      cko_padding;
+       u_int                    cko_cookie;
 };
 
 struct ctl_stats {