[PATCH 2/6] cifs: merge the hash calculation helpers
From: Al Viro
Date: Sat Apr 09 2016 - 16:51:04 EST
three practically identical copies...
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/cifs/cifsencrypt.c | 97 ++++++++++++++++++++++++-------------------
fs/cifs/cifsproto.h | 3 ++
fs/cifs/smb2transport.c | 107 +++++-------------------------------------------
3 files changed, 67 insertions(+), 140 deletions(-)
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 4897dac..6aeb8d4 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -66,45 +66,15 @@ cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
return 0;
}
-/*
- * Calculate and return the CIFS signature based on the mac key and SMB PDU.
- * The 16 byte signature must be allocated by the caller. Note we only use the
- * 1st eight bytes and that the smb header signature field on input contains
- * the sequence number before this function is called. Also, this function
- * should be called with the server->srv_mutex held.
- */
-static int cifs_calc_signature(struct smb_rqst *rqst,
- struct TCP_Server_Info *server, char *signature)
+int __cifs_calc_signature(struct smb_rqst *rqst,
+ struct TCP_Server_Info *server, char *signature,
+ struct shash_desc *shash)
{
int i;
int rc;
struct kvec *iov = rqst->rq_iov;
int n_vec = rqst->rq_nvec;
- if (iov == NULL || signature == NULL || server == NULL)
- return -EINVAL;
-
- if (!server->secmech.sdescmd5) {
- rc = cifs_crypto_shash_md5_allocate(server);
- if (rc) {
- cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
- return -1;
- }
- }
-
- rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
- if (rc) {
- cifs_dbg(VFS, "%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) {
- cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
- return rc;
- }
-
for (i = 0; i < n_vec; i++) {
if (iov[i].iov_len == 0)
continue;
@@ -117,12 +87,10 @@ static int cifs_calc_signature(struct smb_rqst *rqst,
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.sdescmd5->shash,
+ rc = crypto_shash_update(shash,
iov[i].iov_base + 4, iov[i].iov_len - 4);
} else {
- rc =
- crypto_shash_update(&server->secmech.sdescmd5->shash,
+ rc = crypto_shash_update(shash,
iov[i].iov_base, iov[i].iov_len);
}
if (rc) {
@@ -134,21 +102,64 @@ static int cifs_calc_signature(struct smb_rqst *rqst,
/* now hash over the rq_pages array */
for (i = 0; i < rqst->rq_npages; i++) {
- struct kvec p_iov;
+ void *kaddr = kmap(rqst->rq_pages[i]);
+ size_t len = rqst->rq_pagesz;
+
+ if (i == rqst->rq_npages - 1)
+ len = rqst->rq_tailsz;
+
+ crypto_shash_update(shash, kaddr, len);
- cifs_rqst_page_to_kvec(rqst, i, &p_iov);
- crypto_shash_update(&server->secmech.sdescmd5->shash,
- p_iov.iov_base, p_iov.iov_len);
kunmap(rqst->rq_pages[i]);
}
- rc = crypto_shash_final(&server->secmech.sdescmd5->shash, signature);
+ rc = crypto_shash_final(shash, signature);
if (rc)
- cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
+ cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
return rc;
}
+/*
+ * Calculate and return the CIFS signature based on the mac key and SMB PDU.
+ * The 16 byte signature must be allocated by the caller. Note we only use the
+ * 1st eight bytes and that the smb header signature field on input contains
+ * the sequence number before this function is called. Also, this function
+ * should be called with the server->srv_mutex held.
+ */
+static int cifs_calc_signature(struct smb_rqst *rqst,
+ struct TCP_Server_Info *server, char *signature)
+{
+ int rc;
+
+ if (!rqst->rq_iov || !signature || !server)
+ return -EINVAL;
+
+ if (!server->secmech.sdescmd5) {
+ rc = cifs_crypto_shash_md5_allocate(server);
+ if (rc) {
+ cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
+ return -1;
+ }
+ }
+
+ rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
+ if (rc) {
+ cifs_dbg(VFS, "%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) {
+ cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
+ return rc;
+ }
+
+ return __cifs_calc_signature(rqst, server, signature,
+ &server->secmech.sdescmd5->shash);
+}
+
/* must be called with server->srv_mutex held */
int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
__u32 *pexpected_response_sequence_number)
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index eed7ff5..d9b4f44 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -512,4 +512,7 @@ int cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb,
const unsigned char *path, char *pbuf,
unsigned int *pbytes_written);
+int __cifs_calc_signature(struct smb_rqst *rqst,
+ struct TCP_Server_Info *server, char *signature,
+ struct shash_desc *shash);
#endif /* _CIFSPROTO_H */
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 8732a43..bc9a7b6 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -135,11 +135,10 @@ smb2_find_smb_ses(struct smb2_hdr *smb2hdr, struct TCP_Server_Info *server)
int
smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
{
- int i, rc;
+ int rc;
unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
unsigned char *sigptr = smb2_signature;
struct kvec *iov = rqst->rq_iov;
- int n_vec = rqst->rq_nvec;
struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
struct cifs_ses *ses;
@@ -171,53 +170,11 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
return rc;
}
- for (i = 0; i < n_vec; i++) {
- if (iov[i].iov_len == 0)
- continue;
- if (iov[i].iov_base == NULL) {
- cifs_dbg(VFS, "null iovec entry\n");
- 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) {
- cifs_dbg(VFS, "%s: Could not update with payload\n",
- __func__);
- return rc;
- }
- }
-
- /* now hash over the rq_pages array */
- for (i = 0; i < rqst->rq_npages; i++) {
- struct kvec p_iov;
-
- cifs_rqst_page_to_kvec(rqst, i, &p_iov);
- crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
- p_iov.iov_base, p_iov.iov_len);
- kunmap(rqst->rq_pages[i]);
- }
-
- rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
- sigptr);
- if (rc)
- cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
+ rc = __cifs_calc_signature(rqst, server, sigptr,
+ &server->secmech.sdeschmacsha256->shash);
- memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
+ if (!rc)
+ memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
return rc;
}
@@ -395,12 +352,10 @@ generate_smb311signingkey(struct cifs_ses *ses)
int
smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
{
- int i;
int rc = 0;
unsigned char smb3_signature[SMB2_CMACAES_SIZE];
unsigned char *sigptr = smb3_signature;
struct kvec *iov = rqst->rq_iov;
- int n_vec = rqst->rq_nvec;
struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
struct cifs_ses *ses;
@@ -431,54 +386,12 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
return rc;
}
+
+ rc = __cifs_calc_signature(rqst, server, sigptr,
+ &server->secmech.sdesccmacaes->shash);
- for (i = 0; i < n_vec; i++) {
- if (iov[i].iov_len == 0)
- continue;
- if (iov[i].iov_base == NULL) {
- cifs_dbg(VFS, "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.sdesccmacaes->shash,
- iov[i].iov_base + 4, iov[i].iov_len - 4);
- } else {
- rc =
- crypto_shash_update(
- &server->secmech.sdesccmacaes->shash,
- iov[i].iov_base, iov[i].iov_len);
- }
- if (rc) {
- cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n",
- __func__);
- return rc;
- }
- }
-
- /* now hash over the rq_pages array */
- for (i = 0; i < rqst->rq_npages; i++) {
- struct kvec p_iov;
-
- cifs_rqst_page_to_kvec(rqst, i, &p_iov);
- crypto_shash_update(&server->secmech.sdesccmacaes->shash,
- p_iov.iov_base, p_iov.iov_len);
- kunmap(rqst->rq_pages[i]);
- }
-
- rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash,
- sigptr);
- if (rc)
- cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__);
-
- memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
+ if (!rc)
+ memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
return rc;
}
--
2.8.0.rc3