Fix encoding bug in i2c_ASN1_INTEGER
(Imported from upstream's 3661bb4e7934668bd99ca777ea8b30eedfafa871.)
Fix bug where i2c_ASN1_INTEGER mishandles zero if it is marked as
negative.
Thanks to Huzaifa Sidhpurwala <huzaifas@redhat.com> and Hanno Böck
<hanno@hboeck.de> for reporting this issue.
BUG=590615
(Cherry-picked from c4eec0c16b02c97a62a95b6a08656c3a9ddb6baa.)
Change-Id: I61c5556e8a065817e3d36569433bff83a104d4c8
Reviewed-on: https://boringssl-review.googlesource.com/7297
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/asn1/a_int.c b/crypto/asn1/a_int.c
index 9a56534..fcd33a7 100644
--- a/crypto/asn1/a_int.c
+++ b/crypto/asn1/a_int.c
@@ -125,6 +125,8 @@
{
ret=a->length;
i=a->data[0];
+ if (ret == 1 && i == 0)
+ neg = 0;
if (!neg && (i > 127)) {
pad=1;
pb=0;
@@ -158,7 +160,7 @@
p += a->length - 1;
i = a->length;
/* Copy zeros to destination as long as source is zero */
- while(!*n) {
+ while(!*n && i > 1) {
*(p--) = 0;
n--;
i--;