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authorPavel Shilovsky <pshilov@microsoft.com>2016-11-03 16:47:37 -0700
committerSteve French <smfrench@gmail.com>2017-02-01 16:46:36 -0600
commit026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398 (patch)
tree1816fb41fc8a99d0d967a3ebb324f341b5eaee3e /fs/cifs
parentcabfb3680f78981d26c078a26e5c748531257ebb (diff)
downloadlinux-026e93dc0a3eefb0be060bcb9ecd8d7a7fd5c398.tar.bz2
CIFS: Encrypt SMB3 requests before sending
This change allows to encrypt packets if it is required by a server for SMB sessions or tree connections. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Diffstat (limited to 'fs/cifs')
-rw-r--r--fs/cifs/Kconfig2
-rw-r--r--fs/cifs/cifsencrypt.c13
-rw-r--r--fs/cifs/cifsfs.c2
-rw-r--r--fs/cifs/cifsglob.h2
-rw-r--r--fs/cifs/cifsproto.h2
-rw-r--r--fs/cifs/connect.c4
-rw-r--r--fs/cifs/smb2ops.c256
-rw-r--r--fs/cifs/smb2pdu.h5
-rw-r--r--fs/cifs/smb2proto.h3
-rw-r--r--fs/cifs/smb2transport.c41
10 files changed, 320 insertions, 10 deletions
diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig
index ff0d1fe542f7..034f00f21390 100644
--- a/fs/cifs/Kconfig
+++ b/fs/cifs/Kconfig
@@ -174,6 +174,8 @@ config CIFS_SMB2
select CRYPTO_AES
select CRYPTO_SHA256
select CRYPTO_CMAC
+ select CRYPTO_AEAD2
+ select CRYPTO_CCM
help
This enables support for the Server Message Block version 2
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index d8af15f19dd8..058ac9b36f04 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -34,6 +34,7 @@
#include <linux/random.h>
#include <linux/highmem.h>
#include <crypto/skcipher.h>
+#include <crypto/aead.h>
static int
cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
@@ -874,7 +875,7 @@ out:
}
void
-cifs_crypto_shash_release(struct TCP_Server_Info *server)
+cifs_crypto_secmech_release(struct TCP_Server_Info *server)
{
if (server->secmech.cmacaes) {
crypto_free_shash(server->secmech.cmacaes);
@@ -896,6 +897,16 @@ cifs_crypto_shash_release(struct TCP_Server_Info *server)
server->secmech.hmacmd5 = NULL;
}
+ if (server->secmech.ccmaesencrypt) {
+ crypto_free_aead(server->secmech.ccmaesencrypt);
+ server->secmech.ccmaesencrypt = NULL;
+ }
+
+ if (server->secmech.ccmaesdecrypt) {
+ crypto_free_aead(server->secmech.ccmaesdecrypt);
+ server->secmech.ccmaesdecrypt = NULL;
+ }
+
kfree(server->secmech.sdesccmacaes);
server->secmech.sdesccmacaes = NULL;
kfree(server->secmech.sdeschmacsha256);
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 956dd85d7aef..15e1db8738ae 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -1376,6 +1376,8 @@ MODULE_SOFTDEP("pre: nls");
MODULE_SOFTDEP("pre: aes");
MODULE_SOFTDEP("pre: cmac");
MODULE_SOFTDEP("pre: sha256");
+MODULE_SOFTDEP("pre: aead2");
+MODULE_SOFTDEP("pre: ccm");
#endif /* CONFIG_CIFS_SMB2 */
module_init(init_cifs)
module_exit(exit_cifs)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index ff7114d27a69..14196e00f79e 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -136,6 +136,8 @@ struct cifs_secmech {
struct sdesc *sdescmd5; /* ctxt to generate cifs/smb signature */
struct sdesc *sdeschmacsha256; /* ctxt to generate smb2 signature */
struct sdesc *sdesccmacaes; /* ctxt to generate smb3 signature */
+ struct crypto_aead *ccmaesencrypt; /* smb3 encryption aead */
+ struct crypto_aead *ccmaesdecrypt; /* smb3 decryption aead */
};
/* per smb session structure/fields */
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 711718cd73dd..26872f54ca3f 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -445,7 +445,7 @@ extern int SMBNTencrypt(unsigned char *, unsigned char *, unsigned char *,
const struct nls_table *);
extern int setup_ntlm_response(struct cifs_ses *, const struct nls_table *);
extern int setup_ntlmv2_rsp(struct cifs_ses *, const struct nls_table *);
-extern void cifs_crypto_shash_release(struct TCP_Server_Info *);
+extern void cifs_crypto_secmech_release(struct TCP_Server_Info *server);
extern int calc_seckey(struct cifs_ses *);
extern int generate_smb30signingkey(struct cifs_ses *);
extern int generate_smb311signingkey(struct cifs_ses *);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 35ae49ed1f76..b84febf960e9 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2154,7 +2154,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
server->tcpStatus = CifsExiting;
spin_unlock(&GlobalMid_Lock);
- cifs_crypto_shash_release(server);
+ cifs_crypto_secmech_release(server);
cifs_fscache_release_client_cookie(server);
kfree(server->session_key.response);
@@ -2273,7 +2273,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
return tcp_ses;
out_err_crypto_release:
- cifs_crypto_shash_release(tcp_ses);
+ cifs_crypto_secmech_release(tcp_ses);
put_net(cifs_net_ns(tcp_ses));
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index ef8b2a8363b3..54b49358eaaf 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -20,6 +20,8 @@
#include <linux/pagemap.h>
#include <linux/vfs.h>
#include <linux/falloc.h>
+#include <linux/scatterlist.h>
+#include <crypto/aead.h>
#include "cifsglob.h"
#include "smb2pdu.h"
#include "smb2proto.h"
@@ -1547,6 +1549,256 @@ smb2_dir_needs_close(struct cifsFileInfo *cfile)
return !cfile->invalidHandle;
}
+static void
+fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq)
+{
+ struct smb2_sync_hdr *shdr =
+ (struct smb2_sync_hdr *)old_rq->rq_iov[1].iov_base;
+ unsigned int orig_len = get_rfc1002_length(old_rq->rq_iov[0].iov_base);
+
+ memset(tr_hdr, 0, sizeof(struct smb2_transform_hdr));
+ tr_hdr->ProtocolId = SMB2_TRANSFORM_PROTO_NUM;
+ tr_hdr->OriginalMessageSize = cpu_to_le32(orig_len);
+ tr_hdr->Flags = cpu_to_le16(0x01);
+ get_random_bytes(&tr_hdr->Nonce, SMB3_AES128CMM_NONCE);
+ memcpy(&tr_hdr->SessionId, &shdr->SessionId, 8);
+ inc_rfc1001_len(tr_hdr, sizeof(struct smb2_transform_hdr) - 4);
+ inc_rfc1001_len(tr_hdr, orig_len);
+}
+
+static struct scatterlist *
+init_sg(struct smb_rqst *rqst, u8 *sign)
+{
+ unsigned int sg_len = rqst->rq_nvec + rqst->rq_npages + 1;
+ unsigned int assoc_data_len = sizeof(struct smb2_transform_hdr) - 24;
+ struct scatterlist *sg;
+ unsigned int i;
+ unsigned int j;
+
+ sg = kmalloc_array(sg_len, sizeof(struct scatterlist), GFP_KERNEL);
+ if (!sg)
+ return NULL;
+
+ sg_init_table(sg, sg_len);
+ sg_set_buf(&sg[0], rqst->rq_iov[0].iov_base + 24, assoc_data_len);
+ for (i = 1; i < rqst->rq_nvec; i++)
+ sg_set_buf(&sg[i], rqst->rq_iov[i].iov_base,
+ rqst->rq_iov[i].iov_len);
+ for (j = 0; i < sg_len - 1; i++, j++) {
+ unsigned int len = (j < rqst->rq_npages - 1) ? rqst->rq_pagesz
+ : rqst->rq_tailsz;
+ sg_set_page(&sg[i], rqst->rq_pages[j], len, 0);
+ }
+ sg_set_buf(&sg[sg_len - 1], sign, SMB2_SIGNATURE_SIZE);
+ return sg;
+}
+
+struct cifs_crypt_result {
+ int err;
+ struct completion completion;
+};
+
+static void cifs_crypt_complete(struct crypto_async_request *req, int err)
+{
+ struct cifs_crypt_result *res = req->data;
+
+ if (err == -EINPROGRESS)
+ return;
+
+ res->err = err;
+ complete(&res->completion);
+}
+
+/*
+ * Encrypt or decrypt @rqst message. @rqst has the following format:
+ * iov[0] - transform header (associate data),
+ * iov[1-N] and pages - data to encrypt.
+ * On success return encrypted data in iov[1-N] and pages, leave iov[0]
+ * untouched.
+ */
+static int
+crypt_message(struct TCP_Server_Info *server, struct smb_rqst *rqst, int enc)
+{
+ struct smb2_transform_hdr *tr_hdr =
+ (struct smb2_transform_hdr *)rqst->rq_iov[0].iov_base;
+ unsigned int assoc_data_len = sizeof(struct smb2_transform_hdr) - 24;
+ struct cifs_ses *ses;
+ int rc = 0;
+ struct scatterlist *sg;
+ u8 sign[SMB2_SIGNATURE_SIZE] = {};
+ struct aead_request *req;
+ char *iv;
+ unsigned int iv_len;
+ struct cifs_crypt_result result = {0, };
+ struct crypto_aead *tfm;
+ unsigned int crypt_len = le32_to_cpu(tr_hdr->OriginalMessageSize);
+
+ init_completion(&result.completion);
+
+ ses = smb2_find_smb_ses(server, tr_hdr->SessionId);
+ if (!ses) {
+ cifs_dbg(VFS, "%s: Could not find session\n", __func__);
+ return 0;
+ }
+
+ rc = smb3_crypto_aead_allocate(server);
+ if (rc) {
+ cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
+ return rc;
+ }
+
+ tfm = enc ? server->secmech.ccmaesencrypt :
+ server->secmech.ccmaesdecrypt;
+ rc = crypto_aead_setkey(tfm, enc ? ses->smb3encryptionkey :
+ ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);
+ if (rc) {
+ cifs_dbg(VFS, "%s: Failed to set aead key %d\n", __func__, rc);
+ return rc;
+ }
+
+ rc = crypto_aead_setauthsize(tfm, SMB2_SIGNATURE_SIZE);
+ if (rc) {
+ cifs_dbg(VFS, "%s: Failed to set authsize %d\n", __func__, rc);
+ return rc;
+ }
+
+ req = aead_request_alloc(tfm, GFP_KERNEL);
+ if (!req) {
+ cifs_dbg(VFS, "%s: Failed to alloc aead request", __func__);
+ return -ENOMEM;
+ }
+
+ if (!enc) {
+ memcpy(sign, &tr_hdr->Signature, SMB2_SIGNATURE_SIZE);
+ crypt_len += SMB2_SIGNATURE_SIZE;
+ }
+
+ sg = init_sg(rqst, sign);
+ if (!sg) {
+ cifs_dbg(VFS, "%s: Failed to init sg %d", __func__, rc);
+ goto free_req;
+ }
+
+ iv_len = crypto_aead_ivsize(tfm);
+ iv = kzalloc(iv_len, GFP_KERNEL);
+ if (!iv) {
+ cifs_dbg(VFS, "%s: Failed to alloc IV", __func__);
+ goto free_sg;
+ }
+ iv[0] = 3;
+ memcpy(iv + 1, (char *)tr_hdr->Nonce, SMB3_AES128CMM_NONCE);
+
+ aead_request_set_crypt(req, sg, sg, crypt_len, iv);
+ aead_request_set_ad(req, assoc_data_len);
+
+ aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ cifs_crypt_complete, &result);
+
+ rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
+
+ if (rc == -EINPROGRESS || rc == -EBUSY) {
+ wait_for_completion(&result.completion);
+ rc = result.err;
+ }
+
+ if (!rc && enc)
+ memcpy(&tr_hdr->Signature, sign, SMB2_SIGNATURE_SIZE);
+
+ kfree(iv);
+free_sg:
+ kfree(sg);
+free_req:
+ kfree(req);
+ return rc;
+}
+
+static int
+smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq,
+ struct smb_rqst *old_rq)
+{
+ struct kvec *iov;
+ struct page **pages;
+ struct smb2_transform_hdr *tr_hdr;
+ unsigned int npages = old_rq->rq_npages;
+ int i;
+ int rc = -ENOMEM;
+
+ pages = kmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
+ if (!pages)
+ return rc;
+
+ new_rq->rq_pages = pages;
+ new_rq->rq_npages = old_rq->rq_npages;
+ new_rq->rq_pagesz = old_rq->rq_pagesz;
+ new_rq->rq_tailsz = old_rq->rq_tailsz;
+
+ for (i = 0; i < npages; i++) {
+ pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
+ if (!pages[i])
+ goto err_free_pages;
+ }
+
+ iov = kmalloc_array(old_rq->rq_nvec, sizeof(struct kvec), GFP_KERNEL);
+ if (!iov)
+ goto err_free_pages;
+
+ /* copy all iovs from the old except the 1st one (rfc1002 length) */
+ memcpy(&iov[1], &old_rq->rq_iov[1],
+ sizeof(struct kvec) * (old_rq->rq_nvec - 1));
+ new_rq->rq_iov = iov;
+ new_rq->rq_nvec = old_rq->rq_nvec;
+
+ tr_hdr = kmalloc(sizeof(struct smb2_transform_hdr), GFP_KERNEL);
+ if (!tr_hdr)
+ goto err_free_iov;
+
+ /* fill the 1st iov with a transform header */
+ fill_transform_hdr(tr_hdr, old_rq);
+ new_rq->rq_iov[0].iov_base = tr_hdr;
+ new_rq->rq_iov[0].iov_len = sizeof(struct smb2_transform_hdr);
+
+ /* copy pages form the old */
+ for (i = 0; i < npages; i++) {
+ char *dst = kmap(new_rq->rq_pages[i]);
+ char *src = kmap(old_rq->rq_pages[i]);
+ unsigned int len = (i < npages - 1) ? new_rq->rq_pagesz :
+ new_rq->rq_tailsz;
+ memcpy(dst, src, len);
+ kunmap(new_rq->rq_pages[i]);
+ kunmap(old_rq->rq_pages[i]);
+ }
+
+ rc = crypt_message(server, new_rq, 1);
+ cifs_dbg(FYI, "encrypt message returned %d", rc);
+ if (rc)
+ goto err_free_tr_hdr;
+
+ return rc;
+
+err_free_tr_hdr:
+ kfree(tr_hdr);
+err_free_iov:
+ kfree(iov);
+err_free_pages:
+ for (i = i - 1; i >= 0; i--)
+ put_page(pages[i]);
+ kfree(pages);
+ return rc;
+}
+
+static void
+smb3_free_transform_rq(struct smb_rqst *rqst)
+{
+ int i = rqst->rq_npages - 1;
+
+ for (; i >= 0; i--)
+ put_page(rqst->rq_pages[i]);
+ kfree(rqst->rq_pages);
+ /* free transform header */
+ kfree(rqst->rq_iov[0].iov_base);
+ kfree(rqst->rq_iov);
+}
+
struct smb_version_operations smb20_operations = {
.compare_fids = smb2_compare_fids,
.setup_request = smb2_setup_request,
@@ -1793,6 +2045,8 @@ struct smb_version_operations smb30_operations = {
.dir_needs_close = smb2_dir_needs_close,
.fallocate = smb3_fallocate,
.enum_snapshots = smb3_enum_snapshots,
+ .init_transform_rq = smb3_init_transform_rq,
+ .free_transform_rq = smb3_free_transform_rq,
};
#ifdef CONFIG_CIFS_SMB311
@@ -1881,6 +2135,8 @@ struct smb_version_operations smb311_operations = {
.dir_needs_close = smb2_dir_needs_close,
.fallocate = smb3_fallocate,
.enum_snapshots = smb3_enum_snapshots,
+ .init_transform_rq = smb3_init_transform_rq,
+ .free_transform_rq = smb3_free_transform_rq,
};
#endif /* CIFS_SMB311 */
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 35ff9fae1c27..c03b252501a1 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -134,11 +134,14 @@ struct smb2_pdu {
__le16 StructureSize2; /* size of wct area (varies, request specific) */
} __packed;
+#define SMB3_AES128CMM_NONCE 11
+#define SMB3_AES128GCM_NONCE 12
+
struct smb2_transform_hdr {
__be32 smb2_buf_length; /* big endian on wire */
/* length is only two or three bytes - with
one or two byte type preceding it that MBZ */
- __u8 ProtocolId[4]; /* 0xFD 'S' 'M' 'B' */
+ __le32 ProtocolId; /* 0xFD 'S' 'M' 'B' */
__u8 Signature[16];
__u8 Nonce[16];
__le32 OriginalMessageSize;
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index f2d511a6971b..7d30b754e132 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -56,6 +56,8 @@ extern void smb2_echo_request(struct work_struct *work);
extern __le32 smb2_get_lease_state(struct cifsInodeInfo *cinode);
extern bool smb2_is_valid_oplock_break(char *buffer,
struct TCP_Server_Info *srv);
+extern struct cifs_ses *smb2_find_smb_ses(struct TCP_Server_Info *server,
+ __u64 ses_id);
extern void move_smb2_info_to_cifs(FILE_ALL_INFO *dst,
struct smb2_file_all_info *src);
@@ -97,6 +99,7 @@ extern int smb2_unlock_range(struct cifsFileInfo *cfile,
struct file_lock *flock, const unsigned int xid);
extern int smb2_push_mandatory_locks(struct cifsFileInfo *cfile);
extern void smb2_reconnect_server(struct work_struct *work);
+extern int smb3_crypto_aead_allocate(struct TCP_Server_Info *server);
/*
* SMB2 Worker functions - most of protocol specific implementation details
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 93b27752b634..3caa11dd957a 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -31,6 +31,7 @@
#include <asm/processor.h>
#include <linux/mempool.h>
#include <linux/highmem.h>
+#include <crypto/aead.h>
#include "smb2pdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
@@ -114,14 +115,14 @@ smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
return 0;
}
-static struct cifs_ses *
-smb2_find_smb_ses(struct smb2_sync_hdr *shdr, struct TCP_Server_Info *server)
+struct cifs_ses *
+smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
{
struct cifs_ses *ses;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
- if (ses->Suid != shdr->SessionId)
+ if (ses->Suid != ses_id)
continue;
spin_unlock(&cifs_tcp_ses_lock);
return ses;
@@ -141,7 +142,7 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[1].iov_base;
struct cifs_ses *ses;
- ses = smb2_find_smb_ses(shdr, server);
+ ses = smb2_find_smb_ses(server, shdr->SessionId);
if (!ses) {
cifs_dbg(VFS, "%s: Could not find session\n", __func__);
return 0;
@@ -358,7 +359,7 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[1].iov_base;
struct cifs_ses *ses;
- ses = smb2_find_smb_ses(shdr, server);
+ ses = smb2_find_smb_ses(server, shdr->SessionId);
if (!ses) {
cifs_dbg(VFS, "%s: Could not find session\n", __func__);
return 0;
@@ -618,3 +619,33 @@ smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
return mid;
}
+
+int
+smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
+{
+ struct crypto_aead *tfm;
+
+ if (!server->secmech.ccmaesencrypt) {
+ tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
+ if (IS_ERR(tfm)) {
+ cifs_dbg(VFS, "%s: Failed to alloc encrypt aead\n",
+ __func__);
+ return PTR_ERR(tfm);
+ }
+ server->secmech.ccmaesencrypt = tfm;
+ }
+
+ if (!server->secmech.ccmaesdecrypt) {
+ tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
+ if (IS_ERR(tfm)) {
+ crypto_free_aead(server->secmech.ccmaesencrypt);
+ server->secmech.ccmaesencrypt = NULL;
+ cifs_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
+ __func__);
+ return PTR_ERR(tfm);
+ }
+ server->secmech.ccmaesdecrypt = tfm;
+ }
+
+ return 0;
+}