ASN.1: Fix an indefinite length skip error

dhowells · rustyrussell · commit f3537f91f9be · 2012-12-05T11:27:39.000+10:30
Fix an error in asn1_find_indefinite_length() whereby small definite length
elements of size 0x7f are incorrecly classified as non-small.  Without this
fix, an error will be given as the length of the length will be perceived as
being very much greater than the maximum supported size.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
diff --git a/lib/asn1_decoder.c b/lib/asn1_decoder.c
@@ -91,7 +91,7 @@ static int asn1_find_indefinite_length(const unsigned char *data, size_t datalen
 
 	/* Extract the length */
 	len = data[dp++];
-	if (len < 0x7f) {
+	if (len <= 0x7f) {
 		dp += len;
 		goto next_tag;
 	}

Original file line number	Diff line number	Diff line change
`@@ -91,7 +91,7 @@ static int asn1_find_indefinite_length(const unsigned char *data, size_t datalen`
`91`	`91`
`92`	`92`	`/* Extract the length */`
`93`	`93`	`len = data[dp++];`
`94`		`- if (len < 0x7f) {`
	`94`	`+ if (len <= 0x7f) {`
`95`	`95`	`dp += len;`
`96`	`96`	`goto next_tag;`
`97`	`97`	`}`