diff mbox

[-v5,2/4] cifs NTLMv2/NTLMSSP ntlmv2 within ntlmssp autentication code

Message ID 1284590224-5596-1-git-send-email-shirishpargaonkar@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Shirish Pargaonkar Sept. 15, 2010, 10:37 p.m. UTC
None
diff mbox

Patch

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index eed70ca..ab0533a 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 +263,92 @@  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 (blobptr + attrsize > blobend) {
+			cERROR(1, "%s: Invalid attribute size: %d",
+					__func__, attrsize);
+			return -EINVAL;
+		}
+		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 +408,8 @@  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 +421,29 @@  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 +454,14 @@  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:
+	kzfree(ses->tiblob);
+	ses->tilen = 0;
+
+	return rc;
 }
 
 void CalcNTLMv2_response(const struct cifsSesInfo *ses,
@@ -365,6 +475,9 @@  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 88c84a3..c99760a 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     */
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 8882012..42688ec 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -383,6 +383,9 @@  static int decode_ascii_ssetup(char **pbcc_area, int bleft,
 static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
 				    struct cifsSesInfo *ses)
 {
+	unsigned int tioffset; /* challenge message target info area */
+	unsigned int tilen; /* challenge message target info area length  */
+
 	CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
 
 	if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
@@ -405,6 +408,19 @@  static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
 	/* BB spec says that if AvId field of MsvAvTimestamp is populated then
 		we must set the MIC field of the AUTHENTICATE_MESSAGE */
 
+	tioffset = cpu_to_le16(pblob->TargetInfoArray.BufferOffset);
+	tilen = cpu_to_le16(pblob->TargetInfoArray.Length);
+	ses->tilen = tilen;
+	if (ses->tilen) {
+		ses->tiblob = kmalloc(tilen, GFP_KERNEL);
+		if (!ses->tiblob) {
+			cERROR(1, "Challenge target info allocation failure");
+			ses->tilen = 0;
+			return -ENOMEM;
+		}
+		memcpy(ses->tiblob,  bcc_ptr + tioffset, ses->tilen);
+	}
+
 	return 0;
 }
 
@@ -425,7 +441,7 @@  static void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
 	/* BB is NTLMV2 session security format easier to use here? */
 	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
-		NTLMSSP_NEGOTIATE_NT_ONLY | NTLMSSP_NEGOTIATE_NTLM;
+		NTLMSSP_NEGOTIATE_NTLM;
 	if (ses->server->secMode &
 	   (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 		flags |= NTLMSSP_NEGOTIATE_SIGN;
@@ -449,12 +465,14 @@  static void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
    This function returns the length of the data in the blob */
 static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 				   struct cifsSesInfo *ses,
-				   const struct nls_table *nls_cp, bool first)
+				   const struct nls_table *nls_cp)
 {
+	int rc;
+	unsigned int size;
 	AUTHENTICATE_MESSAGE *sec_blob = (AUTHENTICATE_MESSAGE *)pbuffer;
 	__u32 flags;
 	unsigned char *tmp;
-	char ntlm_session_key[CIFS_SESS_KEY_SIZE];
+	struct ntlmv2_resp ntlmv2_response = {};
 
 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 	sec_blob->MessageType = NtLmAuthenticate;
@@ -462,7 +480,7 @@  static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 	flags = NTLMSSP_NEGOTIATE_56 |
 		NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO |
 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
-		NTLMSSP_NEGOTIATE_NT_ONLY | NTLMSSP_NEGOTIATE_NTLM;
+		NTLMSSP_NEGOTIATE_NTLM;
 	if (ses->server->secMode &
 	   (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 		flags |= NTLMSSP_NEGOTIATE_SIGN;
@@ -477,19 +495,25 @@  static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 	sec_blob->LmChallengeResponse.Length = 0;
 	sec_blob->LmChallengeResponse.MaximumLength = 0;
 
-	/* calculate session key,  BB what about adding similar ntlmv2 path? */
-	SMBNTencrypt(ses->password, ses->server->cryptKey, ntlm_session_key);
-	if (first)
-		cifs_calculate_session_key(&ses->server->session_key,
-				       ntlm_session_key, ses->password);
-
-	memcpy(tmp, ntlm_session_key, CIFS_SESS_KEY_SIZE);
 	sec_blob->NtChallengeResponse.BufferOffset = cpu_to_le32(tmp - pbuffer);
-	sec_blob->NtChallengeResponse.Length = cpu_to_le16(CIFS_SESS_KEY_SIZE);
-	sec_blob->NtChallengeResponse.MaximumLength =
-				cpu_to_le16(CIFS_SESS_KEY_SIZE);
+	rc = setup_ntlmv2_rsp(ses, (char *)&ntlmv2_response, nls_cp);
+	if (rc) {
+		cERROR(1, "Error %d during NTLMSSP authentication", rc);
+		goto setup_ntlmv2_ret;
+	}
+	size =  sizeof(struct ntlmv2_resp);
+	memcpy(tmp, (char *)&ntlmv2_response, size);
+	tmp += size;
+	if (ses->tilen > 0) {
+		memcpy(tmp, ses->tiblob, ses->tilen);
+		tmp += ses->tilen;
+	}
 
-	tmp += CIFS_SESS_KEY_SIZE;
+	sec_blob->NtChallengeResponse.Length = cpu_to_le16(size + ses->tilen);
+	sec_blob->NtChallengeResponse.MaximumLength =
+				cpu_to_le16(size + ses->tilen);
+	kzfree(ses->tiblob);
+	ses->tilen = 0;
 
 	if (ses->domainName == NULL) {
 		sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
@@ -501,7 +525,6 @@  static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 		len = cifs_strtoUCS((__le16 *)tmp, ses->domainName,
 				    MAX_USERNAME_SIZE, nls_cp);
 		len *= 2; /* unicode is 2 bytes each */
-		len += 2; /* trailing null */
 		sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 		sec_blob->DomainName.Length = cpu_to_le16(len);
 		sec_blob->DomainName.MaximumLength = cpu_to_le16(len);
@@ -518,7 +541,6 @@  static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 		len = cifs_strtoUCS((__le16 *)tmp, ses->userName,
 				    MAX_USERNAME_SIZE, nls_cp);
 		len *= 2; /* unicode is 2 bytes each */
-		len += 2; /* trailing null */
 		sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 		sec_blob->UserName.Length = cpu_to_le16(len);
 		sec_blob->UserName.MaximumLength = cpu_to_le16(len);
@@ -533,6 +555,8 @@  static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 	sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
 	sec_blob->SessionKey.Length = 0;
 	sec_blob->SessionKey.MaximumLength = 0;
+
+setup_ntlmv2_ret:
 	return tmp - pbuffer;
 }
 
@@ -545,19 +569,6 @@  static void setup_ntlmssp_neg_req(SESSION_SETUP_ANDX *pSMB,
 
 	return;
 }
-
-static int setup_ntlmssp_auth_req(SESSION_SETUP_ANDX *pSMB,
-				  struct cifsSesInfo *ses,
-				  const struct nls_table *nls, bool first_time)
-{
-	int bloblen;
-
-	bloblen = build_ntlmssp_auth_blob(&pSMB->req.SecurityBlob[0], ses, nls,
-					  first_time);
-	pSMB->req.SecurityBlobLength = cpu_to_le16(bloblen);
-
-	return bloblen;
-}
 #endif
 
 int
@@ -580,6 +591,8 @@  CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
 	struct key *spnego_key = NULL;
 	__le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
 	bool first_time;
+	int blob_len;
+	char *ntlmsspblob = NULL;
 
 	if (ses == NULL)
 		return -EINVAL;
@@ -641,6 +654,19 @@  ssetup_ntlmssp_authenticate:
 	}
 	bcc_ptr = str_area;
 
+	/* 5 is an empirical value, large enought to
+	 * hold authenticate message, max 10 of
+	 * av paris, doamin,user,workstation mames,
+	 * flags etc..
+	 */
+	ntlmsspblob = kmalloc(5 * sizeof(struct _AUTHENTICATE_MESSAGE),
+					GFP_KERNEL);
+	if (!ntlmsspblob) {
+		cERROR(1, "Can't allocate NTLMSSP response");
+		rc = -ENOMEM;
+		goto ssetup_exit;
+	}
+
 	ses->flags &= ~CIFS_SES_LANMAN;
 
 	iov[1].iov_base = NULL;
@@ -729,12 +755,22 @@  ssetup_ntlmssp_authenticate:
 			cpu_to_le16(sizeof(struct ntlmv2_resp));
 
 		/* calculate session key */
-		setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
-		/* FIXME: calculate MAC key */
+		rc = setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
+		if (rc) {
+			cERROR(1, "Error %d during NTLMv2 authentication", rc);
+			kfree(v2_sess_key);
+			goto ssetup_exit;
+		}
 		memcpy(bcc_ptr, (char *)v2_sess_key,
-		       sizeof(struct ntlmv2_resp));
+				sizeof(struct ntlmv2_resp));
 		bcc_ptr += sizeof(struct ntlmv2_resp);
 		kfree(v2_sess_key);
+		if (ses->tilen > 0) {
+			memcpy(bcc_ptr, ses->tiblob, ses->tilen);
+			bcc_ptr += ses->tilen;
+			kzfree(ses->tiblob);
+			ses->tilen = 0;
+		}
 		if (ses->capabilities & CAP_UNICODE) {
 			if (iov[0].iov_len % 2) {
 				*bcc_ptr = 0;
@@ -815,12 +851,14 @@  ssetup_ntlmssp_authenticate:
 			if (phase == NtLmNegotiate) {
 				setup_ntlmssp_neg_req(pSMB, ses);
 				iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
+				iov[1].iov_base = &pSMB->req.SecurityBlob[0];
 			} else if (phase == NtLmAuthenticate) {
-				int blob_len;
-				blob_len = setup_ntlmssp_auth_req(pSMB, ses,
-								  nls_cp,
-								  first_time);
+				blob_len = build_ntlmssp_auth_blob(ntlmsspblob,
+							ses, nls_cp);
 				iov[1].iov_len = blob_len;
+				iov[1].iov_base = ntlmsspblob;
+				pSMB->req.SecurityBlobLength =
+					cpu_to_le16(blob_len);
 				/* Make sure that we tell the server that we
 				   are using the uid that it just gave us back
 				   on the response (challenge) */
@@ -830,7 +868,6 @@  ssetup_ntlmssp_authenticate:
 				rc = -ENOSYS;
 				goto ssetup_exit;
 			}
-			iov[1].iov_base = &pSMB->req.SecurityBlob[0];
 			/* unicode strings must be word aligned */
 			if ((iov[0].iov_len + iov[1].iov_len) % 2) {
 				*bcc_ptr = 0;
@@ -931,6 +968,7 @@  ssetup_exit:
 		key_put(spnego_key);
 	}
 	kfree(str_area);
+	kfree(ntlmsspblob);
 	if (resp_buf_type == CIFS_SMALL_BUFFER) {
 		cFYI(1, "ssetup freeing small buf %p", iov[0].iov_base);
 		cifs_small_buf_release(iov[0].iov_base);