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authorDavid Howells <dhowells@redhat.com>2015-08-05 13:54:46 +0200
committerDavid Howells <dhowells@redhat.com>2015-08-05 14:38:07 +0200
commit233ce79db4b23a174bcf30bde5d6ad913d5f46d3 (patch)
treefdf3021db1ab8f6d71908b6cc2a2e3afba94fb21 /lib/asn1_decoder.c
parentASN.1: Fix non-match detection failure on data overrun (diff)
downloadlinux-233ce79db4b23a174bcf30bde5d6ad913d5f46d3.tar.xz
linux-233ce79db4b23a174bcf30bde5d6ad913d5f46d3.zip
ASN.1: Handle 'ANY OPTIONAL' in grammar
An ANY object in an ASN.1 grammar that is marked OPTIONAL should be skipped if there is no more data to be had. This can be tested by editing X.509 certificates or PKCS#7 messages to remove the NULL from subobjects that look like the following: SEQUENCE { OBJECT(2a864886f70d01010b); NULL(); } This is an algorithm identifier plus an optional parameter. The modified DER can be passed to one of: keyctl padd asymmetric "" @s </tmp/modified.x509 keyctl padd pkcs7_test foo @s </tmp/modified.pkcs7 It should work okay with the patch and produce EBADMSG without. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marcel Holtmann <marcel@holtmann.org> Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'lib/asn1_decoder.c')
-rw-r--r--lib/asn1_decoder.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/lib/asn1_decoder.c b/lib/asn1_decoder.c
index 3f74dd3e2910..2b3f46c049d4 100644
--- a/lib/asn1_decoder.c
+++ b/lib/asn1_decoder.c
@@ -24,12 +24,16 @@ static const unsigned char asn1_op_lengths[ASN1_OP__NR] = {
[ASN1_OP_MATCH_JUMP] = 1 + 1 + 1,
[ASN1_OP_MATCH_JUMP_OR_SKIP] = 1 + 1 + 1,
[ASN1_OP_MATCH_ANY] = 1,
+ [ASN1_OP_MATCH_ANY_OR_SKIP] = 1,
[ASN1_OP_MATCH_ANY_ACT] = 1 + 1,
+ [ASN1_OP_MATCH_ANY_ACT_OR_SKIP] = 1 + 1,
[ASN1_OP_COND_MATCH_OR_SKIP] = 1 + 1,
[ASN1_OP_COND_MATCH_ACT_OR_SKIP] = 1 + 1 + 1,
[ASN1_OP_COND_MATCH_JUMP_OR_SKIP] = 1 + 1 + 1,
[ASN1_OP_COND_MATCH_ANY] = 1,
+ [ASN1_OP_COND_MATCH_ANY_OR_SKIP] = 1,
[ASN1_OP_COND_MATCH_ANY_ACT] = 1 + 1,
+ [ASN1_OP_COND_MATCH_ANY_ACT_OR_SKIP] = 1 + 1,
[ASN1_OP_COND_FAIL] = 1,
[ASN1_OP_COMPLETE] = 1,
[ASN1_OP_ACT] = 1 + 1,
@@ -304,7 +308,9 @@ next_op:
/* Decide how to handle the operation */
switch (op) {
case ASN1_OP_MATCH_ANY_ACT:
+ case ASN1_OP_MATCH_ANY_ACT_OR_SKIP:
case ASN1_OP_COND_MATCH_ANY_ACT:
+ case ASN1_OP_COND_MATCH_ANY_ACT_OR_SKIP:
ret = actions[machine[pc + 1]](context, hdr, tag, data + dp, len);
if (ret < 0)
return ret;
@@ -321,8 +327,10 @@ next_op:
case ASN1_OP_MATCH:
case ASN1_OP_MATCH_OR_SKIP:
case ASN1_OP_MATCH_ANY:
+ case ASN1_OP_MATCH_ANY_OR_SKIP:
case ASN1_OP_COND_MATCH_OR_SKIP:
case ASN1_OP_COND_MATCH_ANY:
+ case ASN1_OP_COND_MATCH_ANY_OR_SKIP:
skip_data:
if (!(flags & FLAG_CONS)) {
if (flags & FLAG_INDEFINITE_LENGTH) {