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cifs: consolidate signature generating code
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We have two versions of signature generating code. A vectorized and
non-vectorized version. Eliminate a large chunk of cut-and-paste
code by turning the non-vectorized version into a wrapper around the
vectorized one.

Signed-off-by: Jeff Layton <[email protected]>
Signed-off-by: Steve French <[email protected]>
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@jtlayton @smfrench
jtlayton authored and smfrench committed Oct 13, 2011
1 parent 376b43f commit 826a95e
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Showing 3 changed files with 30 additions and 86 deletions.
103 changes: 21 additions & 82 deletions fs/cifs/cifsencrypt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -37,83 +37,8 @@
* the sequence number before this function is called. Also, this function
* should be called with the server->srv_mutex held.
*/
static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu,
struct TCP_Server_Info *server, char *signature)
{
int rc;

if (cifs_pdu == NULL || signature == NULL || server == NULL)
return -EINVAL;

if (!server->secmech.sdescmd5) {
cERROR(1, "%s: Can't generate signature\n", __func__);
return -1;
}

rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
if (rc) {
cERROR(1, "%s: Could not init md5\n", __func__);
return rc;
}

rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
server->session_key.response, server->session_key.len);
if (rc) {
cERROR(1, "%s: Could not update with response\n", __func__);
return rc;
}

rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
cifs_pdu->Protocol, be32_to_cpu(cifs_pdu->smb_buf_length));
if (rc) {
cERROR(1, "%s: Could not update with payload\n", __func__);
return rc;
}

rc = crypto_shash_final(&server->secmech.sdescmd5->shash, signature);
if (rc)
cERROR(1, "%s: Could not generate md5 hash\n", __func__);

return rc;
}

/* must be called with server->srv_mutex held */
int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
__u32 *pexpected_response_sequence_number)
{
int rc = 0;
char smb_signature[20];

if ((cifs_pdu == NULL) || (server == NULL))
return -EINVAL;

if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
server->tcpStatus == CifsNeedNegotiate)
return rc;

if (!server->session_estab) {
memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);
return rc;
}

cifs_pdu->Signature.Sequence.SequenceNumber =
cpu_to_le32(server->sequence_number);
cifs_pdu->Signature.Sequence.Reserved = 0;

*pexpected_response_sequence_number = server->sequence_number++;
server->sequence_number++;

rc = cifs_calculate_signature(cifs_pdu, server, smb_signature);
if (rc)
memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
else
memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);

return rc;
}

static int cifs_calc_signature2(const struct kvec *iov, int n_vec,
struct TCP_Server_Info *server, char *signature)
static int cifs_calc_signature(const struct kvec *iov, int n_vec,
struct TCP_Server_Info *server, char *signature)
{
int i;
int rc;
Expand Down Expand Up @@ -179,7 +104,7 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
{
int rc = 0;
char smb_signature[20];
struct smb_hdr *cifs_pdu = iov[0].iov_base;
struct smb_hdr *cifs_pdu = (struct smb_hdr *)iov[0].iov_base;

if ((cifs_pdu == NULL) || (server == NULL))
return -EINVAL;
Expand All @@ -200,7 +125,7 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
*pexpected_response_sequence_number = server->sequence_number++;
server->sequence_number++;

rc = cifs_calc_signature2(iov, n_vec, server, smb_signature);
rc = cifs_calc_signature(iov, n_vec, server, smb_signature);
if (rc)
memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
else
Expand All @@ -209,13 +134,27 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
return rc;
}

int cifs_verify_signature(struct smb_hdr *cifs_pdu,
/* must be called with server->srv_mutex held */
int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
__u32 *pexpected_response_sequence_number)
{
struct kvec iov;

iov.iov_base = cifs_pdu;
iov.iov_len = be32_to_cpu(cifs_pdu->smb_buf_length) + 4;

return cifs_sign_smb2(&iov, 1, server,
pexpected_response_sequence_number);
}

int cifs_verify_signature(struct kvec *iov, unsigned int nr_iov,
struct TCP_Server_Info *server,
__u32 expected_sequence_number)
{
unsigned int rc;
char server_response_sig[8];
char what_we_think_sig_should_be[20];
struct smb_hdr *cifs_pdu = (struct smb_hdr *)iov[0].iov_base;

if (cifs_pdu == NULL || server == NULL)
return -EINVAL;
Expand Down Expand Up @@ -247,8 +186,8 @@ int cifs_verify_signature(struct smb_hdr *cifs_pdu,
cifs_pdu->Signature.Sequence.Reserved = 0;

mutex_lock(&server->srv_mutex);
rc = cifs_calculate_signature(cifs_pdu, server,
what_we_think_sig_should_be);
rc = cifs_calc_signature(iov, nr_iov, server,
what_we_think_sig_should_be);
mutex_unlock(&server->srv_mutex);

if (rc)
Expand Down
2 changes: 1 addition & 1 deletion fs/cifs/cifsproto.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -380,7 +380,7 @@ extern void tconInfoFree(struct cifs_tcon *);
extern int cifs_sign_smb(struct smb_hdr *, struct TCP_Server_Info *, __u32 *);
extern int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *,
__u32 *);
extern int cifs_verify_signature(struct smb_hdr *,
extern int cifs_verify_signature(struct kvec *iov, unsigned int nr_iov,
struct TCP_Server_Info *server,
__u32 expected_sequence_number);
extern int SMBNTencrypt(unsigned char *, unsigned char *, unsigned char *);
Expand Down
11 changes: 8 additions & 3 deletions fs/cifs/transport.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -496,13 +496,18 @@ int
cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
bool log_error)
{
dump_smb(mid->resp_buf,
min_t(u32, 92, be32_to_cpu(mid->resp_buf->smb_buf_length)));
unsigned int len = be32_to_cpu(mid->resp_buf->smb_buf_length) + 4;

dump_smb(mid->resp_buf, min_t(u32, 92, len));

/* convert the length into a more usable form */
if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
struct kvec iov;

iov.iov_base = mid->resp_buf;
iov.iov_len = len;
/* FIXME: add code to kill session */
if (cifs_verify_signature(mid->resp_buf, server,
if (cifs_verify_signature(&iov, 1, server,
mid->sequence_number + 1) != 0)
cERROR(1, "Unexpected SMB signature");
}
Expand Down

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