Author: tuexen Date: Mon Oct 1 14:05:31 2018 New Revision: 339042 URL: https://svnweb.freebsd.org/changeset/base/339042
Log: Mitigate providing a timing signal if the COOKIE or AUTH validation fails. Thanks to jmg@ for reporting the issue, which was discussed in https://admbugs.freebsd.org/show_bug.cgi?id=878 Approved by: re (TBD@) MFC after: 1 week Modified: head/sys/netinet/sctp_auth.c head/sys/netinet/sctp_input.c Modified: head/sys/netinet/sctp_auth.c ============================================================================== --- head/sys/netinet/sctp_auth.c Mon Oct 1 14:02:29 2018 (r339041) +++ head/sys/netinet/sctp_auth.c Mon Oct 1 14:05:31 2018 (r339042) @@ -1706,7 +1706,7 @@ sctp_handle_auth(struct sctp_tcb *stcb, struct sctp_au m, offset, computed_digest); /* compare the computed digest with the one in the AUTH chunk */ - if (memcmp(digest, computed_digest, digestlen) != 0) { + if (timingsafe_bcmp(digest, computed_digest, digestlen) != 0) { SCTP_STAT_INCR(sctps_recvauthfailed); SCTPDBG(SCTP_DEBUG_AUTH1, "SCTP Auth: HMAC digest check failed\n"); Modified: head/sys/netinet/sctp_input.c ============================================================================== --- head/sys/netinet/sctp_input.c Mon Oct 1 14:02:29 2018 (r339041) +++ head/sys/netinet/sctp_input.c Mon Oct 1 14:05:31 2018 (r339042) @@ -2554,7 +2554,7 @@ sctp_handle_cookie_echo(struct mbuf *m, int iphlen, in return (NULL); } /* compare the received digest with the computed digest */ - if (memcmp(calc_sig, sig, SCTP_SIGNATURE_SIZE) != 0) { + if (timingsafe_bcmp(calc_sig, sig, SCTP_SIGNATURE_SIZE) != 0) { /* try the old cookie? */ if ((cookie->time_entered.tv_sec == (long)ep->time_of_secret_change) && (ep->current_secret_number != ep->last_secret_number)) { @@ -2563,7 +2563,7 @@ sctp_handle_cookie_echo(struct mbuf *m, int iphlen, in (uint8_t *)ep->secret_key[(int)ep->last_secret_number], SCTP_SECRET_SIZE, m, cookie_offset, calc_sig, 0); /* compare */ - if (memcmp(calc_sig, sig, SCTP_SIGNATURE_SIZE) == 0) + if (timingsafe_bcmp(calc_sig, sig, SCTP_SIGNATURE_SIZE) == 0) cookie_ok = 1; } } else { _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
