From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
Build a av pair blob as part of ntlmv2 (without extended security) auth
request. Include netbios and dns names for domain and server and
a timestamp in the blob.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
---
fs/cifs/cifsencrypt.c | 77 ++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 66 insertions(+), 11 deletions(-)
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 730038a..6a1e50c 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -263,27 +263,82 @@ void calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
}
#endif /* CIFS_WEAK_PW_HASH */
-/* This is just a filler for ntlmv2 type of security mechanisms.
- * Older servers are not very particular about the contents of av pairs
- * in the blob and for sec mechs like ntlmv2, there is no negotiation
- * as in ntlmssp, so unless domain and server netbios and dns names
- * are specified, there is no way to obtain name. In case of ntlmssp,
- * server provides that info in type 2 challenge packet
+/* 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)
+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;
- ses->tilen = 2 * sizeof(struct ntlmssp2_name);
+ if (!ses->domainName)
+ ses->domainName = kstrdup(defdmname, GFP_KERNEL);
+
+ 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->tilen = size + 2 * (2 * dlen) + 2 * (2 * wlen) + 8;
ses->tiblob = kzalloc(ses->tilen, GFP_KERNEL);
if (!ses->tiblob) {
ses->tilen = 0;
cERROR(1, "Challenge target info allocation failure");
return -ENOMEM;
}
- attrptr = (struct ntlmssp2_name *) ses->tiblob;
- attrptr->type = cpu_to_le16(NTLMSSP_DOMAIN_TYPE);
+
+ blobptr = ses->tiblob;
+ 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;
}
@@ -426,7 +481,7 @@ setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
}
}
} else {
- rc = build_avpair_blob(ses);
+ rc = build_avpair_blob(ses, nls_cp);
if (rc) {
cERROR(1, "error %d building av pair blob", rc);
return rc;
--
1.6.0.2
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