[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>
This commit is contained in:
Steve French 2007-11-16 23:37:35 +00:00
parent 8840dee9dc
commit 2442421b17
4 changed files with 77 additions and 18 deletions

View File

@ -1,6 +1,7 @@
Version 1.52
------------
Fix oops on second mount to server when null auth is used.
Enable experimental Kerberos support
Version 1.51
------------

View File

@ -16,7 +16,7 @@ SecurityDescriptors
c) Better pam/winbind integration (e.g. to handle uid mapping
better)
d) Kerberos/SPNEGO session setup support - (started)
d) Verify that Kerberos signing works
e) Cleanup now unneeded SessSetup code in
fs/cifs/connect.c and add back in NTLMSSP code if any servers

View File

@ -110,6 +110,7 @@ struct mac_key {
unsigned int len;
union {
char ntlm[CIFS_SESS_KEY_SIZE + 16];
char krb5[CIFS_SESS_KEY_SIZE + 16]; /* BB: length correct? */
struct {
char key[16];
struct ntlmv2_resp resp;

View File

@ -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 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
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 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
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 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
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 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
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 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
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));