NTLM auth and sign - Allocate session key/client response dynamically
Start calculating auth response within a session. Move/Add pertinet
data structures like session key, server challenge and ntlmv2_hash in
a session structure. We should do the calculations within a session
before copying session key and response over to server data
structures because a session setup can fail.
Only after a very first smb session succeeds, it copy/make its
session key, session key of smb connection. This key stays with
the smb connection throughout its life.
sequence_number within server is set to 0x2.
The authentication Message Authentication Key (mak) which consists
of session key followed by client response within structure session_key
is now dynamic. Every authentication type allocates the key + response
sized memory within its session structure and later either assigns or
frees it once the client response is sent and if session's session key
becomes connetion's session key.
ntlm/ntlmi authentication functions are rearranged. A function
named setup_ntlm_resp(), similar to setup_ntlmv2_resp(), replaces
function cifs_calculate_session_key().
size of CIFS_SESS_KEY_SIZE is changed to 16, to reflect the byte size
of the key it holds.
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 7ac0056..987b479 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -43,15 +43,16 @@
unsigned char *p24);
static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu,
- const struct session_key *key, char *signature)
+ struct TCP_Server_Info *server, char *signature)
{
struct MD5Context context;
- if ((cifs_pdu == NULL) || (signature == NULL) || (key == NULL))
+ if (cifs_pdu == NULL || signature == NULL || server == NULL)
return -EINVAL;
cifs_MD5_init(&context);
- cifs_MD5_update(&context, (char *)&key->data, key->len);
+ cifs_MD5_update(&context, server->session_key.response,
+ server->session_key.len);
cifs_MD5_update(&context, cifs_pdu->Protocol, cifs_pdu->smb_buf_length);
cifs_MD5_final(signature, &context);
@@ -79,8 +80,7 @@
server->sequence_number++;
spin_unlock(&GlobalMid_Lock);
- rc = cifs_calculate_signature(cifs_pdu, &server->session_key,
- smb_signature);
+ rc = cifs_calculate_signature(cifs_pdu, server, smb_signature);
if (rc)
memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
else
@@ -90,16 +90,17 @@
}
static int cifs_calc_signature2(const struct kvec *iov, int n_vec,
- const struct session_key *key, char *signature)
+ struct TCP_Server_Info *server, char *signature)
{
struct MD5Context context;
int i;
- if ((iov == NULL) || (signature == NULL) || (key == NULL))
+ if (iov == NULL || signature == NULL || server == NULL)
return -EINVAL;
cifs_MD5_init(&context);
- cifs_MD5_update(&context, (char *)&key->data, key->len);
+ cifs_MD5_update(&context, server->session_key.response,
+ server->session_key.len);
for (i = 0; i < n_vec; i++) {
if (iov[i].iov_len == 0)
continue;
@@ -146,8 +147,7 @@
server->sequence_number++;
spin_unlock(&GlobalMid_Lock);
- rc = cifs_calc_signature2(iov, n_vec, &server->session_key,
- smb_signature);
+ rc = cifs_calc_signature2(iov, n_vec, server, smb_signature);
if (rc)
memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
else
@@ -157,14 +157,14 @@
}
int cifs_verify_signature(struct smb_hdr *cifs_pdu,
- const struct session_key *session_key,
+ 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];
- if (cifs_pdu == NULL || session_key == NULL)
+ if (cifs_pdu == NULL || server == NULL)
return -EINVAL;
if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
@@ -193,7 +193,7 @@
cpu_to_le32(expected_sequence_number);
cifs_pdu->Signature.Sequence.Reserved = 0;
- rc = cifs_calculate_signature(cifs_pdu, session_key,
+ rc = cifs_calculate_signature(cifs_pdu, server,
what_we_think_sig_should_be);
if (rc)
@@ -209,18 +209,28 @@
}
-/* We fill in key by putting in 40 byte array which was allocated by caller */
-int cifs_calculate_session_key(struct session_key *key, const char *rn,
- const char *password)
+/* first calculate 24 bytes ntlm response and then 16 byte session key */
+int setup_ntlm_response(struct cifsSesInfo *ses)
{
- char temp_key[16];
- if ((key == NULL) || (rn == NULL))
+ unsigned int temp_len = CIFS_SESS_KEY_SIZE + CIFS_AUTH_RESP_SIZE;
+ char temp_key[CIFS_SESS_KEY_SIZE];
+
+ if (!ses)
return -EINVAL;
- E_md4hash(password, temp_key);
- mdfour(key->data.ntlm, temp_key, 16);
- memcpy(key->data.ntlm+16, rn, CIFS_SESS_KEY_SIZE);
- key->len = 40;
+ ses->auth_key.response = kmalloc(temp_len, GFP_KERNEL);
+ if (!ses->auth_key.response) {
+ cERROR(1, "NTLM can't allocate (%u bytes) memory", temp_len);
+ return -ENOMEM;
+ }
+ ses->auth_key.len = temp_len;
+
+ SMBNTencrypt(ses->password, ses->cryptKey,
+ ses->auth_key.response + CIFS_SESS_KEY_SIZE);
+
+ E_md4hash(ses->password, temp_key);
+ mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE);
+
return 0;
}
@@ -465,19 +475,13 @@
}
int
-setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
- const struct nls_table *nls_cp)
+setup_ntlmv2_rsp(struct cifsSesInfo *ses, const struct nls_table *nls_cp)
{
int rc;
- struct ntlmv2_resp *buf = (struct ntlmv2_resp *)resp_buf;
+ int baselen;
+ struct ntlmv2_resp *buf;
struct HMACMD5Context context;
- buf->blob_signature = cpu_to_le32(0x00000101);
- buf->reserved = 0;
- buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
- get_random_bytes(&buf->client_chal, sizeof(buf->client_chal));
- buf->reserved2 = 0;
-
if (ses->server->secType == RawNTLMSSP) {
if (!ses->domainName) {
rc = find_domain_name(ses);
@@ -494,22 +498,38 @@
}
}
+ baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
+ ses->auth_key.len = baselen + ses->tilen;
+ ses->auth_key.response = kmalloc(ses->auth_key.len, GFP_KERNEL);
+ if (!ses->auth_key.response) {
+ rc = ENOMEM;
+ cERROR(1, "%s: Can't allocate auth blob", __func__);
+ goto setup_ntlmv2_rsp_ret;
+ }
+
+ buf = (struct ntlmv2_resp *)
+ (ses->auth_key.response + CIFS_SESS_KEY_SIZE);
+ buf->blob_signature = cpu_to_le32(0x00000101);
+ buf->reserved = 0;
+ buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
+ get_random_bytes(&buf->client_chal, sizeof(buf->client_chal));
+ buf->reserved2 = 0;
+
+ memcpy(ses->auth_key.response + baselen, ses->tiblob, ses->tilen);
+
/* calculate buf->ntlmv2_hash */
rc = calc_ntlmv2_hash(ses, nls_cp);
if (rc) {
cERROR(1, "could not get v2 hash rc %d", rc);
goto setup_ntlmv2_rsp_ret;
}
- CalcNTLMv2_response(ses, resp_buf);
+ CalcNTLMv2_response(ses);
/* now calculate the session key for NTLMv2 */
hmac_md5_init_limK_to_64(ses->ntlmv2_hash, 16, &context);
- hmac_md5_update(resp_buf, 16, &context);
- hmac_md5_final(ses->auth_key.data.ntlmv2.key, &context);
-
- memcpy(&ses->auth_key.data.ntlmv2.resp, resp_buf,
- sizeof(struct ntlmv2_resp));
- ses->auth_key.len = 16 + sizeof(struct ntlmv2_resp);
+ hmac_md5_update(ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+ 16, &context);
+ hmac_md5_final(ses->auth_key.response, &context);
return 0;
@@ -521,20 +541,17 @@
return rc;
}
-void CalcNTLMv2_response(const struct cifsSesInfo *ses,
- char *v2_session_response)
+void CalcNTLMv2_response(const struct cifsSesInfo *ses)
{
+ unsigned int offset = CIFS_SESS_KEY_SIZE + 8;
struct HMACMD5Context context;
+
/* rest of v2 struct already generated */
- memcpy(v2_session_response + 8, ses->cryptKey, 8);
+ memcpy(ses->auth_key.response + offset, ses->cryptKey, 8);
hmac_md5_init_limK_to_64(ses->ntlmv2_hash, 16, &context);
- hmac_md5_update(v2_session_response+8,
- sizeof(struct ntlmv2_resp) - 8, &context);
+ hmac_md5_update(ses->auth_key.response + offset,
+ ses->auth_key.len - offset, &context);
- if (ses->tilen)
- hmac_md5_update(ses->tiblob, ses->tilen, &context);
-
- hmac_md5_final(v2_session_response, &context);
-/* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */
+ hmac_md5_final(ses->auth_key.response + CIFS_SESS_KEY_SIZE, &context);
}