[-v3,2/4,cifs] NTLMv2/NTLMSSP ntlmv2 within ntlmssp autentication code
diff mbox

Message ID 1284405322-31202-1-git-send-email-shirishpargaonkar@gmail.com
State New, archived
Headers show

Commit Message

Shirish Pargaonkar Sept. 13, 2010, 7:15 p.m. UTC
None

Patch
diff mbox

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index eed70ca..960c948 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -27,6 +27,7 @@ 
 #include "md5.h"
 #include "cifs_unicode.h"
 #include "cifsproto.h"
+#include "ntlmssp.h"
 #include <linux/ctype.h>
 #include <linux/random.h>
 
@@ -262,6 +263,87 @@  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
+ */
+static int
+build_avpair_blob(struct cifsSesInfo *ses)
+{
+	struct ntlmssp2_name *attrptr;
+
+	ses->tilen = 2 * sizeof(struct ntlmssp2_name);
+	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);
+
+	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)
+{
+	unsigned int attrsize;
+	unsigned int type;
+	unsigned char *blobptr;
+	unsigned char *blobend;
+	struct ntlmssp2_name *attrptr;
+
+	if (!ses->tilen || !ses->tiblob)
+		return 0;
+
+	if (ses->tilen < sizeof(struct ntlmssp2_name))
+		return 0;
+
+	blobend = ses->tiblob + ses->tilen;
+	blobptr = ses->tiblob;
+	attrptr = (struct ntlmssp2_name *) blobptr;
+
+	while (blobptr <= blobend) {
+		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 (type == NTLMSSP_AV_NB_DOMAIN_NAME) {
+			if (!ses->domainName) {
+				ses->domainName =
+					kmalloc(attrsize + 1, GFP_KERNEL);
+				if (!ses->domainName)
+						return -ENOMEM;
+				cifs_from_ucs2(ses->domainName,
+					(__le16 *)blobptr,
+					attrptr->length,
+					attrptr->length,
+					load_nls_default(), false);
+			}
+		}
+		blobptr += attrsize; /* advance attr  value */
+		attrptr = (struct ntlmssp2_name *) blobptr;
+	}
+
+	return 0;
+}
+
 static int calc_ntlmv2_hash(struct cifsSesInfo *ses,
 			    const struct nls_table *nls_cp)
 {
@@ -321,7 +403,8 @@  calc_exit_2:
 	return rc;
 }
 
-void setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
+int
+setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
 		      const struct nls_table *nls_cp)
 {
 	int rc;
@@ -333,15 +416,29 @@  void setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
 	buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
 	get_random_bytes(&buf->client_chal, sizeof(buf->client_chal));
 	buf->reserved2 = 0;
-	buf->names[0].type = cpu_to_le16(NTLMSSP_DOMAIN_TYPE);
-	buf->names[0].length = 0;
-	buf->names[1].type = 0;
-	buf->names[1].length = 0;
+
+	if (ses->server->secType == RawNTLMSSP) {
+		if (!ses->domainName) {
+			rc = find_domain_name(ses);
+			if (rc) {
+				cERROR(1, "error %d finding domain name", rc);
+				goto setup_ntlmv2_rsp_ret;
+			}
+		}
+	} else {
+		rc = build_avpair_blob(ses);
+		if (rc) {
+			cERROR(1, "error %d building av pair blob", rc);
+			return rc;
+		}
+	}
 
 	/* calculate buf->ntlmv2_hash */
 	rc = calc_ntlmv2_hash(ses, nls_cp);
-	if (rc)
+	if (rc) {
 		cERROR(1, "could not get v2 hash rc %d", rc);
+		goto setup_ntlmv2_rsp_ret;
+	}
 	CalcNTLMv2_response(ses, resp_buf);
 
 	/* now calculate the MAC key for NTLMv2 */
@@ -352,6 +449,14 @@  void setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
 	memcpy(&ses->server->session_key.data.ntlmv2.resp, resp_buf,
 	       sizeof(struct ntlmv2_resp));
 	ses->server->session_key.len = 16 + sizeof(struct ntlmv2_resp);
+
+	return 0;
+
+setup_ntlmv2_rsp_ret:
+	kfree(ses->tiblob);
+	ses->tilen = 0;
+
+	return rc;
 }
 
 void CalcNTLMv2_response(const struct cifsSesInfo *ses,
@@ -365,6 +470,10 @@  void CalcNTLMv2_response(const struct cifsSesInfo *ses,
 	hmac_md5_update(v2_session_response+8,
 			sizeof(struct ntlmv2_resp) - 8, &context);
 
+	if (ses->tilen)
+		hmac_md5_update(ses->tiblob,
+			ses->tilen, &context);
+
 	hmac_md5_final(v2_session_response, &context);
 /*	cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */
 }
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 14dfa9a..c68f31c 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -222,6 +222,8 @@  struct cifsSesInfo {
 	char userName[MAX_USERNAME_SIZE + 1];
 	char *domainName;
 	char *password;
+	unsigned int tilen; /* length of the target info blob */
+	unsigned char *tiblob; /* target info blob in challenge response */
 	bool need_reconnect:1; /* connection reset, uid now invalid */
 };
 /* no more than one of the following three session flags may be set */
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index 14d036d..b0f4b56 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -663,7 +663,6 @@  struct ntlmv2_resp {
 	__le64  time;
 	__u64  client_chal; /* random */
 	__u32  reserved2;
-	struct ntlmssp2_name names[2];
 	/* array of name entries could follow ending in minimum 4 byte struct */
 } __attribute__((packed));
 
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 3f4fa81..c155479 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -367,7 +367,7 @@  extern int cifs_verify_signature(struct smb_hdr *,
 extern int cifs_calculate_session_key(struct session_key *key, const char *rn,
 				 const char *pass);
 extern void CalcNTLMv2_response(const struct cifsSesInfo *, char *);
-extern void setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
+extern int setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
 			     const struct nls_table *);
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 extern void calc_lanman_hash(const char *password, const char *cryptkey,
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index c65c341..13c854e 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -603,13 +603,15 @@  CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 				rc = 0;
 			else
 				rc = -EINVAL;
-
-			if (server->sec_kerberos || server->sec_mskerberos)
-				server->secType = Kerberos;
-			else if (server->sec_ntlmssp)
-				server->secType = RawNTLMSSP;
-			else
-				rc = -EOPNOTSUPP;
+			if (server->secType == Kerberos) {
+				if (!server->sec_kerberos &&
+						!server->sec_mskerberos)
+					rc = -EOPNOTSUPP;
+			} else if (server->secType == RawNTLMSSP) {
+				if (!server->sec_ntlmssp)
+					rc = -EOPNOTSUPP;
+			} else
+					rc = -EOPNOTSUPP;
 		}
 	} else
 		server->capabilities &= ~CAP_EXTENDED_SECURITY;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 67dad54..f8891a2 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1740,6 +1740,8 @@  cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb_vol *volume_info)
 	if (ses == NULL)
 		goto get_ses_fail;
 
+	ses->tilen = 0;
+	ses->tiblob = NULL;
 	/* new SMB session uses our server ref */
 	ses->server = server;
 	if (server->addr.sockAddr6.sin6_family == AF_INET6)
diff --git a/fs/cifs/ntlmssp.h b/fs/cifs/ntlmssp.h
index 49c9a4e..5d52e4a 100644
--- a/fs/cifs/ntlmssp.h
+++ b/fs/cifs/ntlmssp.h
@@ -61,6 +61,21 @@ 
 #define NTLMSSP_NEGOTIATE_KEY_XCH   0x40000000
 #define NTLMSSP_NEGOTIATE_56        0x80000000
 
+/* Define AV Pair Field IDs */
+enum av_field_type {
+	NTLMSSP_AV_EOL = 0,
+	NTLMSSP_AV_NB_COMPUTER_NAME,
+	NTLMSSP_AV_NB_DOMAIN_NAME,
+	NTLMSSP_AV_DNS_COMPUTER_NAME,
+	NTLMSSP_AV_DNS_DOMAIN_NAME,
+	NTLMSSP_AV_DNS_TREE_NAME,
+	NTLMSSP_AV_FLAGS,
+	NTLMSSP_AV_TIMESTAMP,
+	NTLMSSP_AV_RESTRICTION,
+	NTLMSSP_AV_TARGET_NAME,
+	NTLMSSP_AV_CHANNEL_BINDINGS
+};
+
 /* Although typedefs are not commonly used for structure definitions */
 /* in the Linux kernel, in this particular case they are useful      */
 /* to more closely match the standards document for NTLMSSP from     */