+/* Build a proper attribute value/target info pairs blob.
+ * Fill in netbios and dns domain name and workstation name
+ * and client time (total five av pairs and + one end of fields indicator.
+ * Allocate domain name which gets freed when session struct is deallocated.
+ */
+static int
+build_avpair_blob(struct cifsSesInfo *ses, const struct nls_table *nls_cp)
+{
+ unsigned int dlen;
+ unsigned int wlen;
+ unsigned int size = 6 * sizeof(struct ntlmssp2_name);
+ __le64 curtime;
+ char *defdmname = "WORKGROUP";
+ unsigned char *blobptr;
+ struct ntlmssp2_name *attrptr;
+
+ if (!ses->domainName) {
+ ses->domainName = kstrdup(defdmname, GFP_KERNEL);
+ if (!ses->domainName)
+ return -ENOMEM;
+ }
+
+ dlen = strlen(ses->domainName);
+ wlen = strlen(ses->server->hostname);
+
+ /* The length of this blob is a size which is
+ * six times the size of a structure which holds name/size +
+ * two times the unicode length of a domain name +
+ * two times the unicode length of a server name +
+ * size of a timestamp (which is 8 bytes).
+ */
+ ses->auth_key.len = size + 2 * (2 * dlen) + 2 * (2 * wlen) + 8;
+ ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL);
+ if (!ses->auth_key.response) {
+ ses->auth_key.len = 0;
+ cERROR(1, "Challenge target info allocation failure");
+ return -ENOMEM;
+ }
+
+ blobptr = ses->auth_key.response;
+ attrptr = (struct ntlmssp2_name *) blobptr;
+
+ attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME);
+ attrptr->length = cpu_to_le16(2 * dlen);
+ blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
+ cifs_strtoUCS((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
+
+ blobptr += 2 * dlen;
+ attrptr = (struct ntlmssp2_name *) blobptr;
+
+ attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_COMPUTER_NAME);
+ attrptr->length = cpu_to_le16(2 * wlen);
+ blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
+ cifs_strtoUCS((__le16 *)blobptr, ses->server->hostname, wlen, nls_cp);
+
+ blobptr += 2 * wlen;
+ attrptr = (struct ntlmssp2_name *) blobptr;
+
+ attrptr->type = cpu_to_le16(NTLMSSP_AV_DNS_DOMAIN_NAME);
+ attrptr->length = cpu_to_le16(2 * dlen);
+ blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
+ cifs_strtoUCS((__le16 *)blobptr, ses->domainName, dlen, nls_cp);
+
+ blobptr += 2 * dlen;
+ attrptr = (struct ntlmssp2_name *) blobptr;
+
+ attrptr->type = cpu_to_le16(NTLMSSP_AV_DNS_COMPUTER_NAME);
+ attrptr->length = cpu_to_le16(2 * wlen);
+ blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
+ cifs_strtoUCS((__le16 *)blobptr, ses->server->hostname, wlen, nls_cp);
+
+ blobptr += 2 * wlen;
+ attrptr = (struct ntlmssp2_name *) blobptr;
+
+ attrptr->type = cpu_to_le16(NTLMSSP_AV_TIMESTAMP);
+ attrptr->length = cpu_to_le16(sizeof(__le64));
+ blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name);
+ curtime = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
+ memcpy(blobptr, &curtime, sizeof(__le64));
+
+ return 0;
+}
+
+/* Server has provided av pairs/target info in the type 2 challenge
+ * packet and we have plucked it and stored within smb session.
+ * We parse that blob here to find netbios domain name to be used
+ * as part of ntlmv2 authentication (in Target String), if not already
+ * specified on the command line.
+ * If this function returns without any error but without fetching
+ * domain name, authentication may fail against some server but
+ * may not fail against other (those who are not very particular
+ * about target string i.e. for some, just user name might suffice.
+ */
+static int
+find_domain_name(struct cifsSesInfo *ses, const struct nls_table *nls_cp)
+{
+ unsigned int attrsize;
+ unsigned int type;
+ unsigned int onesize = sizeof(struct ntlmssp2_name);
+ unsigned char *blobptr;
+ unsigned char *blobend;
+ struct ntlmssp2_name *attrptr;
+
+ if (!ses->auth_key.len || !ses->auth_key.response)
+ return 0;
+
+ blobptr = ses->auth_key.response;
+ blobend = blobptr + ses->auth_key.len;
+
+ while (blobptr + onesize < blobend) {
+ attrptr = (struct ntlmssp2_name *) blobptr;
+ type = le16_to_cpu(attrptr->type);
+ if (type == NTLMSSP_AV_EOL)
+ break;
+ blobptr += 2; /* advance attr type */
+ attrsize = le16_to_cpu(attrptr->length);
+ blobptr += 2; /* advance attr size */
+ if (blobptr + attrsize > blobend)
+ break;
+ if (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
+ if (!attrsize)
+ break;
+ if (!ses->domainName) {
+ ses->domainName =
+ kmalloc(attrsize + 1, GFP_KERNEL);
+ if (!ses->domainName)
+ return -ENOMEM;
+ cifs_from_ucs2(ses->domainName,
+ (__le16 *)blobptr, attrsize, attrsize,
+ nls_cp, false);
+ break;
+ }
+ }
+ blobptr += attrsize; /* advance attr value */
+ }
+
+ return 0;
+}
+
+static int calc_ntlmv2_hash(struct cifsSesInfo *ses, char *ntlmv2_hash,