+ /*
+ * < 0: decoding error
+ * >= 0 < 32: too short to be plausible
+ */
+ if ((result = from64tobits (&challenge, msgbuf, sizeof(challenge))) < 0
+ || result < 32)
+ {
+ report (stderr, GT_("could not decode BASE64 challenge\n"));
+ /* We do not goto cancelfail; the server has already sent the
+ * tagged reply, so the protocol exchange has ended, no need
+ * for us to send the asterisk. */
+ return PS_AUTHFAIL;
+ }
+
+ /* validate challenge:
+ * - ident
+ * - message type
+ * - that offset points into buffer
+ * - that offset + length does not wrap
+ * - that offset + length is not bigger than buffer */
+ if (0 != memcmp("NTLMSSP", challenge.ident, 8)
+ || challenge.msgType != 2
+ || challenge.uDomain.offset > (unsigned)result
+ || (challenge.uDomain.offset + challenge.uDomain.len) < challenge.uDomain.offset
+ || (challenge.uDomain.offset + challenge.uDomain.len) > (unsigned)result)
+ {
+ report (stderr, GT_("NTLM challenge contains invalid data.\n"));
+ result = PS_AUTHFAIL;
+ goto cancelfail;
+ }