Improve subpacket parsing robustness

[onak.git] / decodekey.c

diff --git a/decodekey.c b/decodekey.c
index 522ad901383dd6a217b0ef5ed2320a93e3d51f8b..be80151d2822c31ddef27de3dfe6cfbfc1d42368 100644 (file)
--- a/decodekey.c
+++ b/decodekey.c
@@ -82,6 +82,10 @@ onak_status_t parse_subpackets(unsigned char *data, size_t len,
                        packetlen <<= 8;
                        packetlen |= data[offset++];
                }
+               /* Check the supplied length is within the remaining data */
+               if (packetlen == 0 || (packetlen + offset) > length) {
+                       return ONAK_E_INVALID_PKT;
+               }
                switch (data[offset] & 0x7F) {
                case OPENPGP_SIGSUB_CREATION:
                        /*