@@ -9,6 +9,7 @@ config CIFS
select CRYPTO_ARC4
select CRYPTO_ECB
select CRYPTO_DES
+ select CRYPTO_SHA256
help
This is the client VFS module for the Common Internet File System
(CIFS) protocol which is the successor to the Server Message Block
@@ -686,12 +686,17 @@ calc_seckey(struct cifs_ses *ses)
void
cifs_crypto_shash_release(struct TCP_Server_Info *server)
{
+ if (server->secmech.hmacsha256)
+ crypto_free_shash(server->secmech.hmacsha256);
+
if (server->secmech.md5)
crypto_free_shash(server->secmech.md5);
if (server->secmech.hmacmd5)
crypto_free_shash(server->secmech.hmacmd5);
+ kfree(server->secmech.sdeschmacsha256);
+
kfree(server->secmech.sdeschmacmd5);
kfree(server->secmech.sdescmd5);
@@ -716,6 +721,13 @@ cifs_crypto_shash_allocate(struct TCP_Server_Info *server)
goto crypto_allocate_md5_fail;
}
+ server->secmech.hmacsha256 = crypto_alloc_shash("hmac(sha256)", 0, 0);
+ if (IS_ERR(server->secmech.hmacsha256)) {
+ cERROR(1, "could not allocate crypto hmacsha256\n");
+ rc = PTR_ERR(server->secmech.hmacsha256);
+ goto crypto_allocate_hmacsha256_fail;
+ }
+
size = sizeof(struct shash_desc) +
crypto_shash_descsize(server->secmech.hmacmd5);
server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
@@ -727,7 +739,6 @@ cifs_crypto_shash_allocate(struct TCP_Server_Info *server)
server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
server->secmech.sdeschmacmd5->shash.flags = 0x0;
-
size = sizeof(struct shash_desc) +
crypto_shash_descsize(server->secmech.md5);
server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
@@ -739,12 +750,29 @@ cifs_crypto_shash_allocate(struct TCP_Server_Info *server)
server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
server->secmech.sdescmd5->shash.flags = 0x0;
+ size = sizeof(struct shash_desc) +
+ crypto_shash_descsize(server->secmech.hmacsha256);
+ server->secmech.sdeschmacsha256 = kmalloc(size, GFP_KERNEL);
+ if (!server->secmech.sdeschmacsha256) {
+ cERROR(1, "%s: Can't alloc hmacsha256\n", __func__);
+ rc = -ENOMEM;
+ goto crypto_allocate_hmacsha256_sdesc_fail;
+ }
+ server->secmech.sdeschmacsha256->shash.tfm = server->secmech.hmacsha256;
+ server->secmech.sdeschmacsha256->shash.flags = 0x0;
+
return 0;
+crypto_allocate_hmacsha256_sdesc_fail:
+ kfree(server->secmech.sdescmd5);
+
crypto_allocate_md5_sdesc_fail:
kfree(server->secmech.sdeschmacmd5);
crypto_allocate_hmacmd5_sdesc_fail:
+ crypto_free_shash(server->secmech.hmacsha256);
+
+crypto_allocate_hmacsha256_fail:
crypto_free_shash(server->secmech.md5);
crypto_allocate_md5_fail:
@@ -128,8 +128,10 @@ struct sdesc {
struct cifs_secmech {
struct crypto_shash *hmacmd5; /* hmac-md5 hash function */
struct crypto_shash *md5; /* md5 hash function */
+ struct crypto_shash *hmacsha256; /* hmac-sha256 hash function */
struct sdesc *sdeschmacmd5; /* ctxt to generate ntlmv2 hash, CR1 */
struct sdesc *sdescmd5; /* ctxt to generate cifs/smb signature */
+ struct sdesc *sdeschmacsha256; /* ctxt to generate smb2 signature */
};
/* per smb session structure/fields */
@@ -65,6 +65,7 @@ extern char *cifs_compose_mount_options(const char *sb_mountdata,
extern struct mid_q_entry *AllocMidQEntry(const struct smb_hdr *smb_buffer,
struct TCP_Server_Info *server);
extern void DeleteMidQEntry(struct mid_q_entry *midEntry);
+extern void cifs_delete_mid(struct mid_q_entry *mid);
extern void cifs_wake_up_task(struct mid_q_entry *mid);
extern int cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
unsigned int nvec, mid_receive_t *receive,
@@ -47,4 +47,8 @@
#define END_OF_CHAIN 4
#define RELATED_REQUEST 8
+#define SMB2_SIGNATURE_SIZE (16)
+#define SMB2_NTLMV2_SESSKEY_SIZE (16)
+#define SMB2_HMACSHA256_SIZE (32)
+
#endif /* _SMB2_GLOB_H */
@@ -118,9 +118,9 @@ smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
/* BB how does SMB2 do case sensitive? */
/* if (tcon->nocase)
hdr->Flags |= SMBFLG_CASELESS; */
- /* if (tcon->ses && tcon->ses->server &&
+ if (tcon->ses && tcon->ses->server &&
(tcon->ses->server->sec_mode & SECMODE_SIGN_REQUIRED))
- hdr->Flags |= SMB2_FLAGS_SIGNED; */
+ hdr->Flags |= SMB2_FLAGS_SIGNED;
out:
pdu->StructureSize2 = cpu_to_le16(parmsize);
return;
@@ -441,6 +441,38 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
rc = -EIO;
goto neg_exit;
}
+
+ cFYI(1, "sec_flags 0x%x", sec_flags);
+ if (sec_flags & CIFSSEC_MUST_SIGN) {
+ cFYI(1, "Signing required");
+ if (!(server->sec_mode & (SMB2_NEGOTIATE_SIGNING_REQUIRED |
+ SMB2_NEGOTIATE_SIGNING_ENABLED))) {
+ cERROR(1, "signing required but server lacks support");
+ rc = -EOPNOTSUPP;
+ goto neg_exit;
+ }
+ server->sec_mode |= SECMODE_SIGN_REQUIRED;
+ } else if (sec_flags & CIFSSEC_MAY_SIGN) {
+ cFYI(1, "Signing optional");
+ if (server->sec_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED) {
+ cFYI(1, "Server requires signing");
+ server->sec_mode |= SECMODE_SIGN_REQUIRED;
+ } else {
+ server->sec_mode &=
+ ~(SECMODE_SIGN_ENABLED | SECMODE_SIGN_REQUIRED);
+ }
+ } else {
+ cFYI(1, "Signing disabled");
+ if (server->sec_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED) {
+ cERROR(1, "Server requires packet signing to be enabled"
+ " in /proc/fs/cifs/SecurityFlags.");
+ rc = -EOPNOTSUPP;
+ goto neg_exit;
+ }
+ server->sec_mode &=
+ ~(SECMODE_SIGN_ENABLED | SECMODE_SIGN_REQUIRED);
+ }
+
#ifdef CONFIG_SMB2_ASN1 /* BB REMOVEME when updated asn1.c ready */
rc = decode_neg_token_init(security_blob, blob_length,
&server->sec_type);
@@ -669,6 +701,8 @@ SMB2_logoff(const unsigned int xid, struct cifs_ses *ses)
/* since no tcon, smb2_init can not do this, so do here */
req->hdr.SessionId = ses->Suid;
+ if (server->sec_mode & SECMODE_SIGN_REQUIRED)
+ req->hdr.Flags |= SMB2_FLAGS_SIGNED;
rc = SendReceiveNoRsp(xid, ses, (char *) &req->hdr, 0);
/*
@@ -1268,10 +1302,12 @@ smb2_readv_callback(struct mid_q_entry *mid)
case MID_RESPONSE_RECEIVED:
credits_received = le16_to_cpu(buf->CreditRequest);
/* result already set, check signature */
- /* if (server->sec_mode &
- (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
- if (smb2_verify_signature(mid->resp_buf, server))
- cERROR(1, "Unexpected SMB signature"); */
+ if (server->sec_mode &
+ (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
+ if (smb2_verify_signature2(rdata->iov, rdata->nr_iov,
+ server))
+ cERROR(1, "Unexpected SMB signature");
+ }
/* FIXME: should this be counted toward the initiating task? */
task_io_account_read(rdata->bytes);
cifs_stats_bytes_read(tcon, rdata->bytes);
@@ -39,6 +39,8 @@ extern char *smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr);
extern __le16 *cifs_convert_path_to_utf16(const char *from,
struct cifs_sb_info *cifs_sb);
+extern int smb2_verify_signature2(struct kvec *, unsigned int,
+ struct TCP_Server_Info *);
extern int smb2_check_receive(struct mid_q_entry *mid,
struct TCP_Server_Info *server, bool log_error);
extern int smb2_setup_request(struct cifs_ses *ses, struct kvec *iov,
@@ -36,6 +36,149 @@
#include "smb2proto.h"
#include "cifs_debug.h"
#include "smb2status.h"
+#include "smb2glob.h"
+
+static int
+smb2_calc_signature2(const struct kvec *iov, int n_vec,
+ struct TCP_Server_Info *server)
+{
+ int i, rc;
+ unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
+ unsigned char *sigptr = smb2_signature;
+ struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
+
+ memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
+ memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);
+
+ rc = crypto_shash_setkey(server->secmech.hmacsha256,
+ server->session_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
+ if (rc) {
+ cERROR(1, "%s: Could not update with response\n", __func__);
+ return rc;
+ }
+
+ rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
+ if (rc) {
+ cERROR(1, "%s: Could not init md5\n", __func__);
+ return rc;
+ }
+
+ for (i = 0; i < n_vec; i++) {
+ if (iov[i].iov_len == 0)
+ continue;
+ if (iov[i].iov_base == NULL) {
+ cERROR(1, "null iovec entry");
+ return -EIO;
+ }
+ /*
+ * The first entry includes a length field (which does not get
+ * signed that occupies the first 4 bytes before the header).
+ */
+ if (i == 0) {
+ if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
+ break; /* nothing to sign or corrupt header */
+ rc =
+ crypto_shash_update(
+ &server->secmech.sdeschmacsha256->shash,
+ iov[i].iov_base + 4, iov[i].iov_len - 4);
+ } else {
+ rc =
+ crypto_shash_update(
+ &server->secmech.sdeschmacsha256->shash,
+ iov[i].iov_base, iov[i].iov_len);
+ }
+ if (rc) {
+ cERROR(1, "%s: Could not update with payload\n",
+ __func__);
+ return rc;
+ }
+ }
+
+ rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
+ sigptr);
+ if (rc)
+ cERROR(1, "%s: Could not generate sha256 hash\n", __func__);
+
+ memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
+
+ return rc;
+}
+
+/* must be called with server->srv_mutex held */
+static int
+smb2_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server)
+{
+ int rc = 0;
+ struct smb2_hdr *smb2_pdu = iov[0].iov_base;
+
+ if (!(smb2_pdu->Flags & SMB2_FLAGS_SIGNED) ||
+ server->tcpStatus == CifsNeedNegotiate)
+ return rc;
+
+ if (!server->session_estab) {
+ strncpy(smb2_pdu->Signature, "BSRSPYL", 8);
+ return rc;
+ }
+
+ rc = smb2_calc_signature2(iov, n_vec, server);
+
+ return rc;
+}
+
+int
+smb2_verify_signature2(struct kvec *iov, unsigned int n_vec,
+ struct TCP_Server_Info *server)
+{
+ unsigned int rc;
+ char server_response_sig[16];
+ struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
+
+ if ((smb2_pdu->Command == SMB2_NEGOTIATE) ||
+ (smb2_pdu->Command == SMB2_OPLOCK_BREAK) ||
+ (!server->session_estab))
+ return 0;
+
+ /*
+ * BB what if signatures are supposed to be on for session but
+ * server does not send one? BB
+ */
+
+ /* Do not need to verify session setups with signature "BSRSPYL " */
+ if (memcmp(smb2_pdu->Signature, "BSRSPYL ", 8) == 0)
+ cFYI(1, "dummy signature received for smb command 0x%x",
+ smb2_pdu->Command);
+
+ /*
+ * Save off the origiginal signature so we can modify the smb and check
+ * our calculated signature against what the server sent.
+ */
+ memcpy(server_response_sig, smb2_pdu->Signature, SMB2_SIGNATURE_SIZE);
+
+ memset(smb2_pdu->Signature, 0, SMB2_SIGNATURE_SIZE);
+
+ mutex_lock(&server->srv_mutex);
+ rc = smb2_calc_signature2(iov, n_vec, server);
+ mutex_unlock(&server->srv_mutex);
+
+ if (rc)
+ return rc;
+
+ if (memcmp(server_response_sig, smb2_pdu->Signature,
+ SMB2_SIGNATURE_SIZE))
+ return -EACCES;
+ else
+ return 0;
+}
+
+static int
+smb2_verify_signature(struct smb2_hdr *smb2_pdu, struct TCP_Server_Info *server)
+{
+ struct kvec iov;
+
+ iov.iov_base = (char *)smb2_pdu;
+ iov.iov_len = get_rfc1002_length(smb2_pdu) + 4;
+ return smb2_verify_signature2(&iov, 1, server);
+}
/*
* Set message id for the request. Should be called after wait_for_free_request
@@ -118,12 +261,11 @@ smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
dump_smb(mid->resp_buf, min_t(u32, 80, len));
/* convert the length into a more usable form */
- /* BB - uncomment with SMB2 signing implementation */
- /* if ((len > 24) &&
+ if ((len > 24) &&
(server->sec_mode & (SECMODE_SIGN_REQUIRED|SECMODE_SIGN_ENABLED))) {
if (smb2_verify_signature(mid->resp_buf, server))
cERROR(1, "Unexpected SMB signature");
- } */
+ }
return map_smb2_to_linux_error(mid->resp_buf, log_error);
}
@@ -141,9 +283,9 @@ smb2_setup_request(struct cifs_ses *ses, struct kvec *iov,
rc = smb2_get_mid_entry(ses, hdr, &mid);
if (rc)
return rc;
- /* rc = smb2_sign_smb2(iov, nvec, ses->server);
+ rc = smb2_sign_smb2(iov, nvec, ses->server);
if (rc)
- delete_mid(mid); */
+ cifs_delete_mid(mid);
*ret_mid = mid;
return rc;
}
@@ -162,11 +304,12 @@ smb2_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
if (mid == NULL)
return -ENOMEM;
- /* rc = smb2_sign_smb2(iov, nvec, server);
+ rc = smb2_sign_smb2(iov, nvec, server);
if (rc) {
DeleteMidQEntry(mid);
return rc;
- }*/
+ }
+
*ret_mid = mid;
return rc;
}
@@ -109,8 +109,8 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
mempool_free(midEntry, cifs_mid_poolp);
}
-static void
-delete_mid(struct mid_q_entry *mid)
+void
+cifs_delete_mid(struct mid_q_entry *mid)
{
spin_lock(&GlobalMid_Lock);
list_del(&mid->qhead);
@@ -423,7 +423,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
if (rc == 0)
return 0;
- delete_mid(mid);
+ cifs_delete_mid(mid);
add_credits(server, 1, optype);
wake_up(&server->request_q);
return rc;
@@ -533,7 +533,7 @@ cifs_setup_request(struct cifs_ses *ses, struct kvec *iov,
return rc;
rc = cifs_sign_smb2(iov, nvec, ses->server, &mid->sequence_number);
if (rc)
- delete_mid(mid);
+ cifs_delete_mid(mid);
*ret_mid = mid;
return rc;
}
@@ -653,11 +653,11 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
rc = ses->server->ops->check_receive(midQ, ses->server,
flags & CIFS_LOG_ERROR);
- /* mark it so buf will not be freed by delete_mid */
+ /* mark it so buf will not be freed by cifs_delete_mid */
if ((flags & CIFS_NO_RESP) == 0)
midQ->resp_buf = NULL;
out:
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
add_credits(ses->server, credits, optype);
return rc;
@@ -763,7 +763,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
rc = cifs_check_receive(midQ, ses->server, 0);
out:
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
add_credits(ses->server, 1, 0);
return rc;
@@ -847,7 +847,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
if (rc) {
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
mutex_unlock(&ses->server->srv_mutex);
return rc;
}
@@ -860,7 +860,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
mutex_unlock(&ses->server->srv_mutex);
if (rc < 0) {
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
return rc;
}
@@ -881,7 +881,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
blocking lock to return. */
rc = send_cancel(ses->server, in_buf, midQ);
if (rc) {
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
return rc;
}
} else {
@@ -893,7 +893,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
/* If we get -ENOLCK back the lock may have
already been removed. Don't exit in this case. */
if (rc && rc != -ENOLCK) {
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
return rc;
}
}
@@ -930,7 +930,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
rc = cifs_check_receive(midQ, ses->server, 0);
out:
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
if (rstart && rc == -EACCES)
return -ERESTARTSYS;
return rc;