[CIFS] Have CIFS_SessSetup build correct SPNEGO SessionSetup request
Have CIFS_SessSetup call cifs_get_spnego_key when Kerberos is
negotiated. Use the info in the key payload to build a session
setup request packet. Also clean up how the request buffer in
the function is freed on error.
With appropriate user space helper (in samba/source/client). Kerberos
support (secure session establishment can be done now via Kerberos,
previously users would have to use NTLMv2 instead for more secure
session setup).
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index ed01ef3..d0cb469 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -29,6 +29,7 @@
#include "ntlmssp.h"
#include "nterr.h"
#include <linux/utsname.h>
+#include "cifs_spnego.h"
extern void SMBNTencrypt(unsigned char *passwd, unsigned char *c8,
unsigned char *p24);
@@ -340,11 +341,12 @@
SESSION_SETUP_ANDX *pSMB;
__u32 capabilities;
int count;
- int resp_buf_type = 0;
- struct kvec iov[2];
+ int resp_buf_type;
+ struct kvec iov[3];
enum securityEnum type;
__u16 action;
int bytes_remaining;
+ struct key *spnego_key = NULL;
if (ses == NULL)
return -EINVAL;
@@ -377,24 +379,32 @@
capabilities = cifs_ssetup_hdr(ses, pSMB);
- /* we will send the SMB in two pieces,
- a fixed length beginning part, and a
- second part which will include the strings
- and rest of bcc area, in order to avoid having
- to do a large buffer 17K allocation */
+ /* we will send the SMB in three pieces:
+ a fixed length beginning part, an optional
+ SPNEGO blob (which can be zero length), and a
+ last part which will include the strings
+ and rest of bcc area. This allows us to avoid
+ a large buffer 17K allocation */
iov[0].iov_base = (char *)pSMB;
iov[0].iov_len = smb_buf->smb_buf_length + 4;
+ /* setting this here allows the code at the end of the function
+ to free the request buffer if there's an error */
+ resp_buf_type = CIFS_SMALL_BUFFER;
+
/* 2000 big enough to fit max user, domain, NOS name etc. */
str_area = kmalloc(2000, GFP_KERNEL);
if (str_area == NULL) {
- cifs_small_buf_release(smb_buf);
- return -ENOMEM;
+ rc = -ENOMEM;
+ goto ssetup_exit;
}
bcc_ptr = str_area;
ses->flags &= ~CIFS_SES_LANMAN;
+ iov[1].iov_base = NULL;
+ iov[1].iov_len = 0;
+
if (type == LANMAN) {
#ifdef CONFIG_CIFS_WEAK_PW_HASH
char lnm_session_key[CIFS_SESS_KEY_SIZE];
@@ -463,8 +473,8 @@
struct ntlmv2_resp */
if (v2_sess_key == NULL) {
- cifs_small_buf_release(smb_buf);
- return -ENOMEM;
+ rc = -ENOMEM;
+ goto ssetup_exit;
}
pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
@@ -499,21 +509,66 @@
unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
} else
ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
- } else /* NTLMSSP or SPNEGO */ {
+ } else if (type == Kerberos) {
+#ifdef CONFIG_CIFS_UPCALL
+ struct cifs_spnego_msg *msg;
+ spnego_key = cifs_get_spnego_key(ses);
+ if (IS_ERR(spnego_key)) {
+ rc = PTR_ERR(spnego_key);
+ spnego_key = NULL;
+ goto ssetup_exit;
+ }
+
+ msg = spnego_key->payload.data;
+ /* bail out if key is too long */
+ if (msg->sesskey_len >
+ sizeof(ses->server->mac_signing_key.data.krb5)) {
+ cERROR(1, ("Kerberos signing key too long (%u bytes)",
+ msg->sesskey_len));
+ rc = -EOVERFLOW;
+ goto ssetup_exit;
+ }
+ ses->server->mac_signing_key.len = msg->sesskey_len;
+ memcpy(ses->server->mac_signing_key.data.krb5, msg->data,
+ msg->sesskey_len);
pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
capabilities |= CAP_EXTENDED_SECURITY;
pSMB->req.Capabilities = cpu_to_le32(capabilities);
- /* BB set password lengths */
+ iov[1].iov_base = msg->data + msg->sesskey_len;
+ iov[1].iov_len = msg->secblob_len;
+ pSMB->req.SecurityBlobLength = cpu_to_le16(iov[1].iov_len);
+
+ if (ses->capabilities & CAP_UNICODE) {
+ /* unicode strings must be word aligned */
+ if (iov[0].iov_len % 2) {
+ *bcc_ptr = 0;
+ bcc_ptr++;
+ }
+ unicode_oslm_strings(&bcc_ptr, nls_cp);
+ unicode_domain_string(&bcc_ptr, ses, nls_cp);
+ } else
+ /* BB: is this right? */
+ ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
+#else /* ! CONFIG_CIFS_UPCALL */
+ cERROR(1, ("Kerberos negotiated but upcall support disabled!"));
+ rc = -ENOSYS;
+ goto ssetup_exit;
+#endif /* CONFIG_CIFS_UPCALL */
+ } else {
+ cERROR(1, ("secType %d not supported!", type));
+ rc = -ENOSYS;
+ goto ssetup_exit;
}
- count = (long) bcc_ptr - (long) str_area;
+ iov[2].iov_base = str_area;
+ iov[2].iov_len = (long) bcc_ptr - (long) str_area;
+
+ count = iov[1].iov_len + iov[2].iov_len;
smb_buf->smb_buf_length += count;
BCC_LE(smb_buf) = cpu_to_le16(count);
- iov[1].iov_base = str_area;
- iov[1].iov_len = count;
- rc = SendReceive2(xid, ses, iov, 2 /* num_iovecs */, &resp_buf_type,
+ rc = SendReceive2(xid, ses, iov, 3 /* num_iovecs */, &resp_buf_type,
CIFS_STD_OP /* not long */ | CIFS_LOG_ERROR);
/* SMB request buf freed in SendReceive2 */
@@ -560,6 +615,8 @@
ses, nls_cp);
ssetup_exit:
+ if (spnego_key)
+ key_put(spnego_key);
kfree(str_area);
if (resp_buf_type == CIFS_SMALL_BUFFER) {
cFYI(1, ("ssetup freeing small buf %p", iov[0].iov_base));