From f435825c0f527a8e52e6ffbc3ad0bc60531d537e Mon Sep 17 00:00:00 2001 From: Nikos Mavrogiannopoulos Date: Mon, 4 Apr 2016 15:06:21 +0200 Subject: _asn1_extract_der_octet: catch invalid input cases early That is, check the calculated lengths for validity prior to entering a loop. This avoids an infinite recursion. Reported by Pascal Cuoq. --- lib/decoding.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/lib/decoding.c b/lib/decoding.c index 4fa045c..6fd60d0 100644 --- a/lib/decoding.c +++ b/lib/decoding.c @@ -767,10 +767,17 @@ _asn1_extract_der_octet (asn1_node node, const unsigned char *der, DECR_LEN(der_len, len3); if (len2 == -1) - counter_end = der_len - 2; + { + if (der_len < 2) + return ASN1_DER_ERROR; + counter_end = der_len - 2; + } else counter_end = der_len; + if (counter_end < counter) + return ASN1_DER_ERROR; + while (counter < counter_end) { DECR_LEN(der_len, 1); -- cgit v1.2.1