On Tue, Nov 12, 2019 at 09:57:31AM +0100, Mike Belopuhov wrote:
> Hi Tobias,
>
> I see, however, I don't think iked would negotiate an SA
> without ESN support if the other side supports ESN, so I'm
> not sure how "enforcing" changes that.
It doesn't, but if I have an iked on both sides one will have to
make the decision. I have another case where I actually can not
use ESN, with two ikeds this can not be configured currently.
> In any case, I'm not opposed to adding a toggle if you guys
> need it, but could you please adjust the grammar so that "esn"
> and "no esn" are used instead of "on" and "off" since that's
> what we're normally doing. "on" and "off" are clutches for
> simple file formats, parse.y allows you to make it a bit nicer.
Makes sense. Here is the updated diff including a fix for bluhms
comment.
Index: iked.conf.5
===================================================================
RCS file: /mount/openbsd/cvs/src/sbin/iked/iked.conf.5,v
retrieving revision 1.57
diff -u -p -r1.57 iked.conf.5
--- iked.conf.5 24 Aug 2019 13:24:49 -0000 1.57
+++ iked.conf.5 12 Nov 2019 13:49:37 -0000
@@ -409,6 +409,7 @@ multiple crypto transforms.
.Ic auth Ar algorithm
.Ic enc Ar algorithm
.Ic group Ar group
+.Ic esn
.Xc
These parameters define the cryptographic transforms to be used for
the Child SA negotiation, also known as phase 2.
@@ -421,6 +422,7 @@ Possible values for
.Ic auth ,
.Ic enc ,
.Ic group ,
+.Ic esn ,
and the default proposals are described below in
.Sx CRYPTO TRANSFORMS .
If omitted,
@@ -849,6 +851,17 @@ not encryption:
.It Li aes-192-gmac Ta "224 bits" Ta "[ESP only]"
.It Li aes-256-gmac Ta "288 bits" Ta "[ESP only]"
.It Li null Ta "" Ta "[ESP only]"
+.El
+.Pp
+The Extended Sequence Numbers option can be enabled or disabled with the
+.Ic esn
+or
+.Ic noesn
+keywords:
+.Bl -column "noesn" "[ESP only]" -offset indent
+.It Em ESN
+.It Li esn Ta "[ESP only]"
+.It Li noesn Ta "[ESP only]"
.El
.Pp
Transforms followed by
Index: parse.y
===================================================================
RCS file: /mount/openbsd/cvs/src/sbin/iked/parse.y,v
retrieving revision 1.84
diff -u -p -r1.84 parse.y
--- parse.y 26 Sep 2019 07:33:36 -0000 1.84
+++ parse.y 12 Nov 2019 13:54:04 -0000
@@ -127,6 +127,8 @@ struct ipsec_transforms {
unsigned int nencxf;
const struct ipsec_xf **groupxf;
unsigned int ngroupxf;
+ const struct ipsec_xf **esnxf;
+ unsigned int nesnxf;
};
struct ipsec_mode {
@@ -259,6 +261,12 @@ const struct ipsec_xf groupxfs[] = {
{ NULL }
};
+const struct ipsec_xf esnxfs[] = {
+ { "esn", IKEV2_XFORMESN_ESN },
+ { "noesn", IKEV2_XFORMESN_NONE },
+ { NULL }
+};
+
const struct ipsec_xf methodxfs[] = {
{ "none", IKEV2_AUTH_NONE },
{ "rsa", IKEV2_AUTH_RSA_SIG },
@@ -395,7 +403,7 @@ typedef struct {
%}
%token FROM ESP AH IN PEER ON OUT TO SRCID DSTID PSK PORT
-%token FILENAME AUTHXF PRFXF ENCXF ERROR IKEV2 IKESA CHILDSA
+%token FILENAME AUTHXF PRFXF ENCXF ERROR IKEV2 IKESA CHILDSA ESN NOESN
%token PASSIVE ACTIVE ANY TAG TAP PROTO LOCAL GROUP NAME CONFIG EAP USER
%token IKEV1 FLOW SA TCPMD5 TUNNEL TRANSPORT COUPLE DECOUPLE SET
%token INCLUDE LIFETIME BYTES INET INET6 QUICK SKIP DEFAULT
@@ -425,6 +433,7 @@ typedef struct {
%type <v.number> byte_spec time_spec ikelifetime
%type <v.string> name
%type <v.cfg> cfg ikecfg ikecfgvals
+%type <v.string> transform_esn
%%
grammar : /* empty */
@@ -802,6 +811,24 @@ transform : AUTHXF STRING {
ipsec_transforms->groupxf = xfs;
ipsec_transforms->ngroupxf++;
}
+ | transform_esn {
+ const struct ipsec_xf **xfs = ipsec_transforms->esnxf;
+ size_t nxfs = ipsec_transforms->nesnxf;
+ xfs = recallocarray(xfs, nxfs, nxfs + 1,
+ sizeof(struct ipsec_xf *));
+ if (xfs == NULL)
+ err(1, "transform: recallocarray");
+ if ((xfs[nxfs] = parse_xf($1, 0, esnxfs)) == NULL) {
+ yyerror("%s not a valid transform", $1);
+ YYERROR;
+ }
+ ipsec_transforms->esnxf = xfs;
+ ipsec_transforms->nesnxf++;
+ }
+ ;
+
+transform_esn : ESN { $$ = "esn"; }
+ | NOESN { $$ = "noesn"; }
;
ike_sas : {
@@ -1180,6 +1207,7 @@ lookup(char *s)
{ "dstid", DSTID },
{ "eap", EAP },
{ "enc", ENCXF },
+ { "esn", ESN },
{ "esp", ESP },
{ "file", FILENAME },
{ "flow", FLOW },
@@ -1198,6 +1226,7 @@ lookup(char *s)
{ "local", LOCAL },
{ "mobike", MOBIKE },
{ "name", NAME },
+ { "noesn", NOESN },
{ "nofragmentation", NOFRAGMENTATION },
{ "nomobike", NOMOBIKE },
{ "ocsp", OCSP },
@@ -2578,6 +2607,10 @@ print_policy(struct iked_policy *pol)
print_verbose(" group ");
xfs = groupxfs;
break;
+ case IKEV2_XFORMTYPE_ESN:
+ print_verbose(" ");
+ xfs = esnxfs;
+ break;
default:
continue;
}
@@ -2830,6 +2863,11 @@ create_ike(char *name, int af, uint8_t i
pol.pol_nproposals++;
} else {
for (i = 0; i < ike_sa->nxfs; i++) {
+ if (ike_sa->xfs[i]->nesnxf) {
+ yyerror("cannot use ESN with ikesa.");
+ goto done;
+ }
+
if ((p = calloc(1, sizeof(*p))) == NULL)
err(1, "%s", __func__);
@@ -2914,7 +2952,8 @@ create_ike(char *name, int af, uint8_t i
ikev2_default_esp_transforms,
ikev2_default_nesp_transforms);
copy_transforms(IKEV2_XFORMTYPE_ESN,
- NULL, 0, &xf, &xfi,
+ ipsec_sa->xfs[i]->esnxf,
+ ipsec_sa->xfs[i]->nesnxf, &xf, &xfi,
ikev2_default_esp_transforms,
ikev2_default_nesp_transforms);
